Prediction of complicated Clostridium difficile infection by pleural effusion and increased wall thickness on computed tomography.

BACKGROUND: Abdominal computed tomography (CT) is often used to evaluate complications in patients with Clostridium difficile infection (CDI), but no study has correlated CT findings with the risk of developing a complicated CDI. Furthermore, the value of CT has not been evaluated since the emergence of the BI/NAP1/027 hypervirulent strain of C. difficile. We sought to describe and correlate abdominal CT findings with complicated CDI and to compare them before and after the emergence of the epidemic strain.

METHODS: We conducted a retrospective cohort study of all hospitalized patients 18 years or older who, from 1 January 1998 through 31 December 2006, underwent abdominal CT within 72 h of their first positive stool sample.

RESULTS: Of 1189 patients with newly diagnosed CDI, 165 satisfied the inclusion criteria. Patients who underwent CT were younger, had higher peak white blood cell counts and serum creatinine levels, and were more likely to experience fever than those who did not undergo CT. No difference in CT findings was noted before and after the emergence of BI/NAP1/027 CDI. Pleural effusion (adjusted odds ratio [AOR], 2.6; 95% confidence interval [CI], 1.1-6.6), colonic wall thickness >15 mm (AOR, 6.0; 95% CI, 1.1-33.9), peak white blood cell count > or =30 x 10(9) cells/L (AOR, 4.8; 95% CI, 1.4-16.4), albumin level <20 g/L (AOR, 6.9; 95% CI, 2.4-20.1), and immunosuppression (AOR, 4.7; 95% CI, 1.5-15.3) were independently associated with complicated CDI.

CONCLUSIONS: In a selected sample of patients with CDI, CT provided prognostic information additional to what could be obtained from clinical and laboratory parameters. No change in CT characteristics was noted after the introduction of the BI/NAP1/027 strain in our center.