What is the initial step in managing a patient with hypotension?

Initial Management of Hypotension

The initial step in managing a patient with hypotension should be a rapid assessment of hemodynamic status followed by immediate intravenous fluid resuscitation with crystalloids (10-20 mL/kg; maximum 1,000 mL) while simultaneously determining the underlying cause. 1

Assessment of Hypotension

Hypotension is defined as:

• Systolic blood pressure <90 mmHg or
• Mean arterial pressure (MAP) <70 mmHg 1

Immediate Bedside Assessment

1. Vital signs monitoring:

   • Blood pressure (including orthostatic measurements)
   • Heart rate and rhythm
   • Respiratory rate
   • Oxygen saturation
   • Temperature

2. Clinical signs of end-organ hypoperfusion:

   • Altered mental status
   • Decreased urine output
   • Cool extremities
   • Delayed capillary refill
   • Mottled skin

3. Point-of-care ultrasound (when available):

   • Assess cardiac function and volume status
   • Identify shock type (hypovolemic, cardiogenic, distributive, obstructive) 1

Management Algorithm

Step 1: Initial Fluid Resuscitation

• Administer crystalloid fluid bolus (10-20 mL/kg; maximum 1,000 mL) 1
• Normal saline or balanced crystalloid solution
• Reassess response after initial bolus

Step 2: Assess Response to Fluid

• Fluid responsive: Continue fluid resuscitation with additional boluses (250-500 mL over 30-60 minutes) 1
• Fluid non-responsive: Proceed to vasopressor therapy

Step 3: Vasopressor Therapy (if hypotension persists despite adequate fluid resuscitation)

• First-line: Norepinephrine infusion 1, 2

  • Dilute in 5% dextrose solution (4 mg in 1,000 mL)
  • Initial rate: 2-3 mL/min (8-12 mcg/min)
  • Titrate to maintain MAP ≥65 mmHg
  • Average maintenance dose: 0.5-1 mL/min (2-4 mcg/min) 2
  • Administer through a central line when possible

• Second-line options:

  • Vasopressin (up to 0.03 UI/min) if hypotension persists
  • Epinephrine (0.05-2 mcg/kg/min) for septic shock with myocardial depression 1

Specific Considerations Based on Etiology

Hypovolemic Shock

• Aggressive fluid resuscitation
• Blood products for hemorrhagic shock
• Identify and control source of fluid loss

Cardiogenic Shock

• Limited fluid resuscitation
• Consider inotropic support (dobutamine)
• Address underlying cardiac cause

Distributive Shock (sepsis, anaphylaxis)

• Fluid resuscitation followed by vasopressors
• Source control for sepsis
• Epinephrine for anaphylaxis

Obstructive Shock

• Identify and treat cause (tension pneumothorax, cardiac tamponade, pulmonary embolism)
• Minimal fluids until obstruction relieved

Monitoring and Titration

• Target MAP ≥65 mmHg 1
• Monitor additional perfusion markers:
  • Lactate clearance
  • Urine output
  • Mental status
  • Central or mixed venous oxygen saturation

Common Pitfalls to Avoid

1. Assuming all hypotension is due to hypovolemia 1
2. Delaying vasopressors in patients with life-threatening hypotension 1
3. Administering vasopressors without adequate fluid resuscitation 1
4. Focusing solely on blood pressure numbers rather than signs of end-organ perfusion 1
5. Failing to identify and address the underlying cause of hypotension 3

Remember that the severity and duration of hypotension correlate with adverse outcomes, with sustained hypotension (all ED systolic BP <100 mmHg for ≥60 min) being the strongest independent predictor of poor hospital outcomes 4. Therefore, prompt recognition and management are essential to prevent end-organ damage and mortality.