Undifferentiated shock

Undifferentiated Hypotension Algorithm

Check/manage the following in order:

• Pulse (assess based on pt's age)
  • Too slow or too fast (to the point where CO is affected)?
    • If so, HR is likely primary etiology of hypotension
    • Pace or cardiovert
• Volume Status
  • What is the LV end-diastolic volume?
    • Approximated by the IVC diameter or CVP
    • If low:
      • Assess for blood loss versus fluid loss
        • FAST for intra-abdominal bleed
        • US for ruptured AAA
        • Guaiac for GI bleed
        • CXR for hemothorax
      • Treat with IVF and/or pRBC depending on cause
• Contractility
  • Is the myocardium severely depressed in its contractile function (cardiogenic shock)?
    • Assess via ultrasound
    • Treat w/ inotrope
  • Is forward flow occurring?
    • Assess for valvular dysfunction (MR, AR)
    • Assess for obstruction (PE, tamponade)
• Systemic Vascular Resistance
  • Pathologic vasodilation (decreased SVR) suggested by:
    • Warm extremities
    • Bounding pulse
  • Treated based on likely etiology of distributive shock (see below)

Differential Diagnosis

Shock

• Cardiogenic
  • Acute valvular Regurgitation/VSD
  • CHF
  • Dysrhythmia
  • ACS
  • Myocardial Contusion
  • Myocarditis
  • Drug toxicity (e.g. beta blocker, CCB, or bupropion OD)
• Obstructive
  • Air embolism
  • Aortic Stenosis
  • Cardiac Tamponade
  • PE
  • Tension pneumothorax
• Distributive
  • Adrenal crisis
  • Anaphylaxis
  • Neurogenic shock
  • Sepsis
  • Toxicologic
• Hypovolemic
  • Severe dehydration
  • Hemorrhagic shock (traumatic and non-traumatic)

See Also

• Ultrasound in Shock and Hypotension
• Cardiogenic Shock

Source

• Tintinalli
• Morchi, Undifferentiated Hypotension and Shock, All LA Conference, 05/06/2010