Cardio: Shock

Question 1

Hemorrhage
Dehydration
Burns

cause what type of shock?

Answer 1

Hypovolemic

Question 2

Acute MI
HF
Valvular dysfunction
Arrhythmias

cause what type of shock?

Answer 2

Cardiogenic

Question 3

Cardiac Tamponade
Pulmonary Embolism
Tension Pneumothorax

cause what type of shock?

Answer 3

Obstructive

Question 4

Sepsis
CNS injury
Anaphylaxis

Answer 4

Distributive (Vasodilatory)

Question 5

First sign of Shock is

Answer 5

Elevated HR

Question 6

Cardiac Output ↓

CVP (right-sided preload) ↓*

PCWP (left-sided preload) ↓

Cardiac index (LV output) ↓

SVR/TPR (after-load) ↑

SvO2 (mixed venous oxygen saturation) ↓

Answer 6

Hypovolemic Shock

Question 7

Cardiac Output ↓

CVP (right-sided preload) ↑

PCWP (left-sided preload) ↑

Cardiac index (LV output) ↓

SVR/TPR (after-load) ↑

SvO2 (mixed venous oxygen saturation) ↓

Answer 7

Cardiogenic Shock

Question 8

Cardiac Output ↓

CVP (right-sided preload) ↑

PCWP (left-sided preload) ↓

Cardiac index (LV output) ↓

SVR/TPR (after-load) ↑

SvO2 (mixed venous oxygen saturation) ↓

Answer 8

Obstructive Shock

*EXCEPT: In tamponade, left-sided preload is decreased, but measured PCWP is paradoxically increased due to external compression by pericardial fluid.

Question 9

Cardiac Output ↑

CVP (right-sided preload) ↓

PCWP (left-sided preload) ↓

Cardiac index (LV output) ↑

SVR/TPR (after-load) ↓

SvO2 (mixed venous oxygen saturation) ↑

Answer 9

Distributive (Vasodilatory) Shock

*EXCEPT: Cardiac index, CO & SvO2 are usually decreased in neurogenic shock (CNS injury) due to impaired sympathetic reflexes

CO ↑ due to ↑ HR

Question 10

Why does Tension Pneumothorax ↓ PCWP (left-sided preload)

Answer 10

Compresses IVC/SVC

Question 11

Why does Pulmonary embolism ↓ PCWP (left-sided preload)

Answer 11

Inhibits RV from pumping blood to the lungs

due to increased vasoconstriction of capillaries

Question 12

Why does CNS injury cause ↓

CO?

Answer 12

Loss of Autonomic tone

Question 13

How does Anaphylaxis cause distributive shock?

Answer 13

widespread release of inflammatory mediators (eg, histamine) that leads to massive peripheral vasodilation.

Question 14

What is the primary disturbance in Distributive (Vasodilatory) Shock?

Answer 14

↓ SVR from Peripheral vasodilation of
arteries → ↑CO (less afterload)
venules → ↓ CVP (less blood returning to RH)

Question 15

1. Except in Cardiac Tamponade a ↓ CVP = _____

2. SvO2 (mixed venous oxygen saturation) is ↑ in what type of shock?

Answer 15

1. ↓ PCWP

2. Distributive (Vasodilatory) Shock

Question 16

pulmonary capillary wedge pressure (PCWP), a reflection of _______.

Answer 16

left atrial pressure

Left side preload

Question 17

What is the primary disturbance in Hypovolemic Shock?

Answer 17

↓ Blood volume

causing reflexive ↑SVR

Question 18

What is the primary disturbance in Obstructive Shock?

EX: PE and PTX

Answer 18

Impeded cardiopulmonary blood flow causing
↑CVP (RAP)
↓PCWP (LAP)

and there is a

reflexive ↑ SVR due to ↓CO

Question 19

What is the primary disturbance in Cardiogenic Shock?

Answer 19

Left ventricular failure  ↓↓CO
causing
↑PCWP (LA pressure)
↑CVP (RA pressure)
due to backward transmission of increased LV pressure

thus there is a
reflexive ↑ in SVR since ↓↓CO

Question 20

Why does Cardiac Tamponade,
cause a paradoxical ↑ PCWP
if ↓ CVP?

Answer 20

left-sided preload (PCWP) is ↓

but measured PCWP is paradoxically ↑ due to external compression by pericardial fluid.

Question 21

How is Distributive (Vasodilatory) Shock treated? (2)

Answer 21

IV fluids
Pressors

*(If anaphylaxis use EPI)

Question 22

How is Cardiogenic Shock treated?

Answer 22

Ionotropes
Diuresis
Anti-arrhythmics

Question 23

How is Hypovolemic Shock treated?

Answer 23

IV fluids

Question 24

↓ CVP occurs when….

Answer 24

blood is not returning enough to RA either from obstruction or not enough blood in circulation

CVP is Right sided pre-load

Question 25

Cardiac Output ↓

CVP (right-sided preload) ↓

PCWP (left-sided preload) ↓

Cardiac index (LV output) ↓

SVR/TPR (after-load) ↓

SvO2 (mixed venous oxygen saturation) ↓

Answer 25

Neurogenic Shock

a unique form of distributive shock

Question 26

Cardiac Output ↓

CVP (right-sided preload) ↑

PCWP (left-sided preload) ↑

Cardiac index (LV output) ↓

SVR/TPR (after-load) ↑

SvO2 (mixed venous oxygen saturation) ↓

Answer 26

Cardiac Tamponade

a unique form of obstructive shock