Reference — Critical Care
Shock Hemodynamics Reference
Hemodynamic parameter patterns by shock type — cardiac output, SVR, CVP, PCWP, and first-line treatment for rapid clinical differentiation.
Educational use only. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Normal Hemodynamic Values
| Parameter | Abbreviation | Normal Range | What It Reflects |
|---|---|---|---|
| Mean Arterial Pressure | MAP | 70–100 mmHg | Average organ perfusion pressure |
| Cardiac Output | CO | 4–8 L/min | Total blood flow from the heart per minute |
| Cardiac Index | CI | 2.2–4.0 L/min/m² | CO adjusted for body surface area |
| Systemic Vascular Resistance | SVR | 800–1,200 dynes·sec/cm⁵ | Resistance in peripheral vasculature (afterload) |
| Central Venous Pressure | CVP | 2–8 mmHg | Right atrial filling pressure (preload estimate) |
| Pulmonary Capillary Wedge Pressure | PCWP | 6–12 mmHg | Left atrial filling pressure (LV preload estimate) |
| Mixed Venous O₂ Saturation | SvO₂ | 60–80% | Tissue oxygen extraction; low = high demand or low delivery |
Hemodynamic Patterns by Shock Type
| Shock Type | CO/CI | SVR | CVP | PCWP | HR | First-Line Treatment |
|---|---|---|---|---|---|---|
| Hypovolemic | ↓↓ | ↑↑ | ↓ | ↓ | ↑↑ | IV fluid resuscitation; identify source of loss |
| Distributive — Septic | ↑ (early) / ↓ (late) | ↓↓ | ↓ | ↓ | ↑↑ | Norepinephrine + fluids + antibiotics (Sepsis Bundle) |
| Distributive — Anaphylactic | ↑ / ↓ | ↓↓ | ↓ | ↓ | ↑↑ | Epinephrine IM (0.3–0.5 mg) + fluids + antihistamines |
| Distributive — Neurogenic | ↓ / ↔ | ↓↓ | ↓ | ↓ | ↓ or normal (bradycardia) | Phenylephrine or norepinephrine; fluids; spine immobilization |
| Cardiogenic | ↓↓ | ↑↑ | ↑ | ↑↑ | ↑ or variable | Dobutamine ± vasopressor; diuresis if overloaded; consider IABP/ECMO |
| Obstructive — Massive PE | ↓↓ | ↑↑ | ↑↑ | ↓ / ↔ | ↑↑ | Anticoagulation; thrombolytics if massive; embolectomy |
| Obstructive — Tamponade | ↓↓ | ↑↑ | ↑↑ | ↑ (equalization) | ↑↑ | Emergent pericardiocentesis; IV fluids to maintain preload |
↑ = elevated | ↓ = reduced | ↑↑ / ↓↓ = significantly elevated/reduced | ↔ = within or near normal range
Key Differentiation Points
- ›Low CO + low SVR = distributive shock (veins are open; need to squeeze).
- ›Low CO + high SVR = cardiogenic shock (heart is failing; pump is not working).
- ›Low CO + low CVP/PCWP = hypovolemic shock (tank is empty).
- ›High CVP with low CO and equalizing filling pressures = cardiac tamponade.
- ›High CVP with low CO and low PCWP = massive PE (right heart is obstructed).
- ›Septic shock early: high CO + low SVR (warm shock). Late septic shock: low CO as myocardial depression develops.
- ›Neurogenic shock: low SVR + relative bradycardia (unlike other shock states which cause tachycardia).
Related Resources
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with Society of Critical Care Medicine (SCCM) · Surviving Sepsis Campaign · American Association of Critical-Care Nurses (AACN). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →