Respiratory Physiology

Question 1

What is the effect of cyanide toxicity on the MvO2?

Answer 1

It elevates the MvO2

Question 2

What clinical signs are associated with sodium nitroprusside infusion related cyanide toxicity?

Answer 2

metabolic acidosis and resistance to the hypotensive effects of the drug

Question 3

What is the concern of nitroprusside administration in a patient with renal failure?

Answer 3

Thiocyanate toxicity

Question 4

FRC is composed of…

Answer 4

ERV + residual volume

Question 5

Postop maximization of FRC reduces the incidence of

Answer 5

atelectasis, hypoxemia, and pneumonia

Question 6

How do you calculate PVR?

Answer 6

(meanPAP - PCWP)/CO x 80

Question 7

What is the normal range for PVR?

Answer 7

50 to 150 dynes-sec-(cm to the negative 5th power)

Question 8

Patients with h/o MI are likely to have another MI on what postoperative day?

Answer 8

Third postop day (for unknown reasons)

Question 9

What is the formula for BMI?

Answer 9

kg/(meters squared)

Question 10

Cardiac output increases by how many L/min per kilogram of adipose tissue?

Answer 10

0.1L/min

Question 11

Normal FEV1/FVC ratio is

Answer 11

0.75 - 0.85

Question 12

What is the FEV1/FVC ratio in mild, moderate, and severe obstructive airway disease?

Answer 12

Mild < 0.7, Mod < 0.6, Severe <0.5

Question 13

What is multifocal atrial tachycardia?

Answer 13

Non-reentrant, ectopic atrial rhythm often seen in COPD.

Question 14

How does multifocal atrial tachycardia differ from atrial fibrillation/flutter/paroxysmal SVT?

Answer 14

It lacks a reentrant mechanism meaning that DC cardioversion won’t work.

Question 15

During the first minute of apnea the PaCO2 will rise by…? And each minute thereafter?

Answer 15

6mmHg in the first minute, 3 - 4 mmHg each minute thereafter

Question 16

How does TPN affect work of breathing?

Answer 16

TPN increases work of breathing due to increased CO2 production.

Question 17

What sort of acidosis is associated with TPN?

Answer 17

Hyperchloremic metabolic acidosis 2/2 HCl formation from amino acid metabolism

Question 18

Do TPN electrolyte disturbances involve elevated or decreased levels?

Answer 18

Generally, decreased levels.

Question 19

What is O2 requirement for an adult in mL/kg/min?

Answer 19

3 - 4 mL/kg/min

Question 20

What is O2 requirement for a newborn in mL/kg/min?

Answer 20

7 - 9 mL/kg/min

Question 21

How does alveolar ventilation in neonates compare to that of adults

Answer 21

Neonatal alveolar ventilation is double that of adults

Question 22

How does tidal volume of a neonate compare to that of an adult?

Answer 22

On a per kg basis, neonatal tidal volume is similar (7 mL/kg) to that of an adult.

Question 23

What is a normal adult tidal volume?

Answer 23

6 - 8 mL/kg

Question 24

What is a normal adult vital capacity?

Answer 24

60 - 70 mL/kg

Question 25

What is the bohr dead space equation?

Answer 25

Vd/Vt = (PaCO2 - PexpiredCO2)/PaCO2