Abstract

Introduction: The association of bacteriuria and candiduria with mortality in patients admitted to the Intensive Care Unit (ICU) is controversial. We prospectively studied ICU patients at National University Hospital, a 1000 bed Singapore teaching hospital to determine the impact of urinary tract infection on mortality. Methods: All patients admitted to the medical or surgical ICU for more than 24 hours from January 2008 to December 2011 were prospectively studied as part of a study of antibiotic use. Bacteriuria and candiduria were defined as the presence of more than 103 colony forming units (CFUs) of microorganisms per millilitre of urine. Pregnant patients and those who had positive urine cultures on ICU admission were excluded. Results: 710 of 2641 patients in the cohort had urine cultures ordered. 439 had negative urine cultures, 113 had bacteriuria, 136 had candiduria and 22 had both. Overall, 219 (30.8%) patients did not survive their hospitalization. There was a significant difference in mortality between patients who had positive urine cultures and those with negative urine cultures (37.6% vs. 26.7%, P=0.002), with the former being an independent marker of mortality (OR 1.435, 95% CI 1.025-2.010). Patients who had candiduria had a significant higher mortality rate compared to patients without candiduria (41.8% vs. 26.7%, P<0.001). In contrast, there was no significant difference in mortality between patients who had bacteriuria and patients who did not (31.1% vs. 26.7%, P=0.311). Candiduria is an independent marker for mortality (OR 1.91, 95% CI 1.26-2.88) after controlling for confounding factors. Conclusion: Candiduria in ICU patients is associated with higher rates of mortality than patients with negative urine cultures and bacteriuria, and may be used as an independent marker of mortality. There is clearly a critical need to identify the patients with candiduria and/or bacteriuria who will go on to develop complications so that therapy can be targeted at those who need it most without causing too much collateral damage.