Einfluss von Dopexamin und Iloprost auf die Plasma-Disappearance-Rate von Indozyaningrün bei Patienten im septischen Schock
Objective: To evaluate the effects of the stable prostacyclin analogue iloprost on hepato-splanchnic blood flow, oxygen exchange and metabolism in patients with septic shock. Design: Prospective clinical study. Setting: Intensive care unit in a university clinic. Patients: Eleven patients with septic shock requiring norepinephrine to maintain mean arterial pressure above 70 mmHg. Interventions: Iloprost was incrementally infused to increase cardiac index by 15%. Measurements and main results: Splanchnic blood flow (Qspl) was measured using the steady-state indocyanine-green infusion technique and endogenous glucose production rate (EGP) using a stable isotope approach. Systemic and splanchnic oxygen consumption (VO2), the hepato-splanchnic uptake rates of the glucose precursors lactate, pyruvate, alanine and glutamine, the hepatic venous redox state and gastric mucosal-arterial PCO2 gradients were determined. After a baseline measurement, iloprost infusion was started. After 90 min all measurements were repeated and a third measurement was obtained after another 90 min following iloprost withdrawal. Qspl (baseline I: 0.82/0.75–1.08 l·min·m2; iloprost: 0.94/0.88–1.29 l·min·m2; baseline II: 0.87/0.74–1.09 l·min·m2) and splanchnic oxygen delivery (baseline I: 122/103–166 ml·min·m2; iloprost: 134/117–203 ml·min·m2; baseline II: 130/98–158 ml·min·m2) significantly increased. While systemic VO2 significantly increased (baseline I: 139/131–142 ml·min·m2; iloprost: 147/136–164 ml·min·m2; baseline II: 143/133–154 ml·min·m2) splanchnic VO2 increased in 9 of 11 patients which, however, did not reach statistical significance. EGP significantly decreased (baseline I: 23/16–26 µmol·kg·min; iloprost: 16/14–21 µmol·kg·min; baseline II: 18/12–20 µmol·kg·min), whereas all other parameters of energy metabolism remained unchanged. Conclusion: In patients with septic shock an iloprost-induced increase in cardiac index increased splanchnic blood flow and shifted oxygen utilization from the energy requiring de novo glucose production rate to other oxygen-demanding metabolic pathways.