Clinical question: How does using procalcitonin levels for adults with acute respiratory infections (ARIs) affect patient outcomes?
Background: While the ARI diagnosis encompasses bacterial, viral, and inflammatory etiologies, as many as 75% of ARIs are treated with antibiotics. Procalcitonin is a biomarker released by tissues in response to bacterial infections. Its production is also inhibited by interferon-gamma, a cytokine released in response to viral infections, therefore, making procalcitonin a biomarker of particular interest to support the use of antibiotic therapy in the treatment of ARIs.
Study design: Cochrane Review.
Setting: Medical wards, intensive care units, primary care clinics, and emergency departments across 12 countries.
Synopsis: The review included 26 randomized control trials of 6,708 immunocompetent adults with ARIs who received antibiotics either based on procalcitonin-guided antibiotic therapy or routine care. Primary endpoints evaluated included all-cause mortality and treatment failure at 30 days. Secondary endpoints were antibiotic use, antibiotic-related side effects, and length of hospital stay. There were significantly fewer deaths in the procalcitonin-guided group than in the control group (286/8.6% vs. 336/10%; adjusted odds ratio, 0.83; 95% confidence interval, 0.70-0.99; P = .037). Treatment failure was not statistically different between the procalcitonin-guided participants and the controls. Of the secondary endpoints, antibiotic use and antibiotic-related side effects were lower in the procalcitonin-guided group (5.7 days vs. 8.1 days; P less than .001; and 16.3% vs. 22.1%; P less than .001). Each of the RCTs had varying algorithms for the use of procalcitonin-guided therapy, so no specific treatment guidelines can be gleaned from this review.
Bottom line: Procalcitonin-guided algorithms are associated with lower mortality, lower antibiotic exposure, and lower antibiotic-related side effects. However, more research is needed to determine best practice algorithms for using procalcitonin levels to guide treatment decisions.
Citation: Schuetz P et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev. 2017 Oct 12. doi: 10.1002/14651858.cd007498.pub3.
Dr. Michele Sundar
Dr. Sundar is assistant professor of medicine in the division of hospital medicine, Emory University, Atlanta.