2025 Southeastern Residency Conference

Title: Impact of Vasopressin Initiation Timing on Outcomes of Septic Shock Patients Receiving Norepinephrine at a Large Community Hospital

Authors: Trish Elder, Mickala Thompson
 
Background: The Surviving Sepsis Campaign Guidelines 2021 recommend use of norepinephrine (NE) as the first-line vasopressor for adult patients with septic shock. If the mean arterial pressure (MAP) cannot be maintained above 65 mmHg with a low to moderate dose of NE (0.25-0.5 mcg/kg/min), vasopressin is recommended second-line. Several research studies have been conducted in recent years to address the ambiguity surrounding the most appropriate timeframe for initiation of vasopressin. Some study findings include an increased time to shock resolution and decreased length of ICU stay with early initiation of vasopressin. The purpose of this study is to assess the effect of vasopressin initiation timing on outcomes of septic shock patients receiving NE at Huntsville Hospital.

Methods: A retrospective, institutional review committee exempt, chart review was conducted to evaluate all non-pregnant patients 18 years or older with active vasopressin and NE infusion orders and a diagnosis of septic shock, between August 1, 2023 and March 31, 2025. Patients were excluded if they received other vasopressors prior to vasopressin, they were located in the Cardiovascular ICU (CVICU), or their NE infusion rates could not be determined. Data was collected from the electronic health record (EHR) and analyzed using descriptive statistics. The primary endpoints were NE dose at time of vasopressin initiation and time from shock presentation to vasopressin initiation. The secondary endpoints included MAP 6 hours post vasopressin initiation, NE dose 6 hours after vasopressin initiation, time to shock resolution and ICU LOS.
 
Results: A total of 58 patients were included in the study: 52 in the “pre-intervention” (PRE) group and 6 in the “post-intervention” (POST) group. The baseline characteristics were similar between groups, apart from race. The number of patients initiated on vasopressin when the dose of NE was >0.5 mcg/kg/min was higher in the PRE group than the POST group with 69% and 17%, respectively. The median dose of NE at time of vasopressin initiation was 0.7 mcg/kg/min in the PRE group and 0.37 mcg/kg/min in the POST group. Due to the high mortality rate in this patient population, the secondary endpoints, time to shock resolution and ICU length of stay had 11 patients in the PRE group and 2 patients in the POST group. Due to the sample size, these outcomes could not be adequately assessed.
 
Conclusion: The implementation of a new order comment on all NE orders demonstrated a positive trend in the reduction of the NE dose when vasopressin was initiated. A larger sample size is needed to fully assess outcomes such as time to shock resolution and ICU length of stay in this patient population. Other limitations included the retrospective study design and limitations of EHR capabilities that led to a delay in intervention implementation.