Whenever you order a lab you must ask yourself the following questions?

Why am I ordering this test?
What am I going to do with the result?

Given that PCT has become a frequently ordered test for many of you I wanted to answer some straightforward questions, and dive into the body of evidence to help support your decision making in the Emergency Department.

What is Procalcitonin?

  • Precursor of calcitonin which is involved in calcium homeostasis
  • Produced by thyroid, lung and intestine w/ half-life of 25 to 30 hours.
  • Below the limit of detection (10 pg/mL) in healthy patients
  • Rises in response to proinflammatory stimuli, especially bacterial, mostly via lung and gut production
  • Starts to rise 6 hours after the onset of infection
  • “It is a helpful biomarker for early diagnosis of sepsis in the critically ill patient,” Wacker et. al. Lancet Infectious Dis, 2013
  • Seems to be the new darling of critical care providers

In general, what do the results mean?

  • <0.5 normal
  • >0.5-2 moderate risk for progression to severe systemic infection
  • >2 high risk for progression to severe systemic infection
  • >10 high likelihood of severe sepsis/septic shock

Let’s take a look at some of the evidence