Risk factors of postoperative infections in adults with complicated appendicitis

Acute appendicitis is the most common surgical emergency. Infectious complications are uncommon but carry significant morbidity especially in complicated appendicitis. This study aimed to determine predictive factors of postoperative infections in adults with complicated appendicitis.

Retrospective review of clinical records from CDARS of Hong Kong Hospital Authority was performed in all patients aged 18 or above, operated with the diagnosis of gangrenous appendicitis, acute appendicitis with generalized peritonitis or peritoneal abscess from January 2003 to December 2005 in a regional hospital. Primary end point was postoperative infections, including wound infection and postoperative intra-abdominal abscess (PIAA). Independent predictors were determined by logistic regression analysis.

One seventy-three patients were operated with the diagnosis of complicated appendicitis. Postoperative infections occurred in 40 patients (23.1%). Thirty-two patients had wound infection and 10 patients had PIAA. Two patients had both infectious complications. There were 2 deaths. Diabetes mellitus was the only significant factor associated with PIAA in univariate analysis (odds ratio, 6.6; 95% confidence interval, 1.67-25.9). No independent factors can be identified in multivariate analysis. Successful laparoscopic appendicectomy was the only independent negative risk factor of wound infection in logistic regression.

Laparoscopic appendicectomy is the first choice of procedure in complicated appendicitis. Patients with diabetes mellitus need close monitoring of postoperative infections.