1. The Continuum: Perfusion Failures

• Shock: Decreased tissue perfusion causing a life-threatening cellular O2 supply/demand imbalance.
• SIRS: Systemic inflammation from infection, trauma, or ischemia, causing capillary leak and endothelial damage.
• Sepsis & Septic Shock: Sepsis is infection + dysregulated host response + organ dysfunction (altered mentation, SBP ≤100, RR ≥22, lactate >1 mmol/L). Septic shock is a subset with persistent hypotension requiring vasopressors to maintain MAP ≥65 mmHg despite aggressive fluid resuscitation.
• MODS: Failure of ≥2 organ systems. Lungs (ARDS) are usually the first to fail.

2. The 4 Main Shock Types

• Cardiogenic: Pump failure (comm ...