Vasopressin and Hypotension due to Sepsis

Gregory S. Martin, MD, MSc

June 08, 2005

Question

Can vasopressin be used as a first ionotropic agent in case of hypotension due to sepsis?

Response from Gregory S. Martin, MD, MSc

You raise an excellent question and one that remains an area of intense debate. Because septic shock is the prototypic form of distributive shock and involves tissue hypoperfusion, fluid resuscitation is the first and perhaps most important immediate intervention. In general, the traditional agent of first choice for hemodynamic support of patients with septic shock has been dopamine.[1] This has been questioned in recent years, with observational studies suggesting better outcomes for patients treated with norepinephrine, compared with dopamine or epinephrine.[2]

Patients with septic shock may be exquisitely sensitive to vasopressin administration, at least in part because of a relative state of insufficiency. Very low doses of vasopressin (from 0.01 to 0.05 units/min) have been shown to improve mean arterial pressure.[3] This hypersensitivity to vasopressin compares favorably to what is often perceived as a blunted vasopressor response to conventional vasopressor agents (ie, norepinephrine). Evidence-based recommendations for the use of vasopressin in septic shock cannot be made because of inadequate data from randomized, controlled trials. Uncontrolled and observational data demonstrate that the addition of vasopressin to standard vasopressor agents allows for dosage reduction of the other agents.[4,5] In addition, doses above 0.04 units/min did not consistently improve hemodynamics and may have contributed to a greater incidence of adverse events.[6] One of the few randomized, blinded trials demonstrated similar hemodynamic effects, including a reduction in other vasopressor requirements.[7]

Fortunately, a large, randomized, controlled trial is currently ongoing that will almost certainly provide important information to use as a basis for making these decisions. This trial, the Vasopressin and Septic Shock Trial (VASST), is planned for completion of patient enrollment in the next 12 months.

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