Practice Variability in Vasopressin Use for Septic Shock: A Survey of the SCCM Discovery Members

Introduction: Septic shock remains a leading cause of mortality in critically ill patients, and vasopressors are crucial for hemodynamic support. Norepinephrine is traditionally the first-line agent, but the optimal timing and threshold for initiating adjunct vasopressin remain unclear. Prior studies such as VASST¹, VANISH², and recent reinforcement learning models³ (OVISS) suggest varying thresholds and outcomes for vasopressin initiation, highlighting significant practice variability and clinical uncertainty.


Methods: We sent a survey to members of the SCCM Discovery and Research Section Membership, with questions focused on institutional vasopressin use in septic shock, covering second-line use, weight-based versus fixed norepinephrine dosing, protocols, initiation thresholds, and maximum dosing. Responses were analyzed descriptively and compared with VASST, VANISH, and OVISS recommendations. Clinicians who showed interest would be invited to a follow-up survey for more detailed and in-depth questions that aim to quantify practice patterns and explore their rationales and barriers, further characterizing inter-institutional variation and informing guideline development.


Results: 137 respondents of the 16,747 members of SCCM (response rate 0.85%) completed the survey in its entirety. Among these respondents, 96% used vasopressin as a second-line agent; 73% used weight-based norepinephrine dosing; only about a fifth have formal vasopressin protocols. Most initiate vasopressin at 0.2 µg/kg/min (or 20 µg/min) of norepinephrine or equivalents; 13% start below 0.1 µg/kg/min, and 11% at ≥0.4 µg/kg/min. Fixed maximum dosing of 0.04 U/min is used by 62%, whereas 15% exceed this, and 10% remain at ≤0.03 U/min. About 7% of participants provided qualitative comments indicating a clinician-dependent approach to vasopressin initiation rather than protocol-driven decisions.


Conclusions: Despite widespread vasopressin use, significant variability exists in timing, dosing, and protocol adherence. This survey helped inform the development of the pragmatic Vaso-Shock trial that will investigate the use of varying thresholds of NE at vasopressin initiation in septic shock.