PURPOSE: The signs of sepsis are relatively non specific making identification of infection in critically ill patients difficult. Since the risk of adverse effects from the delay in treatment is high, patients without infection are subjected to the potential toxic effects of antibiotics without individual benefit. Procalcitonin levels are reported to predict the presence or absence of infection.
METHODS: 49 consecutive ICU patients were enrolled in this investigation. In the first part of the study, 23 patients had procalcitonin levels measured on admission to the ICU. Previously reported work had suggested that an initial level of > 1.5 was highly predictive of bacterial sepsis while a level < .5 is highly predictive of the absence of infection. Levels in between are non discriminating. In the second part of the study 26 patients had daily measurements of procalcitonin performed to determine response to antibiotic therapy or consistency of the negative result.
RESULTS: 25/49 had negative levels of procalcitonin. None of these patients developed overt signs of sepsis. 12 pts had elevated levels of procalcitonin, 9 of these were demonstrated to have sepsis. 9 pts had intermediate levels of procalcitonin, none of these pts met criteria for sepsis. The sensitivity, specificity, PPV and NPV for the non intermediary levels were, 1.0, .89, 75% and 100%, respectively.
CONCLUSION: Procalcitonin levels were highly predictive both of the presence and absence of infection in typical patients admitted to a medical/surgical ICU. Negative levels would have allowed for the discontinuation of antibiotics in 51% of the patients who presented with SIRS but eventually were shown not to have sepsis. There were 3 false positive results primarily in surgical pts.
CLINICAL IMPLICATIONS: It would appear that procalcitonin levels, which are easy to measure and reproducible, are a significantly beneficial biomarker in detecting the presence or absence of sepsis. The use of this biomarker in association with the usual clinical and laboratory markers of sepsis might help avoid over usage of antibiotics.
DISCLOSURE: Aditi Patel, No Product/Research Disclosure Information; Grant monies (from industry related sources) Brahms Diagnostics provided the equimpment and reagents to perform the analysis at no cost to the investigators involved in the study.