Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Patient Monitoring/Instrumentation & SIM > Advanced Hemodynamic Monitoring > Flashcards

Advanced Hemodynamic Monitoring Flashcards

1
Q

Normal value for cardiac index

A

2.2-4.2 L/min/m2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Normal value for central venous pressure

A

5-12 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When is CVP most accurate?

A

When measured at the end of expiration

If the backrest position is between 0 to 60 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Normal value for coronary perfusion pressure

A

Autoregulated between 50-120 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Normal value for mixed venous oxygen saturation (mvO2)

A

60-80% in an awake patient

Roughly equal to central venous oxygen saturation (ScvO2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Normal value for pulmonary artery pressure (PAP)

A

15-30/10 mmHg

Accurate if backrest position is between 0-60 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Normal value for pulmonary hypertension (mild, moderate and severe)

A

Mild: 36-49 mmHg systolic
Moderate: 50-59 mmHg systolic
Severe: >60 mmHg systolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Normal value for pulmonary capillary wedge pressure

A

<12 mmHg (mean pressure)
1-4 mmHg less than pulmonary artery diastolic pressure
Accurate if backrest position is between 0-60 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Normal pulmonary vascular resistance (PVR)

A

100-300 dynesseccm^-5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Normal value for stroke volume in adults

A

60-90 mL/beat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Normal value for stroke volume index

A

20-65 mL/beat/m2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Normal value for systemic vascular resistance (SVR)

A

700-1200 dynesseccm^-5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Normal value for central venous oxygen saturation (ScvO2)

A

25-30% below SaO2 OR 70-75% if pt’s SaO2 is normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Baroreceptor reflex

A
  • Responds to changes in blood pressure in carotid sinus and aortic arch
  • When BP is low, HR increases
  • When BP is high, HR decreases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Bainbridge reflex

A

-Responds to changes in blood volume in the heart
-If R atrial pressure increases, the Bainbridge reflex causes increased HR and vasodilation
(try to get excess blood out of R atrium and causes venous pooling in legs, which decreases venous return)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What causes an increase in HR in the Bainbridge reflex and Baroreceptor reflex?

A

Low CVP through Baroreceptor reflex

High CVP through Bainbridge reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why is a cardiac output of 5L/min not accurate?

A

It may be normal for a 70kg patient, but it is too low for a 200 kg patient and too high for a 30 kg patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the cardiac index equation?

A

Cardiac output/surface area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Stroke volume index equation

A

stroke volume/surface area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Coronary perfusion pressure equations

A
  1. CPP = DBP - LVEDP
  2. CPP = DBP - CVP
  3. CPP = DBP - Pulmonary artery diastolic pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do you estimate Left Ventricular Diastolic Pressure? (LVEDP)

A
  1. LVEDP = left atrial pressure
  2. Left atrial pressure = PCWP
  3. PCWP = Pulmonary artery diastolic pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the thermodilution technique?

A
  1. Inject 10ml cold saline in the R atrium through the Swan Ganz catheter CVP port in <4 seconds
  2. The cold fluid travels to the PA where it encounters the thermistor (the fluid is warmed to a degree before encountering the thermistor)
  3. The monitor produces a waveform depending on how cold it is
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

If cardiac output is high, what happens to the temperature of the fluid at the thermistor?

A

It warms up quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the thermistor curve look like for high cardiac output?

A

The area under the curve is lower than normal (small wave)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

If cardiac output is low, what happens to the temperature of the fluid at the thermistor?

A

It will stay cold for a longer period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does the thermistor curve look like for low cardiac output?

A

The area under the curve is larger than normal (large wave)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens if the saline is injected too slowly to the thermistor?

A

The curve would be larger than normal, underestimating cardiac output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

A patient has a right to left intracardiac shunt. Would thermodilution lead to an overestimation or underestimation of cardiac output, and why?

A

Overestimation; Some cold fluid is lost to the L side, so blood in the pulmonary artery will be warmer and the curve will be smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

A patient has a left to right intracardiac shunt. Would thermodilution lead to an overestimation or underestimation of cardiac output, and why?

A

Overestimation; Cold fluid is diluted by warm blood in the L side, so fluid will be warmer and the curve will be smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

A patient has tricuspid regurgitation. Would thermodilution lead to an overestimation or underestimation of cardiac output, and why?

A

Underestimation; The blood at the thermistor will stay colder for a longer period and the curve will be larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What has replaced thermodilution?

A
  1. Continuous cardiac output pulmonary artery catheters

2. Transesophageal echocardiography (TEE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Oxygen saturation of superior vena cava

A

Central venous O2 saturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How is ScvO2 drawn?

A

Central venous line port

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is a mixed venous oxygen saturation?

A

Blood from the SVC, IVC and coronary sinus taken at the distal tip of the pulmonary artery catheter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the difference between ScvO2 and mvO2?

A

mvO2 will be slightly lower because it has venous blood from the heart (coronary sinus blood)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How do ScvO2 and mvO2 relate to low cardiac output, and why?

A

Low CO = low mvO2/ScvO2
Blood is more deoxygenated by the time it reaches the heart because it traveled slowly through the body and had more time to unload oxygen to the tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How do ScvO2 and mvO2 relate to high cardiac output, and why?

A

High CO = high mvO2/ScvO2
Blood is less deoxygenated by the time it reaches the heart because it traveled quickly throughout the body and had less time to unload oxygen to the tissues

38
Q

Why are ScvO2 and mvO2 rarely used to estimate cardiac output now?

A
  1. It requires drawing blood from central line or Swan catheter
  2. Cardiac output can be estimated through other effective methods such as TEE, CCO Swan, FloTrac sensor
39
Q

What is the equation for Ohm’s law and what is each variable?

A

V= IR
Voltage
I: Current
Resistance

40
Q

What part of Ohm’s law is analogous to cardiac output?

A

The current (I)

41
Q

What part of Ohm’s law is analogous to peripheral and systemic vascular resistance?

A

Resistance (R)

42
Q

What in the body is analogous to voltage in Ohm’s law?

A

The difference between the blood pressure at the arterial end of the body and the blood pressure at the venous end of the body
MAP- CVP

43
Q

What is Ohm’s law in terms of cardiac output systemically?

A

(MAP-CVP) = (SVR)(CO)

44
Q

Rewrite Ohm’s law to solve for cardiac output

A

CO = [(MAP-CVP)/SVR]*80

45
Q

Rewrite Ohm’s law to solve for SVR

A

SVR= [(MAP-CVP)/CO] *80

46
Q

Why use the number “80” in the equations for cardiac output and SVR?

A

80 converts the units for blood pressure and SVR into units for cardiac output

47
Q

How can you calculate PVR using Ohm’s law?

A

PVR = [(PAP-PCWP)/CO] *80

48
Q

How can you calculate cardiac output with pulmonary pressures?

A

CO= [(PAP-PCWP)/PVR] *80

49
Q

What are factors that affect pulse pressure?

A
  1. Stroke volume (increased stroke volume = increased systolic pressure)
  2. SVR (increased SVR/vasoconstriction = increased systolic pressure)
  3. Aortic compliance (good compliance = decreased systolic pressure)
50
Q

Will pulse pressure be wide or narrow in a hypovolemic patient, and why?

A

Narrow

Low SV and vasoconstriction

51
Q

Will pulse pressure be wide or narrow in a patient with CHF, and why?

A

Narrow

Low SV and vasoconstriction

52
Q

Will pulse pressure be wide or narrow after running 3 miles on the treadmill, and why?

A

Wide

Inc SV and vasodilation

53
Q

Will pulse pressure be wide or narrow in a patient with cardiac tamponade, and why?

A

Narrow

Low SV and vasoconstriction

54
Q

Will pulse pressure be wide or narrow in a patient with aortic stenosis, and why?

A

Narrow

Low SV and vasoconstriction

55
Q

Will pulse pressure be wide or narrow in a patient with a milrinone drip, and why?

A

Wide

Increases cardiac contractility and decreases SVR

56
Q

Will pulse pressure be wide or narrow in a patient with aortic regurgitation, and why?

A

Wide

Inc SV and dec DBP

57
Q

What causes high CVP?

A
  1. Fluid overload
  2. Heart failure
  3. Pulmonarty HTN
  4. Trendelenburg
  5. High intrathoracic pressure (tension PNX)
58
Q

What causes low CVP?

A
  1. Hypovolemia

2. Sitting position

59
Q

Causes of low SVR

A

Vasodilation

60
Q

Causes of high SVR

A

Vasoconstriction

61
Q

Causes of low cardiac index

A
  1. Decreased cardiac contractility
  2. Bradycardia
  3. Hypovolemia
  4. Hypervolemia (in CHF patient)
  5. Increased afterload (aortic stenosis or high SVR)
62
Q

Causes of high cardiac index

A
  1. Increased contractility/stroke volume
  2. Tachycardia
  3. Vasodilation
63
Q

Types of hypotension

A
  1. Hypovolemia
  2. Vasodilation
  3. Heart failure (dec contractility)
64
Q

Treatments for hypovolemia

A

Fluids and/or blood products

65
Q

Treatments for vasodilation

A
  1. Vasopressors

2. Reversing of vasodilation such as decreasing level of anesthetic

66
Q

Treatments for heart failure

A
  1. Inotropes

2. Diuretics

67
Q

What happens to cardiac index, CVP and SVR when a patient is hypotensive due to hypovolemia?

A

Cardiac index: Decreased
CVP: Decreased
SVR: Increased

68
Q

If a patient has hypotension due to vasodilation, what happens to cardiac index and SVR?

A

Cardiac index: Increased

SVR: Decreased

69
Q

If a patient has hypovolemia due to decreased contractility, what happens to cardiac index, CVP and SVR?

A

Cardiac index: Decreased
CVP: Increased
SVR: Increased

70
Q

What would be best to treat this patient with a BP of 88/40, HR of 98, cardiac index of 3.0 and SVR of 400?

A

Vasopressor

71
Q

What would be best to treat this patient with a BP of 85/40, HR of 65, SVR of 1100, and cardiac index of 1.8?

A

Inotrope

72
Q

What would be best to treat this patient with a BP of 170/105, HR of 60, SVR of 1700, cardiac index of 2.8 and PVR of 350?

A

Vasodilator

73
Q

What would be the best treatment for a patient with a BP of 84/55, HR of 100, SVR of 1500, PVR of 100, cardiac index of 2, CVP of 2, and PAP of 20/5?

A

Fluid bolus

74
Q

Stroke volume and systolic blood pressure fluctuating during inspiration and expiration

A

Stroke volume variation or pulse pressure variation

75
Q

How much does systolic blood pressure decrease during inspiration in spontaneously ventilating patients?

A

5-10 mmHg

76
Q

Why does systolic blood pressure decrease during inspiration in spontaneously ventilating patients?

A

It decreases 5-10 mmHg due to:

  1. Pulmonary vessels vasodilating
  2. Vasodilation causes blood to pool in lungs
  3. Less blood is available to pump to the body
  4. Slight drop in BP during inspiration
77
Q

What is the expected effect on HR if the patient is hypervolemic? Hypovolemic? and why?

A

HR increases due to the Bainbridge reflex

78
Q

In healthy mechanically ventilated patients, how much does the systolic blood pressure change during inspiration and why?

A

Increases 5-10%

  1. Displaces L ventricular wall inward during systole, assisting ventricular contraction (increasing ejection fraction)
  2. Squeezes blood out of the pulmonary capillaries, into the L atrium and increasing blood volume and stroke volume during inspiration
79
Q

When the stroke volume/systolic blood pressure has wider than expected fluctuations during inspiration and expiration

A

Pulsus paradoxus

80
Q

How do you detect pulsus paradoxus?

A

SpO2 and arterial line waveforms

81
Q

Most common cause of pulsus paradoxus

A

Hypovolemia

82
Q

Other causes of pulsus paradoxus

A

cardiac tamponade, tension pneumothorax, vasodilation, CHF, hypervolemia, and PEEP

83
Q

Cardiac tamponade mechanism for pulsus paradoxus

A
  1. During normal inspiration, blood volume in the R ventricle increases
  2. With cardiac tamponade, the R ventricular wall cannot expand, so it forces the interventricular septum to bulge to the L
  3. This causes a decrease in the volume of the L ventricle, decrease in SV and greater decrease in BP during inspiration
84
Q

Tension PNX mechanism for pulsus paradoxus

A
  1. R ventricular wall cannot expand, causing the interventricular septum to bulge into the L
  2. This causes a decrease in the volume of the L ventricle, decrease in SV and greater decrease in BP during inspiration
85
Q

What does the FloTrac sensor do?

A

Tells us exact stroke volume variation

86
Q

“Cool things” about the FloTrac sensor

A
  1. Noninvasive
  2. Gives real time blood pressure
  3. Measures stroke volume variation, stroke volume and SV index, SVR (from waveform downstroke)
  4. Can calculate cardiac index
87
Q

Disadvantages of FloTrac sensor

A
  1. Arterial lines give access for drawing labs while EV1000 does not
  2. EV1000 is not always accurate
88
Q

Common methods to assess volume status

A
  1. Urine output
  2. hypotension/tachycardia
  3. CVP monitoring
89
Q

How do you manage fluids with the FloTrac sensor?

A

The FloTrac Sensor can give us stroke volume variation. When stroke volume increases by >10-15% on mechanically ventilated patients, hypovolemia is expected.
Titrate until the stroke volume variation is closer to 10%

90
Q

Limitations of the FloTrac Sensor?

A
  1. Patient must be 100% mechanically ventilated for accurate stroke volume variation
  2. Respiratory rate needs to be constant
  3. Tidal volume needs to be >8ml/kg
  4. Regular heart rhythm
  5. PEEP and vasodilators can alter SVV
91
Q

Fluid management protocol for hypotensive patients

A
  1. Give fluids until SVV <10%
  2. If SVV does not respond to therapy, look at the SVI
    - if SVI is <20%, give inotropes
    - if SVI is 40-50%, give vasopressors
    - if SVI is >50%, give diuretics

Patient Monitoring/Instrumentation & SIM (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions