Effect of Vasopressin Dose on Hemodynamic Response in Obese Patients With Septic Shock: A Retrospective Observational Study

Background No clear association between standard vasopressin doses and body mass index exists, despite potential pharmacokinetic and pharmacodynamic variability among patients with septic shock. It is unknown if higher doses may alter hemodynamic response. Objective The purpose of this study was to evaluate the effect of vasopressin dose on hemodynamic response in obese patients with septic shock. Methods A single-center, retrospective cohort study was conducted in adult, obese patients with septic shock receiving catecholamine vasopressors and vasopressin. Patients were analyzed according to vasopressin dose received: standard dose (≤0.04 U/min) and high dose (>0.04 U/min). The primary outcome was percentage change in norepinephrine equivalent (NEQ) dose. Results A total of 182 patients were included in the analysis, with 136 in the standard-dose vasopressin group and 46 in the high-dose vasopressin group. There was no difference in percentage change in NEQ dose at 6 hours after standard- or high-dose vasopressin attainment (−28.6% vs −19.1%; P = 0.166). A greater increase in mean arterial pressure (MAP) at 6 hours was observed with receipt of high-dose vasopressin (23.3% vs 15.3%; P = 0.023). Duration of shock and length of stay were significantly longer in patients who received high-dose vasopressin, with no difference in in-hospital mortality. Conclusion and Relevance This represents the first analysis comparing standard and higher doses of vasopressin in obese patients with septic shock. Receipt of high-dose vasopressin was not associated with a difference in catecholamine requirement or improved outcomes. Further studies are warranted to provide guidance on the use of high-dose vasopressin in septic shock.