Vasopressin Dosing for Septic Shock
For adults with septic (vasodilatory) shock, start vasopressin at 0.03 units/minute as a second-line agent added to norepinephrine, with a maximum dose of 0.03-0.04 units/minute for routine use. 1, 2
Initial Vasopressor Strategy
Norepinephrine is the mandatory first-line vasopressor for septic shock, targeting a mean arterial pressure (MAP) of 65 mmHg after administering at least 30 mL/kg crystalloid resuscitation. 1
Vasopressin should never be used as monotherapy—it must be added to norepinephrine, not used as the sole initial vasopressor. 1
When to Add Vasopressin
Add vasopressin when norepinephrine alone fails to maintain adequate MAP despite appropriate fluid resuscitation, or when you need to decrease norepinephrine dosage while maintaining hemodynamic stability. 1
The Society of Critical Care Medicine recommends adding vasopressin to raise MAP to target or to spare norepinephrine when maximum doses of initial vasopressor cannot achieve target MAP. 1
Specific Dosing Protocol
FDA-approved dosing for septic shock: 2
- Starting dose: 0.01 units/minute
- Dose range: 0.01-0.07 units/minute
- Standard dose when added to norepinephrine: 0.03 units/minute 1
- Maximum routine dose: 0.03-0.04 units/minute 1
Titration approach: 1
- Start at 0.01 units/minute
- Titrate up by 0.005 units/minute at 10-15 minute intervals
- Target MAP ≥65 mmHg
- Do not exceed 0.03-0.04 units/minute for routine use
Critical Dose Ceiling
Doses higher than 0.03-0.04 units/minute should be reserved for salvage therapy only (when other vasopressors have failed to achieve target MAP). 1
Vasopressin doses above 0.03-0.04 units/minute are associated with cardiac, digital, and splanchnic ischemia. 1
Administration Requirements
Dilute the 20 units/mL vial with normal saline or 5% dextrose to either 0.1 units/mL or 1 unit/mL for intravenous administration. 2
Discard unused diluted solution after 18 hours at room temperature or 24 hours under refrigeration. 2
Administer through central venous access with continuous arterial blood pressure monitoring via arterial catheter. 1
Escalation Strategy for Refractory Shock
If target MAP is not achieved with norepinephrine plus vasopressin at 0.03 units/minute: 1
Add epinephrine (0.05-2 mcg/kg/min) as a third vasopressor agent rather than increasing vasopressin beyond 0.03-0.04 units/minute
Consider dobutamine (up to 20 mcg/kg/min) if persistent hypoperfusion exists despite adequate MAP and vasopressor therapy, particularly when myocardial dysfunction is evident
Consider hydrocortisone 200 mg/day for refractory shock when hemodynamic stability cannot be achieved despite adequate fluid resuscitation and vasopressor therapy 3
Common Pitfalls to Avoid
Do not titrate vasopressin like a traditional vasopressor—use the fixed dose of 0.03 units/minute rather than continuously escalating. 1
Do not delay norepinephrine initiation—vasopressin is always a second-line agent, never first-line. 1
Do not exceed 0.04 units/minute except in salvage situations, as higher doses significantly increase risk of ischemic complications. 1
Monitor for ischemic complications: decreased cardiac output, bradycardia, coronary/mesenteric/digital ischemia, and skin necrosis. 2