What is the best approach to manage hypotension?

Management of Hypotension

The optimal approach to manage hypotension requires first determining the underlying cause through bedside assessment, then implementing targeted interventions starting with fluid resuscitation for hypovolemia, followed by vasopressors if fluid-refractory, with a goal of maintaining mean arterial pressure (MAP) ≥65 mmHg. 1, 2

Initial Assessment and Classification

• Define hypotension: Systolic BP <90 mmHg or MAP <70 mmHg 2
• Perform structured bedside assessment to:
  • Determine etiology
  • Select appropriate treatment
  • Consider need for higher level monitoring 1
• Assess for end-organ dysfunction (altered mental status, decreased urine output, lactic acidosis)
• Use passive leg raise (PLR) test to predict fluid responsiveness (92% specificity) 1

Treatment Algorithm

Step 1: Determine Fluid Responsiveness

• Perform PLR test: If cardiac output/blood pressure increases, patient is likely fluid responsive 1
• If fluid responsive (positive PLR):
  • Administer crystalloid fluid bolus (250-500 mL over 30-60 minutes) 1
  • Reassess after 30 minutes; repeat bolus if needed
  • Maximum initial resuscitation: 10-20 mL/kg (not exceeding 1,000 mL) 2

Step 2: For Fluid-Refractory Hypotension

• If hypotension persists despite adequate fluid resuscitation:
  • Initiate vasopressor therapy 1, 2
  • First-line: Norepinephrine 2
  • For septic shock: Epinephrine 0.05-2 mcg/kg/min IV, titrated to desired MAP 3
  • Consider transfer to higher level of care 1

Step 3: Targeted Therapy Based on Hemodynamic Pattern

• Distributive shock (sepsis, anaphylaxis):

  • Norepinephrine as first-line vasopressor after fluid resuscitation 2
  • Consider vasopressin (up to 0.03 UI/min) as second-line 2

• Cardiogenic shock:

  • For myocardial depression: Dobutamine, dopamine, or phosphodiesterase III inhibitors 2
  • For persistent hypotension with tachycardia: Add norepinephrine 2
  • For bradycardia: Consider dopamine (2.5-5.0 μg/kg/min) 2

• Hypovolemic shock:

  • Aggressive fluid resuscitation
  • Blood products if hemorrhagic 1

Monitoring and Targets

• Target MAP ≥65 mmHg in most patients 2
• Monitor additional perfusion markers:
  • Lactate clearance
  • Mixed or central venous oxygen saturations
  • Urine output
  • Mental status 2
• Consider arterial line for precise titration of vasoactive drugs 2

Special Considerations

Postoperative Hypotension

• Only 54% of postoperative patients with suspected hypovolemia respond to fluid bolus 1
• If PLR test negative, focus on vascular tone and chronotropy/inotropy 1

Septic Shock

• Administer epinephrine 0.05-2 mcg/kg/min IV, titrated to achieve desired MAP 3
• After hemodynamic stabilization, wean incrementally over 12-24 hours 3

Intra-abdominal Infections

• Avoid fluid overload in patients with generalized peritonitis 1
• Excessive fluids may aggravate gut edema and increase intra-abdominal pressure 1

Immunotherapy-Related Hypotension

• For grade 2 CRS (hypotension not requiring vasopressors):
  • Administer tocilizumab 8 mg/kg IV (not exceeding 800 mg)
  • Consider dexamethasone for persistent hypotension 1
• For grade 3-4 CRS (requiring vasopressors):
  • Transfer to ICU
  • Administer dexamethasone 10 mg IV every 6 hours 1

Common Pitfalls to Avoid

• Assuming all hypotension is due to hypovolemia 2
• Focusing on BP numbers rather than symptoms and end-organ perfusion 2
• Delaying vasopressors in patients with life-threatening hypotension 2
• Administering vasopressors without adequate fluid resuscitation 2
• Failure to discontinue contributing medications 2

By following this structured approach to hypotension management, clinicians can effectively identify the underlying cause and implement appropriate interventions to improve patient outcomes.