Candida colonization and risk of candidemia in a cardiac surgical intensive care unit

Introduction

The aim of the study was to evaluate the incidence of Candida colonization in a cardiac surgical ICU, the predisposing risk factors and the impact of candidemia on outcome.

Methods

In an effort to answer this question a prospective study was conducted among patients admitted to our 16-bed cardiac surgical intensive care unit ICU during 1 December 2004–30 October 2005. Candida colonization and candidemia were identified. Fungal colonization was defined as colonization index exceeding 0.20 (3 g, at least two samples of seven growing Candida spp.). Candidemia was defined as the isolation Candida spp. in at least one blood culture in a patient with temporally related clinical signs. The demographic characteristics of patients who developed candidemia, as well as the underlying disease and comorbidities, were recorded.

Results

Over a 22-month period, 2,509 critically ill patients were evaluated. Candida spp. was isolated from any site in 141 patients (5.6%), while 10 patients (0.4%) presented ICU-acquired candidemia. They were all hospitalized for more than 7 days (range 7–34 days) in the ICU and had been exposed to broad-spectrum antibiotics (>3 agents). The mean age was 68 years (range 50–82 years) and the mean ICU stay 28 days. Candidemia appeared at a mean of 15.8 days after ICU admission. Candida albicans was the most common isolated pathogen. Candiduria in any count was detected in 12 patients but none of them experienced candidemia, while in seven patients Candida was isolated from urine and the respiratory tract. Six patients had major postoperative complications. Mortality due to candidemia was 60%. All patients received appropriate antifungal treatment. Prophylactic antifungal treatment was used in patients with multifocality colonization and in patients spending more than 7 days in the ICU after cardiac surgery.

Conclusion

C. albicans is the most common fungal pathogen in our ICU. Seven percent of colonized patients developed candidemia. Major postoperative complications, excessive antibiotic exposure and acute renal failure seem to predispose to the development of candidemia. Patients with candidemia have high inhospital mortality, perhaps as a reflection of illness severity.