Cardio: Shock Flashcards
Hemorrhage
Dehydration
Burns
cause what type of shock?
Hypovolemic
Acute MI
HF
Valvular dysfunction
Arrhythmias
cause what type of shock?
Cardiogenic
Cardiac Tamponade
Pulmonary Embolism
Tension Pneumothorax
cause what type of shock?
Obstructive
Sepsis
CNS injury
Anaphylaxis
Distributive (Vasodilatory)
First sign of Shock is
Elevated HR
Cardiac Output ↓
CVP (right-sided preload) ↓*
PCWP (left-sided preload) ↓
Cardiac index (LV output) ↓
SVR/TPR (after-load) ↑
SvO2 (mixed venous oxygen saturation) ↓
Hypovolemic Shock
Cardiac Output ↓
CVP (right-sided preload) ↑
PCWP (left-sided preload) ↑
Cardiac index (LV output) ↓
SVR/TPR (after-load) ↑
SvO2 (mixed venous oxygen saturation) ↓
Cardiogenic Shock
Cardiac Output ↓
CVP (right-sided preload) ↑
PCWP (left-sided preload) ↓
Cardiac index (LV output) ↓
SVR/TPR (after-load) ↑
SvO2 (mixed venous oxygen saturation) ↓
Obstructive Shock
*EXCEPT: In tamponade, left-sided preload is decreased, but measured PCWP is paradoxically increased due to external compression by pericardial fluid.
Cardiac Output ↑
CVP (right-sided preload) ↓
PCWP (left-sided preload) ↓
Cardiac index (LV output) ↑
SVR/TPR (after-load) ↓
SvO2 (mixed venous oxygen saturation) ↑
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
Why does Tension Pneumothorax ↓ PCWP (left-sided preload)
Compresses IVC/SVC
Why does Pulmonary embolism ↓ PCWP (left-sided preload)
Inhibits RV from pumping blood to the lungs
due to increased vasoconstriction of capillaries
Why does CNS injury cause ↓
CO?
Loss of Autonomic tone
How does Anaphylaxis cause distributive shock?
widespread release of inflammatory mediators (eg, histamine) that leads to massive peripheral vasodilation.
What is the primary disturbance in Distributive (Vasodilatory) Shock?
↓ SVR from Peripheral vasodilation of
arteries → ↑CO (less afterload)
venules → ↓ CVP (less blood returning to RH)
- Except in Cardiac Tamponade a ↓ CVP = _____
2. SvO2 (mixed venous oxygen saturation) is ↑ in what type of shock?
- ↓ PCWP
2. Distributive (Vasodilatory) Shock
pulmonary capillary wedge pressure (PCWP), a reflection of _______.
left atrial pressure
Left side preload
What is the primary disturbance in Hypovolemic Shock?
↓ Blood volume
causing reflexive ↑SVR
What is the primary disturbance in Obstructive Shock?
EX: PE and PTX
Impeded cardiopulmonary blood flow causing
↑CVP (RAP)
↓PCWP (LAP)
and there is a
reflexive ↑ SVR due to ↓CO
What is the primary disturbance in Cardiogenic Shock?
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
Why does Cardiac Tamponade,
cause a paradoxical ↑ PCWP
if ↓ CVP?
left-sided preload (PCWP) is ↓
but measured PCWP is paradoxically ↑ due to external compression by pericardial fluid.
How is Distributive (Vasodilatory) Shock treated? (2)
IV fluids
Pressors
*(If anaphylaxis use EPI)
How is Cardiogenic Shock treated?
Ionotropes
Diuresis
Anti-arrhythmics
How is Hypovolemic Shock treated?
IV fluids
↓ CVP occurs when….
blood is not returning enough to RA either from obstruction or not enough blood in circulation
CVP is Right sided pre-load
Cardiac Output ↓
CVP (right-sided preload) ↓
PCWP (left-sided preload) ↓
Cardiac index (LV output) ↓
SVR/TPR (after-load) ↓
SvO2 (mixed venous oxygen saturation) ↓
Neurogenic Shock
a unique form of distributive shock
Cardiac Output ↓
CVP (right-sided preload) ↑
PCWP (left-sided preload) ↑
Cardiac index (LV output) ↓
SVR/TPR (after-load) ↑
SvO2 (mixed venous oxygen saturation) ↓
Cardiac Tamponade
a unique form of obstructive shock
