When should I start vasopressors in septic shock?

Vasopressor Initiation in Septic Shock

Vasopressors should be initiated early in septic shock after initial fluid resuscitation of 30 mL/kg crystalloid if mean arterial pressure (MAP) remains below 65 mmHg, without waiting for completion of full fluid resuscitation. 1, 2, 3

Initial Assessment and Fluid Resuscitation

• Begin with crystalloid fluid resuscitation (30 mL/kg) as recommended by the Surviving Sepsis Campaign 1
• Assess for persistent hypotension despite this initial fluid challenge
• Target MAP: ≥65 mmHg for most patients 1, 2
  • Consider higher targets (75-85 mmHg) for patients with chronic hypertension 2

Vasopressor Initiation Algorithm

1. Timing: Start vasopressors early if MAP <65 mmHg persists after initial fluid bolus

   • Do not delay vasopressor treatment until fluid resuscitation is completed 3
   • Early administration (preferably within first hour of diagnosis) may lead to lower morbidity and mortality 3

2. First-line agent: Norepinephrine is the first-choice vasopressor 1, 2

   • Initial dose: 0.05-0.1 μg/kg/min (approximately 3.5-7 μg/min for a 70kg adult) 2
   • Titrate by 0.05-0.1 μg/kg/min every 5-15 minutes until target MAP is reached 2

3. Adjunctive vasopressors (if needed):

   • Vasopressin (up to 0.03 U/min) can be added to either:
     • Raise MAP to target
     • Decrease norepinephrine dosage 1, 4
   • For septic shock, start vasopressin at 0.01 units/minute and titrate up by 0.005 units/minute at 10-15 minute intervals 4
   • Epinephrine may be considered as an alternative second agent 1

Monitoring and Ongoing Assessment

• Continuous arterial blood pressure monitoring is recommended 2
• Assess tissue perfusion markers:
  • Lactate levels
  • Skin perfusion
  • Mental status
  • Urine output 2

Important Considerations

• Fluid status: Ensure adequate volume status before or during vasopressor therapy 2

  • Inadequate fluid resuscitation should be avoided
  • Continue fluid challenges as long as hemodynamic improvement occurs 1

• Central venous access: Administer norepinephrine through a central line when possible to minimize extravasation risk 2

• Weaning strategy: After target blood pressure has been maintained for 8 hours without catecholamines, taper vasopressin by 0.005 units/minute every hour as tolerated 4

Pitfalls to Avoid

• Delayed initiation: Waiting too long to start vasopressors can prolong hypoperfusion and increase mortality 3

• Overreliance on fluids: Complications of fluid over-resuscitation can delay organ recovery, prolong ICU stay, and increase mortality 3

• Using dopamine: Avoid dopamine except in highly selected patients with low risk of tachyarrhythmias 1

• Ignoring chronic conditions: Failing to adjust MAP targets for patients with chronic hypertension 2

• Neglecting monitoring: Not assessing for end-organ perfusion at high vasopressor doses 2