Peritonitis into the 1990s: changing pathogens and changing strategies in the critically ill.

To study the effect of severe illness on the nature of peritonitis and intra-abdominal abscesses, the microbiology and clinical course of patients operated on over a 1-year period with culture-proven intra-abdominal infections whose preoperative Acute Physiology and Chronic Health Evaluation (APACHE) II scores were greater than or equal to 15 (predicted mortality at least 50%) were examined. Twenty-nine patients were enrolled, and overall mortality was 52 per cent, with increasing mortality correlating with higher APACHE II scores. The organism most commonly isolated from the peritoneum was Candida albicans, followed by Enterococcus species, Enterobacter species, and Staphylococcus epidermidis. An increase in the mean of the APACHE II scores on Days 3 and 7 compared to the preoperative score was associated with a 91 per cent mortality, while a decrease was associated with only a 22 per cent mortality. The authors conclude that the microbiology of intra-abdominal infections is inherently different in severely ill patients and that longitudinal clinical scoring may be more useful than a single scoring in predicting outcome. These data suggest that trials to investigate the broadening of standard perioperative antimicrobial coverage in the ill and use of longitudinal clinical scoring to direct aggressive reintervention may be warranted.