Objective: To study the effect of continuous infusion of vasopressin on the splanchnic circulation in patients with severe septic shock.
Design: Prospective clinical study.
Setting: ICU in a teaching hospital.
Patients: Eleven consecutive patients with documented septic shock who remained hypotensive despite norepinephrine infusion at a rate ≥ 0.2 μg/kg/min.
Interventions: Insertion of a gastric tonometry catheter, and continuous infusion of vasopressin 0.04 U/min during 4 h.
Measurements and main 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 min, 30 min, 60 min, 120 min, and 240 min.
Results: The median P(g-a)CO2 gap increased from 5 mm Hg at baseline to 19 mm Hg after 4 h (p = 0.022). Mean arterial pressure increased from 61 ± 13 mm Hg at baseline to 68 ± 9 mm Hg after 4 h (p = 0.055). 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 GI hypoperfusion.