Pulmonary Circulation

Question 1

What is the typical source of hemoptysis, where does this structure drain, and what is the significance?

Answer 1

bronchial circulation
drains into the left atrium
acts as a shunt because doesn’t get oxygenated

Question 2

How do you calculate pulmonary vascular resistance (PVR)?

Answer 2

PAP - LAP = CO x PVR

Question 3

Which has higher resistance, systemic or pulmonary circulation?

Answer 3

systemic

Question 4

which has high elastance/low compliance, systemic or pulmonary circulation?

Answer 4

systemic circulation

Question 5

which has a low pressure, systemic or pulmonary circulation?

Answer 5

pulmonary circulation

Question 6

What are the 2 methods for measuring pulmonary arterial pressure and which one is better?

Answer 6

method 1 = echo for estimation (+/- 10 mmHg)

method 2 = pulmonary artery wedge/occlusion pressure BEST ONE

Question 7

What are the normal pressures for RA, RV, PA, MAP PA, PCWP, CO, and PVR?

Answer 7

RA = 0-5 mmHg
RV = 25/10 mmHg
PA = 25/10 mmHg
MAP PA = 15-20
PCWP = 5-8 mmHg
CO = 5 L/min
PVR = 1-2 woods units (WU)

Question 8

On a swan Ganz cath, which top humps should be even if normal?

Answer 8

right ventricle and pulmonary artery

Question 9

on a Swan Ganz Cath, which bottom humps should be even if normal?

Answer 9

• Right atrium to right ventricle

- Pulmonary artery to pulmonary artery occlusion/wedge pressure

Question 10

If the cardiac output increased from 5L/min to 20L/min but the pulmonary pressure only increases 1/2 of expected increase, what are the mechanisms?

Answer 10

2 mechanisms

• high capacitance (more distensible vessels than systemic arteries)
• recruitment of unperfused vessels (west zones of the lung)

Question 11

True of False: Gravity affects air pressure

Answer 11

False: gravity only affects blood pressure but not air pressure

Question 12

Where are MAP and MVP highest in the lung?

Answer 12

at the bases due to gravity

Question 13

Where is the mean alveolar pressure greatest?

Answer 13

it is the same everywhere

Question 14

Where are West Zone 2 and when does blood flow occur?

Answer 14

West Zone 2 = Apices
Blood flow only occurs during systole and not during diastole because systole makes the Pa >PA but not enough pressure during diastole to make Pa >PA anymore so capillaries close

Question 15

Where is West Zone 3 and what happens there?

Answer 15

Base of the lungs, blood flow always occurs in this area during systole and diastole

Question 16

Where is West Zone 1 and what happens there?

Answer 16

West Zone 1 doesn’t exist in healthy individuals

there is no blood flow ever at this area because Pa

Question 17

What does Zone 2 provide when CO increases?

Answer 17

vascular reserve because the pulmonary pressure is increased so there will not be collapse during diastole

Question 18

what happens to the zones when a patient is given a bolus of fluid?

Answer 18

Zone 2 becomes Zone 3

Question 19

what causes cariogenic pulmonary edema?

Answer 19

increased vascular hydrostatic pressure

Question 20

what causes non-cariogenic pulmonary edema?

Answer 20

increased permeability of vessel and proteins leave the vasculature pulling fluid with it

Question 21

how is cariogenic pulmonary edema related to pulmonary capillary wedge pressure?

Answer 21

when the pulmonary capillary wedge pressure increases, there is an increase of hydrostatic pressure leading to cardiogenic pulmonary edema

Question 22

What is the classic CXR finding for pulmonary edema and why does it occur?

Answer 22

Kerley B lines,

occurs because interlobular septae fill with fluid

Question 23

Which type of pulmonary edema forms faster given the same microvascular pressure?

Answer 23

non-cardiogenic pulmonary edema because there is increased permeability due to damaged vessels

Question 24

If a patient comes in with respiratory failure and has a capillary wedge pressure of 20 mmHg, how would you treat them?

Answer 24

use diuretic

capillary wedge pressure = LAP which means that there is fluid overload which can be treated through diuresis

Question 25

If a patient comes in with a crush injury and develops respiratory failure 6 hours later, what is the treatment?

Answer 25

lung protective ventilation

Question 26

True or False: Diuretics help treat non-cariogenic shock

Answer 26

False, non-cardiogenic shock is not caused by fluid overload from heart failure but rather from leaky vessels within the lung