The clinical significance of Candida colonization of respiratory tract secretions in critically ill patients

Abstract

Purpose: Clinical uncertainty exists regarding the significance of colonization confined to respiratory tract secretions with Candida sp in critically ill patients. Our objectives were to describe such colonization, its associated risk factors, and to examine the clinical outcomes in patients with a clinical suspicion of ventilator-associated pneumonia with isolated Candida colonization compared to those without.

Materials and methods: In a retrospective analysis of the Canadian ventilator-associated pneumonia study, patients were divided into 2 groups according to the isolated presence or absence of Candida in the respiratory tract enrollment culture. We compared length of mechanical ventilation, intensive care unit and hospital stay, and mortality outcomes between groups. We used multiple logistic regression analysis to determine factors independently associated with Candida colonization and hospital mortality.

Results: Of the 639 eligible patients, 114 (17.8%) were colonized with Candida in the enrollment culture. A multivariate analysis identified female sex (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.02-2.65), number of comorbidities (OR, 1.35; 95% CI, 1.08-1.71), worsening or persistent infiltrate at randomization (OR, 1.92; 95% CI, 1.09-1.38), antibiotics started within 3 days of randomization (OR, 3.16; 95% CI, 1.71-5.83), and on antibiotics at randomization but all started more than 3 days before randomization (OR, 3.04; 95% CI, 1.68-5.50) as variables associated with Candida respiratory tract colonization. A significant increase in median hospital stay (59.9 vs 38.6 days, P = .006) and hospital mortality (34.2% vs 21.0%, P = .003) was observed in patients with Candida colonization. In a multivariate model, Candida colonization of the respiratory tract was independently associated with hospital mortality (OR, 2.47; 95% CI, 1.39-4.37).

Conclusion: Respiratory tract Candida colonization is associated with worse clinical outcomes and is independently associated with increased hospital mortality. However, it is unclear whether Candida colonization is causally related to poor outcomes or whether it is a marker for increased morbidity and mortality.