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..
Dr. Sundar is assistant professor of medicine in the division of hospital medicine, Emory University, Atlanta.