The relationship between Candida species cultured from the respiratory tract and systemic inflammation in critically ill patients with ventilator-associated pneumonia

Abstract

In patients with ventilator-associated pneumonia (VAP), the isolation of Candida species (spp.) in respiratory secretions has been associated with worse outcomes. It is unclear whether Candida colonization is causally related or is a marker of disease severity. The objective of this study was to compare systemic inflammatory markers in patients with a clinical suspicion of VAP with Candida in respiratory tract (RT) cultures vs patients who have bacteria and those with no pathogens. This was a prospective observational study in adults with a clinical suspicion of VAP who were enrolled within 24 hr of intensive care unit (ICU) admission. Patients were divided into four groups according to RT cultures, i.e., bacterial pathogens only, Candida spp. only, culture negative, and a control group with no clinical suspicion of VAP. Clinical outcomes were collected and compared as were systemic inflammatory and coagulation markers, including procalcitonin (PCT), C-reactive protein (CRP) and interleukin (IL)-6. The PCT, CRP, and IL-6 levels were similar in the Candida, bacterial pathogen, and culture negative groups but were significantly increased between the Candida group and the control group (P<0.05). In the first 28days, the number of ICU free days was significantly lower in the Candida group compared with the other groups, and mortality at 28days was greater (Candida 42.9%, bacterial pathogen 25.0%, culture negative 19.8%, control 0.0%; P<0.05). In patients with a clinical suspicion of VAP, the presence of Candida spp. only in the RT is associated with similar levels of inflammation and worse clinical outcomes compared with patients without Candida in RT secretions.