Cardiogenic Shock Flashcards

1
Q

What is the definition of shock?

A

Profound reduction in devlivery of O2 and other nutrients to tissues leads first to REVERSIBLE and then if prolonged to IRREVERSIBLE cell injury

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

What are the 4 forms of shock?

A

Cardiogenic
Extracardiac (obstructive)
Hypovolemic
Distributive (septic)

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

What is the clinical diagnosis of shock?

A

<90 mm Hg systolic
PLUS
Poor perfusion (CNS = confusion, Skin = cold, clammy)

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

What are the 3 types of cardiogenic shock?

A

Large LV MI
RV MI
MR os VSD

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

What is the definition of filling pressure?

A

Pressure the atrium must rise to fill the ventricle

aka ventricular end diastolic pressure

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

How can you measure the filling pressures of the RV and LV?

A

Swan-Ganz pulmonary artery flotation catheter

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

What is a normal LV EDP?

A

<12 mmHg

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

What is a normal RV EDP?

A

<5 mmHg

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

How can the Swan Ganz catheter measure LV EDP?

A

Floats through RA, RV, to pulmonary capillaries
Blocks capillary and tip measures pressure
This pressure = LA pressure = LV EDP

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

What is a normal CO?

A

3.5 - 5.0 L/min

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

When there is a large LV MI, what happens to the following characteristics:

  • LV EDP
  • RV EDP
  • CO
  • Murmur (y/n)
A

LV EDP - increased
RV EDP - no change
CO - decreased
Murmur - No

In Large LV MI, systolic function (pump function) is bad

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

What is the prognosis for a patients with large LV MI?

A

> 90% mortality

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

What are two ways that the myocardial tissue can “act dead”?

A

Stunning - blood has reperfused tissue, requires time for muscle to start working again

Hibernating - blood has not yet reperfused

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

What are ways of maintaining viability of “acting dead” tissue?

A

Inotropic support
Vasopressors
Mechanical devices - best option

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which drugs can be used to provide inotropic and vasopressor support to try and maintain perfusion in large LV MI?

A

Dopamine - best option, positive inotrope and causes vasoconstriction

NE - potent vasopressor, give if dopamine inadequate

Dobutamine - should not be used if patient is hypotensive! Causes vasodilation

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

What mechanical devices can be used to try and maintain perfusion in large LV MI?

A

Intraaortic balloon pump
Left ventricular assist device
Extracorporal membrane oxygenator

17
Q

How does the intraaortic balloon pump work?

A

During diastole - inflate - aortic diastolic pressure increased - fills coronary arteries

During systole - deflate - aortic systolic pressure decreased - LV empties better

18
Q

When there is a RV MI, what happens to the following characteristics:

  • LV EDP
  • RV EDP
  • CO
  • Murmur (y/n)
A

LV EDP - normal or increased
RV EDP - increased
CO - decreased
Murmur - No

Pump function is bad

19
Q

Why can the LV EDP be normal or increased when there is a RV MI?

A

RV MI is due to blockage of right coronary artery, causing inferior wall infarction

RCA supplies the entire inferior wall, including part of the LV

So, in some inferior MIs, see decreased LV function and increased LV EDP

20
Q

What is the primary way to acutely treat RV MI and why?

A

Trial of VOLUME

RV is low-pressure pump, contractility depends on preload
When RV is not functioning well, need to raise RA pressure to drive blood into RV and through to the PA
Hence, need to increase volume to increase preload

21
Q

Why must you titrate the volume in RV MI instead of giving it all at once?

A

If there is LV damage, increased volume could be detrimental, causing congestion and pulmonary edema

22
Q

How can you use EKG to determine if there is an RV MI?

A

ST elevation in leads 2, 3, and avF indicate an inferior wall infarct
BUT, this could also include LV dysfunction. So need to add RIGHT SIDED CHEST LEADS and look for ST elevation and abnormal Q wave

23
Q

In RV MI, what will happen to the patient if they are given nitroglycerine?

A

HYPOTENSION

Vasodilation - volume will go to legs, exact opposite of the volume increase needed in RV MI

24
Q

When there is a VSD or MR, what happens to the following characteristics:

  • LV EDP
  • RV EDP
  • CO
  • Murmur (y/n)
A

LV EDP = increased
RV EDP = normal
CO = decreased
Murmur = Yes

VSD = During diastole blood from RV can go into LV, increasing LV EDP
MR = during systole, blood went back into the LA, increasing the amount of volume there. During diastole, this excess volume of blood enters LV, increasing LV EDP
25
Q

How can you diagnose VSD?

A

Measure O2 sat in the LV, RV, and RA

Will see oxygen step up in RV since oxygenated blood from LV is coming over

26
Q

When there is volume depletion, what happens to the following characteristics:

  • LV EDP
  • RV EDP
  • CO
  • Murmur (y/n)
A

LV EDP = decreased
RV EDP = decreased
CO = decreased
Murmur = no

This is hypovolemic shock, not cardiogenic

27
Q

What type of fluid should be given if the fluid loss is blood loss?

A

Blood

28
Q

What type of fluid should be given if the fluid loss is inflammatory plasma loss?

A

Albumin

29
Q

What type of fluid should be given if the fluid loss is dehydration?

A

Electrolytes, saline

30
Q

What type of fluid should be given if the fluid loss is inanition (lack of food and water)?

A

Glucose in water

31
Q

How is MR or VSD cardiogenic shock treated?

A

Surgery