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

Abstract

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.

Figures

FIGURE 1. Illustration of the microdialysis catheter. 1, Dialysis membrane. 2, Inlet tube for perfusion fluid. 3, Outlet tube for collecting dialysate. 4, Vial holder. 5, Luer-lock connection for perfusion fluid syringe. 6, Microvial.

FIGURE 2. Study groups. MOF, multiple organ failure.

FIGURE 3. Time course of intraperitoneal (upper panel) and subcutaneous (lower panel) lactate/pyruvate ratios in patients with (closed circles) and without (open circles) complications. Data are presented as mean and standard error of the mean; ANOVA was significant for difference between groups (P = 0.026) but not for time (P = 0.67). Presented P values on the graph after modified T test with Bonferroni correction. NS, not significant.

FIGURE 4. Evolution of individual intraperitoneal lactate/pyruvate ratios in group without complications (left, panel A) and group with complications (right, panel B).

FIGURE 5. Receiver operator characteristic curve for the intraperitoneal (A) and subcutaneous (B) lactate/pyruvate ratio at day 1. The best cutoff for intraperitoneal L/P ratio at day 1 is 22. AUC, area under the curve.