The relevance of ESBL producing isolates in patients surgically treated for acute appendicitis.

BACKGROUND In India, there is a high prevalence of ESBL producing organisms among intraabdominal isolates and in stool flora of 'normal' individuals. Hence, it may be presumed that unless antimicrobial therapy effective for ESBL flora is used perioperatively for abdominal surgery, the outcome will be adverse. We selected patients surgically treated for appendicitis as a model to explore the relevance of ESBL producing isolates in this retrospective observational study. AIMS AND OBJECTIVES To assess the impact of ESBL producing isolates in patients surgically treated for acute appendicitis and to determine whether the perioperative antibiotic use needs to be changed in view of the high ESBL prevalence. METHOD Chart review of 221 consecutive patients who had undergone appendicectomy between January 2004 and December 2009. RESULTS 55 of 221 patients had cultures of relevant specimens done based on the discretion of the treating surgeon. 40 yielded 1 or more organisms. 19 showed ESBL producing Enterobacteriaceae (ESBL+) and 21 showed non ESBL producing Enterobacteriaceae (ESBL-). 118 of 221 patients had presented without any complications and had a good outcome after surgery. The other 33 of 221 patients had complications like perforation or an abscess at presentation. Out of these, 16 patients received inappropriate therapy and 17 received appropriate therapy. The patients with appropriate therapy had good outcome. Among the 16 patients with inappropriate therapy 15 were ESBL+and 1 was ESBL-. Out of the 15 ESBL+isolates, 9 developed an initial postoperative complication like postoperative fever or wound infection. The cultures of the relevant specimen were done in all these 9 patients, all of which were positive. Therapy was changed in 7 of these 9 patients to pathogen directed therapy like amikacin, chloramphenicol and levofloxacin. Meropenem was used in only one case. All these 7 patients as well as the 2 patients whose treatment was not changed made a complete recovery. CONCLUSION For patients surgically treated for acute appendicitis, a change of perioperative antibiotics to those effective for ESBL+organisms is not needed at present only on the basis of ESBL prevalence rates. Routine cultures may not be necessary. Cultures are needed if there is a complication such as an abscess or perforation at presentation or an initial post operative complication. A change to pathogen directed therapy, including even to older or non beta-lactam antimicrobials may be needed in these cases. Our results support continuing the use of older antimicrobials rather than changing to carbapenems and beta-lactamase-beta-lactamase inhibitor combination in low risk surgically treated patients. This may prevent generation of further resistance without compromising outcomes.