WASHINGTON — Mechanical ventilation significantly increases the risk that a hospitalized patient will develop Clostridium difficile-associated diarrhea, Dr. Chad A. Spangler and Dr. George F. Risi reported in a poster at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
This novel finding “has the potential to support new, additional prevention and control strategies in high-risk patient populations,” said Dr. Spangler and Dr. Risi, of St. Patrick Hospital, Missoula, Mont.
The incidence of C. difficile-associated diarrhea (CDAD) increased from 1.6 to 8.0 cases per 1,000 discharges between 2001 and 2004 at the investigators' 200-bed hospital, with most cases occurring in the intensive care unit. There was no change in the rate of CDAD cases between 2003 and 2004 despite a reduction in the use of both antipseudomonal penicillins and fluoroquinolones during that period.
Among 3,247 patients who received antibiotics and had a length of stay greater than 3 days between January 2004 and March 2005, a total of 19% required ventilation. Of those 614, CDAD developed in 47 (7.6%). With the ventilated population excluded, the infection rate was just 1.2%, the investigators reported at the meeting, which was sponsored by the American Society for Microbiology.
Other significant risk factors for CDAD included ICU stay; use of either proton pump inhibitor or H2-blocker antacids; and exposure to carbapenems, third-generation cephalosporins, or antipseudomonal penicillins. In the mechanically ventilated population, those requiring more than 2 days on the ventilator were 11 times more likely to develop CDAD than were those requiring less ventilation, they reported.