Exploring vasopressin use in septic shock: a retrospective cohort study from Türkiye (VASCO-TURK)

Vasopressin is a peptide hormone and often added to reduce catecholamine dose and side effects according to recent guidelines. Despite increasing global interest in vasopressin use in septic shock, real-world data from low- to middle-income countries, including Türkiye, remain scarce.

This study was conducted as a single-center, retrospective, observational study in a tertiary intensive care unit, with the diagnosis of septic shock according to Surviving Sepsis Campaign guidelines and who received norepinephrine alone and both norepinephrine with vasopressin as an adjunctive vasopressor.

A total of 146 septic shock patients were included in the study, with 113 (77.4%) in the norepinephrine group and 33 (22.6%) in the patients receiving adjunctive vasopressin therapy. Overall survival: 24.2% in adjunctive vasopressin group vs. 24.8% in norepinephrine group (p = 1.000). Median norepinephrine dose decreased significantly from 0.55 mcg/kg/min (IQR: 0.44-0.84) at baseline to 0.43 mcg/kg/min (IQR: 0.27-0.72) by the 6th hour (p = 0.010), supporting a vasopressor-sparing effect of vasopressin. Adjunctive vasopressin initiation time was 14 h (IQR 5-25 h), and the initial norepinephrine dose at the time of vasopressin introduction was, 0.56 mcg/kg/min (IQR 0.445-0.880). Mean arterial pressure (MAP), improved from 60 mmHg (IQR: 54-66) at hour 0 to 70 mmHg (IQR: 63.08-75.75) at hour 2 and 74 mmHg (IQR: 61.75-83.5) at hour 6 (p < 0.001). Heart rate initially remained stable between baseline and the 2nd hour (110 vs. 110 bpm), but decreased significantly by the 6th hour to a median of 97.5 bpm (IQR: 88.75-120.5; p = 0.003).

This single center study, with a limited number of patients, is valuable as it reflects the first national experience with vasopressin. In this study, no difference in mortality was observed between patients receiving norepinephrine alone and those receiving vasopressin in combination with norepinephrine. Vasopressin demonstrated a significant norepinephrine-sparing effect, improved heart rate control, and increased mean arterial pressure, suggesting potential hemodynamic stabilization.

The study is registered at ClinicalTrials.gov (NCT06953297). Public release date: April 23, 2025.