CICM SAQ 2010.1 Q23
Question
Critically evaluate the role of Procalcitonin (PCT) as a biomarker in the diagnosis and management of sepsis.
Answer
Answer and interpretation
Diagnosis
- PCT is synthesized physiologically by thyroid C cells but in sepsis has extrathyroidal origin from the inflamed/infected tissue
- The biochemical and clinical profile well described
- It is easy to perform (Blood test), not too expensive and provides a quick answer in about 30 minutes. Blood cultures can take up to 24 hours.
- PCT is no gold standard for infection. There number of reports of PCT elevation in non-septic SIRS, immediately after surgery and trauma.
- Data from meta-analyisis are conflicting, some suggesting it is superior to CRP, whilst others have concluded it is a weak biomarker in critical illness.
- PCT is not elevated in viral infection, autoimmune disorders and immunocompromised patients – hence empiric therapy still the way in these
- patients.
- PCT does not tell you the site of infection/inflammation. History, clinical examination and other investigations like CT scan can.
- PCT is a biomarker and cannot replace good history taking, systematic clinical examination, appropriate investigations for the source of sepsis.
Management
- Few prospective randomised studies using PCT as a guide to antibiotic therapy have shown that prescription rate and the cost of antibiotics was reduced significantly with similar outcomes compared to the conventional approach
- Mention of the recent Lancet paper (Jan2010 – ProRata study) and its conclusions is worthy of extra credit
Examination Library
CICM
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
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