Respiratory Apex Review Flashcards
What does oxygen content (CaO2) tell you?
How much oxygen is present in 1 deciliter (100 mL) of blood
What is the formula for CaO2?
CaO2 = (1.34 x Hgb x SaO2) + (PaO2 x 0.003)
What does DO2 tell you?
How much O2 is delivered to the tissues per minute
What is the formula for DO2?
DO2 = CaO2 x CO x 10
___ is needed for oxygen delivery but not oxygen-carrying capacity.
CO
What is the reference value for CaO2?
20 mL O2 /dL
What is the reference value for DO2?
1,000 mL O2 per minute
What is the definition of oxygen consumption?
The difference between the amount of O2 that leaves the lungs and the amount of O2 that returns to the lungs
What is the formula for VO2?
VO2 = CO x (CaO2 -CvO2) x 10
What is the reference value for VO2?
250 mL/min or 3.5 mL/kg/min
What is 1 deciliter equal to?
100 mL
What two ways is oxygen transported by the blood?
- reversibly w/ Hgb (97%)
- Dissolves in the plasma (3%)
What percentage of oxygen reversibly binds with Hgb?
97%
What percentage of oxygen is dissolved in the plasma?
3%
Each gram of Hgb molecule can carry a theoretical max of ___ mL of molecular oxygen.
1.39
What is the normal Hgb for a male?
15 g/dL
What is the normal Hgb for a female?
13 g/dL
What is the normal Hct for a male?
45%
What is the normal Hct for a female?
39%
How is dissolved O2 measured?
By PaO2
What does PaO2 determine?
Gas exchange in the lungs (not a measure of oxygen content in the blood)
Oxygen dissolves in the plasma according to ____ law.
Henry’s
What is the solubility coefficient for oxygen?
0.003 mL/dL/mmHg
Oxygen is _____x less soluble than CO2.
20
What is the driving mechanism of DO2?
CO
VO2 stands for ______
oxygen consumption
What principle can be used to calculate oxygen consumption?
Fick’s principle
What does the oxyhemoglobin dissociation curve tell us?
the tendency of Hgb to bind to oxygen
A right-shifted curve of the oxyhemoglobin dissociation curve means Hgb has a ____ affinity for oxygen.
lower (right = release)
A left-shifted curve of the oxyhemoglobin dissociation curve means Hgb has a ____ affinity for oxygen.
higher (left = love or locked in)
What is the P50?
When Hgb is 50% saturated by oxygen
A low P50 indicates a ____ shifts of the oxyhemoglobin dissociation curve.
left
A high P50 indicates a ____ shifts of the oxyhemoglobin dissociation curve.
right
A left shift of the oxyhemoglobin dissociation curve is caused by _____, ______ temperature, and _______ 2,3-DPG.
alkalosis, decreased temperature, and decreased 2,3-DPG
A right shift of the oxyhemoglobin dissociation curve is caused by _____, ______ temperature, and _______ 2,3-DPG.
acidosis, increased temperature, increased 2,3-DPG
What three hemoglobin species can cause a left shift of the oxyhemoglobin dissociation curve?
- fetal hemoglobin
- methemoglobin
- carboxyhemoglobin
Above a PaO2 of _____ mmHg, hemoglobin is fully saturated with oxygen.
100
What does the Bohr effect say?
An increased partial pressure of CO2 and decreased pH cause Hemoglobin to release O2
Max O2 loading occurs at a PaO2 of what?
100 mmHg
Tissues with a high metabolic rate consume more ___ and produce more _____, ______, and ______.
O2; CO2, hydrogen ions, and heat
When is 2,3-DPG produced?
during RBC glycolysis (Rapoport-Luebering pathway)
What increases 2,3-DPG production?
Hypoxia
2,3 DPG is an important compensation mechanism during chronic ____.
anemia
In _____, the concentration of 2,3-DPG falls.
banked blood
What does not respond to 2,3-DPG?
Hgb F
What is the energy currency in the body?
Adenosine triphosphate (ATP)
What is the primary substrate used for ATP synthesis?
Glucose
What 3 key processes are involved in aerobic metabolism?
- glycolysis
- krebs cycle
- oxidative phosphorylation
How many ATP are gained with glycolysis?
net gain of 2 ATP
How many ATP are gained with Krebs cycle?
Net gain of 2 ATP
How may ATP are gained with oxidative phosphorylation?
net gain of 34 ATP
Anaerobic metabolism occurs when?
in the absence of oxygen
In the absence of oxygen, ______ is converted to lactic acid.
Pyruvate acid
Why does lactic acidosis occur during the absence of oxygen?
B/c pyruvate acid is converted to lactic acid during anaerobic metabolism
How is ATP produced?
by the oxidation of proteins, carbohydrates, and fats
The phosphate bond in ATP is a _____ energy bond.
high
Why must ATP be continuously replenished?
It cannot be stored
Which form of metabolism produces much more ATP?
aerobic
What is the primary goal of glycolysis?
to convert 1 glucose to 2 pyruvic acid molecules
The fate of pyruvic acid depends on whether or not _____ is available.
oxygen
In the absence of O2, pyruvic acid is converted to lactate where?
in the cytoplasm
If oxygen is present, where is pyruvic acid transported after glycolysis?
the mitochondria
During glycolysis of aerobic metabolism, the 2 molecules of pyruvic acid are converted into what?
2 molecules of acetyl coenzyme A
When is 2,3-DPG produced?
about halfway through glycolysis
During what pathway is 2,3-DPG produced?
the rapoport-luebering pathway
Where does the Krebs cycle take place?
in the matrix of the mitochondria
The krebs cycle is also known as what?
citric acid cycle
During the krebs cycle, the reaction begins when _____ and ______ react to produce citric acid.
acetyl coenzyme A
and
oxaloacetic acid
The Krebs Cycle reaction ends with the production of ____, ____, and _____.
oxaloacetic acid, NADH, and CO2
What is the primary goal of the krebs cycle reaction?
to produce a large quantity of H+ ions in the form of NADH
What is the primary goal of glycolysis and the Krebs cycle?
to liberate hydrogen from glucose
The NADH produced during the Krebs cycle is split into what?
NAD+, H+, and 2 electrons
During oxidative phosphorylation, the electrons produced from NADH are fed into the chemiosmotic mechanism. And a proton gradient is generated across a membrane which drives ________ with the help of ______.
ATP synthesis; ATP synthase
What serves at the final electron acceptor during oxidative phosphorylation?
oxygen
What are the 2 end products of oxidative phosphorylation?
- 34 ATP molecules
- water
What is the end product of anaerobic metabolism?
lactic acid
How much ATP molecules are created from pyruvic acid during the lactic acid pathway?
2 ATP
What type of acidosis is lactic acidosis?
anion gap metabolic acidosis
Why is there altered homeostasis in the setting of acidosis?
the body’s enzymes tend to not function properly in an acidic environment
How is serum lactate cleared?
the liver
What is the primary by-product of aerobic metabolism?
Carbon dioxide
What are the 3 primary ways that CO2 is transported/buffered in the blood?
- as bicarbonate
- bound to Hgb
- dissolved in the plasma
What % of CO2 is transported/buffered as bicarbonate?
70%
What % of CO2 is transported/buffered bound to Hgb?
23%
What % of CO2 is transported/buffered dissolved in the plasma?
7%
What is the enzyme that facilitates the formation of carbonic acid (H2CO3) from H2O and CO2?
Carbonic anhydrase
To maintain electroneutrality, for every molecule of HCO3- that leaves the erythrocyte, 1 _____ ion is transported in.
Cl-
What is the Hamburger shift?
To maintain electroneutraility, for every molecule of HCO3- that leaves the erythrocyte, 1Cl- ion is transported in.
Why is venous blood slightly more acidic?
The PvCO2 (venous blood) is about 5 mmHg higher than the PaCO2 (arterial blood).
What is the normal venous pH?
7.36 (as opposed to normal arterial pH = 7.4)
Metabolically active tissues create a more _____ environment.
acidic
A more acidic environment, enhances _____ from hemoglobin (Bohr effect) and _____ loading on hemoglobin (Haldene effect).
O2 offloading; CO2 loading
What is the Haldene effect?
CO2 loading onto Hgb in acidic environment
What is the Bohr effect?
O2 offloading in acidic environment
How is CO2 eliminated from the pulmonary blood?
alveolar ventilation
What is the Bicarbonate - Carbonic Acid Buffer Reaction?
H2O + CO2 <—> H2CO3 <—> H+ + HCO3-
What is required for the bicarbonate - carbonic acid buffer reaction to take place?
carbonic anhydrase
Where is carbonic anhydrase present? And where is it not?
Present in the erythrocyte
NOT present in the plasma
Why does the formation of carbonic acid reaction have to be fast?
RBCs only remain in capillary blood for a short period of time
What facilitates the formation of carbonic acid (H2CO3)?
Carbonic anhydrase
What is H2CO3?
Carbonic acid
Carbonic acid rapidly dissociates into ____ and _____.
H+ and HCO3-
What happens to the dissociates of carbonic acid?
the H+ is buffered by Hgb
the HCO3- is transported to plasm to act as a buffer
Where does the chloride shift (Hamburger shift) happen in reverse?
in the lungs as CO2 is excreted from the body
Venous Hct is _____ than arterial Hct.
@3% higher
Why is venous Hct higher than arterial Hct?
The chloride shift adds osmotically active ions (Cl-) to the erythrocyte in venous circulation. Water follows isosmotically, causing the erythrocyte to swell. The cell volume is increased relative to the plasm volume.
What is the carbamino compound buffer?
CO2 binds with amino groups on Hgb as well as other plasma proteins
What is the solubility coefficient of dissolved CO2?
0.067 mL/dL/mmHg
CO2 is 20x more soluble in the blood than what?
O2
The Haldene effect states that in the presence of deoxygenated Hgb, the CO2 dissociation curve shifts ____.
to the left
What does the Haldane effect describe?
CO2 carriage
The Haldane effect states that oxygen causes the erythrocyte to release ____.
CO2
The presence of oxygenated Hgb shifts the CO2 dissociation curve to the ____.
Right
The presence of deoxygenated Hgb shifts the CO2 dissociation curve to the ____.
left
What does the Bohr effect describe?
O2 carriage
The Bohr effect says what?
That CO2 and decreased pH cause the erythrocyte to release oxygen.
Why does oxygenated Hgb shift the CO2 dissociation curve to the right?
Blood can hold less CO2
Why does deoxygenated Hgb shift the CO2 dissociation curve to the left?
Blood can hold more CO2
Where in the body is the CO2 dissociation curve right shifted?
the lungs
Why is the CO2 dissociation curve right-shifted in the lungs?
This facilitates CO2 elimination
Where in the body is the CO2 dissociation curve left-shifted?
The systemic capillaries
Why is the CO2 dissociation curve left-shifted in the systemic capillaries?
This facilitates CO2 loading and transport by Hgb
Hypercapnia is defined as a PaCO2 > than ____mmHg.
45
What are the 3 etiologies of hypercapnia?
- increased CO2 production
- decreased CO2 elimination
- rebreathing
Sepsis, MH, thyroid storm, burns, and shivering are all causes of _____ CO2 production.
increased
Airway obstruction, ARDS, COPD, and opioid OD are all causes of ______ CO2 _____.
decreased CO2 elimination
What are some causes of rebreathing?
exhausted soda lime, faulty unidirectional valve in a circle system, or inadequate FGF in a Mapleson circuit
What are some consequences of hypercarbia?
hypoxemia, acidosis, cardiac depression, SNS stimulation, increased ICP
What is the formula for PaCO2?
PaCO2 = CO2 production / alveolar ventilation
With hypercapnia, the oxyhemoglobin curve shifts ____.
right
CO2 is a ______ depressant.
myocardial
CO2 directly ____ the peripheral vasculature
dilates
CO2 activates the ____ and increases ____ release from the adrenal medulla
SNS; catecholamine
With mild acidosis, the SNS stimulation r/t hypercapnia offsets what other s/e?
cardiac depression and direct peripheral vasodilation
CO2 is a smooth muscle dilator with the exception of what?
pulmonary vasculature
CO2 has what affect of PVR?
Hypercapnia increases PVR
An increased PVR increases the workload of the ____
right heart
Hypercapnia activates the ____ pump
H+/K+ …. Buffers CO2 acid in exchange for releasing K+ into plasma
What electrolyte effects does hypercapnia cause?
Increased K+ and increased Ca+
With acidosis, plasma proteins buffer H+ and release _____.
Ca+
Can CO2 freely diffuse across the BBB?
yes
Hypercapnia _____ ICP
increases
CO2 narcosis occurs when the PaCO2 is greater than what?
90 mmHg
During respiratory acidosis, the kidneys do what?
excrete H+ and conserve bicarbonate to return pH to normal
With acute respiratory acidosis, for every PaCO2 10 mmHg increase above 40 mmHg, pH decreases by ____.
0.08
With chronic respiratory acidosis, for every PaCO2 10 mmHg increase above 40 mmHg, pH decreases by ____.
0.03
Why is the decrease in pH less for chronic respiratory acidosis versus acute respiratory acidosis?
With chronic respiratory acidosis, there is HCO3- retention built up by the kidney
The carbon dioxide ventilatory response curve describes the relationship between ____ and ______.
PaCO2 and minute ventilation
What is the primary monitor of PaCO2?
the central chemoreceptor in the medulla
What are secondary monitors for PaCO2?
the peripheral chemoreceptors in the carotid bodies and transverse aortic arch
Where are the peripheral chemoreceptors that monitor PaCO2 located?
carotid bodies and transverse aortic arch
What conditions shift the CO2 response curve down and to the right?
- volatiles
- opioids
- NMBD
- metabolic alkalosis
- CEA
What conditions shift the CO2 response curve to the left?
- hypoxemia
- metabolic acidosis
- surgical stimulation
- intracranial HTN
What is the apneic threshold?
the highest PaCO2 at which a person will not breathe (once exceeded, the patient will begin to breathe)
Minute ventilation increases w/ PaCO2 in a linear fashion when PaCO2 is between ____ - ____ mmHg.
20-80
CO2 is a respiratory depressant when PaCO2 exceeds ____ - _____ mmHg.
80-100 mmHg
MAC of CO2 = _____ mmHg
200
What does the slope of the carbon dioxide ventilatory response curve represent?
The sensitivity of the entire respiratory apparatus to PaCO2
A left shift and increased slope of the carbon dioxide ventilatory response curve indicates what?
That Ve is higher than expected for a given PaCO2. This creates respiratory alkalosis
A right shift and decreased slope of the carbon dioxide ventilatory response curve indicates what?
That Ve is lower than expected for a give PaCO2. This creates respiratory acidosis.
What is the pacemaker for normal breathing?
Dorsal respiratory center
Where is the respiratory center located?
In the reticular activating system in the medulla and pons
The respiratory center receive afferent input from the central and peripheral chemoreceptors as well as _____.
Stretch receptors in the lungs
What two respiratory groups are a part of the medullary respiratory centers?
dorsal respiratory group and ventral respiratroy group
When is the dorsal respiratory group active?
During inspiration
When is the ventral respiratory group active?
During expiration
What two centers are part of the pontine respiratory centers?
pneumotaxic center and apneustic center
Where is the pneumotaxic center located?
upper pons
Where is the apneustic center located?
lower pons
What center inhibits the DRG?
pneumotaxic center (upper pons/of pontine)
What center stimulates DRG?
apneustic center (lower pons/pontine)
The respiratory rate & pattern are determined by what?
Medulla, Carotid bodies & Aortic arch & Lung baroreceptors
Where is the neural control of respiration located?
Respiratory center of medulla
The locations for chemical control of respiratory rate & pattern are determined by?
central chemoreceptors - medulla
peripheral chemoreceptors - carotid bodies and aortic arch
Where do the efferent pathways of the respiratory system terminate?
diaphragm, intercostals, and accessory muscles
What can modify the efferent response of the respiratory center?
The cerebral cortex
What is located in the medulla?
Dorsal respiratory group and ventral respiratory group
When is the DRG (dorsal respiratory group active)?
primarily active during inspiraiton
The respiratory pacemaker function is performed by the central pattern generator, which includes the ____, ______ (in the VRG), and other medullary strucutres.
DRG, pre-Botzinger complex (per Apex, if you see a question on this on the exam, first pick pre-botzinger complex if it is an option, if not pick DRG)
When is the ventral respiratory group active?
primarily active during expiration
When does the ventral respiratory group become more important?
during exercise or stress
What is located in the pons?
pneumotaxic center and apneustic center
What does the pneumotaxic center do?
inhibits the DRG (inhibits the pacemaker)
What does the apneustic center do?
stimulates the DRG (stimulates the pacemaker)
Is the pneumotaxic center located in the upper or lower pons?
Upper
What is the function of the pneumotaxic center?
To trigger the end of inspiration by inhibiting DRG
A strong stimulus of the pneumotaxic center promotes what kind of breathing?
rapid, shallow
A weak stimulus of the pneumotaxic center promotes what kind of breathing?
slow and deep
The apneustic center is located in the ____ pons.
lower
The apneustic center _____ the pneumotaxic center which causes inspiration.
antagonizes
What receptors are pulmonary stretch receptors?
J receptors
The action of the apneustic center is inhibited by what?
pulmonary stretch receptors/J receptors
What does the DRG do?
cause inspiration
Where is the DRG located?
Medulla
Where specifically in the medulla is the DRG located?
nucleus tractus solitarius
What does the VRG do?
causes expiration
Where is the VRG located?
medulla
Where specifically in the medulla is the VRG located?
nucleus ambiguous and nucleus retroambigus
The VRG has ___ and ___ function
inspiration and expiration
What does the VRG cause?
Expiration
When is the VRG primarily active?
expiration
What contains the pre-botzinger complex?
The Ventral Respiratory Group
Central chemoreceptors resond indirectly to what?
PaCO2
The BBB separates ___ from ____
blood from CSF
Which of the following can freely diffuse through the BBB: CO2, H+, and HCO3-?
Only CO2
After CO2 enter CSF, what does it do?
Dissociates into H+ and HCO3- (the rise in H+ is what stimulates respiration)
Respiratory changes to correct acidosis occur _____
within minutes
Can non-volatile (such as lactic acid) acids pass through BBB?
NO
How long is therapeutic hyperventilation (to reduce ICP) effective for?
A few hours to approximately 2 days
What respiratory technique is used to reduce ICP?
hyperventilation
What stimulates the central chemoreceptor?
hyeprcarbia and hypoxemia
What depresses the central chemoreceptors?
PROFOUND** hypercarbia and hypoxemia
Where are the central chemoreceptors located?
a few microns below the surface of the anterolateral aspect of the medulla
Ions, glucose, and amino acids can freely cross the BBB. T/F
False, are carried via active transport
What drives the respiratory pacemaker in the DRG?
H+
Do non-volatiles acids influence Ve on a short-term or long-term basis?
longer-term
HCO3= equilibrates between the blood & CSF - this process begins after a _____ and peaks at ____.
few hours; @2 days
What is the normal pH of CSF?
7.32
Where do peripheral chemoreceptors reside?
in the carotid bodies and aortic arch
What part of the carotid bodies do peripheral chemoreceptors reside?
bifurcation of the common carotid artery
What part of the aortic arch do peripheral chemoreceptors reside?
transverse aortic arch
What is the chief responsibility of the carotid body?
Monitor hypoxemia (PaO2 <60 mmHg)
Does the carotid body respond to SaO2 or CaO2?
No, neither - they respond to PaO2/hypoxemia
What is severed during CEA?
the afferent limb of the hypoxic ventilatory response
Why don’t we do bilateral CEA simultaneously or very close to each other?
B/c CEA severs the afferent limb of the hypoxic ventilatory response and it takes time for the body to recalibrate
What do sub-anesthetic doses of inhalation and IV anesthetics (0.1 MAC) do to the hypoxic ventilatory drive?
Depress the hypoxic ventiltory drive
What are secondary responsibilities of the carotid bodies?
monitoring of PaCO2, H+, and perfusion pressur
PaO2 <60 mmHg closes the ______ channels in ____ cells.
oxygen-sensitive K+; Type 1 Glomus
During the hypoxic ventilatory response, an action potential is propagated alon what nerve?
Hering’s nerve
Herings’s nerve –> _______ nerve
Glossopharyngeal nerve
CN 9 is what nerve?
Glossopharyngeal
The afferent pathway of the hypoxic ventilatory response terminates ______.
in the inspiratory center in the medulla
Volatile anesthetics impair ____,___,and ____ muscle function.
diaphragmatic, intercostal, and upper airway muscle function
CaO2 is reduced w/ these two processes but PaO2 usually remains normal: _____ and _____
anemia and carbon monoxide poisoning
Why does anemia and carbon monoxide poisoning not stimulate the hypoxic ventilatory response?
Even though CaO2 is reduced, PaO2 usually remains normal
Which reflex prevents alveolar overdistension?
Hering-Breuer inflation reflex
What receptors in smooth airway muscle in the lung influence respiratory pattern?
stretch receptors
What does the Hering-Breuer inflation reflex do?
Lung hyperinflation turns off the respiratory drive
What does the Hering-Breuer inflation reflex help to avoid?
overinflation
What is the Hering-Breuer deflation reflex?
Activates the respiratory drive when lung volume is too small
What does the Hering-Breuer deflation reflex help to prevent?
Atelectasis
J receptors are also known as _____ receptors
pulmonary C-fiber receptors
What increases the RR in the setting of pulmonary embolism or CHF?
J receptors (J receptors are activated by things that Jam traffic in the pulmonary vasculature).
What causes a newborn baby to take her first breath?
Paradoxical reflex of Head
What is the paradoxical reflex of head?
it causes a newborn to take its first breath
How do stretch receptors in the smooth airway muscle work?
they transduce pressure conditions inside the airway
Stretch receptors transmit pressure conditions along the _____ nerve to the _______.
vagus nerve; DRG
What is CN 10
Vagus
When does the Hering-Breuer Inflation reflex “turn off” the DRG/inspiration?
when lung inflation >1.5 L above FRC or 3x normal TV
J receptor stimulation causes _____
tachypnea
What is HPV?
A local reaction that occurs in response to a reduction in alveolar oxygen tension (not arterial PO2)
What is the goal of HPV?
To improve matching of ventilation and perfusion (aka minimize shunt)
What is the only region in the body that responds to hypoxia with vasoconstriction?
the pulmonary vasular bed
HPV is inhibited by volatile anesthetics > ____ MAC
1.5
What types of medications inhibit HPV?
phosphodiesterase inhibitors and dobutamine, vasodilators, and some CCB
Does hypervolemia or hypovolemia inhibit HPV?
Hypervolemia
_____ PEEP and _____ TV inhibits HPV.
Excessive; large
HPV is or is not inhibited by Ketamine, Propofol, and opioids?
HPV is NOT inhibited
HPV response begins within ____ and achieves full response in ____.
seconds; 15 minutes
HPV selectively increases the pulmonary vascular resistance in ______ areas to minimize shunt flow to these areas.
poorly ventilated
Neo, Epi, and Dopamine ____ shunt flow
Increase
What may distended constricted vessels in pulmonary vasculature and increase shunt flow?
Hypervolemia (LAP >25 mmHg) and elevated CO
Excessive PEEP or high TV increase what that would reduce optimal V/Q matching?
dead space
What 3 chemicals contribute to increased airway resistance?
- inositol triphosphate
- phospholipase C
- leukotrienes
The ___ of the airway has the most significant contribution to airflow resistance.
radius
What contributes to bronchoconstriction?
PNS (vagus nerve) and mast cells & non-cholinergic PNS
Non-cholinergic PNS (Nitric oxide) –> broncho____
dilation
SNS (circulating catecholamines) –> broncho____
dilation
Mast cells & non-cholingergic PNS –> broncho____
constriction
PNS (vagus nerve) –> broncho____
constriction
The vagus nerve supplies what kind of innervation to airway smooth muscle?
Parasympathetic
Stimulation of the ____ receptor produces bronchoconstriction
M3
What Mu receptor when stimulated produces bronchoconstriction?
M3
There are no sympathetic or para-sympathetic nerve endings in airway smooth muscle?
sympathetic
There is no ____ nerve endings in airway smooth muscle.
sympathetic
What receptors embedded in airway smooth muscle are activated by catecholamines in systemic circulation?
B2
Smooth muscle contraction –> _____ airway diameter
decreased
Decreased airway diameter –> increased ____
airway resistance
Smooth muscle relaxation –> ____ airway diameter
increased
The ____ nerve supplies parasympathetic innervation to airway smooth muscle.
Vagus nerve
Cholinergic nerve endings release Ach on to M3 receptors - parasympathetic or sympathetic?
Parasympathetic
What is a M3 receptor coupled to?
Gq protein
M3 receptor activation turns on the ___ protein, and this activates ____.
Gq; phospholipase C (PLC)
PLC activates what?
Inositol triphosphate (IP3) (ex of second messenger…. M3 –> PLC —> IP3)
What does IP3 stimulate and from where?
Release of Ca+2 from sarcoplasmic reticulum
Increased iCa2+ activates ____, and this enzyme enables the contractile mechanism –> bronchoconstriction.
myosin light chain kinase
Are mast cells in smooth airway epithelium?
Yes, highly concentrated
Coughing, allergy, or infection activate ____, ___, and ____, which in turn amplify the inflammatory response.
IgE, cytokines, and complement
__________-fibers release chemicals that promote bronchoconstriction.
Non-cholingergic c-fibers
Mast cell mediator?
histamine
B2 receptor is coupled to a ___ protein in airway smooth muscle
Gs
Activation of B2 receptor turns on Gs protein and this activates what?
Adenylate cyclase
Adenylate cyclase activates ____ (the second messenger)
cAMP
What does cAMP reduce?
release of Ca+2 from the sarcoplasmic reticulum
The bronchodilation pathway is turned off when _______ deactivates cAMP by converting it to AMP.
phosphodiesterase 3
NO is a potent smooth muscle ____
relaxant
Non-cholingergic PNS nerves release what onto airway smooth muscles?
vasoactive intestinal peptide
What increases NO production?
VIP
What does NO stimulate?
cGMP
What does cGMP do regarding the airway smooth muscle?
Smooth muscle relaxation and bronchodilation
What drug class is theophylline?
Methylxanthine
What drug class is zafirlukast?
Leukotriene modifier
What drug class is cromolyn?
mast cell stabilizer
What drug class is triamcinolone?
corticosteroid
What are the 3 types of pulmonary medications?
- bronchodilators
- anti-inflammatories
- methylxanthines
What are the 2 types of direct acting bronchodilators?
- beta 2 agonists
- anticholingergics
Beta __ agonists are bronchodilators
2
What are some beta 2 agonist examples?
albuterol, metaproterenol, salmeterol
What are some anticholinergics that are direct acting bronchodilators?
Atropine, glycopyrrolate, ipratropium
Anti-inflammatories that are pulmonary medications include: _____, ____, and ______.
inhaled corticosteroids, cromolyn, and leukotriene modifiers.
What are examples of leukotriene modifiers?
zileuton and montelukast
What are examples of inhaled corticosteroids?
beclomethasone, fluticasone, triamcinolone
Methylxanthines include what?
Theophylline
_____ and _____ are anesthetics with bronchodilating properties.
Volatile anesthetics and ketamine
What is the MOA of beta 2 agonists?
beta 2 stimulation –> increased cAMP –> decreased iCa2+
What are s/e of beta 2 agonists?
tachycardia, dysrhythmias, hypokalemia, hyperglycemia, tremors
Beta 2 agonists stabilize ______
mast cell membranes (which decrease mediator release)
What is the MOA of anticholingergics?
M3 antagonism –> decreased IP3 –> decreased iCa2+
What are s/e of anticholingergics?
inhibits secretions, urinary retention, blurry vision, cough
Anticholingergics increase ______ with narrow angle glaucoma.
intraocular pressure
Beclomethasone, Budesonide, Flunisolide, Fluticasone, and Triamcinolone are all what?
inhlated corticosteroids
What is the MOA of inhlaed corticosteroids?
stimulation of intracellular steroid receptors; regulates inflammatory protein synthesis (lowers airway inflammation and hyperresponsiveness)
S/e of inhaled corticosteroids?
dysphonia, myopathy of laryngeal muscles, oropharyngeal candidiasis, possible adrenal suppresion
What is the MOA of cromolyn?
Stabilizes mast cell membrane
What are the s/e of cromolyn?
neglibible s/e
Zileuton, Montelukast, Pranlukast, and Zarfirlukast are all what type of drug?
Leukotriene modifiers
What is the MOA of Leukotriene modifiers?
inhibits 5-lipoxygenase enzyme
Leukotriene modifiers decrease ____ synthesis
leukotriene
What are the s/e of leukotriene modifiers?
negligible
What is the MOA of methylxanthines?
inhibits phosphodiesterase –> increased cAMP
Theophylline is what type of drug?
methylxanthines
Methylxanthines inhibit what 2 things?
phosphodiesterase and adenosine receptors
Methylxanthines ____ endogenous catecholamine release
increase
What are the s/e of methylxanthines in plasma concentrations greater than 20?
N/V, diarrhea, HA, and disrupted sleep
When do seizures, tachydysrhythmias, and CHF occur with methylxanthine use?
plasma concentration >20
Steroids ____ arachidonic acid.
block
Which pulmonary function test is the MOST sensitive indicator of small airway disease?
Forced expiratory flow 25-75%
What measures how much air the lungs can hold at a single point in time?
Static lung volumes
What are examples of static lung volumes?
RV, ERV, TV, IRV, FRC, IC, VC, and TLC
What measures how quickly air can be moved in and out of the lungs over time?
Dynamic lung volumes
What are examples of dynamic lung volumes?
FEV1, FVC, FEV1/FVC, and MMEF
_________ measures how well the lungs can transfer gas across the alveolocapillary membrane.
Diffusing capacity
What is a normal FEV1
> 80% of predicted value
What is a normal FEV1/FVC ration?
> 75-80%
How are lung volumes and capcities measured?
spirometry
What is forced expiratory volume in 1 second (FEV1)?
volume of air that can be exhaled after a max inhalation in 1 second
FEV1 ____ with age
declines
What is forced vital capacity (FVC)?
Volume of air that can be exhaled after a max inhalation
What is the normal FVC for a male?
4.8 L
What is the normal FVC for a female?
3.7 L
What is FEV1/FVC ratio?
Compares volume of air expired in 1 second and total volume of air expired
The FEV1/FVC ratio is useful when diagnosis _____ vs _____
obstructive versus restrictive diseases
FEV1/FVC ratio <70% suggests what?
obstructive disease
A normal FEV1/FVC ratio occurs in what disease?
Restrictive
What is a normal FEV1/FVC?
> 75-80% of predicted value
What is forced expiratory flow at 25-75% vital capacity also called?
mid maximal expiratory flow rate (MMEF)
What does forced expiratory flow at 25-75% vital capacity show?
measures airflow in the middle of FEV (FEV 25-75%)
What is a normal forced expiratory flow at 25-75% vital capacity?
100 +/- 25% PREDICTED VALUE
What is maximum voluntary ventilation (MMV)?
max volume of air that can be inhaled and exhaled over the course of 1 minute
Maximum voluntary ventilation is the best test of ______-
endurance
What is the normal MMV for a male?
140-180 L
What is the normal MMV for a female?
80-120 L
What is diffusion capacity (DLCO)?
The volume of carbon monoxide that can traverse the alveolocapillary membrane per a given alveolar partial pressure of carbon monoxide
DLCO is based on _______ law
Fick’s law of diffusion
What is a normal DLCO?
17-25 mL/min/mmHg
Flow volume loops allow us to differentiate betwen what?
obstructive and restrictive respiratory diseases
On a flow-volume loop, _____ produces a waveform that moves from right to left with a negative deflection.
inhalation
On a flow-volume loop, _____ produces a waveform that moves from left to right with a positive deflection.
exhalation
What cannot be measured with spirometry.
RV
Independent risk factors that are patient-related for post-op pulmonary complication?
old age (>60)
COPD
CHF
smoking (>40 pack years)
ASA >2
Independent risk factors that are procedure-related for post-op pulmonary complication?
surgery >2 hours; GA; aortic or abdominal surgery
Independent risk factors that are diagnostic-related for post-op pulmonary complication?
Albumin <3.5 g/dL
What is a short-term benefit of smoking cessation?
reduction in carboxyhemoglobin
When should smoking cessation be done?
at least 6 weeks
What do you treat expiratory airflow obstruction with?
bronchodilators and corticosteroids
Moderate asthma, ABG analysis, and PFT have or have not been sown to increase the risk of post-op pulmonary complications for non-thoracic surgery.
HAVE NOT (key word = non-thoracic surgery)
What is smokings effects on the respiratory system?
- risk factor for pulmonary dx
- decreased mucociliary clearance
- airway hyperactivity
- reduced pulmonary immune function
What is smokings effects on the CV system?
- risk factor fo CV dx
- carbon monoxide –> decreased DO2
- catecholamine release
- coronary vasoconstriction
- decreased exercise tolerance
Short term effect of smoking cessation: carbon monoxide t1/2 = ___
4-6 hours
Short term effect of smoking cessation: P50 returns to near normal in ______
12 hours
Does short term cessation of smoking reduce pulmonary complciations?
no
Return of pulmonary function after smoking cessation takes at least ______.
6 weeks
A peak airway pressure of ____ is required to for initial reopening of the atelectatic regions.
30 cm H2O
Increasing the PIP to ____ for _____ appears to reverse anesthesia induced atelectasis almost completely.
40 cmH2O for 8 seconds (give a breath of 40 for 8 seconds)
A high FiO2 significantly contributes to what?
absorption atelectasis
Why should you use the lowest FiO2 the patient will tolerate?
B/c a high FiO2 significantly contributes to absorption atelectasis
List 3 types of surgery w/ the highest risk of PPC.
- aortic
- thoracic
- upper abdominal = neuro= peripheral vascular
A patient with severe kyphoscoliosis is expected to have a reduced ____ and ______. (pulmonary tests)
FRC; FEV1
_________ disease is characterized by small airway obstruction and increased resistance to expiratory flow.
obstructive
What type of respiratory disease has a proportionate reduction in all of the lung volumes along with poor compliance?
Restrictive
Restrictive respiratory disease has what type of lung volumes?
small
When is FEV1/FVC ratio decreased?
obstructive diseases
Patients with restrictive disease tend to have decreased ____ and ____, yet normal _____.
FEV1 and FRC; FEV1/FVE ratio
Getting air ____ is the problem in obstructive disease.
out
Restrictive or obstructive airway disease:
FEV1 ↓ to ↓↓↓↓
Obstructive
Restrictive or obstructive airway disease:
FEV1 ↓ to ↓↓↓
Restrictive
Restrictive or obstructive airway disease:
FVC ↑ to ↓↓↓
Obstructive
Restrictive or obstructive airway disease:
FVC ↓ to ↓↓↓
Restrictive
Restrictive or obstructive airway disease:
FEV1 to FVC Ratio ↓↓↓
Obstructive
Restrictive or obstructive airway disease:
FEV1 to FVC ratio normal
Restrictive
Restrictive or obstructive airway disease:
FEF 25-75% ↓↓↓
Obstructive
Restrictive or obstructive airway disease:
FEF 25-75% Normal
Restrictive
Restrictive or obstructive airway disease:
RV Normal to ↑
Obstructive
Restrictive or obstructive airway disease:
RV ↓↓↓
Restrictive
Restrictive or obstructive airway disease:
FRC Normal to ↑
Obstructive
Restrictive or obstructive airway disease:
FRC ↓↓↓
Restrictive
Restrictive or obstructive airway disease:
TLC Normal to ↑
Obstructive
Restrictive or obstructive airway disease:
TLC ↓↓↓
Restrictive
A normal spirometry waveform looks like what?
an up-side down ice cream cone
An example of a obstructive respiratory disease?
COPD
What does a spirometry waveform look like in obstructive disease?
The expiratory limb has a concave shape
LOOKS LIKE A CARRIAGE
“someone took a bite out of my ice cream cone”
What does a spirometry waveform look like in a restrictive lesion?
The shape of the loop is similar to the normal loop, but SMALLEr and RIGHT shifted
“on a restrictive diet you have to eat a smaller cone”
Pulmonary fibrosis is a ________ respiratory disease.
restrictive
In a fixed respiratory disease, the spirometry wvaeform is?
flat (both inspiratory and expiratory limbs)
“someone smashed my ice cream cone”
It needs to be fixed
What is an example of a fixed respiratory disease?
tracheal stenosis
In an extrathoracic obstruction, the patient ______ and the airway collapses.
inhales
In an extrathoracic obstruction, the patient exhales and____________.
pushes the obstruction open
What limb is flat for an extrathoracic obstruction spirometry waveform?
inspiratory limb is flat
The patient inhales and pulls open the obstruction in what type of thoracic obstruction?
intrathoracic
The patient exhales and the airway collapes in a _______obstruction.
intrathoracic
What limb is flat for an intrathoracic obstruction spirometry waveform?
expiratory limb
A bronchospasm immeditately following intubation in an asthma patient is MOST likely the result of?
Vagal stimulation
Airway smooth muscle is not innervated by the ______
SNS
What is the definition of asthma?
acute, reversible airway obstruction that is accompanied by chronic airway inflammation and bronchial hyperreactivity
With asthma, there is an acute, reversible ________, along with chronic airway and bronchial ________.
airway obstruction; inflammation; hyper-reactivity
What is atopy?
condition of being “hyper-allergic”
What is the greatest risk for developing asthma?
atopy
FEV1, FEV1/FVC ratio, and FEF 25-75% in asthma
all are reduced but improve w/ bronchodilator therapy
FEV1, FEV1/FVC ratio, and FEF 25-75% in asthma
all are reduced but improve w/ bronchodilator therapy
What is most common ABG for asthma?
respiratory alkalosis with hypocarbia
An elevated PaCO2 in asthma suggests what 3 possibilies?
- air trapping
- respiratory muscle fatigue
- impending respiratory failure
Key s/s of asthma:
wheezing, dyspnea, chest discomfort or tightness, productive or non-productive cough, prolonged expiratory phase, eosinophilia
During mechanism ventilation of an asthma patient, limit ____, prolong _____, and tolerate _____.
limit inspiratory time
prolong expiratory time
tolerate moderate permissive hypercapnia
What medications should be avoided in asthma patients?
Non-selective beta blockers and histamine releasing drugs
For asthma, use anesthetic agents that promote what?
bronchodilation
What anesthetic agents promote bronchodilation?
sevo, iso, ketamine, propofol, lidocaine
Name 4 drugs that release histamine.
- Sux
- Atracurium
- Morphine
- Meperidine
Smooth muscle hypertrophy, fibrosis, angiogenesis, and hypersecretion of mucus occur in what?
asthma
What type of external stressors provoke asthma S/S?
vagal stimulation and cold air
What drugs provoke asthma S/S? (4 total)
aspirin, nsaids, beta blockers, sulfites
What might the EKG show during a severe asthma attack?
RV strain with right axis deviation
Why might an EKG show RV strain with right axis deviation during a severe asthma attack?
PVR increases, and this increases workload of right heart
In asthma, PVR increases or decreases?
increases
The tachypnea and hyperventilation that occur during asthma attacks are the result of what?
Neural reflexes
Why might severe bronchospasm cause hypoxemia?
V/Q mismatch
PFTs are or are not predictive of post-op pulmonary complications.
ARE NOT
For what one surgery are PFT predictive of post-op pulmonary complications?
Lung reduction surgery
In asthma _____ may increase due to air trapping, but ______remains WNL.
FRC; TLC
CXR of asthma?
hyper-inflated lungs w/ diaphragmatic flattening
What is the preferred extubation technique for asthma patients?
Deep extubation (if not possible, use lidocaine or opioids)
What might benefit a patient with exercise-induced asthma during ventilation?
HME
What volatile agent reduces the risk of coughing and risk of bronchospasm?
Sevo
What is the only IV induction drug that causes bronchodilation?
Ketamine
What IV induction drug suppresses airway reflexes?
Propofol
_________1-3 minutes before extubation suppresses airway reflexes.
Lidocaine 1-1.5 mg/kg
How do you differentiate between light anesthesia and bronchospasm?
NMBD improve pulmonary compliance with light anesthesia but NOT bronchospasm
What is ketorolac’s effect on the airway?
it can increase airway resistance (caution in asthma)
What histamine receptor, when stimulated, reduces histamine release?
Presynaptic H2 receptor
What are some H2 antagonists?
Ranidtine and Famotidine
H2 antagonists allow for unopposed H1 stimulation, which can cause what in asthma patients?
bronchospasm (very low risk)
What BB is the best choice in asthma patients and why?
Esmolol b/c of its short t1/2 and B1 selectivity
What is F2 alpha prostaglandin?
a naturally occuring hormone
What does carboprost (hemabate) mimic?
the action of F2 alpha prostaglandin
What is the use of carboprost (hemabate)?
it is used to stop uterine bleeding
What is a s/e of carboprost (hemabate)?
bronchoconstriction in asthmatics
Which drug is LEAST likley to be effective in relieving s/s of acute bronchospasm?
1. Ketamine 1 mg/kg IV
2. Epi 1 mcg/kg IV
3. Hydrocortisone 2 mg /kg IV
4. Lidocaine 1.5 mg /kg IV
Hydrocortisone 2 mg /kg IV
What are causes of wheezing, besides asthma, when ventilated?
Kinked ETT, end-bronchial intubation, pulmonary aspiration
How does intraoperative bronchospasm present?
- wheezing
- decreased breath sounds
- increased PIP (/t decreased dynamic compliance)
- increased alpha angle on ETCO2 waveform
How do you treat acute bronchospasm?
100% FiO2, deepen anesthetic
short acting inhaled B2 agonist
inhaled ipratropium
epi 1 mcg/kg IV
hydrocortisone 2-4 mg /kg IV (doesn’t treat, prevents additional problems)
aminophylline
helium -oxygen gas mix
Name differential diagnosis for intra-op bronchospams/wheezing:
- mechanical obstruction of ETT
- light anesthesia
- acute asthma attack
- endobronchial intubation
- pneumo
- aspiration
- pulmonary edema
- PE
With light anesthesia, coughing and straining occur. This ____ FRC.
Decreases
Name 4 mechanical obstructions of ETT.
kinking, biting, secretions, overinflation of cuff
Why do increased PIP with normal plateau pressures occur during bronchospam?
d/t decreased dynamic pulmonary compliance
During bronchospasm, PIP is ____ and plateua pressure is _______
PIP is increased; plateau is normal
Is montelukast used in the treatment of acute bronchospasm?
NO
Alpha-1 antitrypsin deficiency: (select 2).
1. increases the risk of bronchospasm
2. causes pan-lobular emphysema
3. can be treated with IgG
4. is the most common metabolic disease affecting the liver
2 & 4
Pan-lobular emphysema and most common metabolic dx affectign the liver
COPD is characterized by a reduction in ___________ and a slower forced emptying of the lungs.
maximal expiratory flow
How is COPD different than asthma?
Air flow obstruction is not fully reversible
COPD is an umbrella term for what two diseases?
Chronic bronchitis and emphysema
What is the pathophysiology of chronic bronchitis?
hypertrophied bronchial mucus glands and chronic inflammation
What is the pathophysiology of emphysema?
enlargement and destruction of the airways distal to the terminal bronchioles
Etiologies of COPD include ____, ____, ____, and ____.
smoking, respiratory infection, exposure to environmental pollutants, and alpha-1 antitrypsin deficiency
Alpha-1 antitrypsin deficiency is r/t what disease?
COPD
Inability to fully exhale —> _____
gas trapping (↑RV)
ABG of chronically elevated PaCO2
respiratoyr acidosis
To combat respiratory acidosis, what do the kidneys do?
reabsorb bicarb
What happens if you administer supplemental O2 to patient with severe COPD?
it can cause oxygen-induced hypercapnia
Oxygen-induced hypercapnia in COPD is caused by what 2 things?
- inhibition of HPV
- Haldane effect
To minimize the risk of oxygen-induced hypercapnia in patients with severe COPD, titrate FiO2 to maintain the SaO2 ___ to ___
88-92%
With COPD there is progressive deterioration of what components in the lung?
elastic components
What happens b/c of the deterioration of elastic components of the lungs of COPD patients?
there is a decreased recoil –> air trapping –> ↑RV
In COPD there is a ____ airway rigidity.
reduced (causes collapse during exhalation)
COPD Pathophysiology: ________ –> decreased pressure in airways –> airway collapse –> air trapping
increased gas velocity through narrowed airways
What causes airflow obstruction and bronchospasm in COPD patients?
secretions
Why does air trapping occur in COPD? (3 reasons)
- progressive deterioration of elastic components/decreased recoil
- reduced airway rigidity
- increased gas velocity
In COPD, patients have a problem getting air ____
out
COPD patients ahve _____ lungs
hyperinflated
What are 3 changes to the lungs that occur with COPD?
- flattened diaphragm
- increased AP diameter
pulmonary bullae
COPD: _____ diaphragm
flattened
COPD: ____ AP diameter
increased
What happens if you try to restore a chronic COPDer to a normal PaCO2 on the vent?
The reabsorbed bicarb in the blood (d/t kidney compensation of acidosis) will then lead to risk of severe alkalosis –> reduced oxygen unloading and apnea
Chronic bronchitis is defined by the presence of cough and sputum production for > ____ for ____.
3 months; 2 consecutive years
What is the common cause of chronic bronchitis?
smoking
Why does blood viscosity increase in chronic bronchitis?
RBCs are overproduced (erythrocytosis) to compensate for V/Q mismatch and hypoxemia
Explain the pathophysiology of cor pulmonale in chronic bronchitis.
Chronic hypoxemia and hypercarbia –> increase PVR –> PHTN –> RV strain (right axis deviation) –> cor pulmonale
____ heart function is normal in chronic bronchitis related cor pulmonale
left
What is the most efficacious therapy for PHTN and prevention of erythrocytosis in chronic bronchitis?
oxygen therapy
Blue bloaters are _____
chronic bronchitis
_____ is associated with enlargement and destruction of the airways distal to the terminal bronchioles.
Emphysema
Pink puffers are _____
emphysema
____ is reduced in emphysema, which leads to increased dead space
surface area for gas exchange (r/t destruction of airways distal to terminal bronchioles)
Why does PHTN occur in emphysema?
the pulmonary capillary beds are destroyed and the same amount of blood must travel to a smaller network of blood vessles
Alpha-1 antitrypsin deficiency can cause what?
emphysema
Emphysema PaO2 = ____
normal - slightly reduced
Emphysema PaCO2 = ______
normal - decreased
What is alpha-1 antitrypsin?
an enzyme
Where is alpha-1 antitrypsin produced?
by the liver
In alpha-1 antitrypsin deficiency, the ____ is unable to secrete this enzyme so it accumulates there. What does this cause?
Hepatocyte; cell death and cirrhosis
What breaks down pulmonary connective tissue?
alveolar elastase
What keeps the alveolar elastase enzyme in check?
alpha-1 antitrypsin
Alpha-1 antitrypsin allows for an overactivity of what?
alveolar elastase enzyme
COPD: RV is ↑ or ↓?
Increased
COPD: FRC is ↑ or ↓?
Increased
COPD: TLC is ↑ or ↓?
Increased
COPD: FEV1 is ↑ or ↓?
Decreased
COPD: FEV1/FVC is ↑ or ↓?
Decreased
COPD: FEF 25-75% is ↑ or ↓?
Decreased
An _______________ after bronchodilator therapy is diagnostic of COPD.
FEV1/FVC ratio <70%
Supplemental O2 in COPD patients impairs the hypoxic drive. T/F
False - it can cause oxygen-induced hypercapnia
What is the Haldane effect?
Describes how the oxygen tension in the blood determines the blood’s ability to buffer CO2
According to the Haldane effect, well-oxygenated blood has a _____ capacity to buffer CO2 than deoxygenated blood.
Lower
Identify the MOST appropriate strategy for mechanical ventilation in the patient with COPD.
a. I:E ratio 1:1
b. FiO2 <50%
c. RR 7
d. TV 10-12 mL/kg
RR 7
For COPD patients, do not consider neuraxial anesthesia if the patient requires sensory block > ___.
T6
What block is contraindicated in severe COPD? Why?
interscalene block; it causes paralysis of the ipsilateral hemidiaphragm
In COPD patients, select a volatile with ______
low blood:gas solublity
What are volatile agents affect upon HPV?
they impair HPV at >1.5 MAC and therefore increase shunt
What volatile is associated with rupture of pulmonary blebs?
N2O
COPD vent settings: TV _____
6-8 mL/kg IBW
For vent settings of COPD, increase ____ time
expiratory
Why should you avoid neuraxial anesthesia in COPD patients that would require sensory block > T6?
Block causes:
expiratory muscle function impairment, reduced ERV, and inability to cough and clear secretions
What volatile is less likely to cause airway irritation in COPD?
Sevo
What can be used to help gas redistribute from high compliance areas to those with longer time constants in COPD patients?
slow inspiratory flows
When does dynamic hyperinflation occur?
When a new breath is given before the patient was able to exhale the previous breath fully
Dynamic hyperinflation is also known as ____
breath staking
What are 3 risk factors for dynamic hyperinflation?
- high minute ventilation
- increased airway resistance
- reduced expiratory flow (COPD)
What are the consequences of dynamic hyperinflation?
barotrauma, pneumothorax, hypotension
What is the treatment for dynamic hyperinflation/auto-PEEP?
remove the patient from the breathing circuit
Removing the patient from the breathing circuit to treat auto-PEEP/dynamic hyperinflation allows what to happen?
allows the pressure in the lungs to equalize with atmospheric pressure
What will show on the vent with dynamic hyperinflation?
The waveform’s baseline will increase with each breath
What will the flow-volume loop look like with air trapping?
It will not return to zero at the end of expiration
All of the following are examples of restrictive lung disease EXCEPT:
a. sarcoidosis
b. cystic fibrosis
c. negative pressure pulmonary edema
d. flail chest
Cystic fibrosis
Restrictive lung disease describe disorders in which the lung is impaired when?
normal lung expansion during INSPIRATION is impaired
Where are the areas of restriction in restrictive lung diseases?
pulmonary interstitium, pleura, rib cage, and/or abdomen
Acute intrinsic restrictive ventilatory defects… name 2
aspiration
UA obstruction
reversal of opioid OD
cocaine OD
re-expansion of collapsed lung
neurogenic
Chronic intrinsic restrictive ventilatory defects… name 2
Sarcoidosis
Amiodarone-induced pulmonary fibrosis
Disease of the chest wall, mediastinum, and pleura restrictive ventilatory defects… name 3
Flail chest, pleural effusion, and ankylosing spondylitis
Miscellanious restrictive ventilatory defects… name 3
Pregnancy, obesity, ascites
FEV1 and FVC ______ is diagnostic for restrictive lung disease.
<70%
Although FEV1 and FVC are decreased in restrictive lung disease, FEV1/FVC ration is ______
unchanged
What is the most significant risk of restrictive lung disease?
barotrauma
Vent settings for restrictive lung disease: TV - ____
6 mL/kg IBW (on smaller side)
Vent settings for restrictive lung disease: RR - ____
14-18 breaths/min (on faster side)
Vent settings for restrictive lung disease:PIP - ____
PIP <30 cm H2O
Vent settings for restrictive lung disease: I:E ratio - ____
1:1 (prolonged inspiratory time)
What are the characteristics of restrictive lung diseases? (name 3)
- decreased lung volumes and capacities
- decreased compliance
- intact pulmonary flow rates
In _______ WOB is increased, manifesting as rapid and shallow breathing pattern.
restrictive respiratory disease
What NM disorders cause restrictive ventilatory defects?
muscular dystrophies
Guillain-Barre
Spinal cord transection
Diseases of NM transmission
Why are people with restrictive lung diseases more prone to rapid arterial desaturation during apnea?
B/c they have a reduced FRC
All of the following reduce the incidence of ventilator-associated pneumonia EXCEPT:
a. oropharyngeal decontamination
b. minimizing the duration of mechanical ventilation
c. limiting sedation
d. PPI
PPI
When does aspiration most commonly occur peri-op?
during anesthetic induction and intubation or within 5 minutes of extubation
Aspiration can lead to what?
airway obstruction, bronchospasm, impaired gas exchange, bacterial respiratory infection
What are risk factors for aspiration pneumonitis?
pregnancy, trauma, emergency surgery, GI obstruction
What is Mendelson’s syndrome?
A chemical aspiration pneumonitis first described in OB patients receiving inhalation anesthesia
What are risk factors for Mendelson’s syndrome?
gastric pH <2.5
Gastric volume >25 mL (0.4 mL/kg)
What is the hallmark sign of aspiration?
hypoxemia
What are S/S of aspiration?
hypoxemia, dyspnea, tachypnea, cyanosis
What are the primary treatments for aspiration?
tilting head down or to side
suctioning upper airway
securing the airway
applying PEEP
What are the rules regarding post-op care of aspirated patient?
A patient can be safely d/c home if they do NOT experience any of the following within 2-hours of the aspiration event:
- new cough or wheeze
- radiographic evidence of injury
- SpO2 decrease >10% or pre-op
- A-a gradient >300 mmHg
What is the best method to prevent ventilator-associated pneumonia of the intubated patient?
minimize duration of mechanical ventilation
Aspiration: gastric contents enter airway –> _____
risk of airway obstruction
Aspiration: gastric contents cause a chemical burn to the airway and lung parenchyma –> ______
risk of bronchospasm and impaired gas exchange
Aspiration: infectious material enters airway –» ______
bacterial infection
T/F: All aspiration leads to infection.
False
T/F: Routine use of prophylactic agents to prevent aspiration is recommended.
False
Anticholinergics to reduce the risk of aspiration is or is not recommended.
Is NOT
T/F: Many patients who experience aspiration remain asymptomatic.
True
The most common findings of a CXR after aspiration are _____ and infiltrates in the _____ regions.
pulmonary edema; perihiar and dependent lung
For aspiration, ABX are only indicated when?
The patient develops a fever or an increased WBC count > 48 hours
What percent of people die after aspiration?
5%
What percent of people require ventilation for longer than 6 hours after aspiration?
15%
What percent of people require supportive care after aspiration?
20%
What percent of people remain asymptomatic after aspiration?
60%
Why does intubation have a risk for VAP?
the presence of an ETT bypasses the host’s defense mechanisms of cough and mucociliary clearance and allows organisms direct passage between the mouth and bronchopulmonary tree
What does micoraspiration allow?
contaminants to slide between the ETT cuff and trachea
What is leukocytosis?
high WBC
What are early signs of VAP?
increased secretions in ETT and increasing O2 requirements (also high WBC and/or fever should raise suspicions)
T/F: a CXR alone is non-specific for VAP.
True - could also be ARDS, atelectasis, or lung contusion
What are the most common culprits of VAP?
Pseudomonas aeruginosa and S. aureus
What is 1st line treatment for tensionpneumothorax?
a. chest tube insertion
b. 14g angiocath insertion at the 2nd ICS midclavicular line
c. pericardiocentesis
d. CPR
B (1st line in emergency; chest tube insertion is. the definitive treatment)
What are the 3 types of pneumothorax?
close, communicating, and tension
What are the hallmark characteristics of a tension pneumo?
hypoxemia
increased airway pressures
tachycardia
hypotension
elevated CVP
What does point-of-care US show for a tension pneumo?
a lack of lung sliding and the absence of comet tails
If you suspect a pneumo, you must d/c what immediately?
N2O
Where can a 14g angiocath be inserted for a tension pneumo? (2 places)
2 ICS at mid-clavicular line OR 4th or 5th ICS at anterior axillary line
What gauge angiogath is used in emergent treatment for tension pneumo?
14 g
What causes flail chest?
blunt chest trauma w/ multiple fib fractures
What is the key characteristic of flail chest?
paradoxical movement of the chest wall at the site of the fractures
What are consequences of flail chest?
alveolar collpase, hypoventilation, hypercarbia, hypoxia
What is. thetreatment for flail chest?
reducing pain with epidural or intercostal nerve block
_______ pneumo: the defect is in the pulmonary tree or lung tissue, and air enters and exits the pleural space through the defect
closed
T/F: In closed pneumos there is no communication between the pleural cavity and the atmosphere.
True
Which pneumos present with mediastinal shift?
tension is the only one
_____ pneumo: the defect is the chest wall, and air passes between the pleural space and the atmosphere
Open
With an open pneumo, the lung collapses on _____ and partially re-expands on ____.
inspiration; expiration
Treatment. ofa closed pneumo??
observation, catheter aspiration, chest tube
Treatment of an open pneumo?
occlusive dsg that does not let air in (but lets air out), O2, chest tube, possible intubation
Does a tension pneumo occur with a closed or open defect?
it can occur with either
What is the pathophysiology of a tension pneumo?
Tension (aka increased intrathoracic pressure) is created when air enters the pleural space through a ball-valve defect in the chest wall - air is allowed to enter, but not exit, the pleural space
In a tension pneumo, increased intrathoracic pressure causes a mediastinal shift towards _____ side.
the contralateral side.
Why does hypotension occur with tension pneumos?
compression of the heart and vasculature reduces venous return and CO
Why do you create an opening during emergent treatment of tension pneumo?
it will release the tension and relieve hemodynamic instability (does not cure however - that is CT)
What line placement can cause a pneumothorax?
CVL insertion
What block placement can cause a pneumothorax?
supraclavicular, interscalene, intercostal nerve blocks
What surgeries can cause a pneumothorax?
Radical neck dissection
shoulder arthroscopy
mastectomy
axillary lymph node dissection
mediastinoscopy
laparoscopy
nephrectomy
_____ after a chest trauma should raise suspicion about a pneumo.
Increasing peak inspiratory pressures
What respiratory things can cause pneumo?
barotrauma, high PEEP, high PIP
What is the blood:gas coefficient of N2O?
0.47
What is a chylothorax?
lymph in chest
What is a hemothorax?
blood in chest
What is a fibrothorax?
organized blood clot in chest
What is a pyothorax (empyema)?
pus in chest
What is a pleural effusion?
serous fluid in chest
What is the most common cause of hemothorax?
bleeding intercostal vessels
WIth a hemothorax, what are the indications for thoracotomy?
Initial drainage >1,000 mL
continued bleeding >200 mL/hr
white lung on CXR
large air leak
When can a patient with a hemothorax be managed with a VATS?
hemodynamically stable with bleeding <150 mL/hr
The thoracic duct empties lymph into the _____.
left subclavian vein
Injury to the thoracic duct during CVL insertion is more likely on the right tor left side?
left side
Injury to the thoracic duct during CVL insertion can cause what?
chylothorax
Negative intrathoracic pressure occurs during inspiration or expiration?
inspiration
Positive intrathoracic pressure occurs during inspiration or expiration?
expiration
During inspiration the chest wall moves ____ and lungs ____
out and lungs expand
in flail chest, during inspiration the injured rib moves ____
in (and collapses affected region)
in flail chest, during expiration the injured rib moves ____
out (and affected region doesn’t empty)
Place the monitors for VEA in order according to their relative sensitivities (#1 is most sensitive).
a. TEE
b. precordial doppler
c. ETCO2
d. CVP
- TEE
- Doppler
- ETCO2
- CVP
When a VAE of significant size travels to the R heart, what happens?
It lodges in the pulmonary outflow tract or pulmonary artery and produces an airlock that converts distal alveolar units to dead space
Place in order (sitting, prone, lateral, supine)
In NS patient, the risk for VAE from highest to lowest: __>___>___>____
sitting > supine > prone > lateral
What is the most sensitive diagnostic tool for VAE?
TEE
What will a precordial doppler show with VAE?
“mill wheel” murmur
VAE: ETCO2 ____
decreases
VAE: EtN2 ____
increases
VAE: BP ____
decreases
What are consequences of VAE?
dysrhythmias, hypoxia, cyanosis, CV collapse
Treatment for VAE?
FiO2 100%
Flood surgical field
d/c insufflation
left lateral decubitus position
What is the durant maneuver?
left lateral decubitus position for VAE
Consequences of air trapped in pulmonary circulation: _____ PAP
increased
Consequences of air trapped in pulmonary circulation: _____ RV stroke work index
increased
VAE can lead to what type of HF?
RV failure
Consequences of air trapped in pulmonary circulation: _____ pulmonary venous return
decreased
Consequences of air trapped in pulmonary circulation: _____ LV preload
decreased
Consequences of air trapped in pulmonary circulation: _____ CO
decreased
With durant maneuver, air will _____.
rise in the right heart (and minimizes entry into the pulmonary circulation)
A patient with PHTN develops tricuspid regurgitation. Which treatments will MOST likely improve the patients conditions? (Select 3).
a. Hypothermia
b. NO
c. Nitroglycerin
d. N2O
e. PEEP
f. Hyperventilation
b, c, f
PHTN is defined as a mean PAP >____
25 mmHg
PVR increases as a function of _____, ____, and/or ____.
increased vascular smooth muscle tone, vascular cell proliferation, and/or pulmonary thrombi
With PHTN you want to avoid conditions that increase what?
PVR
What conditions increase PVR?
hypoxemia
hypercarbia
acidosis
hypothermia
PHTN can progress to what?
RV failure aka cor pulmonale
What are anesthesia considerations for PHTN?
- do not hold preop meds that lower PVR
- CO is fixed, pts are sensitive to inadequate preload
- Treat hypotension aggressively
- epidural anesthesia > spinal anesthesia
- inhaled NO
- high-frequency jet ventilation
In PHTN, CO is dependent upon _____
preload
Why does tricuspid regurg occur with PHTN?
There is a decreased RV stroke volume and increased RV volume at end of diastole. This stretches the tricuspid annulus leading. to regurg.
List causes of PHTN.
COPD
Hypoxemia & Hypercarbia
LH dysfunction
Mitral valve dx
Congenital heart dx
Connective tissue disorders
Chronic thromboembolism
Portal HTN
What is the formula for PVR?
PVR = (mean PAP - PAOP)/CO x 80
What is normal PVR?
150-250 dynes
What drugs increase PVR?
N2O
Ketamine
Des
What drugs decreased PVR?
NO
Nitroglycerin
Phosphodiesterase Inhibitors (sildenafil)
Prostaglandins PGE1 and PGI2
CCB
ACEI
Elevated RA pressures can open what? What happens if this occurs?
Foramen ovale, it causes right-to-left intracardiac shunt
Hypoxemia increases or decreases PVR?
Increases PVR
Hypercarbia increases or decreases PVR?
Increases PVR
Acidosis increases or decreases PVR?
increases PVR
SNS stimulation increases or decreases PVR?
Increases PVR
Pain increases or decreases PVR?
Increases
Hypothermia increases or decreases PVR?
Increases PVR
Mechanical ventilation increases or decreases PVR?
Increases PVR
PEEP increases or decreases PVR?
Increases
Atelectasis increases or decreases PVR?
Increases
Alkalosis increases or decreases PVR?
Decreases
PHTN patients are____ dependent.
Preload
Carbon monoxide:
a. shifts the oxyhemoglobin dissociation curve to the right
b. production is highest with Iso
c. binds to the O2 binding site on Hgb with an affinity 200x that of O2
d. poisoning is reversed with methylene blue
C
Carbon monoxide shifts the oxyhemoglobin curve to the _____.
left
Place in order the volatiles production of carbon monoxide.
Sevoflurane, Desflurane, Isoflurane
Des > Iso»_space;> Sevo
Des produces the most
Where is carbon monoxide produced in the anesthesia circuit?
soda lime, (particularly after desiccation)
How is carbon monoxide poisoning treated?
Oxygen therapy
What does Methylene blue treat?
Methemoglobinemia
What patients are at risk for carboxyhemoglobinemia?
Burn victims, smokers, patients exposed to desiccated soda lime
With Carboxyhemoglobin, CaO2 ____
is decreased
What is required to dx carboxyhemoglobinemia?
Co-oximeter
T/F: A pulse ox can be used to measure CoHgb.
False, pulse-ox does not measure carboxyhemoglobin and may give a falsely elevated result
CO has an affinity for the binding site on Hgb ____x that of oxygen.
200x
What two ways does carbon monoxide poisoning deprive tissues of O2?
- CO binds on Hgb, displacing O2 from Hgb and reducing CaO2
- Causes a left shift in oxyhemoglobin dissociation curve (less O2 released)
Carbon monoxide poisoning results in an impairment of _____, reducing ATP production.
oxidative phosphorylation
ABG in carbon monoxide poisoning: ______
metabolic acidosis
T/F: Patients with carbon monoxide poisoning will appear cyanotic.
False - will have cherry red apperance
The t1/2 of carboxyhemoglobin is ______ breathing RA.
4-6 hours
Treating a patient with carbon monoxide poisoning with 100% supplemental O2 reduces the t1/2 of carboxyhemoglobin to _____.
60-90 minutes
How long is O2 therapy continued. incarbon monoxide poisoning?
Until CoHgb is <5% or for 6 hours
When is hyperbaric O2 indicated for carbon monoxide poisoning?
If CoHgb >25% or patient is symptomatic
Soda lime is hydrated to _____.
13-15%
What does desiccated mean regarding soda lime?
Becomes dehydrated
In the presence of desiccated soda lime, what happens to Sevo?
Sevo forms compound A
Compound A increases the risk of _____.
fire
Identify the strongest indications for intubation and mechanical ventilation. (select 2)
a. PaCO2 > 60 mmHg
b. vital capacity 25 mL/kg
c. inspiratory force <25 cm H2O
d. RR 35
A and C
Indications for mechanical ventilation -
Vital capacity _______
<15 mL/kg (normal = 65-75 mL/kg)
Indications for mechanical ventilation -
Inspiratory force _______
<25 cm/H2O (normal = 75-100 cm/H2O)
Indications for mechanical ventilation -
PaO2 _______
<200 mmHg (on 100% O2) (normal on 100% is >400)
Indications for mechanical ventilation -
A-a gradient _______
> 450 mmHg (on 100% O2) (normal on 100% is <100)
Indications for mechanical ventilation -
PaCO2 _______
> 60 mmHg
Indications for mechanical ventilation -
RR_______
> 40 OR <6
What drugs can be given via ETT in emergency situation?
NAVEL
Narcan
Atropine
Vasopressin
Epinephrine
Lidocaine
Identify the absolute indications for one-lung ventilation. (Select 2).
a. esophageal resection
b. bronchopleural fistula
c. pulmonary infection
d. thoracic aortic aneurysm repair
B and C
List 3 predictors of post-op pulmonary complications for patients undergoing pulmonary surgery.
- FEV1 <40% predicted
- DLCO <40% predicted
- VO2 max <15 mL/kg/min
______ is indicated when pre-op assessment suggests an increased risk of post-op pulmonary complications in patients undergoing pulmonary surgery.
Split lung V/Q function testing
Name 3 absolute indications for one-lung ventilation.
infection, massive hemorrhage, and bronchopleural fistula
Name 3 relative indications for one-lung ventilation.
Improved surgical exposure, pulmonary edema, severe hypoxemia d/t lung disease
A ____-sided double-lumen tube is typically preferred. Except when?
LEFT
The left main bronchus has distorted anatomy (tumor, TAA) OR surgical procedures - left pneumonectomy, left lung transplant, or left sleeve resection
What is the ideal DLT size for females?
35-37
What is the ideal DLT size for males?
39-41
DLT should not be used for kids under ____
8 years of age
What is the normal VO2 max for male?
35-40 mL/kg/min
What is the normal VO2 max for female?
27-31 mL/kg/min
What does VO2 measure?
cardiopulmonary reserve
If you do not have a VO2 max reading, what can you ask teh pateint to gather similar info?
“can you climb 2 flights of stairs”
What is the volume of the bronchial cuff of a DLT?
1-2 mL air
The bronchial cuff of a DLT is a ___volume, ___ pressure cuff.
low; high
How far should a DLT be inserted on a female?
@27 cm
How far should a DLT be inserted on a male?
@29 cm
What is the DLT size for kids 8-9?
26
What is. theDLT size for kids 10 and up?
28 or 32
During anesthesia in the lateral decubitus position, the ____ lung is better ventilated and the ____ lung is better perfused. What does this cause?
non-dependent lung; dependent
V/Q mismatch
During OLV, blood from both lungs mix. What does this cause?
An increased shunt fraction and significant source of hypoxemia
OLV: TV ____
6-8 mL/kg IBW
OLV: RR _____
12-15
What is the stepwise approach to hypoxemia during OLV?
- Verify delivery of 100% O2
- Check position of ETT via fiberoptic
- rule out physiologic cause (low CO, bronchospasm, mucus plug, etc)
- Apply CPAP to non-dependent lung or use a suction catheter to insufflate O2
- PEEP 5-10 to dependent lung
If standard interventions work for hypoxemia during OLV, what should you do next?
a. intermittently reinflate non-dependent lung
b. ligate pulmonary artery
c. eliminate drugs that inhibit HPV
If the DLT is in too far –> _______________
upper lobe is not ventilated
If the DLT is not deep enough –> _______________
failure to achieve lung separation
If the DLT is in the wrong bronchus –> _______________
wrong lung collapses
What is the most common problem associated with one-lung ventilation?
intrapulmonary shunt
How does the body attempt to compensate for V/Q mismatch during OLV?
HPV
V/Q mismatch during OLV is made worse by ____, ____, and _____.
NMBD, Positive pressure ventilation, and surgical positioning devices
What is the best method to verify the DLT is in the correct position?
Fiberoptic bronchoscope
When confirming DLT placement, what structures should be visualized?
Tracheal lumen (incomplete c-rings that open posteriorly)
Blue of bronchial cuff barely visible in the correct bronchus w/ no herniation present
When viewing the right bronchus, ___ takeoffs are rpesent.
3
When viewing the left bronchus, ___ takeoffs are present.
2
How do you auscultate to verify correct DLT positioning?
- inflate both cuff, clamp tracheal lumen, ventilate bronchial lumen (should hear BS on left for LDLT or right for RDLT)
- Clamp bronchial lumen and ventilate tracheal (should hear opposite of above)
- deflate bronchial cuff, keep bronchial lumen clamped, ventilate tracheal lumen (BS right and left)
Right upper lobe take off of the lungs is only _____ beyond the carina.
a few centimeters
When should you confirm DLT placement?
After insertion and after you change positions
Why are left-sided DLT preferred?
Right upper lobe takeoff is only a few centimeters beyond the carina, and you must be careful to not occlude the RUL with right-sided DLT
When you are ready. to begin OLV, you _____.
inflate teh bronchial cuff.
Where do you apply the clamp for OLV?
Distal to. the y-piece and proximal to. the cap that you open to deflate. the lung
What is the ideal inspiratory pressure during OLV?
<20 cmH2O above PEEP
What serial assessment should you perform during OLV?
ABGs
What is the normal I:E ratio?
1:2
Why do some people recommended TIVA for OLV?
Volatiles impair HPV (if you do use, limit to 1-1.5 MAC)
Apply ____ to the _____ lung starting at 2 cm H2O for hypoxia with OLV. What is the max?
CPAP, non-dependent, 10 cm H2O
Is hypoxemia during OLV mroe common during surgery. onteh right or left lung?
Right lung, the left lung is smaller than the right, so there is less surface area for gas exchange when the left lung is ventilated (during right lung surgery)
Unlike a DLT, the bronchial block CANNOT: (select 3):
a. insufflate O2 into the isolated lung
b. ventilate. the isolated lung
c. provide lung separation in nasotracheal intubation
d. prevent contamination from contralateral lung infection
e. provide lung separation in kids
f. suction secretions from isolated lung
B, D, F
What are the two downsides to bronchial blockers?
- The operative lung is slow to collapse
- The high-pressure balloon can easily slip to enter the trachea (can cause contamination and block ventilation. of both lungs)
Why is the lung on teh same side of the bronchial blocker slow to collapse?
The lumen of the bronchial blocker is narrow
What can the lumen of the bronchial blocker do?
insufflate O2 into. the non-ventilated lung and suction air form the non-ventilated lung
T/F: The lumen of the bronchial blocker can be used to suction blood, pus, or secretions from teh non-ventilated lung.
False
Why is a bronchial blocker not the best choice for contamination?
The high-pressure ballon can easily slip out of place into the trachea
ID the MOST common serious complications of mediastinoscopy (select 2)
a. chylothorax
b. pneumothorax
c. LRLN injury
d. Hemorrhage
B and D
Why is a medistinoscopy performed?
To diagnose and stage lung CA
What is an absolute CI to mediastinoscopy?
previous mediastinoscopy (d/t scarring)
What can be compressed during mediastinoscopy?
Innominate artery
Compression of the innominate artery can cause what?
Impairs cerebral perfusion
Where should you place your pulse-ox during mediastinoscopy?
on RUE (compression of innominate artery –> dampened waveform)
Where should you place your BP cuff during mediastinoscopy?
LUE (compression of innominate artery will not affect BP measurement)
What. isa risk with mediastinoscopy?
Severe hemorrhage
There is an association between oat cell carcinoma and _______.
Easton-Lambert syndrome
Patients with ELS are sensitive. to what medications?
Sux and ND NMBD
What are indications for tracheal resection?
Tracheal stenosis, tracheomalacia, tumor vascular lesions, and congenital malformations
What is a post-op consideration for tracheal resection that would required fiberoptic intubation?
To reduce tension on the tracheal anastomosis, the patient’s neck must maintain a flexed position
Where is. the incision made for medisastinoscopy?
midline of the lower neck at the suprasternal notch
During mediastinoscopy, the scope is placed anterior to the ____ and posterior to the ____ and ___.
trachea; innominate artery and thoracic aorta
A pneumothorax that occurs during mediastinoscopy most commonly occurs on the ____ side.
right
What vital structures are at risk for injury during mediastinoscopy? (name 6)
thoracic aorta
innominate artery
vena cava
trachea
thoracic duct
phrenic and RLN
Relative CI for mediastinoscopy?
tracheal deviation, thoracic aortic aneurysm, SVC obstruction
Innominate (brachiocephalic) a. –> _____ artery —> _____ artery –> ______ artery
right common carotid –> right internal carotid –> right cerebral circulation at circle of willis
What does innominate compression compromise?
circulation to the right side of the circle of willis
Pre-op to tracheal resection, you must asses the patient for ____.
airflow limitations
If a patient is at risk for airway obstruction during anesthetic induction, you should choose a technique that _____.
preserves spontaneous ventilation (ex: sevo)
What are options to provide ventilation during tracheal resection?
ETT, jet ventilation, ECMO
With. an upper tracheal lesion resection with a standard ETT, the ETT is ____or ____
advanced distally before the surgeon opens the trachea OR second ETT is placed into distal trachea after trachea is opened
Where is the second ETT placed during lower tracheal lesion resection?
left main bronchus
What. isat risk for compression during tracheal resection?
innominate artery
What is a complication of neck hyperflexion?
Tetraplegia
What are the MOST important strategies for managing mechanical ventilation. in patient w/ ARDS? (select 2)
a. low TV
b. reducing plateau pressure
c. high-frequency oscillatory ventilation
d. permissive hypocapnia
A and B
____ is a form of non-cardiogenic pulmonary edema.
ARDS
What. is the most common pulmonary etiology for ARDS?
Pneumonia
What. is the most common extra-pulmonary etiology for ARDS?
Sepsis
What causes ARDS?
inflammation injury (mediated by neutrophils and PLTs) –> diffuse alveolar destruction
What are key features of ARDS:
1. _____
2. _____
3. _____
4. _____
Protein-rich pulmonary edema
loss of surfactant
hyaline membrane formation
possible long-term injury
What does a CXR reveal in ARDs?
bilateral opacities
For ARDs, diffuse patchy alveolar infiltrates appear peripherally about _____ after the inital insult, which then can progress. tocomplete alveolar consolidation.
12 hours
The prone position may improve ____ during ARDS.
V/Q matching
ARDs vent settings:
______ ventilation
PC
ARDs vent settings:
______ TV
LOW TV (4-6 mL/kg IBW)
ARDs vent settings:
TV ___ to ___ mL/kg IBW
4-6
ARDs vent settings:
plateau pressure ____
<30 cm H2O
ARDs vent settings:
RR ______
6-35
ARDs vent settings:
I:E ratio of _____
1:1 - 1:3
What is the target oxygenation goal for ARDs?
PaO2 55-80 mmHg or SpO2 88-95%
What is used to make the diagnosis of ARDS?
Berlin definition
What is mild form of ARDS?
PaO2/FiO2 ratio <201-300 mmHg with PEEP or CPAP >/= 5 cm H2O
What is moderate form of ARDS?
PaO2/FiO2 ratio <101-200 mmHg with PEEP >/= 5 cm H2O
What is severe form of ARDs?
PaO2/FiO2 ratio <100 mmHg with PEEP >/= 5 cm H2O
Other than pneumonia or COVID, what are some pulmonary causes of ARDS? (name 3)
- aspiration
- smoke inhalatoin injury
- near-drowning
What is the first satge of ARDs?
exudative
What is. the onset of stage 1 ARDs?
6-72 hours after initial insult
What. is the duration of stage 1 of ARDs?
7 days
ARDS: injury to ______ disrupts the integrity of their tight junctions.
type 1 pneumocytes
ARDS: damaged surfactant –> ___ alveolar surface tension –> increased alveolar ____ –> decreased _____
increased; collapse; gas exchange
Why do alveoli collapse in ARDs?
There is not enough surfactant
The damaged cells that accumulate in the airways during ARDs are called what?
Hyaline membranes
What is the hallmark of ARDs?
hypoxemia despite increased supplemental oxygen
ARDS: ____ A-aDO2 gradient
increased
What is. the second stage of ARDs?
proliferative
What is the duration of the second stage of ARDs?
7-21 days
During the second stage of ARDs, the body does what?
creates new pulmonary surfactant, new type. 1 pneumocytes, tight junctions are restored, and alveolar fluid is drained by lymphatics
What is stage 3 of ARDs?
fibrotic stage
Extensive fibrotic changes from ARDS cause irreversible damage to the lung architecture and fibrosis. ofthe pulmonary vasculature lead sto _________
irreversible PHTN
What are the 2 core strategies for mechanical ventilation in ARDs?
- low TV
- PEEP
T/F: ARDs affects all alveoli in the same way.
False
What is biotrauma?
excessive stretch of alveoli stimulates the release of inflammatory mediators
Why should you use low TV with ARDs?
Positive pressure breaths, the TV follows the path of least resistance so stiff alveoli fill minimally and normal alveoli fill too much b/c the TV has to go somewhere
When the lungs are ventilated at relatively low volumes, ____ can occur as repetitive opening and closing of recuritbal alveoli are exposed to high shear forces.
atelectrauma
Why does PEEP reduce atelectrauma?
It maintains transpulmonary pressure above closing pressure, which prevents alveolar collapse during expiration
For ARDs, weaning. by PS can begin when the FiO2/PEEP ration is ____
<0.4/8
High inspired oxygen (>50%) causes ____ to the lung
oxidative stress
With ARDs, permissive ____ may be required.
Hypercapnia
What is the max FiO2 for a regualr nasal cannula?
40%
What is teh fluid management strategy with ARDs?
Conservative fluid management supports oxygenation by reducing the hydrostatic pressure in the pulmonary capillaries
The Mallampati exam assesses the _____.
oropharyngeal space
The Inter-incisor gap exam assess _____.
How well the patient can open his mouth.
What axis do you align for the sniffing position?
Oral, pharyngeal, and laryngeal
A small inter-incisor gap creates a more acute angle between the ___ and ___ openings.
Oral and glottic
What is a normal inter-incisor gap?
2-3 FB (4 cm)
What can you see in Class 1 Mallampatti?
Pillars, Uvula, Soft Palate, Hard Palate (PUSH)
What can you see in Class 2 Mallampatti?
Uvula, soft palate, hard palate
What can you see in Class 3 Mallampatti?
Soft and hard palate (base. ofthe uvula may be seen)
What can you see in Class 4 Mallampatti?
Hard palate
To expose the glottic opening during DL, you must displace the tongue into the ____ space.
submandibular
The _____ helps to estimate the size of the submandibular space.
thyromental distance
What might happen if the submandibular space is small or poorly compliant?
You might not be able to move the tongue enough to expose the glottis
A TMD less than ___ or greater than ___ correlates with an increased risk of difficult intubation.
6 cm; 9 cm
The ____ assesses the function of the TMJ.
Mandibular protrusion test (MPT)
How is a mandibular protrusion test performed?
The patient subluxes the jaw, and. the position of the lower incisors is compared to the position of the upper incisors
What class MPT correlates with an increased difficulty of intubation?
3
The ability to palce the patient into the sniffing position is highly dependent on the mobility of the ____ joint.
Atlanto-occpital joint
What are some conditions that impair AO mobility? (name 3)
Arthritis, trauma, and down syndrome
What. are the borders of the submandibular space:
superior border = __________
inferior border = ____________
lateral border = ___________
Superior = mentum
Inferior = hyoid bone
lateral = either side of neck
How. do you assess for thyromental distance?
With the neck extended and mouth closed, you can measure the distance from the tip of the thyroid cartilage to the tip of the mentum
DL may be more difficult if the TMD is <___ cm or >__ cm.
6 (3 FB); 9
If. theTMD is >9 cm, the larynx assumes a more ___ position.
caudal
If. theTMD is >9 cm, the larynx assumes a more ___ position.
caudal
The upper lip bite test is also known as the _____ test.
mandibular protrustion
Define a Class 1 MPT.
The patient can move LI past UI and bite the vermilion of the lip (where the lip meets the facial skin)
Define a Class 2 MPT.
Patient can move LI in line with UI.
Define a Class 3 MPT.
Patient cannot move LI past UI.
What is normal AO flexion and extension?
90-165 degrees
What is a normal AO extension?
35 degrees
DL is difficult with an AO extension < ____ degrees.
23
Explain the 3-3-2 Rule.
Inter-incisor gap > 3 FB
TMD > 3 FB
Thyrohyoid > 2 FB
Tetanus does or does not impair AO mobility?
Does not
Klippel-Feil does or does not impair AO mobility?
DOES
Down Syndrome does or does not impair AO mobility?
Does
Diabetes does or does not impair AO mobility?
does
Pierre Robin Sequence does or does not impair AO mobility?
does not
Beckwith syndrome does or does not impair AO mobility?
does not
Ankylosing Spondylitis does or does not impair AO mobility?
does
What. isthe Cormack and Lehane grading system?
Measures the laryngoscopic view we obtain during DL
What can you see in a grade 1 cormack and lehane?
Complete or nearly complete view of glottic opening
What can you see in a grade 2A cormack and lehane?
Posterior region of the glottic opening
What can you see in a grade 2B cormack and lehane?
corniculate cartilages and posterior vocal cords (no glottic opening)
What can you see in a grade 3 cormack and lehane?
epiglottis only
What can you see in a grade 4 cormack and lehane?
soft palate only
What can you not see with a grade 2 cormack and lehane score?
anterior commissure
What can you not see with a grade 3 cormack and lehane score?
any part of the glottic opening
What can you not see with a grade 4 cormack and lehane score?
any part of the larynx
Identify the BEST predictors of difficult mask ventilation (SELECT 3)
a. mallampati class 3
b. old age
c. edentulousness
d. small mouth opening
e. high, arched palate
f. presence of a beard
B, C, F
Always ask these 5 questions before you anesthetize anyone:
- will I be able. to mask ventilate? (BONES)
- Will I be able to intubate? (LEMON)
- Will I be able to place a supraglottic airway? (RODS)
- Will I be able to place an invasive airway? (SHORT)
- How fast must I secure the airway? (2,4,6,8)
What. are complications r/t cricoid pressure?
Airway obstruction, difficult DL, impaired glottic visualization, difficult intubation, reduced LES tone
What are the risk factors for difficult mask ventilation?
BONES
B - Beard
O - Obese (BMI > 26)
N - No teeth
E - elderly (>55)
S - Snoring
What are risk factors for difficult supraglottic device placement?
Limited mouth opening
upper airway obstruction
altered pharyngeal anatomy (can prevent seal)
poor lung compliance (requires excessive PIP)
increased airway resistance (requires excessive PIP)
lower airway obstruction
What are current NPO guidelines?
2 hours - clear liquids
4 hours - breast milk
6 hours - nonhuman milk, infant formula, solid food
8 hours - fired or fatty food
Ingestion of clear liquids ___ before surgery reduces gastric volume. and increases gastric pH>
2 hours
What does LEMON for difficult intubation stnad for?
L - Look externally (obesity, neck, head)
E - Evaluate 3-3-2
M - Mallampati
O - Obstruction?
N - Neck mobility
What does RODS stand for for supraglottic airway placement?
R - Restricted mouth opening
O - Obstruction
D - Distorted airway
S - Stiff lungs or C-spine
What does SHORT stand for for difficult surgical airway placement?
S - Surgery (neck surgery/previous scar)
H - Hematoma
O - Obesity
R - Radiation
T - Tumor
Cricoid pressure is pressure applied to. thecricoid ring against ___ vertebra.
C5
Cricoid Pressure: Pressure before LOC = ________
20 Newtons or @2 kg
Cricoid Pressure: Pressure after LOC = ________
40 Newtons or @4 kg
Pierre Robin sequence - difficutl maskin gor difficult DL?
DL
Patient on CPAP - difficult masking or difficult DL?
Masking
Geriatric Patient - difficult masking or difficult DL?
Masking
Klippel-Feil - difficult masking or difficult DL?
DL
Endentulous - difficult masking or difficult DL?
Masking
What congenital conditions are associated with cervical spine anomalies? (select 2.)
a. treacher collins
b. klippel-feil
c. goldenhar
d. pierre robin
B and C
____ is the chief concern in the patient with angioedema.
Upper airway obstruction
Name 3 causes of angioedema.
- anaphylaxis
- ACEI
- C1 esterase deficiency
How do you treat angioedema caused. byanaphylaxis?
Epinephrine, Antihistamines, and steroids
How do you treat angioedema caused by ACEI or C1 esterase deficiency?
Icatibant, ecallantide, FFP, or C1 esterase concentrate
What is Ludwig’s angina?
A bacterial infection characterized by rapidly progressing cellulitis in the floor of the mouth
What is the most significant concern with Ludwig’s angina?
Posterior displacement of the tongue resulting in comple, supraglottic airway obstruction
What is the best method to secure the airway in Ludwig’s angina?
Awake nasal intubation or awake trach
Name 7 congenital conditions that impact airway management.
- Pierre Robin
- Treacher Colliins
- Trisomy 21
- Klippel-Feil
- Goldenhar
- Beckwidth
- Cri du Chat
Angioedema is the result of ____ that can lead to swelling of the face, tongue, and airway.
increaed vascular permeability
Why can ACEI cause angioedema?
They prevent bradykinin breakdown (genetics likley determine who is at risk)
What is Icatibant?
Bradykinin receptor antagonist
What is Ecallantide?
A plasma kallidrein inhibitor - stops the conversion of kinonogen to bradykinin
Why can FFP be used at treatment for ACEI angioedema?
It contains enzymes that metabolize bradykinin
What deficiency is the cause of hereditary angioedema?
C1 esterase deficiency
What patients should receive prophylaxis of Danazol or C1 Esterase concentrate for procedures that require tracheal intubation or dental surgery?
Patients with hereditary angioedema
For Ludwig’s Angina, _____ is contraindicated in patients with infection above the level of the trachea.
Retrograde intubation
What congenital conditions impact airway management due to a large tongue? (2)
Beckwith syndrome
Trisomy 21 (down syndrome)
“Big Tongue”
What congenital conditions impact airway management due to a small/underdeveloped mandible? (4)
Pierre Robin
Goldenhar
Treacher Collins
Cri du Chat
“Please Get That Chin”
What congenital conditions impact airway management due to a cervical spin anomaly? (3)
Klippel-Feil
Trisomy 21
Goldenhar
“Kids Try GOLD”
What physiologic characteristics occur with Pierre Robin?
- small/underdeveloped mandible (micrognathia or mandibular hypoplasia)
- tongue falls back & down (glossoptosis)
- cleft palate
NEONATES OFTEN REQUIRE INTUBATION
What physiologic characteristics occur with Treacher Collins?
- Small mouth
- Small/underdeveloped mandible
- nasal airway is blocked by tissue (choanal atresia)
- ocular & auricular anomalies
What physiologic characteristics occur with Trisomy 21?
- Small mouth
- Large tongue
- Atlantoaxial instability
- Small sublottic diameter (subglottic stenosis)
What physiologic characteristics occur with Klippel-Feil?
There is congenital fusion of cervical vertebrae –> neck rigidity.
What physiologic characteristics occur with Goldenhar?
- Small/underdeveloped mandible
- Cervcical spine abnormality
What physiologic characteristics occur with Beckwith Syndrome?
Large otngue
What physiologic characteristics occur with Cri du Chat?
- Small/underdeveloped mandible
- Laryngomalacia
- Stridor
What is the optimal position for tracheal intubation?
a. cervical flexion only
b. atlanto-occpital joint extension only
c. cervical flexion and atlanto-occipital joint extension
d. cervical extension and atlanto-occipital joint flexion
C
What 3 axises are aligned in the sniffing position?
oral, pharyngeal, and laryngeal
The “sniffing position” consists of ___ flexion and _____ extension.
cervical; atlanto-occpital
Why are the three axes misaligned when a morbidly obese patient lies supine?
Excess adipose on the neck, shoulders, and back place the chest higher than the head
What position should be used to align axes in. the morbidly obese during DL?
HELP position (Head Elevated Laryngoscopy Position)
Put the bed in reverse Trend. to unload the diaphragm and help prolong time between apnea and desaturation
How does the head position affect the position of the ETT after intubation?
Nose to chest —> ______________
ETT tip moves towards the carina @2cm
(risk of endobronchial intubation)
How does the head position affect the position of the ETT after intubation?
Nose away from chest —> ______________
ETT tip moves away from carina @ 2cm (risk of extubation)
How does the head position affect the position of the ETT after intubation?
Lateral rotation of the head @0.7 cm —> ______________
ETT tip moves away from carina (risk of extubation)
Cervical flexion moves _______ .
the chin towards the chest
Atlanto-occipital extension _______.
extends the head on the neck
When is optimal positioning achieved with the HELP position?
When the sternum and external auditory meatus are in the same horizontal plane
How does steep trendelenburg position cause a risk for endobronchial intubation?
The abdominal contents are shifted towards the chest, reducing thoracic volume
Explain the risk related to aggressive jaw thrust.
Aggressively thrusting the jaw anteriorly (excessive traction at the angle of. the mandible) can stretch the FACIAL nerve
Explain how a patient with a nerve injury related to aggressive jaw thrust might present.
- Affected side of face may sag
- May drool
- Chewing will be affected
What is the risk related to a face mask strap that is too tight?
It can compress the BUCCAL branch. ofthe FACIAL nerve CN7
Explain how a patient with a nerve injury related to a face mask strap that was too tight might present.
The patient will have difficulty opening and closing lips (ORBICULARES ORIS muscle is impaired)
What is the nerve risk of the ETT connector resting on the face?
It can compress the supraorbital nerve
How does a patient with supraorbital nerve injury present?
Eye pain, forehead numbness, photophobia
Contraindications to the use of a nasopharyngeal airway include (SELECt 2)
a. dental trauma
b. coagulopathy
c. pierre robin syndrome
d. Le Fort 2 fracture
B and D
How. do oral or nasal airways relieve upper airway obstruction?
It opens the airway by displacing hte tongue and epiglottis from the posterior wall of the pharynx
How. doyou size an OPA?
Measure from the corner of the mouth to the earlobe or the angle. ofthe mandible
How do you size a NPA?
Measure from the nare to the earlobe or the angle of the mandible
Is a OPA or NPA better tolerated in a lightly anesthetized patient?
NPA (OPA can –> vomiting or laryngospasm)
What are the 5 contraindications for NPA?
- Cribriform plate injury (LeFort 2 or 3 fracture)
- Coagulopathy
- Nasal fracture
- Previous transsphenoidal hypophysectomy
- Previous Caldwell-Luc procedure
What are the uses of Wililams and Ovassapian OPAs?
Fiberoptic intubation (they have a hole in the center)
What OPA do we use at Baptist?
Berman
How should. an OPA sit in the mouth?
The flange should protrude outside the lips and the pharyngeal end should rest at the base of the tongue
What can happen if an OPA is too short?
Airway can be obstructed. by causing the tongue to kink against the roof of the mouth
What can happen if an OPA is too long?
The epiglottis can be displaced towards the glottis - causing trauma or obstruction
To insert an NPA, gently retract the tip of the nose and introduce the airway in line with _____, _____ to. theface.
nasal passage; perpendicular
What can happen with an NPA that is too short?
The obstruction is not relieved
What can happen with an NPA that is too long?
The epiglottis can be displaced towards the glottis - causing trauma or obstruction
Why is NPA inserted for cribriform plate injuries contraindicated?
Risk of brain injury
What are S/S of cribriform plate injuries?
CSF rhinorrhea, Raccoon eyes, periorbital edema
What is the cribriform plate?
A boney structure that separates the nasal cavity from the anterior cranial fossa
Can you ID a Berman OPA?
look up on google lol
Can you ID a Guedel OPA?
look up on google lol
Can you ID a Ovassapian OPA?
look up on google lol
Can you ID a Williams OPA?
look up on google lol
Name 4 fractures that preclude the use of a NPA.
- LeFort 2
- LeFort 3
- Nasal
- Basiliar
Name 3 fractures that lead to cribriform plate injury.
- LeFort 2
- LeFort 3
- Basilar
Which intervention demonstrates the MOST accurate understanding of inflating the cuff on the endotracheal tube?
a. assess the pressure inside the pilot balloon with your fingers
b. add 10 mL air to the pilot balloon
c. attach. amanometer to the pilot balloon
d. attach a syringe to the balloon to create a minimal occlusive pressure
C
What is the BURP maneuver?
With difficult glottic visualization during DL,
Backward
Upward,
Rightward
Pressure
may improve your view
When does tracheal ischemia occur with an ETT?
If the cuff pressure exceeds tracheal mucosal perfusion pressure
Cuff pressure should be less than ____.
25 cm H2O
What is the murphy eye?
A small hole on the opposite side of the bevel
What is the purpose of the Murphy eye?
To provide an alternate passage for air movement in case the tip of the ETT becomes occluded or abuts th tracheal wall
PEDS ETT SIZE FORMULA???
Without cuff = ______
(age/4) + 4
PEDS ETT SIZE FORMULA???
With cuff = ______
(age/4) + 3.5
PEDS ETT
Depth Placement = ______
Internal diameter x 3
The Macintosh blade ____ exposes. the glottis by applying tension to the ______ (in the ____) which lifts the epiglottis.
indirectly; hyoepiglottic ligament; vallecula
The Miller blade ___ exposes the glottic opening by directly lifting the ____.
directly; epiglottis
_____ diameter = ETT size
Internal
What does inflation of the ETT cuff permit?
Positive pressure ventilation and protection from aspiration of gastric contents
Which ETT have a low-volume, hihg-pressure cuff?
- red rubber tube
- silicon tube for LMA-Fastrach
- Bronchial balloon on a double lumen ETT
Which ETT has high-volume, low-pressure cuffs?
Nearly all tubes in modern practice
Cuff compliance - Low or high?
Low-Volume, High-Pressure Cuff
Low - it takes a small volume to increase the pressure inside the cuff
Cuff compliance - Low or high?
High-Volume, Low-Pressure Cuff
High - it takes a larger volume to incrase the pressure inside the cuff
Can you measure the internal pressure?
Low-volume, High-Pressure Cuffs
No
Can you measure the internal pressure?
High-volume, Low-Pressure Cuffs
Yes - best to use a manometer
What are the benefits of a low-volume, high-pressure cuff?
Better proctection against aspiration, lower incidence of sore thorat, easier visualization during intubation
What are the benefits of a low-volume, high-pressure cuff?
Better protection against aspiration, lower incidence of sore throat, easier visualization during intubation
What are the benefits of a high-volume, low-pressure cuff?
Cuff pressure closely resembles the pressure exerted on the trachea
Risks with a low-volume, high-pressure cuff?
Prolonged intubation –> tracheal ischemia
Risks with a high-volume, low-pressure cuff?
- Believing you can accurately estimate how much pressure is in the cuff
- Adding too much air or using N2O –> increased cuff pressure –> tracheal ischemia
- Easy to pass things around the cuff (esophageal stethoscopes, OGT, temp probe)
- Protection against aspiration isn’t as good as a low-volume, high-pressure cuff
An ETT with a _____ valve is one method to protect patient against cuff pressure.
Lanz pressure-regulating
Which findings are MOST strongly associated with difficult video-assisted laryngoscopy? (select 2.)
a. history of neck radiation
b. mandibular protrusion score of 3
c. obesity
d. mallampati 4
A and B
Name 3 non-channeled video laryngoscopes.
Glidescope, C-MAC, and McGrath
Name 2 channeled video laryngoscopes.
Airtraq Avant and King Vision
What is the greatest risk with video laryngoscopy?
Pharyngeal injury
The GlideScope has a _____ anterior bend.
60-degree
What is anon-channeled video laryngoscope device?
It exposes the glottic structures, but the ETT is passed into. thetrachea separate from teh laryngoscope
What does an acute-angle blade facilitate?
Glottic exposure of a more anterior glottic opening
What is. achanneled video laryngoscope?
It integrates a channel or the ETT into the device (good for when you have trouble passing the tube)
What are predictors of a difficult VAL?
neck pathology (radiation, tumor, scar), short TMD, limited cervical motion, thick neck, Class 3 upper lip bite test
Match each LMA region with the anatomical border it touches.
Sides Pyriform sinuses
Distal end Upper esophageal sphincter
Proximal end Base of tongue
Sides - Pyriform sinuses
Distal end - upper esophageal sphincter (cricopharyngeus muscle)
Proximal end - base of tongue
what is the most commonly used supraglottic airway?
LMA
LMA:
Max PPV pressure = ______
20 cm H2O
LMA:
Max cuff pressure = ______
60 cm H2O
LMA:
Target cuff pressure = ______
40-60 cm H2O
What is the most common cause of nerve injury with an LMA?
cuff overinflation
What nerves are at risk for injury with LMA cuff overinflation?
lingual, hypoglossal, and RLN
If your LMA cuff pressure >60 cmH2O and you still cannot get a good seal, what could be the issue?
improper position, inadequate anesthesia, partial or complete laryngospasm
What prevents the epiglottis from obstructing the LMA airway tube?
two aperture bars across teh tube’s orifice
A ___ iscreasted after iar is added to the LMA’s inflatable cuff.
seal
While an LMA shields the larynx from pharyngeal secretions, it does not reliably protect against _____.
gastric regurgitation
The integrity of an LMA’s seal is primarily dependent on __ and ___ and less dependent on cuff volume and pressure.
size and position
What are other causes of nerve injuries due to LMA besides cuff overinflation?
Too small LMA, lidocaine lubrication, traumatic insertion
LMA Size 1
Patient Size - ____ kg
<5 kg
LMA Size 1.5
Patient Size - ____ kg
5-10 kg
LMA Size 2
Patient Size - ____ kg
10-20 kg
LMA Size 2.5
Patient Size - ____ kg
20-30 kg
LMA Size 3
Patient Size - ____ kg
30-50 kg
LMA Size 4
Patient Size - ____ kg
50-70 kg
LMA Size 5
Patient Size - ____ kg
70-100 kg
LMA Size 1
Cuff Inflation = ___ mL
4
LMA Size 1.5
Cuff Inflation = ___ mL
7
LMA Size 2
Cuff Inflation = ___ mL
10
LMA Size 2.5
Cuff Inflation = ___ mL
14
LMA Size 3
Cuff Inflation = ___ mL
20
LMA Size 4
Cuff Inflation = ___ mL
30
LMA Size 5
Cuff Inflation = ___ mL
40
LMA Size 1
Largest ETT that Fits = _____ mm
3.5
LMA Size 1.5
Largest ETT that Fits = _____ mm
4.0
LMA Size 2
Largest ETT that Fits = _____ mm
4.5
LMA Size 2.5
Largest ETT that Fits = _____ mm
5.0
LMA Size 3
Largest ETT that Fits = _____ mm
6.0
LMA Size 4
Largest ETT that Fits = _____ mm
6.0
LMA Size 5
Largest ETT that Fits = _____ mm
7.0
LMA Size 1
Largest Flexible Endoscope that Fits = _____ mm
2.7
LMA Size 1.5
Largest Flexible Endoscope that Fits = _____ mm
3.0
LMA Size 2
Largest Flexible Endoscope that Fits = _____ mm
3.5
LMA Size 2.5
Largest Flexible Endoscope that Fits = _____ mm
4.0
LMA Size 3
Largest Flexible Endoscope that Fits = _____ mm
5.0
LMA Size 4
Largest Flexible Endoscope that Fits = _____ mm
5.0
LMA Size 5
Largest Flexible Endoscope that Fits = _____ mm
5.5
Match each LMA with its unique feature:
LMAS - LMA ProseaL, LMA Flexible, LMA Fastrach
Features - Gastric drain, Designed for intubation, or wire-reinforced ariay tube
LMA ProSeal - Gastric drain
LMA Fastrach - designed for tracheal intubation
LMA Flexible - Wire-reinforced airway tube
What are features of hte LMA ProSeal?
- gastric drain tube
- larger mask
-built-in bite block
What is the max PIP for PPV for the LMA ProSeal?
30 cm H2O (vs. 20 for LMA classic)
The LMA Fastrach is a _____ LMA.
intubating
What special feature does the LMA C-Trach contain?
A camera so you can visualize intubation
What are the chracteristics of the LMA Flexible?
- has a flexible airway tube
- is wire-reinforced
-is useful for head and neck surgery
T/F: You can place suction directly to the gastric drain tube of LMA ProSeal for gastric decompression.
False. -Do NOT place suction directly to the drain tube. Instead, you must pass an OGT through the tube to decompress the stomach.
The LMA Supreme is a disposable version of the LMA _____.
ProSeal
T/F: You must leave the LMA Fastrach in place after using it for endotracheal intubation.
False - it can be removed after intubation or remain in place throughout the surgical procedure
When is an LMA Fastrach contraindicated and why?
During MRI; it has a metal handle
The specially designed endotracheal tube for LMA Fastrach uses a _____.
high-pressure cuff
The LMA Flexible is ___ and ___ than the LMA Classic.
longer and narrower
What type of surgery is the LMA Flesxible useful for?
Head and neck
What is the iGel?
A supraglottic airway that is an alternative to LMA. It can be used for spontaneous of or controlled ventilation.
How do you intubate though an iGel?
It requires guidance with a fiberoptic bronchoscope
What 2 LMA types are not safe for MRI?
LMA Flexible and LMA Fastrach
Does the iGel has a cuff?
No - can contribute to poor seal
Does the iGel has a gastric por?
Yes
What are complicatiosn of iGel airway?
tongue trauma, mucosal erosion of the cricoid cartilage, compression of the trachea, nerve injury, airway obstruction, regurgitation and aspiration
All of the following are CI to a LMA EXCEPT:
a. gastroparesis
b. asthma
c. tracheal tumor
d. hiatal hernia
B - asthma
What is the “go to” airway in the “can’t intubate and can’t ventilate” scenario?
LMA
When shoudl an LMA not be used?
- risk of gastric regurg/aspiration
- airway obstruction @ or below glottis
- poor lung compliance
- high airway resistance
- Risk. for tracheal collapse (tracheomalacia or external tracheal compression)
Which is preffered in a patient with reactive airway disease: LMA or ETT?
LMA
Compared to intubation, the ____ is less likely to activate the SNS.
LMA
Less anesthesia is needed to tolerate an LMA or an ETT?
LMA
Why do you need to maintain a deep enough plane of anesthesia during LMA?
To prevent swallowing which –> gastric insufflation –> increased risk of aspiration
When should you remove the LMA?
At the first sign of rejection during emergence; waiting until the patient is fully awake and following commands increases risk of aspiration
How can you assess for gastric insufflation?
Epigastric auscultation
What should you do if you see gastric contents inside the lMA?
- Leave LMA in place (may be gastric contents behind the LMA cuff, and removing it can worsen situation)
- Place. in trendelenburg (30 degrees) and deepen anesthesia if needed
- Give 100% FiO2 via a self-inflating resuscitation bag
- Use low FGF and TV
- Use flexible suction catheter to suction through the LMA
- Use FOB to evaluate (if gastric content is present in trachea consider intubation)
Why should you use a self-infalting resusctiation bag with possible aspiration with an LMA?
If gastric contents are present inside the breathing circuit you don’t want to push them into the lungs
The LMA shields the ____ opening.
Glottic
What do volatiles do to the pulmonary reflexes?
they obtund the reflexes
(As the patient emerges from GA, these reflexes wake up, ETT may trigger reflexes and –> cough or bronchospasm)
Why is there less risk of bronchospasm with an LMA?
The LMA sits over the glottis, there’s nothing inside the trachea to stimulate it during emergence
Place in order from most to least stimulating of the tendency of airway device placement to activate the SNS.
- combitube
- DL
- fiberoptic
- LMA
What is a Combitube?
A supraglottic, double lumen device that is blindly placed in the hypopharynx
What are CI the use of a Combitube?
- intact gag reflex
- prolonged use (>2-3 hours)
- esophageal disease (zenker’s diverticulum)
- ingestion of caustic substances
Do not use a Combitube size 37 Fr in someone <____.
4 feet
Do not use a Combitube size 41 Fr in someone <____.
6 feet
ID the CI to the Combitube airway: (select 3)
a. full stomach
b. zeker’s diverticulum
c. obesity
d. intact gag reflex
e. klippel-feil
f. prolonged use
B, D, F,
T/F: A Combituve airway does provide a secure airway.
true
What size Combitube is used for patients 4-6 feet tall?
Size 37 Fr
What size Combitube is used for patients >6 feet tall?
Size 41 Fr
What size Combitube is used for patients <4 feet tall?
There are no options for patients <4 feet tall.
What are benefits of Comtibue airways?
- minimal training required
- useful for obese population
- can decompress the stomach
-provides a secure airway
How does the King Laryngeal tube differ from the Combitube airway?
King only has a single lumen for ventilation and a single inflation port
What is the King LTS-D?
A disposable device that includes a second lumen that allows you to pass a gastric tube ot suction the stomach.
Inflation of the oropharyngeal balloon (proximal cuff) of the Combitube airway occludes the ____.
hypopharynx
Inflation of the distal balloon (distal cuff) of. theCombitube airway ocludes the ____.
esophagus
What balloon. is inflated first in a Combitube airway?
The oropharyngeal balloon
How much air do you place in a size 37 oropharyngeal balloon of a Combitube airway?
40-85 mL
How much air do you place in a size 41 oropharyngeal balloon of a Combitube airway?
40-100 mL + option for additional 50 mL
How much air do you place in the distal balloon of a Combitube airway?
5-12 mL air for both sizes
Cuff pressures of a Combitube airway should not exceed ____.
60 cm H2O
What is a risk of overzealous inflation of the cuffs of a Combitube airay?
Esophaugs rupture
What is Zenker’s Diverticulum?
A condition where diveticulum (pouches) form in the pharyngeal mucosa
The distal cuff of the King airway obstructs the ___, while the proximal cuff seals the __ and ___.
upper esophagus; oral and nasal pharynxes
How many inflation porst are there on a King’s airway?
1 - simultaneously inflates both the proximal and distal cuffs
What is the minimum weigh tfor a child-size Kings airway?
10 kg
For a king’s airway, the patient can only be ventilated through _____ betwene the two cuffs.
fenestrated apertures
When the tip of the Combitube airway is in the esophagus what lumen do you use to ventilate?
Blue -esophageal
When the tip of the Combitube airway is in the trachea what lumen do you use to ventilate?
The clear - tracheal tip
Regarding the operation of the flexible fiberoptic bronchoscope: (select 2)
a. the oral, pharyngeal, and laryngeal axes must align
b. pushing the level down points the tip up
c. the non-dominant hand controls the level
d. mask ventilation is impossible while the scope is in place
B and C
What is the gold standard for managina difficult airway in the awake, spontaneously ventilating patient?
FOB
What are the absolute CI for FOB?
there are none
What are the relative CI for FOB?
Hypoxia, bleeding, lack of cooperation
What should you use before nasal approach of FOB?
Defogger, antisialagogue, and vasoconstrictor
How does a flexible FOB work?
Light from an external source travels along the fiberoptic bundle and out from the distal tip. This light is reflected off the patient’s anatomy, allowing the operator to view the anatomy form the eyepiece or a camera attached to the eyepiece
FOB Scope movement:
non-dominant hand = _____
moves the level
FOB Scope movement:
dominant hand = _____
holds the cord
FOB Scope movement:
Pushing the lever down moves the tip ___.
up
FOB Scope movement:
Pushing the lever up moves the tip ___.
down
Horizontal movement of the FOB _____ the scope in either direction.
Rotates
What are indications for FOB besides difficult airway?
C-spine limitation - severe cervical stenosis, cervical fracture, Chiari malformation, vertebral artery insufficiency
Limited mouth opening - TMJ, facial burns, mandibular-maxillary fixation
What should be applied ot the tip of the FOB?
Anti-fog solution
hat type of drugs are best choices for awake FOB?
Short DOA and/or minimal respiratory depression
Ex: Precedex, REmifentanil, Ketamine, Midazolam
What should you do if the bevel of the ETT hangs up on the right arytenoid during fiberoptic intubation?
Pull back a little bit, rotate the ETT 90 degrees counterclockwise and advance the ETT again
What should you do in the FOB gets stuck in the Murphy eye during fiberoptic intubation?
You must remove the FOB and the ETT and repeat the procedure
The RLN is a brach of CN ___
10
The RLN provides sensory function to where?
below the vocal cords –> trachea
The RLN provides motor function to where?
All intrinsic muscles EXCEPT the cricothyroid
The Superior laryngeal nerve is. a branch of CN _
10
The external branch of the SLN provides sensory function ot where?
Nowhere
The internal branch of the SLN provides sensory function to where?
the posterior side of the epiglottis –> level of vocal cords
T/F: The true vocal cords are innervated by the RLN.
False - the true vocal cords are ligaments and are not innervated
The external branch of the SLN provides motor function to where?
Cricothyroid muscles
The internal branch of the SLN provides motor function to where?
Nowhere
What role does the cricothyroid muscle play?
Tenses vocal cords
What branch of the SLN provides motor function?
External branch
What branch of the SLN provides sensory function?
Internal branch
What CN is the glossopharyngeal nerve?
CN 9
What is the sensory function of the glossopharyngeal nerve?
Soft palate
oropharynx
tonsils
posterior 1/3 of tongue
vallecula
anterior side of epiglottis
afferent limb of gag reflex
What is the motor function of the glossopharyngeal nerve?
Swallowing and phonation
What CN is the trigeminal nerve?
CN 5
What is the V1 branch of the trigeminal nerve?
Ophthalmic (anterior ethmoidal)
What is the V2 branch of the trigeminal nerve?
Maxillary (sphenopalatine)
What is the V3 branch of the trigeminal nerve?
Mandibular (lingual)
What is the sensory function of Trigeminal V1?
nares & anterior 1/3 of nasal septum
What is the sensory function of Trigeminal V2?
Turbinates and septum
What is the sensory function of Trigeminal V3?
Anterior 2/3 of tongue
What is the motor function of Trigeminal V1?
None
What is the motor function of Trigeminal V2?
None
What is the motor function of Trigeminal V3?
None
What is the Bullard laryngoscope?
A rigid, fiberoptic device used for indirect laryngoscopy
When is the Bullard recommended?
For patients with small mouth openings, impaired cervical spine mobility, short thick necks, and congenital airway syndromes
Compared with DL, the Bullard casues less _____.
cervical spine displacement
What are the types of rigid, fiberoptic devices?
Bullard, WuScope, and UpsherScope
What is the minimum mouth opening for a Bullard laryngoscope?
7 mm
When using the Bullard, the patient’s head and neck must be in what position?
A neutral or slightly flexed position - any extension will make glottic visuialization more difficult
How do you expose the glottis with the Bullard?
The handle (blade) is pulled straight up (90 degree angle to the spine)
The Bullard has a disposable tip extender for tall patients. What is a consideration when using this?
Make sure to recover it - it is too large to be aspirated but can obstruct the upper airway
Compared to FOB, intubation with the BUllard is usually faster or slower?
faster
What are the names of the intubating styles?
Eschmann introducer and gum elastic bougie
The angled tip (coude) of an intubating stylet is used to facilitate intubation of a very _____ glottis. What Cormack & Lehane scores are it most useful for?
anterior; 2B or 3
Best time to use the EI = Class _____ view
3 (ei = eschmann introducer)
Second best time to use the EI = Class _____ view
2B
Worst time to use the EI = Class _____ view
3 - LOW change of success
What confirms placement when using the intubating stylet?
feeling the click of the tracheal rings
If you don’t feel the click of the tracheal rings to confirm placement of an intubating stylet, what is asecondary way to confirm placement?
“hold-up” sign - EI will encounter resistance at the carina (35-40 cm) … if you don’t feel this, you are in the esophagus!!
If using an intubating stylet when do you remove the laryngoscope?
After the entire intubation process
How far should the Eschmann introdducer be advanced into the trachea?
23-25 cm
Indications for the lighted stylet include: (select 3)
a. super morbid obesity
b. oropharyngeal bleeding
c. mandibular hypoplasia
d. epiglottitis
e. can’t ventilate and can’t intubate scenario
f. microstomia
B - severe oropharyngeal bleeding
C - mandibular hypoplasia
F - microstomia
What is a lighted stylet?
A blind intubation tehcnique that transilluminates the anterior neck to facilitate endotracheal intubation
What do you see when the lighted stylet is in the trachea?
A well-defined circumscribed glow below the thyroid prominence
What do you see when the lighted stylet is in the esophagus?
A more diffuse transillumination of the neck without the circumscribed glow
When the patient is supine, the trachea is located ____ to the esophagus.
anterior
What airways are lighted stylets useful for?
anterior airway, small mouth opening
T/F: The lighted stylet is a helpful tool to use in an emergency.
False - it should not be used in an emergency or a can’t ventilate can’t intubate scenario
When is a lighted stylet contraindicated?
Traumatic laryngeal injuries
(Also shouldn’t be used with tumors, foreign bodys, airway injury, or epiglottitis)
the trachlight in the adult, the tip should be bent to a ___ degree angle.
90
When using the Trachlight in a kid ,the angle should be ____ degrees to accomodate a more cephalad glottic opening.
60-80
Choose. theMOST appropriate indications for retorgrade intubation. (Select 2).
a. tracheal stenosis
b. unstable cervical spine
c. upper airway bleeding
d. can’t ventilate and can’t intubate scenario
B and C
What is retrograde intubation?
A blind procedure, where the tracheal intubation is accomplished by passing the ETT over a wire
What are contraindications for retrograde intubation?
Poor anatomy (neck deformity or mass)
Laryngotracheal disease (stenosis)
coagulopathy
infection
What are complications from retrograde intubation?
Bleeding, pneumothorax, trigeminal nerve trauma
What is the 1st step for retrograde intubation?
PUncture the cricothyroid membrane with a 14-18 g needle
How do you confirm proper placement of the needle in the tracheal lumen during retrograde intubation?
Aspirate for air
When is retrograde intubation best used and why?
When intubation has failed but ventilation is still possible; requires 5-7 minutes
Match each percutaneous airway technique with its absolute CI.
Transtracheal jet ventilation, cricothyroidotomy, tracheostomy
<6 y/o, UA obstruction, None
Jet ventilation - UA obstruction
Cricothyroidotomy - <6 y/o
Trach - none
What are the 3 ways to create a surgical airway?
- percutaneous cricothyroidotomy w/ transtracheal jet ventilation
- surgical cricothyroidotomy
- tracheostomy
Transtracheal jet ventilation requires a ____ oxygen source (___ psi) during inspiration. Exhalation is ____.
high-pressure; 50; passive
Why is transtracheal jet ventilation CI in UA obstruction?
Exhalation is passive, and UA obstruction can prevent exhalation –> barotrauma
Why does percutaneous cricothyroidotomy require a high-pressure oxygen source?
B.c the airway diameter is narrow
B/c ventilation can’t be controled durign percutaneous circothyroidotomy, the aptient is at risk for ___
hypercapnia
Why is surgical cricothyroidotomy CI in kids <6?
They have more pliable and mobile laryngeal and cricoid cartilages making it incredibly challenging; additionally, the thyroid isthmus commonly covers he cricothyroid membrane in kids
Besides kids <6, what are other CI for surgical cricothyroidotomy?
Laryngeal fracture or neoplasm
What is the mergency surgical airway technique of choice for kids <6?
percutaneous transtracheal ventilation (needle cric)
Incision for tracheostomies are usually made between the __ and __ tracheal rings.
2nd and 3rd
Following induction of GA, initial intubation attempts are unsuccessful and face mask ventilation is not adequate. According to the ASA Difficult Airway Algorithm, waht is the NEXT step?
a. supraglottic airway device
b. wake up patient
c. cricothyroidotomy
d. call for help
D - HELLLLPPPP
A reasonable approach is to limite attempts with any airway technique class to ___ attempts + ___ atempts by a clinicaln with higher skills.
3; 1
Anoxic injury can occur in as little as ___ minutes and can quickly progress to organ damage and death within the following ___ minutes.
4; 4-6
Deep extubation provides the MOST significant benefit in the patint with (select 2):
a. asthma
b. OSA
c. parkinson’s
d. CAD
A and D
___ and ___ are risks of deep extubation.
Airway obstruction and aspiration
What are the risks associated with awake extubations?
SNS stimulation increased
Increased ICP, IOP and IAP
Deep anesthetic plane = airway reflexes ____
attenuated
Light anesthetic plane = airway reflexes ____
hyperreactive (increased risk of laryngospasm)
Awake-disoriented anesthetic plane = airway reflexes ____
intact
What is Guedal stage 3?
Deep anesthetic plane
What is Guedal stage 2?
Light anesthetic plane
What is Guedal stage 1?
Awake-disoriented
What type of gaze occurs during light plane of anethesia?
disconjugate
What can you give to prevent CV and SNS stimluation during awake extubation?
BB, CCB, and vasodilators
What can you give to prevent coughing during awake extubation?
Lidocaine (IV or inside ETT cuff) and opioids
What is the BEST technique to manage the patient at high risk fo failed extubation?
a. eschmann introducer
b. airway exchange catheter
c. nasal airway
d. shikani stylet
B
What is an airway exchange catheter?
A long, thing, flexible hollow tube that maintains direct access to the airway following tracheal extubation
Besides being used for reintubation, the lumen of the airway exchange catheter can also be used to do what 3 things:
- measure ETCO2
2.Jet ventilate - Insufflate O2
The distal end of the AEC remains in the ____ (@____. cm at the lip).
trachea; 25-26 cm
The AEC can stay in place for how long?
Up to 72 hours
