What is the recommended starting dose of vasopressin (Vasopressin) infusion for patients in the Intensive Care Unit (ICU)?

Vasopressin Infusion Dosing in ICU

The recommended starting dose of vasopressin infusion in the ICU is 0.01 units/minute for septic shock and 0.03 units/minute for post-cardiotomy shock, with titration up by 0.005 units/minute at 10-15 minute intervals until target blood pressure is reached. 1

Preparation and Administration

• Vasopressin must be diluted in normal saline (0.9% sodium chloride) or 5% dextrose in water (D5W) prior to intravenous administration
• Unused diluted solution should be discarded after 18 hours at room temperature or 24 hours under refrigeration 1
• Titrate to the lowest dose compatible with a clinically acceptable response

Dosing Guidelines by Shock Type

Septic Shock

• Starting dose: 0.01 units/minute
• Titration: Increase by 0.005 units/minute every 10-15 minutes
• Maximum dose: 0.07 units/minute (limited data for doses above this threshold) 1

Post-Cardiotomy Shock

• Starting dose: 0.03 units/minute
• Titration: Increase by 0.005 units/minute every 10-15 minutes
• Maximum dose: 0.1 units/minute (limited data for doses above this threshold) 1

Monitoring and Weaning

• After target blood pressure has been maintained for 8 hours without catecholamines, taper vasopressin by 0.005 units/minute every hour as tolerated 1
• Monitor continuously: blood pressure, heart rate, urine output, skin perfusion, mental status
• Regular assessment of lactate clearance and renal/liver function tests 2
• Target mean arterial pressure (MAP) ≥ 65 mmHg 2

Vasopressin in Vasopressor Algorithm

1. Start with norepinephrine as first-line vasopressor (0.05-0.1 μg/kg/min) 2
2. Add vasopressin (up to 0.03 U/min) when norepinephrine alone doesn't maintain target MAP 2
3. Consider epinephrine (0.1-1.0 mcg/kg/min) if norepinephrine and vasopressin together don't maintain target MAP 2

Safety Considerations and Adverse Effects

• Doses higher than 0.04 U/min have not shown increased effectiveness and may be associated with higher adverse effects 3
• Potential adverse effects include:
  • Decreased cardiac output
  • Bradycardia
  • Tachyarrhythmias
  • Hyponatremia
  • Ischemia (coronary, mesenteric, skin, digital) 1
• Cardiac arrests have been reported at vasopressin doses of 0.05 U/min or higher 3

Clinical Pearls

• Vasopressin is particularly effective in vasodilatory shock states where there may be relative vasopressin deficiency 4
• Low-dose vasopressin (0.01-0.04 U/min) can decrease catecholamine requirements in patients with septic shock 4
• Vasopressin infusion has been shown to increase mean arterial pressure and urine output while decreasing catecholamine requirements 3
• Always ensure adequate fluid resuscitation before initiating vasopressors 2

Common Pitfalls

• Using doses above 0.04 U/min, which may increase risk of adverse effects without improving efficacy 3
• Failing to dilute vasopressin properly before administration
• Not monitoring for signs of tissue ischemia, which can occur with vasopressin therapy
• Titrating vasopressin like other vasopressors rather than using it as a fixed-dose adjunct to catecholamines

Remember that vasopressin should be used as part of a comprehensive approach to shock management that includes appropriate fluid resuscitation and addressing the underlying cause of shock.