Deep Dive: Procalcitonin
Procalcitonin is an acute phase reactant that is a propeptide processed into the hormone calcitonin
When you aren’t sick your body produces procalcintonin from the thyroid
We don’t know what its role in healthy patients are except as a precursor to calcitonin
A wide range of tissues produce procalitonin in infection
We still don’t know what it’s role in the body’s response to infection is
elevated somewhere between 2-12 hours after bacterial infection
Peak levels are typically reached at 24-48 hours after bacterial infection
broken down from peptide to an amino acid by enzymes
Why does it matter?
Reduce antibiotic use
A global health priority by numerous organizations
Providers still giving antibiotics for bronchitis and similar diseases despite CDC recommendations against it
Procalcitonin Use in LRTI’s (CAP, Bronchitis, COPD AE)
ProHOSP the initial trial published in JAMA 2009 that created the procalcitonin guidelines we still use
Wang W, Zhang X, Ge N, et al. Procalcitonin testing for diagnosis and short-term prognosis in bacterial infection complicated by congestive heart failure: a multicenter analysis of 4,698 cases. Crit Care 2014; 18:R4.
Maisel A, Neath SX, Landsberg J, et al. Use of procalcitonin for the diagnosis of pneumonia in patients presenting with a chief complaint of dyspnoea: results from the BACH (Biomarkers in Acute Heart Failure) trial. Eur J Heart Fail 2012; 14:278.
Don’t Use PCT to Withhold or Stop Antibiotics in Severe COPD AE going to ICU
PCT and Sepsis: Abx Discontinuation
Do not use to determine initiation of antibiotics in sepsis
Can be used to guide antibiotic discontinuation in sepsis (SAPS)
Number is < 0.5 in Sepsis (0.25 in LRTI)
PCT and Sepsis: Risk Assessment
Independent predictor of mortality (MOSES Study CCM 5/2017)
Used by Paul Marik to determine who got Marik Protocol in that famous study
Reduction of PCT by 80% in 72 hours shows treatment effectiveness in sepsis and the lack of 80% reduction or increase in PCT indicates treatment failure.
New Study: ProACT:
Large, multicenter RCT, > 1600 patients at 14 academic centers
They looked specifically at patients that presented to the ED with a suspected LRTI and for whom the treating physician was uncertain whether abx therapy was indicated
primary endpoints were antibiotic days and percentage of patients with adverse outcomes
No reduction in antibiotic days (4.2 vs 4.3) and no difference in adverse events
Clinicians adhered to the PCT guideline recommendation 73% of the time in the PCT group
CAP had the lowest adherence at 39%
study did not force clinicians in the PCT group to stop abx based on the PCT level
hospitals with excellent pneumonia quality metrics
What else can elevate PCT?
Medullary thyroid carcinoma or islet cell tumors can have elevations in PCT > 10,000
Trauma, burns, multiorgan failure, and recent major surgery
patients with ESRD who haven’t had regular dialysis treatments in a few days can have elevated PCT levels without an infection
pancreatitis, prolonged cardiogenic shock, MODS, autoimmune disorders, liver dysfunction or recent liver transplant, prolonged arrest and resuscitation, and rhabdo
FDA recommendations which were expanded for PCT in February 2017.
It is recommended to be used when starting and stopping antibiotics in community acquired LRTIs
Recommended to be used in stopping antibtiocs in sepsis.
It was initially recommendation was to assess mortality in sepsis
2016 IDSA Antimicrobial Stewardship Guidelines: weak recommendation
2018 Surviving Sepsis Campaign: weak recommendation
2016 IDSA/ATS HAP/VAP Guidelines: weak recommendation for discontinuation, do not use for initiation
2007 IDSA CAP Guidelines: currently refreshing