ITE Pulm Flashcards
Cormack-Lehane system
- Grade 1
Complete glottis visible
Cormack-Lehane system
- Grade 2b
Anterior glottis not visible.
Only posterior arytenoids and epiglottis visible.
Cormack-Lehane system
- Grade 3
Epiglottis, but not glottis is visible
Cormack-Lehane system
- Grade 4
Epiglottis is not visible
First line treatment for asthma exacerbation in OR
- bronchospasm
- airway inflammation
- mucous plugging
100% FIO2
then deepen the anesthetic
*Beta agonists can worsen oxygenation d/t changes in V/P mismatch
Inhaled corticosteroids for asthma treatment take ____ (time) to see significant changes
6-12 hours
- treat inflammatory component
Heliox is a ____ andis a useful adjunct in that it helps to decrease the density of delivered gases (ie: Beta2 agonists and steroids get past obstruction), resulting in less pt effort needed to get the same volume of gas.
mixture of 70% helium and 30% oxygen
How does giving a beta-2-agonist in pts having a bronchospasm worsen the oxygenation?
d/t changes in V/P mismatch
- The under-ventilated alveoli will have concomitent pulmonary vasoconstriction to decrease the amount of shunting
- When B2-agonist is used, some bronchodilation occurs, but inflammation and mucous plugging continues
- there is increased perfusion to poorly ventilated lung units -> V/Q mismatch
Bronchospasm affects ____ muscle, and nondepolarizing relaxants affect ____ muscle
smooth
skeletal
________ block occurs in 100% of patients undergoing interscalene blockade, even with dilute solns of local anesthetics and results in a ___% reduction in pulmonary function
Ipsilateral phrenic nerve block
- results in diaphragmatic paresis
Most common level for placement of interscalene block
Between Anterior and middle scalene m
- at the cricoid cartilage or C6 vertebrae lvl
- Where the cervical n roots C5-6 leave the spine
The interscalene block may spare the ____ nerve.
ulnar nerve.
Intraarterial injection of local anesthetics would cause what type of symptoms?
CNS symptoms
immediate sz
intrathecal injection of massive amts of local anesthetics would cause what type of symptoms?
total spine
LOC +
respiratory insufficiency/apnea
Foreign body in children display signs of ______, while adults often display signs of ______
Children
- air trapping: hyperinflation with obstructive emphysema
Adults
- atelectasis
Two most feared complications of mediastinal mass in anesthesia
- Complete airway obstruction w/ inability to maintain gas exchange
- Cardiovascular collapse from compression of vital structures.
GA approaches to pts with mediastinal mass
- local/regional anesthesia whenever possible
- Awake intubation.
- Secure airway beyond lesion.
- Confirm ability to ventilate and oxygenate
- Have thoracic surgeon in room during induction
- Ensure availability of rigid bronchoscopy if obstruction occurs
______ results in a flow-volume loop with an:
- expiratory phase with a quick peek followed by a much lower than normal plateau phase. *kink
- normal inspiratory phase
- Graph shifts to L
COPD
Assuming full inspiratory and expiratory efforts are made, end INSPIRATION volume is equal to ______, and end EXPIRATION is equal to ____
total lung capacity
residual volume
Examples of intrathoracic airway obstruction and extrathoracic airway obstruction
intrathoracic airway obstruction
- distal tracheal tumor
- mediastinal mass
extrathoracic airway obstruction
- vocal cord paralysis/dysfunction
- proximal tracheal tumor
- glottic strictures
What causes a flow-volume loop with plateaued AND decreased inspiratory and expiratory flows?
Fixed upper airway obstruction or fixed large airway obstruction?
A variable INTRATHORACIC airway obstruction produces a flow-volume loop with a plateaued (inspiratory/expiratory) curve.
expiratory
A variable EXTRATHORACIC airway obstruction produces a flow-volume loop with a plateaued (inspiratory/expiratory) curve.
inspiratory
FEV1/FVC <70% =
FEV1/FVC >80% =
Obstruction in adults
- Low
restrictive
- normal/increased
*80% is normal
Staging of COPD (gold staging)
- FEV1/FVC < 70%
I: mild - FEV1 > 80% predicted
II: moderate - FEV1 50-80%
III: Severe- FEV1 30-50%
IV: very severe- FEV1 <30%
What is vital capacity?
IRV + TV + ERV
What is FRC?
Amount of air in the lungs after normal respiration
ERV + RV
*usually ~ 3000mL
What is the forced vital capacity (FVC)?
Maximal expiration after maximal inspiration
Sulfhemoglobin is a condition caused by irreversible binding of sulfur to the porphyrin ring of heme of hgb. This shifts the oxyhemoglobin dissociation curve to the (right/left).
Right
*opposite of methemoglobinemia: shifts curve to the Left. Methemoglobinemia is less able to be tolerated than sulfhemoglobin. Tx with -methylene blue
Blood color of:
Methemoglobin
Sulfemoglobin
Methemoglobin: chocolate brown
Sulfemoglobin: dark greenish-black
What shifts the hgb dissociation curve to the left? (5)
- fetal hgb
- carboxyhemoglobin
- cold temp
- alkalosis
- decreased 2,3-DPG (ie: pRBC transfusion, septic shock, hypophosphatemia, hypocarbia)
What shifts the hgb dissociation curve to the Right?
- Sickle cell
- pregnancy
- hyperthermia
- acidosis
- increased 2,3-DPG (chronic anemia, CHF)
- Hypercarbia
Alkalosis shifts the oxyhemoglobin dissociation curve to the (Right/Left)
Left
CADET face right! mneumonic
rightward shift of oxyhemoglobin dissociation curve
- Carbon dioxide
- Acidosis
- 2,3-DPG
- Exercise
- Temperature
Diffusing capacity of the lung for carbon monoxide (DLCO) is decreased in _____
pulmonary embolism
- increase in dead space ventilation -> prevents nl amount of carbon monoxide from being absorbed
DLCO is (increased/decreased) in asthma
Increased
- Increased total lung volumes
- Increased expiratory times
- No parenchymal disease
- Increased amount of CO that can be absorbed.
DLCO is (increased/decreased) in exercise
increased
- more blood flow through pulm vessels, more hgb present to bind more CO
DLCO is (increased/decreased) in L->R cardiac shunt
increase
- increased blood volume -> overload of pulm circ -> more CO is abs by more blood passing thru pulm vasculature.
“Double peak” appearance in capnography in pts with_____
COPD w/ single lung transplant
- 1st peak: from normal (transplanted) lung, and second peak is the exhalation from the native, diseased lung)
In capnography, phase 3-4 is the expiratory alveolar plateau, and represents ____.
continued exhalation of CO2 from the lung alveoli
Vital capacity is ?
Maximal amt of air that can fill the lungs and participate in gas exchange
TLC - RV
or
TV+IRV+ERV
Forced vital capacity is?
Amt of gas that can be forcefully and maximally exhaled from a maximal inhaled volume
Both FEV1 and FVC are reduced with (restrictive/obstructive) lung pathology
restrictive
amiodarone is often used for _____ in difficult to control afib or ______
rate control
ventricular arrhythmias
Amiodarone is associated with _____ and _____, especially with the use of supplemental O2 and higher FiO2 concentrations.
pulmonary fibrosis, pneumonitis
3 Drugs known to cause pulmonary toxicity and fibrosis (dry cough, dyspnea on exertion, decrease in DLCO)
- Methotrexate
- Bleomycin
- Amiodarone
B/l recurrent laryngeal nerve injury after thyroid sx can cause _____
loss of function of posterior cricoarytenoid m. (the only muscle that abducts the vocal cords) –> unopposed vocal cord adduction –>respiratory distress and failure
Unilateral recurrent laryngeal nerve injury after thyroid sx can cause _____
unopposed adduction of ipsilateral vocal cord –> difficulty with phonation but not respiratory distress.
B/l superior laryngeal nerve injury after thyroid sx can cause _____
hoarseness and tiring of the voice (no airway compromise)
*superior laryngeal n innervates the cricothyroid membrane
Which West lung zone has the largest dead space ventilation?
West zone 1:
higher alveolar pressure > pulmonary arterial and venous pressure
PA > Pa > Pv
- no pulmonary blood flow in zone 1
- does not exist in human lung except in positive pressure ventilation
Which West lung zone?
PA > Pa > Pv
Pa > PA > Pv
Pa > Pv > PA
(A = alveolar a = arterial v = venous)
Zone 1
Zone 2
Zone 3
Most human lung is comprised of which West lung zone?
Zone 3
Pa > Pv > PA
*most dependent area of the lung
Why do COPD patients have auto-PEEP?
COPD results in loss of elements that keep the lungs open during expiration.
During exhalation, the airways close, resulting in air trapping.
Smoking cessation immediate benefits
- Decrease cyanide levels (improve oxygen use)
- Decrease CO (improve oxygen use)
- Decrease nicotine levels (better vasodilation)
What causes a decrease in FRC?
mneumonic PANGOS
- Pregnancy, ascites, neonates, GA, Obesity, Supine position
More aggressive strategies for preoxygenation before intubation if 100% FiO2 via face mask isn’t enough in a spontaneously ventilating pt?
CPAP or BIPAP
- replace nitrogen with oxygen in lungs, create O2 reservoir.
- Provides PEEP
*HFNC mayyy provide intrinsic PEEP
BVM limitations in pre-oxygenating pts
- Not meant for spontaneously breathing pts
- FiO2 can range from 21%-100%
- Do not allow for high flows > 15LPM
Corticosteroid administration can take ___ hours after the first dose to see any appreciable changes in airway edema
> 12h
Gold standard test for laryngeal edema
nasopharyngeal fiberoptic exam
- need cooperative pts and appropriate equipment
*CT and MRI can image, but not safe if pts can have airway compromise at any moment.
How does racemic epinephrine 50/50 mixture help with airway edema?
- alpha-adrenergic receptor stimulation in airway ->
Mucosal vasoconstriction, decrease amt of fluid present in the airway - beta-adrenergic stimulation in bronchial tissue ->
bronchodilation -> prevent bronchoconstriction
Stridor post-extubation (~30-60min) is often the result of ___________
laryngeal edema
How does CO poisoning cause lactic acidosis?
Formation of CO-hgb –>
less oxygen binding sites and reduction in O2 release –>
decrease O2 delivery to tissues –>
lactic acidosis
*CO binds to hgb < 200x affinity than O2