Early identification of peritonitis by peritoneal cytokine measurement

The assessment of plasma cytokine levels adds a useful tool to the diagnostic measures in severe inflammatory diseases. Proinflammatory cytokine levels in abdominal fluid after abdominal surgery have been shown to far exceed plasma cytokine levels. Thus, we investigated the local release of interleukin 1beta, interleukin 6, and tumor necrosis factor-alpha in patients after colorectal surgery during the early postoperative period to evaluate whether it may serve as an indicator of evolving peritonitis.

In a prospective, observational pilot study, the first 12 consecutive patients who did not develop any postoperative complications (Group I), and the first 12 patients with secondary peritonitis caused by an anastomotic leakage (Group II), were included in the study. Interleukin 6, interleukin 1beta, and tumor necrosis factor-alpha levels were determined in the abdominal exudate and compared between the groups within the first four days after colorectal surgery.

Abdominal fluid interleukin 6 levels in Group II patients were higher (162,500 +/- 105,800 pg/ml) as early as the first postoperative day compared with Group I (27,940 +/- 13,860 pg/ml; P < 0.0001); this lasted for the whole observation period. The same applies to tumor necrosis factor-alpha levels (461.4 +/- 167.8 pg/ml vs. 175.8 +/- 178.6 pg/ml on day 1; P = 0.0007). The difference in interleukin 1beta cytokine levels became statistically significant on the third postoperative day. Moreover, abdominal fluid cytokine levels rose in Group II, whereas they remained virtually unchanged or even tended to decrease over time in Group I.

We suggest that the estimation of the peritoneal cytokine levels might be an additional diagnostic tool that can support the early recognition of peritonitic complications in colorectal surgery.