Human Intraperitoneal Microdialysis: Increased Lactate/Pyruvate Ratio Suggests Early Visceral Ischaemia

Abstract
Previous studies suggest that visceral ischaemia precedes shock and multiple organ failure, though methods for studying humans are lacking. We aimed to evaluate intraperitoneal microdialysis, a new technique for detecting splanchnic ischaemia in clinical practice. Right-sided hemicolectomy was performed in eight patients who were studied by microdialysis postoperatively for glucose, lactate, pyruvate and glycerol levels. Six of the eight patients showed a normal postoperative course and had lactate/pyruvate ratios between 7.1 and 21.7, glucose between 4.5 and 14.3 mmol/L and glycerol between 10.4 and 296 micromol/L. In one patient, intraperitoneal lactate/pyruvate ratio and glycerol increased and glucose decreased 5 h before low oxygenation appeared. Another patient exhibited a period of increased lactate/pyruvate ratio before a period of atrial fibrillation. Intraperitoneal microdialysis was performed safely. Two out of the eight patients exhibited changes of metabolic markers followed by clinical symptoms that were probably related to transient visceral ischaemia. Our findings suggest that intraperitoneal microdialysis may become a useful tool for monitoring splanchnic ischaemia in clinical practice.