Hemodynamic monitors & equipment 3

Question 1

When does pulmonary artery occlusion pressure overestimate left ventricular end-diastolic volume? (Select 2)
a. PA catheter tip in West zone 3
b. PEEP
c. Diastolic dysfunction
d. aortic insufficiency

Answer 1

b. PEEP
c. diastolic dysfunction

Question 2

Conditions where PAOP overestimates LVEDP include

Answer 2

mitral valve disease
COPD
pulmonary hypertension
PEEP
non West zone 3 placement of PAC
impaired LV compliance (ischemia)
left-to-right cardiac shut
tachycardia
PPV

Question 3

_________ causes PAOP to underestimate LVEDV

Answer 3

Aortic insufficiency

Question 4

Which situation underestimates cardiac output obtained by the thermodilution method?
a. over warmed injectate
b. right-to-left intracardiac shunt
c. high injectate volume
d. partially wedged pulmonary artery catheter

Answer 4

c. high injectate volume

Question 5

_________ is the most common method of measuring cardiac output.

Answer 5

The thermodilution method

Question 6

Cardiac output is underestimated when

Answer 6

the injectate volume is too high or the injectate solution is too cold

Question 7

Cardiac output is overestimated when

Answer 7

the injection volume is too low, the injectate is too hot, the PAC is partially wedged, or there’s a thrombus on the tip of the PAC

Question 8

Advantages of continuous cardiac output monitoring includes

Answer 8

providing continuous data & avoiding inaccuracies from the human element

Question 9

The major drawback of continuous cardiac output monitoring includes

Answer 9

slower response time & the data is typically averaged over time

Question 10

An injection of _______________________ is bolused through _____________- for the thermodilution method

Answer 10

5% dextrose or 0.9% NaCl of known quantity & temperature is bolused through the proximal port on the PAC

Question 11

Each injection should occur during

Answer 11

the same phase of the respiratory cycle and be completed in <4 seconds

Question 12

If CO is high, the injectate

Answer 12

rapidly travels towards the distal tip of the PAC

Question 13

The area under the curve will be _______________, if CO is higher.

Answer 13

smaller

Question 14

These conditions can make it difficult to predict the accuracy of CO:

Answer 14

intracardiac shunt
tricuspid regurgitation

Question 15

When would it be preferential to measure CO using the standard thermodilution technique over continuous cardiac output?

Answer 15

in a hemodynamically unstable patient (due to a delay time between measurement and the data appearing on the monitor)

Question 16

Factors that increase mixed venous oxygen saturation include: (select 2)
a. thyroid storm
b. sodium nitroprusside toxicity
c. anemia
d. sepsis

Answer 16

b. sodium nitroprusside toxicity
d. sepsis

Question 17

SvO2 is a function of four variables:

Answer 17

cardiac output
arterial oxygen saturation
amount of hemoglobin
oxygen consumption

Question 18

When Hgb, SaO2, and VO2 are held constant, then SvO2 becomes an indirect monitor of

Answer 18

cardiac output

Question 19

Factors that decrease SvO2 can be split into two categories:

Answer 19

increased O2 consumption
decreased O2 delivery

Question 20

Examples of increased O2 consumption include

Answer 20

stress, pain, thyroid storm, shivering, fever

Question 21

Examples of decreased O2 delivery include

Answer 21

Decreased SaO2, Hgb, or CO

Question 22

Factors that increase SvO2 can be split into two categories:

Answer 22

decreased O2 consumption
increased O2 delivery

Question 23

Examples of decreased O2 consumption include

Answer 23

hypothermia
cyanide toxicity

Question 24

Examples of increased O2 delivery include

Answer 24

O2 therapy
increased Hgb
increased CO

Question 25

Normal SvO2 is

Answer 25

65-75%

Question 26

The equation for SvO2 is

Answer 26

SaO2 - (VO2)/(CO x 1.34 x Hgb x 10)

Question 27

Why do you need a PA catheter to measure SvO2?

Answer 27

a true mixed venous sample must contain blood returning from the superior vena cava, inferior vena cava, and the coronary sinus & the PA artery is the best place to get the sample

Question 28

Preload responsiveness is expected to be present if a 250 mL fluid bolus increases the stroke volume in excess of:

Answer 28

10%

Question 29

____________ analysis provides a measure of preload responsiveness

Answer 29

Pulse contour analysis

Question 30

Methods of pulse contour analysis include

Answer 30

plethysmogroapthy variability index (requires pulse ox) stroke volume variation (requires esophageal doppler) systolic pressure variation (requires direct arterial pressure) pulse pressure variation (requires arterial pressure)

Question 31

To ensure accuracy of pulse contour analysis, the patient must be receiving

Answer 31

positive pressure ventilation

Question 32

As a general rule, preload responsiveness can be assumed when a 200-250 mL fluid bolus improves SV more than

Answer 32

10%

Question 33

Factors that reduce the accuracy of pulse contour analysis include

Answer 33

spontaneous ventilation open chest RV dysfunction dysrhythmias small tidal volume PEEP

Question 34

A _____________- patient will have a greater degree of stroke volume variation through the respiratory cycle as a function of __________________________

Answer 34

hypovolemic; intrathoracic pressure's effect on RV filling & function

Question 35

Which conditions limit the reliability of the esophageal Doppler monitor? Select 2 a. hypovolemia b. aortic stenosis c. aortic cross-clamp placement d. esophageal disease

Answer 35

b. aortic stenosis c. aortic cross-clamp placement

Question 36

What can the esophageal doppler measure?

Answer 36

stroke volume stroke index stroke volume variation stroke distance peak velocity flow time

Question 37

The esophageal Doppler can help you determine if you should treat with

Answer 37

fluid vasopressors or inotropes

Question 38

Where should the esophageal Doppler be positioned?

Answer 38

~35 cm from the incisors (T5-6)

Question 39

The position of the probe is based on

Answer 39

the sound and waveform quality

Question 40

The esophageal Doppler should not be used if the patient has

Answer 40

esophageal disease

Question 41

Factors that reduce the reliability of the esophageal doppler data include

Answer 41

aortic valve disease aortic cross-clamping disease of the thoracic aorta pregnancy after CPB