Cardiogenic Shock Flashcards
Mortality rates for patients with cardiogenic shock
50 to 85%
Define shock
Syndrome characterized by decreased tissue perfusion and impaired cellular metabolism
Imbalance in supply/demand for O2 and nutrients
Definition of low blood flow cardiogenic shock
Systolic or diastolic dysfunction and compromised cardiac output
Precipitating causes of cardiogenic shock
MI, cardiomyopathy, blunt cardiac injury, severe systemic or pulmonary HTN, cardiac tamponade, myocardial depression from metabolic problems
Early manifestations of cardiogenic shock
Tachycardia, hypotension, narrowed pulse pressure, increased myocardial oxygen consumption
Presentation of cardiogenic shock is similar to
Acute decompensated heart failure
The heart’s inability to pump blood forward will result in
Low CO: less than 4 L/min
Low cardiac index: less than 2.5 L/min/m2
Physical examination of cardiogenic shock:
Tachypnea, pulmonary congestion, pallor, cool, clammy skin, decreased capillary refill time, anxiety, confusion, agitation
Increased PAWP
Decrease renal perfusion and UO
Laboratory studies used in diagnosing cardiogenic shock
Troponin Cardiac enzymes BNP ECG Chest x ray Echocardiogram
What goes on in the Initial stage of shock
Usually not clinically apparent
Metabolism changes from aerobic to anaerobic
Lactic acid accumulates and must be removed by blood and broken down in the liver
Process requires unavailable O2 ( give o2)
Describe the Compensatory stage of shock
Clinically apparent: neural, hormonal, biochemical compensatory mechanisms
Attempts are aimed at overcoming consequences of anerobic metabolism and maintaining homeostasis.
Classic sign of shock
Drop in bp, which occurs because of a decrease in CO and narrowing of pulse pressure
Progressive stage of shock
Compensatory mechanisms fail
Requires aggressive interventions to prevents multiple organ dysfunction syndrome
Important changes in the progressive stages
Patients mental status
Describe the irreversible stage of shock
Exacerbation of anaerobic metabolism, accumulation of lactic acid. Increased capillary permeability
What does increased permeability allow?
Fluid and plasma to leave the vascular space and move to the interstitial space
Decreased coronary blood flow leads to
Worsening myocardial depression and further decline in CO
Loss of intravascular volume worsens
Hypotension and tachycardia and decreased coronary blood flow
What happens in the irreversible stage of shock
Profound hypotension and hypoxemia, tachycardia worsens, failure of one organ system affects others, recovery is unlikely
What does the failure of liver, lungs, and kidneys lead to?
Accumulation of waste products such as lactate, urea, ammonia, and carbon dioxide
Important to remember about diagnosing shock
Through hx and physical examination. No single study to determine shock. Use blood studies, base deficit, elevation of lactate, 12 lead EKG, chest x ray, hemodynamic monitoring
Lateral wall MI
Has no wall movement and is a huge risk for cardiogenic shock
Collaborative care for shock
Ensure patent airway, maximize oxygen delivery.
May need a mechanical vent and a medical coma to preserve myocardial function
What fluids are used for initial resuscitation of shock
Isotonic crystalloids- example normal saline
