10. Cardiogenic shock

Question 1

When compensatory mechanisms fail to maintain the CO, the most extreme end on the continuum of heart failure occurs:

Answer 1

cardiogenic shock

Question 2

Cardiogenic shock has several causes.

Answer 2

Most commonly, it is due to an extreme drop in stroke volume secondary to systolic dysfunction, which results in:

-Elevated left ventricular preload (PAOP) with associated pulmonary symptoms

-Elevated left ventricular after load (SVR) due to vasoconstrictive compensatory mechanisms

-a resultant drop in CO to the point where perfusion to the organs is no longer adequate

Question 3

Clinical presentation of Cardiogenic Shock: Compensatory Stage

Answer 3

-tachycardia
-tachypnea
-crackles, mild hypoxemia
-ABG with respiratory alkalosis or early metabolic acidosis
-Anxiety, irritability
-Neck vein distention
-S3 heart sounds (S4 heart sounds if there is also an acute MI)
-Cool skin
-Urine output is down
-NARROW PULSE PRESSURE
-BP is maintained or lower than baseline

Question 4

Clinical presentation of Cardiogenic Shock: Progressive Stage

Answer 4

-Hypotension
-Worsening tachycardia, tachypnea, oliguria
-Metabolic acidosis
-Worsening crackles and hypoxemia
-skin is clammy, motled
-Worsening anxiety or lethargy
*At any time, chest pain or arrhythmias may occur

Question 5

Etiologies of Cardiogenic shock

Answer 5

-Acute MI
-Chronic HF
-Cardiomyopathy
-Dysrhythmias
-Cardiac tamponade
-Papillary muscle rupture
-obliterates the mitral
-life-threatening emergency
-requires immediate surgical intervention

Question 6

Treatment of Cardiogenic shock

Answer 6

-Identify the cause
-Manage arrhythmias (brady, tachy) that may be contributing to a decrease in cardiac output
-Reperfusion if there is a STEMI (PCI or fibrinolytic therapy)
-Emergent sx if cardiogenic shock is due to a mechanical problem – ruptured papillary muscle, VSD
-Mechanical support
-Enhance effectiveness of pump
-Decrease demand on pump

Question 7

Treatment of cardiogenic shock: enhance effectiveness of pump

Answer 7

Positive inotrope support
-norepinephrine (levophed)
- dopamine 4 -10 mcg/kg/min
- dobutamine, milrinone (primacor)

AVOID negative inotropic agents!
Vasodilators
-May be used in conjunction with intra-aoritc balloon pump (IABP) therapy and positive inotropic agents if the pt is in the progressive stage with hypotension

Question 8

Treatment of cardiogenic shock: decrease demand on pump

Answer 8

-Preload reduction 9or optimization)
-Afterload reduction
-optimize oxygenation
-mechanical ventilation
-treat pain
-IABP for short term support
-Ventricular assist device (VAD) may be used for longer periods of time than IABP