Vasopressin-Based Versus Norepinephrine-Based Strategy in Vasoplegic Syndrome After Cardiac Surgery: A Randomized Controlled Trial

Background Vasoplegic syndrome (VS) is a prevalent complication associated with cardiac surgery that is typically managed with norepinephrine (NE). We conducted a comparative analysis of clinical and physiological effects of vasopressin (VP)-based strategy versus an NE-based strategy as first-line management for VS following cardiopulmonary bypass (CPB). Methods This single-center, randomized controlled trial included 90 patients who underwent VS following CPB. Patients were randomized to a VP-based strategy (0.01-0.1U/min) or an NE-based strategy (0.01-0.1μg/kg/min), with standardized rescue NE allowed in both groups if hemodynamic targets were not met. The primary outcome was the length of hospital stay. Secondary outcomes included hemodynamic stability, lactate clearance, cardiac biomarkers, left ventricular ejection fraction (LVEF), and endocrine markers (copeptin and Arginine Vasopressin(AVP)). Results The VP-based strategy significantly reduced the length of hospital stays compared to NE-based (Median 7.0 days [IQR 6.0-8.0] vs Median 8.0 days [IQR 7.0-11.0]; Per-protocol p = .0036). Patients treated with VP achieved higher mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) at 12 and 24 h (P < .05). Furthermore, the VP-based group showed faster lactate normalization and a more pronounced reduction in cardiac biomarkers. Endocrine markers (copeptin and AVP) peaked significantly higher in the VP-based group but did not correlate with clinical outcomes (|r| < .15, p > .05). Adverse event rates were balanced between groups. Conclusion A VP-based strategy provided effective hemodynamic stabilization and is associated with shorter hospital stays compared to NE-based strategy in patients with VS following cardiac surgery. While NE continues to be effective, these findings suggest VP may be considered a viable early alternative or adjunctive vasopressor strategy for managing VS in the post-operative setting.