Shock: Classification, Diagnosis & Management

Shock is a state of circulatory failure resulting in inadequate oxygen delivery to meet tissue metabolic demands. Early recognition and classification guide targeted resuscitation. The four types are distributive, hypovolemic, cardiogenic, and obstructive.

• 1Distributive (septic, anaphylactic, neurogenic): high CO, low SVR, warm extremities
• 2Hypovolemic (hemorrhagic, dehydration): low CO, high SVR, cool extremities
• 3Cardiogenic (MI, HF, myocarditis): low CO, high SVR, elevated filling pressures
• 4Obstructive (PE, tamponade, tension PTX): low CO, high SVR, elevated CVP
• 5Vasopressors: norepinephrine first-line for distributive; dopamine/dobutamine for cardiogenic
• 6Fluid resuscitation: 30 ml/kg crystalloid for septic shock; balanced crystalloids preferred

• Mixed shock is common — always consider multiple etiologies
• Bedside echo (POCUS) is the fastest way to differentiate shock types
• Tension pneumothorax: absent breath sounds + tracheal deviation + hypotension → needle decompression
• Anaphylaxis: epinephrine IM 0.3–0.5 mg is first-line, not antihistamines