Prediction of postoperative complications after urgent laparotomy by intraperitoneal microdialysis: A pilot study.

Objective: The aim of the present study was to investigate the role of intraperitoneal microdialysis (IPM) techniques in monitoring the evolution of postoperative critically ill patients requiring urgent laparotomy.

Summary Background Data: Postoperative intraabdominal sepsis is associated with an important degree of morbidity and mortality in acutely ill patients. Early diagnosis is critical to improve outcomes.

Methods: : The study included 25 consecutive patients admitted to the intensive care unit (ICU) after urgent laparotomy. Measurements of microdialysate fluid were performed through a microdialysis catheter, positioned intraperitoneally, during the first 5 postoperative days and lactate/pyruvate (L/P) ratios calculated. Patients were followed until hospital discharge.

Results: Ten patients had a complicated postoperative course, including 4 deaths (3 refractory shock, 1 mesenteric ischemia), 3 reinterventions (1 necrotic collection, 1 mesenteric ischemia, 1 biliary leak), 2 secondary peritonitis, and 1 intraabdominal collection. The IPM L/P ratio in these patients was already significantly higher during the first 24 postoperative hours compared with patients who had no complications (35 +/- 21 vs. 18 +/- 6, P < 0.01). An IPM L/P ratio above 22 on postoperative day 1 had a sensitivity of 0.64 and a specificity of 0.79 for complications. There were no significant differences between the two groups in pH, lactate, white blood cell count, or subcutaneous L/P ratio. No complication was associated with the technique.

Conclusions: IPM is safe and reliable and provides valuable information after urgent laparotomy. Persistently high L/P values should raise the possibility of serious postoperative complications.