Peritoneal fluid culture and antibiotic treatment in patients with perforated appendicitis in a Pacific Island

Little data on the usefulness of microbiological samples in appendicular peritonitis (AP) are available. The objectives of the study were to document the clinical value of systematic peritoneal swabbing in complicated appendicitis, to establish whether they influence postoperative outcome, and to help to optimize empirical preoperative treatment. Charts of all consecutive patients undergoing appendicectomy for acute perforated appendicitis were analyzed over a 7-year period from 2005 to 2011 in a tertiary hospital in New Caledonia. From prospectively recorded data, microbiological culture results, and sensitivity of isolates were obtained in relation to histopathological findings and infective morbidity. Overall, 144 cases including 47 (33%) children and 97 (67%) adults with perforated appendicitis were included in the study. Fifty-one (35%) had generalized peritonitis treated laparoscopically in 30 (59%) cases. Peritoneal fluid samples yielded a positive culture in 104 (74%) patients. The most commonly recovered species were Escherichia coli (81%), Streptococcus milleri group (12%), and Pseudomonas aeruginosa (12%). Postoperative infectious complications occurred in 32 (22%) including intra-abdominal abscess (n = 20) and wound infection (n = 12). Probabilist antibiotic regimen was less often suitable in children than in adults (p = 0.003). Infectious complications occurred more often in cases with an unsuitable antibiotic regimen after culture results compared with a suitable antibiotic regimen before culture results (p = 0.01). Although antibiotic use may be considered as an adjunct to surgical intervention of AP, the appropriate use of preoperative antibiotics and modifications according to culture results are essential to prevent infectious complications