The use of procalcitonin in sepsis has been evolving rapidly in the recent literature. The theory behind procalcitonin is that, typically, it is rapidly converted to calcitonin. However, in the presence of gram-positive and gram-negative sepsis, circulating endotoxin results in a rapid rise in procalcitonin levels not seen during viral infection. There’s a nice study showing use of procalcitonin levels allows for reductions in antibiotic use in the ICU, without a corresponding increase in mortality – which makes it a promising test to assist in antibiotic stewardship.
This is a little bit different spin on the question addressing the use of procalcitonin levels in a population that is febrile all the time – pediatrics. Most of the time, when children are febrile, the infectious etiology is either readily identifiable as bacterial or presumed to be viral. However, in the subset of children with indwelling central venous catheters – they’re treated presumptively as line sepsis until proven otherwise, despite the preponderance of viral etiologies.
This is a small case series of 62 children with indwelling lines, 14 of whom eventually grew positive blood cultures. Using procalcitonin levels drawn in the Emergency Department to rule out bacteremia gave an AUC of 0.82 (0.70 to 0.93) with the “optimal” cutoff at 0.3 ng/mL giving a sensitivity of 93% and specificity of 63%. I’m not sure I’d settle for anything less than 100% sensitivity for line sepsis, but there is a point at which the risks associated with healthcare delivery are equivalent to the risks of bloodstream infection. This is a nice idea I wasn’t previously familiar with that hopefully will be confirmed in subsequent evaluation.
“Procalcitonin as a Marker of Bacteremia in Children With Fever and a Central Venous Catheter Presenting to the Emergency Department”
www.ncbi.nlm.nih.gov/pubmed/23023470