Shock Flashcards
(17 cards)
What is shock?
Shock is a life-threatening condition where the cardiovascular system fails to maintain adequate tissue perfusion, leading to widespread cellular dysfunction, organ failure, and potentially death.
What are the main types of shock?
Cardiogenic – heart fails to pump effectively
Obstructive – obstruction in major vessels/heart
Hypovolemic – significant loss of blood/fluid volume
Distributive (includes neurogenic, anaphylactic, septic) – widespread vasodilation and altered blood distribution
What causes impaired cellular metabolism during shock?
Decreased tissue perfusion leads to:
↓ Oxygen → anaerobic metabolism → lactic acid → metabolic acidosis
↓ ATP → Na⁺/K⁺ pump failure → cell swelling/dysfunction
↓ Glucose → protein & fat catabolism → nitrogenous waste, ketones, further acidosis
Inflammatory & coagulation cascades → capillary leakage, organ damage
What are the 4 phases of hypovolemic shock?
Phase I: Initial fluid loss → drop in vital signs
Phase II: Compensation → ↑ HR/RR, sweating, thirst
Phase III: Compensation fails → hypotension, confusion
Phase IV: Irreversible → organ failure, coma, non-detectable vitals
What causes cardiogenic shock?
Decreased cardiac output despite normal blood volume, usually from:
Myocardial infarction (MI)
Cardiomyopathy
Arrhythmias
Valve defects
Myocarditis
Acidosis
Signs and symptoms of cardiogenic shock?
Pulmonary edema
Hypotension
Oliguria
Cool/clammy skin
Mental confusion
SOB, nausea, signs of cardiac ischemia
Treatment of cardiogenic shock?
Reperfuse myocardium: GTN, inotropes, antiarrhythmics, thrombolytics
Coronary interventions: stent, CABG
Mechanical support: intra-aortic balloon pump
Oxygen, fluid management, dialysis if needed
What causes obstructive shock?
Mechanical blockage of blood flow due to:
Pulmonary embolism
Cardiac tamponade
Tension pneumothorax
Pulmonary hypertension
Constrictive pericarditis
Signs/symptoms & treatment of obstructive shock?
Similar to cardiogenic: hypotension, cool skin, mental changes
Treat the cause (e.g., drain fluid, remove embolism, relieve pressure)
What causes hypovolemic shock?
Loss of ≥15% blood/fluid volume from:
Hemorrhage
Burns (plasma loss)
Dehydration, vomiting, diarrhea
Diabetes (polyuria), excessive diuresis
Treatment for hypovolemic shock?
Rapid fluid resuscitation (crystalloids/blood products)
Control underlying cause (e.g., stop bleeding)
What causes neurogenic shock?
Disruption of sympathetic outflow from:
Spinal cord/medulla injury
Drugs or anesthetics
Severe emotional stress/pain
↓ Oxygen or glucose to medulla
signs & treatment of neurogenic shock?
Hypotension & bradycardia
Cool extremities, mental changes
Treatment: fluids, vasopressors to raise BP
What causes anaphylactic shock?
Type I hypersensitivity reaction (IgE-mediated) to allergens like:
Insect venom, peanuts, shellfish, latex, drugs
Signs & treatment of anaphylactic shock?
Hypotension, edema, airway constriction, rash, nausea, anxiety
Treat immediately: remove allergen, IM adrenaline, fluids, antihistamines, corticosteroids
What causes septic shock?
Systemic infection → overactivation of immune/inflammatory responses
Leads to vasodilation, ↑ permeability, ↓ myocardial function
Signs & treatment of septic shock?
Fever or hypothermia, tachycardia, ↑ RR, oliguria, confusion, jaundice, coagulopathies
Treatment: antibiotics, fluids, vasopressors, oxygen/ventilation, inotropes
