pulm review

Question 1

What is equation for lung compliance?

Answer 1

C = V/P

Question 2

What are the 3 forces that control respiratory system?

Answer 2

1. chest wall expansive force
2. lung elastic collapsing force
3. frictional resistance determines lung compliance

Question 3

equation for pulmonary vascular resistance (PVR)

Answer 3

PVR = (mPAP - mLAP) / CO

pulm artery P - left atria P

Question 4

systolic and diastolic pulmonary artery pressure?

Answer 4

systolic: 25 mmHg
diastolic: 10 mmHg

Question 5

Normal Patm

Answer 5

760 mmHg

Question 6

Normal Ph2o?

Answer 6

47 mmHg

Question 7

Normal FiO2 [fraction of inspired O2]

Answer 7

0.21

Question 8

What is R?

Answer 8

respiratory quotient = 0.8

Question 9

What is normal cardiac output?

Answer 9

6 L/min

Question 10

What is normal V/Q?

Answer 10

0.8

Question 11

What is normal PaCO2?

Answer 11

40 mmHg

Question 12

What is normal A-a gradient?

Answer 12

< 10 mmHg

Question 13

What is equation for minute ventilation rate [Ve]

Answer 13

Ve = Vt * RR
Vt = tidal volume
RR = respiratory rate

Question 14

What are two equations for alveolar ventilation rate? [hint: one uses Vt and one uses Vco2]

Answer 14

V[A] = (Vt - Vd) * RR
Vt = tidal volume
Vd = dead space

V[A] = Vco2 * K / PACO2
Vco2 = rate of CO2 production
PACO2 = alveolar PCO2
K = 863 mmHg for BTPS conditions

Question 15

What is equation for physiologic dead space?

Answer 15

Vd = Vt * (PaCO2 - PECO2)/PaCO2

PaCO2 = alveolar or arterial PCO2
PECO2 = expired PCO2

Question 16

What is normal Vd/Vt ratio?

Answer 16

1/3

Question 17

What is normal Vd?

Answer 17

150 mL

Question 18

What is normal Vt?

Answer 18

450 mL

Question 19

What is normal RR?

Answer 19

14 / min

Question 20

What is the alveolar gas equation?

Answer 20

PAO2 = FiO2(Patm - Ph2o) - PaCO2/R

Question 21

What is AA gradient?

Answer 21

PAO2 - PaO2

Question 22

Is V/Q ratio higher at bottom or top of lung?

Answer 22

higher at top of lung [less blood flow]

Question 23

In dead space what are PAO2 and PACO2?

Answer 23

PAO2 = 150 
PACO2 = 0

Question 24

Normal body temp?

Answer 24

37 C

Question 25

Fraction of O2, N2, and CO2 in atm at dry air 760 mmHg?

Answer 25

``` O2 = 21% N2 = 79% CO2 = 0% ```

Question 26

What is solubility of O2 in blood?

Answer 26

0.003 mL O2/100 mL blood / mmHg

Question 27

Daltons law for partial pressure of gas?

Answer 27

Px = (Pb - PH2O) * fraction of gas that is x

Question 28

What is henry's law for concentration of dissolved gas in solution?

Answer 28

``` Cx = Px * solubility Px = partial pressure of gas ```

Question 29

Between O2, CO2, and CO which are diffusion and perfusion limited?

Answer 29

O2 and CO2 perfusion limited | CO diffusion limited

Question 30

What is equation for O2 content of blood

Answer 30

O2 content = (1.34 * Hb conc * % saturation) + (0.003*PaO2)

Question 31

What is equation for rate of diffusion?

Answer 31

DA delta P / delta X | diffusion coefficient * surface area * driving pressure difference / thickness of barrier

Question 32

What is equation for O2 delivery?

Answer 32

O2 delivery = CO * O2 content of blood

Question 33

What is the O2 binding capacity of Hb?

Answer 33

1.34 *Hb

Question 34

What is the normal P50 of Hb?

Answer 34

25 mmHg

Question 35

What is venous PO2 and PCO2?

Answer 35

``` PO2 = 40 PCO2 = 46 ```

Question 36

What 4 things decrease the affinity of Hb for O2?

Answer 36

shift curve right - low pH - high PCO2 - high temp - high 2,3 DPG

Question 37

What are 5 causes of hypoxemic hypoxia?

Answer 37

``` high altitude hypoventilation V/Q mismatch right to left shunt diffusion deffect ```

Question 38

What will pulse ox show in CO poisoning?

Answer 38

normal -- because Hb is still bound

Question 39

In restriction: - FEV1 - FVC - FEV1/FVC - RV - TLC

Answer 39

- FEV1: lower - FVC: lower - FEV1/FVC: same or higher - RV: lower - TLC: lower obesity, pulmonary fibrosis

Question 40

In obstruction: - FEV1 - FVC - FEV1/FVC - RV - TLC

Answer 40

- FEV1: lower - FVC: slightly lower - FEV1/FVC: lower - RV: higher - TLC: higher asthma, emphysema, chronic bronchitis, COPD