Respiratory APEX Flashcards
Intrinsic muscles (larynx)
Chubby tired leprochauns piss terrible venom
Cricothyroid
Thyroaryetnoids
Lateral cricoaryetnoids
Posterior cricoaryetnoids
Traverse/ aryepiglottc / Inter aryetnoids
Vocalis
Cricothyroid pneumonic
Cords tense (elongate)
ThyroaRyetnoids pneumoic
They Relax
Lateral vs posterior cricoarytenoids
Lateral- Adduct cords
Posterior- Abduct cords (ABs at the POSTERIOR of a work out)
External muscles (larynx)
HYOID
Omohyoid
Sternohyoid
Sternothyroid
Mylohyoid
Stylohyoid
Thryohyoid
Digastric (anterior and posterior)
What is the role of the intrinsic vs extrinsic muscles of the larynx?
Intrinsic- phonation, vocal cords
Extrinsic- Swallowing
What innervates the muscles (motor) of the larynx?
RLN- all except cricothyroid
SLN (EB)- cricothryoid
Airway innervation nerves (4)
Trigeminal (CN5)
Glossopharyngeal (CN9)
SLN (CNX)
RLN (CNX)
SLN IB ranges from ___ to ___
Posterior epiglottis to the top of the vocal cords
What does the SLN EB sense?
Nothing, motor only
Trigeminal Nerve branches
TRI- 3 branches
V1 Opthalmic nares and anterior 1/3 septum
V2 Maxillary Turbinates and posterior 2/3 septum
V3 Mandibular anterior 2/3 tongue
CN9 sensory
Posterior 1/3 tongue
Oropharynx
Valeculla
Anterior epiglottis
Afferent vs Efferent limb of gag reflex
CN9
CN10
What cranial nerve serves the epiglottis
CN9- anterior
CNX SLN- posterior
Which RLN is more susceptible to injury and why?
Left bc it loops around the aortic arch instead of the subclavian
Risk factors for L RLN injury
PDA ligation
LA enlargement (from mitral stenosis)
Aortic arch aneurysm
Thoracic tumor
Risk factors for RLN injury to either side
Pressure from ETT or LMA
Thyroid or parathyroid surgery
Neck stretching
Neoplasm
Which branch of X is high risk for emergency if injured?
Biltateral RLN (makes sense, its most of the muscles motor)
What cranial nerve is for chewing?
CN5, branch V3, mandibular (lingual)
Cranial nerves of airway innervation
5
9
10
Landmark for SLN block
Superior Greater
Greater cornu of hyoid bone
What nerves must be blocked from airway? (3)
Glossopharyngeal (9)
SLN
RLN
Landmark for glossopharyngeal block
Palatoglossal arch
Glossopharyngeal block aspiration of air vs blood
Air- too far
Blood- in carotid artery
How much anesthetic for glossopharyngeal, SLN, RLN
1-2 ml
2ml
3-5 ml
Where does RLN block go?
Cricothyroid membrane
Larynx position C spine
C3-C6
Paired vs unpaired cartilages of larynx
Paried- aryetnoids, corniculate, cuneiform
Unpaired- epiglottis, cricoid, thyroid
2 instances when you would need to place a needle thru the cricothyroid membrane
Transtracheal block for RLN
Cricothyroidotomy
What ligament pulls the epiglottis via the vallecula?
Thyroepiglottic
Narrowest airway in adults and children
Adults- glottis
Children- glottis dynamic, cricoid fixed
Manuever of laryngospasm
LARSONS - firm pressure to laryngospasm notch just behind earlobe , breaks spasm by causing a lightly anesthetized patient to sigh, also opens airway as a jaw thrust
Hold for 3-5 seconds an released for 5-10 seconds
Signs of laryngospasm
Rocking horse chest wall movement
Inspiratory stridor
Absent etco2
Risk factors for laryngospasm
Recent URI
Second hand smoke exposure
GERD
<1yr
Light anesthesia
Saliva/blood in airway
hypocapnia
Procedures of the airway
Laryngospasm interventions/ prevention
Avoid airway manipulation during light anesthesia
CPAP 5-10 during induction and extubation
Remove secretions before extubation
Extubation when deep or awake, not inbetween
Lidocaine (laryngeal or iv)
Laryngospasm treatment
Fio2 100%
Deepen anesthetic
CPAP 15-20
Larsons
SUCC IV 1mg/kg or 2mg/kg for infants
SUCC IM 4mg/kg or 5mg/kg for infants
Atroping 0.02 for children under 5
Valsalva vs Mullers
Opposites
Exhalation against closed glottis- coughing, bucking
Inhalation against closed glottis- pulmonary edema, bites ett and breathes in
Which nmb can be given IM?
Succ 4mg/kg adults, 5mg/kg kids
Roc
Where can the upper airway obstruct and what muscle will cause it?
Soft palate- tensor palatine
Tongue- genioglossus
Epiglottis- hyoid
Trachea C spine location
C6-T5
Degree of L and R mainstem bronchus
L- 45 degrees, also 2.5 cm from carina
R- 25 degrees, 5cm from carina
Alveoli cell type
Squamous epithelium
Distance from teeth to carina
13cm from teeth to larynx
13cm from larynx to carina
26cm total
Bronchi angle on children
55 degrees for both for children under 3
Goblet vs ciliated cells
Goblet- mucus production in large airways, decrease as airway bifurcates
Ciliated- clears mucus in carina
BOTH decrease with airway bifurcation, lungs start to only focus on gas exchange
What is the angle of louis and where is it C spine
Correspond with the carina
T5
What are pores of Khon?
Air movement between alveoli
What is an example of Boyles law?
Contraction of the inspiratory muscles reduces thoracic pressures and increases thoracic volume
Muscles of inspiration
Sternocleidomastoid (accessory)
Scalenes (accessory)
EXternal intercostals
Diaphragm
Conducting, transitional, and respiratory zones
No gas exchange, dead space
Dual funciton of air conduit and gas exchange via the respiratory bronchioles
Gas exchange
Muscles of expiration
I let the air out of my TIRE
Transverse abdominus
Internal intercostals
Rectus abdominus
External obliques
Transplural pressure, example of it
Alveolar pressure-Interplueral pressure
If positive, stays open, if negative, airway collapses
0-(-5)= 5
Should always be positive
When is alveolar pressure more and less positive
More positive (barely) on expiration
Less positive (or negative) on inhalation
When is interpleural pressure positive and negative?
Always negative to keep lung inflated
Can become positive during forced exhalation
Where does gas exchange end and begin?
Ends at the terminal bronchioles
Starts right after at respiratory bronchioles
Normal dead space (Vd) in percentage and weight based
33%
2ml/kg
Alveolar ventilation equation
(Vt-Vd)xrr
Primary determinant of CO2 elimination, not Ve
What can increase Paco2-etco2 ? Decrease?
Things that increase deadspace
Neck extension
PPV
Hypotension by reducing pulmonary bloodflow
Bronchodilators increase conducting zone to increase deadspace
Decreease- ETT,LMA, neck flexion
What is physiologic deadspace?
Alveolar + anatomic deadspace
What is the most common cause of increased deadspace under GA? How would it present?
Reduction in CA
Decrease in ETCO2
What increases deadspace
Apparatus like facemask, HME, PPV
Anticholinergics open conducting zone
Old age sigh longer
Neck extension opens airway
Decreased CO, COPD, PE
Sitting
What decreases deadspace
ETT, LMA, Trach
Neck flexion
Supine, trend
HPV minimizes ____
shunt
Most common cause of hypoxemia in the PACU
VQ mismatch
Treatment of VQ mismatch in the PACU
O2
Deep breathing, mobility, spirometry
When is surfactant produced?
Starts at 26 weeks
Completion at 36
Law of laplace formula
tension= pressure x radius
alveoli, blood vessels
What can be used to hasten fetal lung maturity?
Corticosteroids
Shunts not in the lungs
Thesbian
Pleural
Bronchiolar
West zone is associated with hypotension?
1
Not enough blood flow causes deadspace
Alveolar oxygen formula
fio2 x (pb-h2o [47]) - (paco2/RQ[.8])
RQ formula
CO2 production/ O2 Consumption
200/250= 0.8
5 causes of hypoxemia
VQ mm (most common, increased Aa)
Shunt (increased Aa)
Diffusion limitation (increased Aa)
Hypoxic mixture (normal Aa)
Hypoventilation (normal Aa)
What are things that increase Aa
Aging
Vasodilators (prevent HPV)
Diffusion limitation ()
RL shunt (atelectasis are basically closed)
VQ mm- copd, 1LV
Estimation of shunt
1% for every 20mmHg of Aa gradient
5% normally
TLC, VC, IC, FRC
5.8L
4.5L
3.5L
2.3L
IRV, Vt, ERV, RV
3L
.5L
1.1L
1.2L
What reduces FRC
Obesity
pulmonary edema
How is FRC measured?
Nitrogen washout
Helium washin
Body pleth
Formula to determine how long FRC will last
FRC (in O2) / VO2
FRC if 100% oxygen is 2300ml
FRC if .21 O2 is 483
Vo2 always 250
Closing capacity vs closing volume
CC- The absolute volume in the lungs when airways begin to collapse
CV- The volume above RV where small begin to collapse
CC=CV+RV
What is the relationship between FRC and CC?
FRC should always be bigger, otherwise airways will close during normal breathing
What is the consequence of CC>FRC?
Shunting
Hypoxemia
How can you treat CC>FRC?
PEEP open the airways
How does aging effect FRC, CC, RV, and VC?
Increase all except VC decreases
The relationship of age, anesthesia and CC
At 30, CC=FRC when under GA (supine)
At 44, CC=FRC when supine (awake)
At 66, CC=FRC when standing (awake)
CaO2, DO2, VO2 formula
(1.34xhgbxsao2) + (pao2x.003)
Cao2 x 10 co
Cao2-cvo2 x 10 x co
How does HgF, methemoglobin and carboxyhemoglobin affect oxyhemoglobin dissociation curve?
All shift left
Effect of 2,3 DPG on oxyhemoglobin dissociation curve
Increase- right shift
Decrease- left shift
Glycolysis, krebs cycle, oxidative phosphorylation ATP production
2,2,34
All aerobic
What does glycolysis turn into, and then what does that turn into? (anaerobic and aerobic)
Glycolysis (2 atp) always turns into pyruvic acid
In anaerobic- this turns into lactic acid, then 2 atp
In aerobic, it turns into acetyl CoA, then goes to the krebs cycle (2 atp) and oxidative phosphorylation / electron transport (34 atp)
How much atp from pyruvate/ lactic acid pathway?
2
For what process is the hamburger shift?
Co2 + H2o-> H2CO3-> h HCO3
The HCO3 goes into plasma, and the Cl- goes into RBC
How is CO2 transported in the blood?
HCO3- 70%
HGB- 23%
Plasma- 7%
What enzyme is needed to convert CO2 + H2o into H2CO3?
Carbonic anhydrase
Haldane vs Bhor pneumonic
Haldan holds CO2- left
Bhor Byeeeeee O2- right
What things increase CO2 production?
Shivering
MH
Overfeeding
Seizures
Burns
Thyriod storm
Sepsis
What decreases CO2 elimination?
Hypoventilation
Airway obstruction
Increased Vd
ARDS
COPD
CO2 effect on heart and lungs
Myocardial depressant
However, it also stimulates SNS which should offset
Increases PVR (unlike SVR)
How much does 10mmHg CO2 decrease PH?
0.08 (1 for memory purposes)
Less for chronic CO2 holders- 0.03
Effects of K and Ca by increased CO2
Increases both
What drugs left shift CO2 ventilatory curve? R shift?
Aspirin
Norepi
Aminophylline
Doxapram
—-
Opioids
Volatile anesthetics
NMB
Do you want a left or right shift apneic thershold?
Left! will stimulate u to breathe sooner
Right shift will not make u breathe until co2 is higher like 75
What is the pace maker for breathing?
Old- DRG
New- (pre-botzinger) in the VRG
Location of Pneumotaxic and Apneic centers
Upper and low pons
Location of DRG and VRG
Medulla for both
Nucleus tractus solitarus
Nucleus ambigous and retro ambiguous