In septic shock, physiologic stores of vasopressin maybe depleted due to prolonged vasopressin release and serum levels may therefore be inappropriately low.1 Studies have shown that the addition of vasopressin in low doses increases mean arterial pressure (MAP) and decreases the requirements of other vasoactive agents.2,3,4 However, it remains unclear whether we can use vasopressin alone for initial resuscitation in septic shock.
The updated Surviving Sepsis campaign guidelines, released earlier this year, recommend norepinephrine as the initial vasopressor of choice to target a MAP greater than or equal to 65 mm Hg. Vasopressin is only recommended as an adjuvant treatment to norepinephrine and not it's not recommended that it be used alone.5
In the March issue of the Annals of Pharmacotherapy journal, a retrospective cohort study evaluated adults who received monotherapy with either norepinephrine or vasopressin as initial vasopressor for the management of septic shock. Patients were mainly excluded if the treatment arm was not monotherapy or if they were admitted to a cardiology or cardiothoracic surgery service.6
A total of 130 patients were included, 65 in each treatment arm. The proportion of patients who achieved a goal MAP in the vasopressin group and norepinephrine group was 63% (95% CI 51%-75%) and 67.7% (95% CI 56%-79%), respectively. The observed difference between the two groups in terms of goal MAP did not exceed the predefined noninferiority margin of -25% suggesting that vasopressin is non-inferior to norepinephrine for initial resuscitation.
It is important to note however that this is a retrospective study which makes it difficult to assess the influence of comorbidities and acute concurrent illness on the attained MAP. In addition, critical care practitioners should keep in mind that vasopressin secretion exhibits a biphasic response in septic shock and relative deficiency does not occur until 36 hours after the onset of septic shock. Therefore, when using vasopressin, progression or improvement of septic shock should always be a consideration.
1. Holmes CL, Patel BM, Russell JA, et al. Physiology of vasopressin relevant to management of septic shock. Chest 2001;120:989-1002.
2. Obritsch MD, Jung R, Fish DN, et al. Effects of continuous vasopressin infusion in patients with septic shock. Ann Pharmacother 2004;38:1117-22.
3. Dunser MW, Mayr AJ, Ulmer H, et al. The effects of vasopressin on systemic hemodynamics in catecholamine resistant septic and postcardiotomy shock: a retrospective analysis. Anesth Analg 2001;93:7-13.
4. Lauzier F, Levy B, Lamarre P, et al. Vasopressin or norepinephrine in early hyperdynamic septic shock. Intensive Care Med 2006;32:1782-9.
5. Dellinger RP, Levy M, Rhodes A, et al. Surviving Sepsis Campaign: International Guidelines for Management of Severe Sepsis and Septic Shock: 2012. Crit Care Med 2013;41:580–637.
6. Daley M, Lat I, Mieure K, et al. A comparison of initial monotherapy with norepinephrine ...