Shock Flashcards
What is shock?
Inadequate tissue perfusion marked by decreased delivery of required metabolic substrates and inadequate removal of cellular waste products
Untreated shock leads to…
Organ dysfunction, organ failure, and death
6 types of shock?
Hypovolemic
Cardiogenic
Septic
Neurogenic
Traumatic
Obstructive
What are the four different categories of shock based on hemodynamic findings?
Hypovolemic (hemorrhagic, GI/UT volume loss, third spacing)
Cardiogenic (myocardial pump failure)
Distributive (sepsis, anaphylaxis, spinal cord injury, corticosteroid insufficiency)
Obstructive (cardiac tamponade, tension pneumothorax, PE)
Hypovolemic shock
HR:
MAP:
CVP:
PAOP:
SVR:
HR: high
MAP: low
CVP: low
PAOP: low
SVR: high
Cardiogenic Shock (Left ventricular failure)
HR:
MAP:
CVP:
PAOP:
SVR:
HR: Increased
MAP: Variable
CVP: normal
PAOP: High
SVR: High
Cardiogenic shock (right ventricular failure)
HR:
MAP:
CVP:
PAOP:
SVR:
HR: High
MAP: variable
CVP: High
PAOP: Normal
SVR: High
Cardiogenic Shock (Biventricular failure)
HR:
MAP:
CVP:
PAOP:
SVR:
HR: High
MAP: Variable
CVP: High
PAOP: High
SVR: High
Distributive Shock (Early vs Late)
HR:
MAP:
CVP:
PAOP:
SVR:
HR: Both High
MAP: Both Low
CVP: low or normal (early); high or normal (late)
PAOP: Low or normal (early); high or normal (late)
SVR: Low for both
Obstructive shock
HR:
MAP:
CVP:
PAOP:
SVR:
HR: high
MAP: low
CVP: high
PAOP: high
SVR: high
Chance of mortality with shock
Hypovolemic:
Cardiogenic:
Septic:
Hypovolemic: Very variable
Cardiogenic: 60%-90%
Septic: 35% - 40%
What are some determinants of shock?
- Loss of circulating intravascular volume
- Inadequate capillary and tissue perfusion
- Disturbed cell metabolism
- Mismatch of oxygen delivery and oxygen demand
What are the four stages of shock?
Initial
Compensatory
Progresive
Refractory
What happens during each stage of shock?
Initial:
Compensatory:
Progressive:
Refractory:
Initial: hypo-perfusion, tissue hypoxia, lactic acidosis
Compensatory: cytokine release, hypervent. endogenous catecholamine release
Progressive: failing compensation, capillary leakage and metabolic acidosis, increased blood viscosity, organ dysfunction (MODS)
Refractory: irreversible organ damage, cell death, degradation of ATP
What is the systemic response to shock?
- Progressive vasoconstriction
- Increased BF to vital organs
- Increase in CO/CI
- Increase in respiratory rate and tidal volume
- Reduced urine production
- Reduction in gastric and intestinal activity
What types of organ dysfunction are associated with shock?
Acute kidney injury
Liver congestion
Gastrointestinal ischemia
ARDS
What is cardiogenic shock?
Critical reduction in myocardial pump capacity (loss of > 40%) leading to malperfusion of tissues
What differential factors should be excluded in cardiogenic shock?
Hypovolemia
Arterial hypoxia
Vasovagal reaction
What percentage of patients with acute MI develop a cardiogenic shock?
5-10%
What are some of the clinical signs of cardiogenic shock?
- Signs of centralized circulation and organ dysfunction
- Agitation
- Pale, cool, clammy skin
- RV dysfunction
- LV dysfunction (leads to pulmonary edema)
Hemodynamic effects of Cardiogenic shock?
Systolic BP < 90mmHG or blood pressure drop by 30mmHG for > 30 min
May need inotropic therapy or balloon pump to stabilize BP
Increased LVEP
Reduced cardiac index
Myocardial etioligies of Cardiogenic shock
Acute MI
Myocarditis
Cardiomyopathy
RV pump failure
Myocardial depressoin
Mechanical etiologies of cardiogenic shock
Acute mitral insufficiency
Aortic insufficiency
Rupture of ventricular septum
Rupture of free ventricular wall
Obstruction