Procalcitonin ratio and on-demand relaparotomy for septic peritonitis: validation of the focus index (FI).

PURPOSE: Secondary peritonitis remains challenging to manage and some recent evidence suggests that on-demand relaparotomy is more appropriate than planned relaparotomy. This study was designed to validate the predictive power of postoperative procalcitonin (PCT) changes in relation to elimination of the septic abdominal focus. METHODS: In this prospective trial, postoperative PCT serum levels were monitored in 234 surgical patients with secondary peritonitis. The PCT ratio on postoperative days (PODs) 1 and 2 (focus index; FI) was calculated and correlated with the success of the operation. RESULTS: A cutoff value of 1.1 was calculated for the FI. Values below 1.1 indicated insufficient elimination of the focus and values above 1.1 correlated with effective treatment. The optimal time for first PCT sampling was found to be 12-24 h after the index operation. After the respective data cleanup, successful elimination of the intraabdominal focus could be confirmed, with a sensitivity of 93 % and a specificity of 71 %. CONCLUSIONS: The FI is a single parameter-based reliable predictor of successful surgical eradication and strengthens the on-demand relaparotomy concept as the method of choice to treat secondary peritonitis.

Combined immunosuppressive and antibiotic therapy improves bacterial clearance and survival of polymicrobial septic peritonitis.

Effective immunosuppressive therapy is essential to prevent transplant rejection but renders patients vulnerable to opportunistic infections. The present study investigates the effects of common immunosuppressive drugs on the course of septic peritonitis in an experimental mouse model. We show that treatment with a combination of tacrolimus, mycophenolate mofetil, and methylprednisolone resulted in highly elevated lethality of septic peritonitis. When immunosuppressive drugs were combined with antibiotic therapy, however, mice were almost completely protected. The combination of mycophenolate mofetil and methylprednisolone was shown to be required and sufficient to improve outcome of septic peritonitis in the presence of antibiotic therapy. Combined immunosuppressive and antibiotic therapy, but not antibiotic therapy alone, resulted in enhanced bacterial clearance. These beneficial effects were linked to an elevated expression of activation markers and an increased production of reactive oxygen metabolites by peritoneal neutrophils and correlated with a reduced messenger RNA expression of the inhibitory cytokine IL-22. In contrast, systemic or peritoneal levels of IL-10, IL-12, TNF-alpha, keratinocyte chemoattractant, and monocyte chemoattractant protein 1, and splenic messenger RNA levels of IFN-gamma were not influenced by the immunosuppressive therapy. These results therefore suggest that combined immunosuppressive and antibiotic therapy may improve bacterial clearance and survival of septic peritonitis by a mechanism that involves enhanced activation and antimicrobial activity of neutrophils and reduced production of IL-22.