PA Catheters

Question 1

CVP measured and reflects

Answer 1

Measured in the RA or SVC, measure of RV filling or diastolic pressure

Question 2

What are the 4 ports of the thermodilution catheter?

Answer 2

1) Distal –> PAP, PCWP, SVO2
2) Inflation –> Balloon 1.5cc air inflatable
3) Thermistor –> Measures core temp, CO
4) Proximal –> RAP/CVP, can infuse solutions, prn meds

Question 3

Where can we infuse meds in PA catheter?

Answer 3

Proximal, but not continuous meds. Only PRN push meds and fluids only

Question 4

Can we infuse blood through PA catheter?

Answer 4

No, small diameter risk of occlusion and damage to RBCs

Question 5

Right atrium normal pressure

Answer 5

3-8

Question 6

Right ventricle normal pressure

Answer 6

15-25 (Systolic)

0-8 (End diastolic)

Question 7

Pulmonary Artery normal pressure

Answer 7

15-25 (Systolic)
8-15 (Diastolic)
10-20 (Mean)

Question 8

PCWP normal pressure

Answer 8

6-12 (non vented pt)

Question 9

What causes the diacrotic notch on the PA waveform?

Answer 9

Closure of the pulmonic valves

Question 10

Where is the phlebostatic axis?

Answer 10

4th ICS mid clavicular line

Question 11

What does CVP/ RAP reflect?

Answer 11

Preload of the RA, indicator of RV function

Question 12

What can elevate CVP/RAP?

Answer 12

Hypervolemia, tricuspid valve stenosis/regurg, RV failure, RV MI, constrictive pericarditis, pulmonary HTN, LV failure, intrathoracic pressures

Question 13

What does PASP reflect?

Answer 13

Pressure in PA when RV ejecting blood into it. Reflects RV function and indirectly left heart (via pressure changes in pulmonary circulation)

Question 14

What can elevate PASP?

Answer 14

Constrictive pericarditis, hypoxemia (pulmonary arterioles constrict), LV dysfunction, mitral valve stenosis/regurg, increased pulmonary blood flow due to shunting

Question 15

What does PADP reflect?

Answer 15

In absence of pulm HTN, reflects left heart pressures (pressure in left ventricle at end of diastole). Affected by changes in pulmonary circulation and left heart

Question 16

What can elevate PADP?

Answer 16

Volume overload, LV failure, mitral valve issues, intrathoracic pressures, pulm HTN

Question 17

What does PCWP reflect?

Answer 17

Left atrial filling pressures (in systole the wedge reflect LAFP, in diastole LVEDP). Is recorded as a mean reflecting left heart function.

Question 18

How does the PADP relate to PCWP?

Answer 18

When pulm vascular resistance is normal, PADP correlates to PCWP (PADP is 1-4 above PCWP), so PADP can be used to monitor left heart pressures ONLY if the pt has no significant pulmonary disease that raises PA pressures

Question 19

Why is PADP and PCWP useful in fluid management

Answer 19

Changes show up 24-48 hrs before changes reflect in CVP in response to left ventricular failure

Question 20

How is PCWP affected by breathing

Answer 20

Decreases during inspiration, increases during expiration (spontaneous breathing)

When ventilated, PCWP increases during positive pressure inspiration and decreases during expiration

Question 21

When should PCWP reading be taken

Answer 21

At end of expiration where there is no gas going in or out of lungs

Question 22

What are complications of wedging?

Answer 22

1) Over wedging (Tracing climbs up in straight line)
2) Spontaneous wedge
3) Rupture of PA balloon
4) PA hemorrhage, rupture
5) Clot in lumen, air bubbles, kink in lumen causes dampened pressure tracing

Question 23

How is cardiac output correlated to surface area under the time-temperature curve?

Answer 23

Normal cardiac output –> Smooth upstroke to peak, then gradual downslope to baseline. Smooth curve

High cardiac output –> Fast upstroke to peak, quick downstroke. Small area under curve

Low cardiac output –> Slow upstroke to peak. slow recovery to baseline (large area under curve)

Question 24

What is the selection criteria for cardiac output curve?

Answer 24

1) Minimum of 3 cardiac outputs taken
2) Curves as “normal” as possible
3) +- 10% variability around median value

Question 25

What is cardiac index?

Answer 25

Calculated using pt body surface area obtained from Dubois chart (dry weight used)

Question 26

What is normal CO and CI?

Answer 26

CO: 4-8 L/min
CI: 2.5-4.5 L/min

Question 27

What is PVR?

Answer 27

Pulmonary Vascular Resistance –> Measures afterload of right ventricle

Normal PVR = 155-255 dynes/sec/cm-5

Question 28

What is SVR?

Answer 28

Systemic vascular resistance –> Measures afterload of left ventricle

Normal SVR = 800 - 1200 dynes/sec/cm-5

Question 29

What can increase PVR?

Answer 29

Lung problems causing pulmonary HTN, hypoxemia causing arteriole constriction, pulmonic valve stenosis,

Question 30

What can increase SVR?

Answer 30

Hypothermia, shock, catecholamines, drugs, hypovolemia

Question 31

What can decrease PVR and SVR?

Answer 31

Vasodilation, sepsis, hyperthermia, endotoxins

Question 32

What measurements monitor preload?

Answer 32

RAP (R heart)
PCWP (L heart)
PADP

Question 33

What measurements monitor afterload?

Answer 33

PVR (R heart)

SVR (L heart)

Question 34

What measurements monitor contractility?

Answer 34

CO

CI

Question 35

What treatments can decrease preload?

Answer 35

Diuretics, morphine, vasodilators (NTG, nipride)

Question 36

What treatments can increase preload?

Answer 36

Fluids, vasopressors (decrease venous pooling)

Question 37

What treatments can decrease afterload?

Answer 37

Vasodilators (NTG, nipride), ACE inhibitors, milrinone, antihypertensives, nitric oxide, flolan, IABP

Question 38

What treatments can increase afterload?

Answer 38

Vasopressors
Inotropes
Treat cause

Question 39

What treatments can improve contractility?

Answer 39

Inotropes (dobutamine, dopamine, milrinone, epi, dig)
Calcium (not given unless deficiency)
Correct cause