Intraperitoneal micro-organisms and the severity of peritonitis

To find out if there was any correlation between the type or number of pathogenic bacteria in peritoneal exudate, the values of various prognostic scores, the inflammatory response, and the outcome, in patients with peritonitis.

Prospective open study.

University hospital, Germany.

51 Consecutive patients with secondary peritonitis.

Laparotomy within 12 hours of admission or within 8 hours of diagnosis in 9 patients with postoperative peritonitis.

Correlation between the severity of the disease (APACHE II score, Septic Severity Score, Mannheim Peritonitis Index, Peritonitis Index Altona II, and outcome), the intraperitoneal and the systemic inflammatory response, intraperitoneal and systemic endotoxin concentrations, and type and number of micro-organisms grown from peritoneal fluid.

Intra-abdominal microbiological findings did not correlate with severity of illness judged by the scoring systems, the later incidence of infective complications, or the final outcome. The presence of intra-abdominal microbes was associated with signs of a systemic inflammatory response (median activation index 3 (range 1-3) compared with 2 (range 1-3)), the length of history (median 52 hours (range 3-72) compared with 16 hours (range 3-56), and local and systemic concentrations of endotoxin (peritoneal exudate: median 4800 EU/ml (range 0.06-136674) compared with 220 EU/ml (range 0.00-1800); plasma: median 0.05 EU/ml (range 0.00-1.32) compared with 0.04 EU/ml (range 0.00-0.13)). The sensitivity of the organisms to the antibiotics given (cefuroxime and metronidazole) did not influence the incidence of later infective complications or the outcome.

These results do not suggest micro-organisms invading the peritoneal cavity and respective antibiotic treatment to be major determinants of the clinical course of peritonitis.