(1504) Vasopressin Dose Escalation in Critically Ill Patients With Septic Shock

Introduction: Vasopressor support is a critical intervention in septic shock. Norepinephrine (NE) is the preferred first-line vasopressor. Vasopressin (AVP), is recommended as an adjunct to NE at a fixed dose of 0.03 units/min when mean arterial pressure is < 65 mmHg. Limited data exits to support higher doses, or titration of AVP, as the package insert recommends. Our institution recently allowed titration of AVP to a max of 0.06 units/min. The goal of this study was to assess the impact of AVP titration on shock.

Methods: This is a retrospective study of adult patients with septic shock, admitted to three hospitals within a large academic center. Patients were divided into two groups: fixed-dose of AVP (F-AVP) and titrated AVP > 0.03 units/min (T-AVP). The primary outcome was NE duration, dose at hour 6 after AVP, and total dose. Secondary outcomes included ventilator and ICU-free days, acute kidney injury, and incidence of new arrhythmias.

Results: A total of 130 patients were included; F-AVP (n=76) and T-AVP (n=54). Average age was 64±14 years, 58% were men, and 66% African American. Patients in the T-AVP group had higher SOFA (13±3 vs. 11±4, p=0.013) and APACHE-II Scores (30±8 vs. 26±7, p=0.005). NE dose at the time of AVP initiation was 0.64 and 0.79 mcg/kg/min in the F-AVP and T-AVP groups respectively, p=0.06. The max dose of NE was significantly higher in the T-AVP group (1.6 vs 1.2 mcg/kg/min, p=0.013. Total NE (mg) was higher in the F-AVP group (170±190 vs. 129±148, p< 0.001), and duration was longer (5.8±6 vs. 4.5±7 days, p=0.11). No difference was seen in percent of patients in the F-AVP and T-AVP groups with a positive response at hour 6 after AVP, 54% vs. 60% respectively, p=0.84. No difference was seen in ICU or ventilator-free days at day 28. ICU mortality was significantly higher in the T-AVP group (83% vs 60%, p< 0.01).

Conclusions: Patients who received T-AVP required higher NE doses and had higher mortality than patients who received F-AVP. Very few patients had AVP started at doses of ≤ 0.25 mcg/kg/min, as per current guideline recommendations and titration was often done late. Patients in our study who received T-AVP had more severe septic shock at baseline. Future goals will focus on education to implement titration earlier to potentially prevent arrhythmias and improve outcomes.