Impact of Candida species on clinical outcomes in patients with suspected ventilator-associated pneumonia.

BACKGROUND The significance of Candida species in respiratory tract (RT) secretions in critically ill patients is unclear. METHODS A retrospective analysis of the Canadian ventilator-associated pneumonia (VAP) trial was conducted. Only patients with suspected VAP whose initial cultures failed to grow any known pathogens were included. Using two fundamentally different statistical techniques that adjusted for important confounding variables, the clinical outcomes of patients with Candida species recovered from RT cultures were compared with patients whose RT cultures were not positive for Candida species. RESULTS RT cultures yielded no identifiable bacterial pathogens in 274 patients; 68 patients had Candida species in the RT alone, while 206 patients did not have Candida species recovered from any site. The unadjusted OR of hospital mortality for patients with Candida species was 2.9 (95% CI 1.6 to 5.2; P<0.001). The hazard ratio of time to hospital discharge was 0.54 (95% CI 0.38 to 0.77; P=0.001). Logistic regression analysis demonstrated that age, Acute Physiology score and Chronic Health Evaluation (APACHE) II score, primary diagnosis of respiratory failure, two or more comorbidities and Candida species were independently associated with increased hospital mortality. Similar trends were observed with time to hospital discharge. The association between Candida species and increased mortality remained after controlling for potential confounders using both propensity score stratification and multivariable modelling approaches. CONCLUSIONS Patients with suspected VAP, in whom no bacterial pathogen was identified and in whom Candida species were isolated from RT cultures, exhibited a greater burden of illness compared with similar patients without Candida. Whether Candida species colonization of RT secretions is a marker of disease severity or actually contributes to poorer clinical outcomes remains unclear.