Increased bypass time not a predictor of candidemia in cardiac surgery patients

Predictive factors for developing candidemia in patients undergoing cardiac surgery are more or less the same as those of the general intensive-care-unit (ICU) population, according to the findings of a new prospective observational study [1].

Dr Daniela Pasero (University of Turin, Italy) and colleagues reported their findings online December 22, 2010 in Interactive Cardiovascular and Thoracic Surgery.        

According to researchers, candidemia is a well-recognized complication in critically ill patients who are hospitalized, and the "incidence of invasive infections from Candida [species] has increased dramatically in the last three decades in the ICU setting." A previous study had identified cardiopulmonary bypass time as a possible risk factor for candidemia in patients admitted to the cardiac ICU (cICU); the current study was designed to determine whether this theory held true and whether other risk factors are also associated with candidemia in the cICU setting.

From July 2005 to December 2007, 1955 patients were admitted to the cICU and stayed for at least 48 hours after cardiac surgery. Of those, 349 patients met the selection criteria. Exclusion criteria included solid organ or bone-marrow transplant, previous diagnosis of candidemia or other invasive infections, and/or admission to the cICU prior to surgery. Candidemia was diagnosed with at least one positive blood culture for Candida.

Of the patients studied, 1.3% developed candidemia. In addition, patients developed candidemia a median of 20 days (interquartile range 8-49 days) after admission to the cICU, which was later than reported in the general ICU setting.

Predictors of candidemia appeared to be similar to those reported in the general ICU population, the study found. Multiple regression analysis identified several independent risk factors, including total parenteral nutrition (odds ratio 9.56, 95% CI 1.741-52.534), severe sepsis (OR 4.20; 95% CI 1.292-13.667), simplified acute physiology score II (OR 1.16, 95% CI 1.052-1.278); and ICU length of stay >20 days (OR 6.38, 95% CI 1.971-20.660).

This study did not indicate that cardiopulmonary bypass time is a risk factor for candidiasis, although Pasero and colleagues note that only patients with an ICU stay >48 hours were included in the study.

According to the researchers, these results underscore the importance of "general and well-known ICU risk factors" for candidemia infection, rather than specific risk factors related to cardiac surgery.

"These results could suggest that candidemia is not a frequent event in this kind of population, but it is expression of severity of these ICU patients and it is not a variable that increases the risk of death," they conclude.