Peritoneal fluid culture in appendicitis: review in changing times

Appendicectomy is one of the commoner operations with a lifetime risk as high as 12% or 23% in males or females, respectively. Since the 1940s intra-operative intra-peritoneal swabs have commonly been taken from the appendix site, the spectrum of infecting organisms and their antibiotic sensitivity may be gauged from the culture results. This approach remains common but in recent years, studies have claimed that intra-peritoneal swabs are unnecessary; however, they relied upon retrospective patient groups predating wider use of laparoscopic appendicectomy, increasing numbers of immunocompromised people at risk of appendicitis and the clinical/medicolegal significance of increasing risk of antibiotic-associated Clostridium difficile colitis. Therefore, a key-word literature research was done to identify relevant publications from 1930 to June 2009. Newer features relating to intra-peritoneal swabs in appendicectomy have been discussed against this background information for periabdominal appendicectomy with or without appendicular perforation, laparoscopic appendicectomy and appendicectomy in the growing numbers of immunocompromised patients. All studies questioning the use of intra-peritoneal swabs were open, non-randomised, and retrospective with incompletely matched control groups, non-standardised swab collection techniques, and consequently lacked power to inform surgical practice. They concluded that an appropriately powered randomised, blinded, prospective, controlled clinical trial is needed to test for absolute efficacy in the use of peritoneal swabs in patient management. Until controlled trial data becomes available, it may be wise to continue peritoneal swabs at least in high-risk patients to decrease clinical and medicolegal risk.