Because polymicrobial peritonitis is believed to be caused by bowel perforation in peritoneal dialysis patients, surgical exploration is often recommended. However, there is recent evidence that antibiotic therapy may be a safe alternative.

We studied 140 consecutive episodes of dialysis-related polymicrobial peritonitis from January 1995 to June 2001. All episodes were treated primarily with intraperitoneal antibiotics. When there was no response, the Tenckhoff catheter was removed, usually after about 10 days of treatment. Laparotomy was performed only when there was clinical suspicion of surgical pathology.

Ninety patient-episodes (64%) responded to antibiotics alone by day 10; 56 patients (40%) had complete cure with no relapse in 4 months. Nine patients (6%) died within 2 days. Laparotomy was performed in 8 patients who did not respond by day 10, but only 3 had underlying surgical disease (strangulated hernia, ischemic colitis, and colonic cancer). In a multivariate logistic regression analysis, age and the presence of fungus, anaerobes, or Pseudomonas species in the dialysis fluid were independent predictors of poor primary response; and presence of fungus was the only independent predictor of failure to cure in 4 months.

Most patients with dialysis-related polymicrobial peritonitis responded to antibiotic therapy, and surgical exploration was needed only in a few patients. A careful examination of isolated organisms may help in identifying patients who need Tenckhoff catheter removal or surgical intervention.