The Effect of Vasopressin on Gastric Perfusion in Catecholamine-Dependent Patients in Septic Shock

Abstract

Objectives: To study the effect of continuous infusion of vasopressin on the splanchnic circulation in patients with severe septic shock. Methods: Prospective clinical study. ICU in a teaching hospital. Eleven consecutive patients with documented septic shock who remained hypotensive despite norepinephrine infusion at a rate ≥0.2μ g/kg/min. Insertion of a gastric tonometry catheter, and continuous infusion of vasopressin 0.04 units/min during 4 hours. Results: Difference between gastric and arterial CO₂ partial pressure (P[g-a]CO₂ gap), mean arterial pressure, and cardiac index were recorded at baseline and after 15 minutes, 30 minutes, 60 minutes, 120 minutes, and 240 minutes. The median P[g-a]CO₂ gap increased from 5 mm Hg at baseline to 19 mm Hg after 4 hours (p = .022). Mean arterial pressure increased from 61 ± 13 mm Hg at baseline to 68 ± 9mm Hg after 4 hours (p = .055). No significant changes in cardiac index were noted. Conclusions: In norepinephrine-dependent patients in septic shock, continuous infusion of low-dose vasopressin results in a significant increase of the P[g-a]CO₂ gap compatible with gastrointestinal hypoperfusion.