# Lange Ch22 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

How much is physiologic dead space? Per weight?

A

1 cc per lb. so average physiologic dead space is 150cc

2
Q

Bohr equation for dead space to tidal volume ratio Vd/Vt

A

Vd/Vt = (PACO2 - PeCO2) / PACO2. Avg ratio is 33% for 150/450. PeCO2 is mixed expired

3
Q

Relationships of Pa, Pv, and PA in the 3 lung zones

A

Zone 1: PA > Pa > Pv, high V/Q
Zone 2: Pa > PA > Pv
Zone 3: Pa > Pv > PA, low V/Q
Ventilation and perfusion improve in dependent areas

4
Q

How to calculate PAO2?

A

PAO2 = FiO2*(760-47) - (PCO2 / 0.8)

PAO2 ~ FiO2 * 6

5
Q

MC mechanism of hypoxemia

A

Increased A-a gradient caused by R->L shunt, V/Q mismatch, low MvO2 (low cardiac output, high O2 consumption, anemia)

6
Q

A

Qs/Qt = (CcO2 - CaO2) / (CcO2 - CvO2)

Normal shunt is 5%

7
Q

Total oxygen delivery (DO2) equation

A

DO2 = cardiac output * arterial O2 content

8
Q

Oxygen consumption VO2 equation

A

VO2 = cardiac output * (arterial O2 content - mixed venous O2 content)

9
Q

Oxygen content equation

A

(O2sat * hgb * 1.31) + (PO2 * 0.003)

10
Q

Mixed venous oxygen content equation

A

CvO2 = CaO2 - (VO2 / Qt)
VO2 oxygen consumption ~ 250 mL/min
Qt cardiac output

11
Q

Basic breathing rhythm originates from what part of brain?

A

Medulla

12
Q

Effect of anesthesia on peripheral ventilatory response to hypoxemia

A

Abolished response