How do you manage a patient with hypotension?

Management of Hypotension

For patients with hypotension, initial fluid resuscitation with crystalloids (preferably balanced solutions) should be administered, followed by norepinephrine as the first-line vasopressor if fluid therapy is inadequate to maintain target blood pressure. 1

Initial Assessment and Diagnosis

When managing hypotension, it's crucial to:

1. Identify the cause of hypotension:

   • Hemorrhagic/hypovolemic shock
   • Septic shock
   • Cardiogenic shock
   • Anaphylactic shock
   • Neurogenic shock
   • Medication-induced hypotension
   • Endocrine causes (adrenal insufficiency)

2. Assess hemodynamic status:

   • Measure blood pressure (target MAP ≥65 mmHg for most adults)
   • Evaluate heart rate and rhythm
   • Assess tissue perfusion (capillary refill, urine output, mental status)
   • Use bedside echocardiography to evaluate cardiac function and volume status 1
   • Consider passive leg raise (PLR) test to determine fluid responsiveness 1, 2

Treatment Algorithm

Step 1: Fluid Resuscitation

• Initial fluid therapy: Administer 0.9% sodium chloride or balanced crystalloid solution 1

  • For adults: 10-20 mL/kg (maximum 1,000 mL) as an initial bolus 1
  • For children: 10-20 mL/kg bolus 1
  • Caution: Avoid hypotonic solutions like Ringer's lactate in patients with severe head trauma 1
  • Caution: Restrict colloid use due to adverse effects on hemostasis 1

• Assess fluid responsiveness:

  • Perform passive leg raise test to predict fluid responsiveness 1, 2
  • If cardiac output increases after PLR, patient is likely fluid responsive
  • If no improvement after initial fluid bolus, proceed to vasopressors 1

Step 2: Vasopressor Therapy

• First-line vasopressor: Norepinephrine 1

  • Dosing: 0.05-2 mcg/kg/min, titrated to achieve desired MAP 3
  • Target MAP of 65 mmHg in most patients 1

• Second-line vasopressor: Vasopressin can be added when increasing doses of norepinephrine are required 1

• For myocardial dysfunction: Add dobutamine for inotropic support 1

Step 3: Additional Interventions Based on Specific Causes

• Septic shock:

  • Administer appropriate antibiotics
  • Consider hydrocortisone (50 mg IV q6h or 200 mg infusion) for refractory shock requiring high-dose vasopressors 1

• Anaphylactic shock:

  • Administer epinephrine (50 μg IV for adults) 1
  • Give chlorphenamine 10 mg IV and hydrocortisone 200 mg IV 1

• Hemorrhagic shock:

  • Control bleeding source
  • Consider blood product transfusion
  • Use permissive hypotension (MAP 50-65 mmHg) until bleeding is controlled 1
  • Caution: Permissive hypotension is contraindicated in TBI and spinal injuries 1
  • Caution: Carefully evaluate implementing permissive hypotension in elderly patients 1

• Neurogenic shock:

  • Norepinephrine is recommended (lowest dose to guarantee tissue perfusion) 1
  • Monitor for cardiac arrhythmias

• Medication-induced hypotension:

  • For calcium channel blocker toxicity: Calcium chloride 20 mg/kg IV, vasopressors (norepinephrine or epinephrine) 1
  • For beta-blocker toxicity: High-dose epinephrine infusion, consider glucagon 1

Special Considerations

Elderly Patients

• Avoid routine use of vasopressors in elderly patients with hemorrhagic hypotension 1
• Carefully assess preexisting conditions and medication history before choosing vasopressors 1
• Monitor tissue perfusion with base excess, lactate levels, urine output, and neurologic assessment 1

Patients with Cirrhosis

• Use balanced crystalloids and/or albumin for fluid resuscitation 1
• Target MAP of 65 mmHg in cirrhotic patients with septic shock 1
• Consider screening for adrenal insufficiency in refractory shock 1

Postoperative Hypotension

• Only 54% of patients with suspected postoperative hypovolemia respond to fluid boluses 1
• Use PLR test to guide fluid administration decisions 1
• If PLR test does not correct hypotension, focus on vascular tone and chronotropy/inotropy 1

Common Pitfalls to Avoid

1. Overaggressive fluid resuscitation can lead to tissue edema, hypoxemia, and organ dysfunction
2. Delayed vasopressor initiation when fluid therapy is inadequate
3. Failure to identify and treat the underlying cause of hypotension
4. Inappropriate use of permissive hypotension in patients with TBI or elderly patients
5. Not considering endocrine causes such as adrenal insufficiency in refractory hypotension 4

By following this structured approach to hypotension management, focusing on appropriate fluid resuscitation followed by vasopressor therapy when needed, clinicians can effectively stabilize patients while addressing the underlying cause of hypotension.