Serum procalcitonin measurement contribution to the early diagnosis of candidemia in critically ill patients

Background: Candidemia is a life-threatening infection in the ICU whose prognosis is highly dependent on the stage at which it is recognized. Procalcitonin (PCT) levels have been shown to accurately distinguish between bacteremia and noninfectious inflammatory states in critically ill patients with clinical signs of sepsis. Little is known about the accuracy of PCT for the diagnosis of candidemia in this setting. Setting: A medical intensive care unit in a teaching hospital. Patients and methods: Review of the medical records of every non-neutropenic patient with either bacteremia or candidemia and clinical sepsis in whom PCT dosage at the onset of infection was available between May 2004 and December 2005. Results: Fifty episodes of either bacteremia (n = 35) or candidemia (n = 15) were included. PCT levels were found to be markedly higher in patients with bacteremia than in those with candidemia. Moreover, a low PCT value was found to be an independent predictor of candidemia in the study population. According to the calculation of the area under the receiver operating characteristic curve, PCT was found to be accurate in distinguishing between candidemia and bacteremia (0.96 [0.03]). A PCT level of higher than 5.5 ng/ml yields a 100% negative predictive value and a 65.2% positive predictive value for candidemia-related sepsis. Conclusion: A high PCT value in a critically ill non-neutropenic patient with clinical sepsis is unlikely in the setting of candidemia.