Dobutamine and gastric-to-arterial carbon dioxide gap in severe sepsis without shock

. Objectives : To evaluate the effect of an early dobutamine infusion on gastrointestinal perfusion in patients with severe sepsis. Design : Prospective, randomized, controlled, multicenter clinical study. Setting : Six medical and/or surgical intensive care units (ICU) of teaching hospitals. Patients : Forty-two patients with severe sepsis. Interventions : Patients were divided into two groups according to gastric-to-arterial CO 2 gap (ΔCO 2 ) [normal ΔCO 2 group ( n =17): ΔCO 2 ≤8 mmHg; increased ΔCO 2 group ( n =25): ΔCO 2 >8 mmHg]. Patients within each group were then randomized to receive either dobutamine (5 µg/kg per min) or saline for 72 h. Measurements and main results : SAPS II was similar in both groups [group 1: 44.0 (33.0–56.5); group 2: 48.5 (40.5–59.0), p =0.27]. At ICU admission, mean arterial pressure was lower in the high ΔCO 2 group [73.0 (67.0–79.5) mmHg, p =0.03] than in the normal ΔCO 2 group [84.0 (73.7–104.0) mmHg] while blood lactate [normal ΔCO 2 group: 1.6 (0.8–2.3); high ΔCO 2 group: 1.6 (1.1–1.9) mmol/l] was similar for the two groups. ΔCO 2 was significantly lower in the normal ΔCO 2 group [5.0 (2.0–6.0) mmHg)] than in the high ΔCO 2 group [11.0 (10.0–19.0) mmHg]. Dobutamine infusion did not significantly change hemodynamics, blood lactate concentration or tonometric parameters in any group within the first 72 h and had no particular beneficial effect in this population. Conclusions : An early infusion of dobutamine at a fixed dose of 5 µg/kg per min during the first 72 h of severe sepsis does not influence gastric ΔCO 2 .