Respiratory

Question 1

What is oxygen consumption in an adult?

Answer 1

3 mL/kg/min

Question 2

What causes R shift of CO2 response curve

Answer 2

narcotics
chronic obstruction
metabolic alkalosis
volatile agents

Question 3

What are peripheral vs central chemoreceptors?

Answer 3

peripheral = O2 triggered

1) carotid body (CN9), ventillatory effects, pick up PaO2 60-65
2) aortic arch/bodies (CN10), circulatory effects

central = medulla = CO2, triggered by CSF and respiratory acidosis

inhibited by volatile anesthetics

Question 4

What causes L shift of CO2 response curve?

Answer 4

metabolic acidosis
doxapram / dopram = respiratory stimulant
hypoxemia

Question 5

What decrease the slope of the CO2 response curve?

Answer 5

benzodiazepines
propofol
volatiles (decrease slope and R-shift)

Question 6

how do you calculate anion gap?

Answer 6

(Na + K) - (Cl + HCO3)

normal 8-12

Question 7

What are the direct inhibitors of HPV?

Answer 7

hypocarbia
infection
vasodilators (nitroglycerin, nicardapine, nitroprusside) 
metabolic alkalosis 
volatile anesthetics MAC > 1

Question 8

what is the alveolar gas equation?

Answer 8

PAO2 = PiO2 - PaCO2/R

PiO2 = FiO2*(Pbar - PH2O)

Question 9

What is the rise in bicarb for acute vs chronic respiratory acidsosis

Answer 9

acute = 0.2 mmol/L for each 1mmHg rise in CO2 above 40
chronic = 0.4 mmol/L

Question 10

how does the effect of PEEP change in a normal patient vs patient w/ CV

Answer 10

peep increased intra-thoracic pressure and RV afterload

normal patient = decreased pre-load and CO
CHF patient = volume overloaded, decreased pre-load is good, reduced LVEDP, decreased afterload

Question 11

When does FRC drop the most?

Answer 11

from upright 60deg to flat 0deg

from flat 0deg to -30deg T-berg

Question 12

what decreases closing capacity?

Answer 12

ACLSS
Age 
Chronic Bronchitis
LV failure
Smoking
Surgery

Question 13

smoking cessation effects

Answer 13

• 24-48hrs: R shift carboxyhemoglobin curve
• 2 weeks: worsens ciliary function and sputum production
• 2 to 3 months: improved cilia, less secretions, improved closing volume, increased FEF25-75%