Norepinephrine Tapering and Vasopressin Initiation Protocol
When to Start Vasopressin
Add vasopressin at 0.03 units/minute when norepinephrine requirements remain elevated or when you need to decrease norepinephrine dosage to achieve a MAP target of 65 mmHg. 1, 2
Timing Considerations
Early addition (within 3 hours of norepinephrine initiation) is associated with faster shock resolution (37.6 hours vs 60.7 hours) and shorter ICU length of stay (4.3 vs 5.3 days) compared to late addition. 3
Start vasopressin when norepinephrine alone fails to maintain adequate MAP despite appropriate fluid resuscitation (at least 30 mL/kg IV crystalloid). 1, 4
Never use vasopressin as the sole initial vasopressor—it must be added to norepinephrine, not used as monotherapy. 1, 2, 4
Dosing Protocol
Standard dose: 0.03 units/minute (fixed rate, not titrated). 1, 2
Acceptable range: 0.01-0.03 units/minute for standard therapy. 2, 4
Doses exceeding 0.03-0.04 units/minute should be reserved only for salvage therapy when other vasopressors have failed to achieve target MAP. 1, 2
Norepinephrine Tapering Protocol
General Principles
Titrate norepinephrine to maintain MAP ≥65 mmHg with continuous arterial blood pressure monitoring. 1, 2, 4
Once vasopressin is added, you can either raise MAP to target OR decrease norepinephrine dosage while maintaining hemodynamic stability. 1, 2
Weaning Strategy
Begin tapering when hemodynamic stability is achieved (sustained MAP ≥65 mmHg, adequate tissue perfusion markers including lactate clearance, urine output, mental status, and skin perfusion). 4
The vasopressin trial showed no mortality difference between vasopressin and norepinephrine groups (35.4% vs 39.3% at 28 days), but vasopressin reduced renal replacement therapy requirements (25.4% vs 35.3%). 5, 6
Gradual dose reduction is preferred over abrupt discontinuation, though specific tapering increments are not defined in guidelines. 1
Alternative Considerations
If norepinephrine requirements remain high despite vasopressin addition, consider adding epinephrine as a third agent rather than increasing vasopressin beyond 0.03-0.04 units/minute. 1, 4
For patients with persistent hypoperfusion despite adequate vasopressor support, add dobutamine (up to 20 μg/kg/min) rather than escalating vasopressors further. 1, 4
Critical Monitoring Requirements
Arterial catheter placement is recommended for all patients requiring vasopressors as soon as practical. 1, 2, 4
Central venous access is required for norepinephrine administration, though peripheral administration may be considered for low doses (<0.1 μg/kg/min) for less than 24 hours in select cases. 7
Monitor for serious adverse events, which occur at similar rates with vasopressin (10.7%) and norepinephrine (8.3%). 6
Common Pitfalls to Avoid
Do not use dopamine for renal protection—this is strongly discouraged and has no benefit. 1, 2, 4
Avoid using dopamine as first-line therapy; it is associated with higher mortality and more arrhythmias compared to norepinephrine, and should only be used in highly selected patients with bradycardia or low tachyarrhythmia risk. 1, 4
Do not delay vasopressin addition excessively—earlier addition (within 3 hours) appears more beneficial than late addition. 3
Phenylephrine should not be used except in specific circumstances (norepinephrine-induced arrhythmias, high cardiac output with persistent hypotension, or salvage therapy). 1, 4