In critically ill patients the procalcitonin level can be misleading
1 Department of Critical Care, University Medical Center Groningen, University of Groningen, Postbus 30.001, 9700 RB Groningen, The Netherlands
2 Laboratory of Microbiology, Twente Achterhoek, Postbus 377, 7500 AJ Enschede, The Netherlands
3 Department of Clinical Chemistry, Medisch Spectrum Twente, Postbus 50.000, 7500 KA Enschede, The Netherlands
4 Department of Internal Medicine, Medisch Spectrum Twente, Postbus 50.000, 7500 KA Enschede, The Netherlands
Critical Care 2011, 15:422 doi:10.1186/cc10132Published: 28 April 2011
First paragraph (this article has no abstract)
Three recently published articles in Critical Care concerning the usefulness of procalcitonin (PCT) in critically ill patients elicited this cautionary comment of the present article's title [1-3]. PCT has been introduced as a test with high sensitivity and specificity for bacterial infection in patients in the emergency department. The test's negative predictive value is thought to be sufficient to withhold antibiotics in cases of low PCT [4,5]. PCT has also been evaluated as a diagnostic tool in critically ill patients. This would be of help because there is no immediately available test that proves or disproves a bacterial infection. Especially, the number of true and false negative patients cannot be estimated. We therefore cannot determine the test characteristics of PCT in these patients. We can determine with more certainty the true positive patients and measure their PCT level.