Sepsis Definition
Life-threatening organ dysfunction caused by a dysregulated host response to infection (Δ SOFA ≥ 2)
Septic Shock Criteria
Vasopressors needed for MAP ≥ 65 mmHg AND Lactate > 2 mmol/L despite fluids
First-Line Vasopressor
Norepinephrine (Levophed) (potent alpha-1 with modest beta-1 inotropic support)
Distributive Hemodynamics
High Cardiac Output, LOW Systemic Vascular Resistance (SVR), Warm extremities
Master Hemodynamic Shock Comparison Table
Pulmonary artery catheter (Swan-Ganz) hemodynamic profiles across the 4 major shock categories:
| Shock Classification | Cardiac Output (CO) | Preload (PCWP / CVP) | Afterload (SVR) | Mixed Venous O2 (SvO2) |
|---|---|---|---|---|
| Hypovolemic Shock (Hemorrhage, Dehydration) | Decreased (↓) | Decreased (↓↓) | Increased (↑↑ compensatory vasoconstriction) | Decreased (↓) |
| Cardiogenic Shock (MI, Severe HF, Arrhythmia) | Decreased (↓↓) | Increased (↑↑ back-up of fluid) | Increased (↑↑) | Decreased (↓) |
| Distributive / Septic Shock (Early warm phase) | Increased (↑↑ hyperdynamic) | Decreased or Normal (↓/↔) | Decreased (↓↓ profound vasodilation) | Increased (↑↑ impaired O2 extraction) |
| Obstructive Shock (PE, Tamponade, Tension PTX) | Decreased (↓↓) | Increased (↑↑) in Tamponade; Low in PE | Increased (↑↑) | Decreased (↓) |
Surviving Sepsis Campaign 1-Hour Bundle
Initiate immediately upon recognition of sepsis or septic shock:
1. Measure Serum Lactate
Re-measure within 2–4 hours if initial lactate is > 2 mmol/L to guide resuscitation adequacy.
2. Blood Cultures Prior to Antibiotics
Obtain 2 sets of blood cultures (aerobic and anaerobic) before initiating antimicrobial therapy, provided this does not cause significant delay (> 45 min).
3. Administer Broad-Spectrum Antibiotics
Infuse empiric broad-spectrum coverage (e.g., Vancomycin + Cefepime or Piperacillin-Tazobactam) within 1 hour of recognition.
4. Crystalloid Fluid Resuscitation
Administer 30 mL/kg of balanced IV crystalloid (Lactated Ringer's) within 3 hours for hypotension or lactate ≥ 4 mmol/L.
5. Apply Vasopressors
If MAP remains < 65 mmHg after fluid resuscitation, initiate Norepinephrine immediately. Second-line agent: add Vasopressin (0.03 units/min).
COMLEX / OMM Integration
NBOME High-Yield Correlate
Autonomic and Lymphatic Considerations in Sepsis
- Rib Raising: Rhythmic rib raising normalizes sympathetic chain tone, reducing splanchnic vasoconstriction and improving microvascular organ perfusion.
- Caution with Lymphatic Pumps: Avoid aggressive thoracic lymphatic pump techniques during active acute bacteremia with high fevers to avoid sudden shower of inflammatory cytokines.
- Caution with Lymphatic Pumps: Avoid aggressive thoracic lymphatic pump techniques during active acute bacteremia with high fevers to avoid sudden shower of inflammatory cytokines.
Board Traps & Common Distractors
- Trap: Choosing Dopamine over Norepinephrine as first-line vasopressor in septic shock. Dopamine causes significantly more tachyarrhythmias and increased mortality; Norepinephrine is the undisputed drug of choice.
- Trap: Delaying vasopressors until all 30 mL/kg fluid is completely infused. If diastolic BP is profoundly low (< 40 mmHg), start Norepinephrine peripherally while fluids are running!