Intra-operative culture in appendicitis: traditional practice challenged

Abstract

Introduction: Traditionally, microbiological swabs are taken for culture during appendicectomy. However, the pathogens encountered are largely predictable, and sensitive to broad-spectrum antibiotics. Thus, we aimed to examine the clinical value of this practice, by determining the influence of microbiological results on postoperative outcome in patients undergoing appendicectomy.

Patients and methods: The study population comprised 721 consecutive patients undergoing appendicectomy for suspected acute appendicitis in a single district general hospital. Microbiological culture results and sensitivities of isolates were recorded in relation to histopathological findings and infective morbidity, to establish whether they influenced postoperative outcome.

Results: Swabs were taken during 463 (64%) appendicectomies. Only 113 (24%) yielded positive cultures ('coliforms', anaerobes and Streptococcus milleri were most frequently isolated). Organisms resistant to broad-spectrum antibiotics were encountered in only 11 of 463 patients (2%) where swabs were taken. Overall, 39 patients (5%) developed significant infective complications postoperatively. Neither the presence of a positive intra-operative culture, nor the isolation of resistant organisms were significant in predicting infective complications (P = 0.11 and 0.17, respectively).

Conclusions: In the population studied, the results of intra-operative culture did not influence clinical outcome in patients undergoing appendicectomy. The practice of taking routine microbiological swabs for culture must be seriously questioned.