The impact of pseudomembrane formation on the outcome of Clostridium difficile-associated disease

Although pseudomembranes are the hallmark manifestation of Clostridium difficile-associated diarrhea (CDAD), there are scant data specifically addressing their impact on the clinical outcome. We investigated whether the formation of pseudomembranes predicts a worse CDAD outcome.

CDAD patients hospitalized during 2010 underwent sigmoidoscopy and were followed prospectively. In addition, all hospitalized CDAD patients in the period 01/2000-12/2009 who underwent lower endoscopy were retrospectively identified and their charts reviewed. Patients with detectable pseudomembranes on endoscopy were compared to those in whom pseudomembranes were absent. Thirty-day mortality and a composite outcome comprised of mortality within 30 days of diagnosis, admission to the intensive care unit (ICU), colectomy, peritonitis, hemodynamic instability, or respiratory insufficiency were addressed. Additional clinical outcomes used for comparison between the two groups were 60-day mortality, duration of hospitalization, and the failure of metronidazole and vancomycin.

A total of 117 CDAD patients (mean age 62.9 ± 19 years) who underwent lower endoscopy were included; 46 with pseudomembranes and 71 without. Seven out of the 46 patients with pseudomembranes died within 30 days compared to 9/71 in the non-pseudomembrane group [odds ratio (OR) 1.2, 95% confidence interval (CI) 0.4-3.6, P = 0.8]. Similarly, there was no correlation between the occurrence of pseudomembranes and the rate of the composite adverse outcome (P = 0.6). In contrast, acute renal insufficiency (OR 15, 95% CI 3.2-72, P < 0.001) and hypoalbuminemia (OR 5.7, 95% CI 1.8-18, P = 0.002) were both independently predictive of a severe clinical outcome.

Our findings suggest that the presence of pseudomembranes is not associated with an adverse outcome in CDAD patients.