Vasopressin (ICU)

How it works

Acting on vascular V1 receptors it causes potent vasoconstriction through a catecholamine-independent pathway, raising systemic vascular resistance and mean arterial pressure.

Prescribing in practice

• Its intense vasoconstriction can provoke cardiac, mesenteric, and peripheral/digital ischaemia, so it is titrated carefully and delivered via central access with continuous monitoring.
• It is generally used as a fixed-rate adjunct to noradrenaline rather than titrated alone as a first-line vasopressor.
• Caution is needed in coronary artery disease and where splanchnic or peripheral perfusion is already compromised.

Monitoring

Monitor mean arterial pressure, peripheral and digital perfusion, urine output, and for signs of mesenteric or cardiac ischaemia during the infusion.

Counselling the patient

• Explain to the team that vasopressin is an adjunct to catecholamine vasopressors and given by central line.
• Highlight the need to watch extremities and mesenteric perfusion for ischaemia.
• Note that it should not be abruptly stopped without considering the effect on blood pressure.

Evidence & guidelines

The VASST trial informs the use of vasopressin as an adjunct to noradrenaline in septic shock, and it features in international Surviving Sepsis Campaign recommendations.