Procalcitonin in bacteraemia

• procalcitonin is a prohormone of calcitonin that has been reported to be present in increased levels in the blood of infected patients
• the ability to accurately and rapidly identify patients with bacteraemia is an important management issue for emergency physicians
  • a potential use of the procalcitonin test in the emergency department (ED) is as a screening test for bacteraemia
    • young children are often unable to localize their infection and the management, disposition, and prognosis all change according to the presence or absence of bacteraemia
    • in adults, approximately 50% of patients evaluated in the ED with undifferentiated hypotension or hypotension of uncertain cause are ultimately diagnosed with sepsis
• a systematic review investigated the test characteristics of procalcitonin as a marker for bacteraemia (1)
  • the authors found the diagnostic performance of the procalcitonin test for identifying bacteremia in ED patients to be moderate
• however
  • an individual study in patients with exacerbations of COPD revealed evidence for the use of the test in identifying patients who required antibiotic treatment (2)
    • the study included 208 patients randomized at the index exacerbation to procalcitonin-guided or standard antibiotic therapy
      • patients receiving procalcitonin-guided therapy were treated with antibiotics according to serum procalcitonin levels; standard-therapy patients received antibiotics according to the attending physician
    • procalcitonin guidance reduced antibiotic prescription (40% vs 72%, respectively; p < 0.0001) and antibiotic exposure (relative risk [RR], 0.56; 95% confidence interval [CI], 0.43 to 0.73; p < 0.0001) compared to standard therapy
    • procalcitonin guidance at the index exacerbation allowed a significant sustained reduction in total antibiotic exposure for up to 6 months (RR, 0.76; 95% CI, 0.64 to 0.92; p = 0.004)
    • the authors concluded that procalcitonin guidance for exacerbations of COPD offers a sustained advantage over standard therapy in reducing antibiotic use for up to 6 months with a number-needed-to-treat of 3
  • a systematic review investigated the accuracy of serum procalcitonin as a diagnostic test for sepsis, severe sepsis, or septic shock in adults in intensive care units or after surgery or trauma, alone and compared with C-reactive protein (3)
    • the study authors concluded that procalcitonin represents a good biological diagnostic marker for sepsis, severe sepsis, or septic shock, difficult diagnoses in critically ill patients. Based on the study resulst, procalcitonin was superior to C-reactive protein
      
      
  • a randomized controlled trial investigated the use of procalcitonin level-guided treatment in exacerbations of COPD (4)
    • the study revealed that procalcitonin guidance for exacerbations of COPD offered a sustained advantage over standard therapy in reducing antibiotic use for up to 6 months with a number-needed-to-treat of 3
      
      
  • a randomized controlled trial in primary care relating to the treatment of acute respiratory tract infection (5):
    • revealed that procalcitonin-guided therapy markedly reduces antibiotic use for acute respiratory tract infections in primary care without compromising patient outcome
    • authors suggest that procalcitonin-guided therapy could be achieved with 1 to 2 procalcitonin measurements in patients for whom the physician intends to prescribe antibiotics
      
      
  • evidence shows that procalcitonin-guided care can reduce antibiotic use without increasing infection or harm in patients with acute pancreatitis (6)

Reference:

1. Jones AE et al. Procalcitonin Test in the Diagnosis of Bacteremia: A Meta-analysis.Ann Emerg Med. 2006 Dec 8.
2. Stolz D et al. Antibiotic Treatment of Exacerbations of COPD: A Randomized, Controlled Trial Comparing Procalcitonin-Guidance With Standard Therapy. Chest. 2007 Jan;131(1):9-19
3. Uzzan B et al. Procalcitonin as a diagnostic test for sepsis in critically ill adults and after surgery or trauma: a systematic review and meta-analysis. Crit Care Med. 2006 Jul;34(7):1996-2003.
4. Stolz D et al. Antibiotic treatment of exacerbations of COPD: a randomized, controlled trial comparing procalcitonin-guidance with standard therapy. Chest. 2007 Jan;131(1):9-19.
5. Briel M et al. Procalcitonin-guided antibiotic use vs a standard approach for acute respiratory tract infections in primary care. Intern Med. 2008 Oct 13;168(18):2000-7; discussion 2007-8
6. Siriwardena A et al. A procalcitonin-based algorithm to guide antibiotic use in patients with acute pancreatitis (PROCAP): a single-centre, patient-blinded, randomised controlled trial . Lancet Gastroenterology & Hepatology 2022 DOI: https://doi.org/10.1016/S2468-1253(22)00212-6