The American Thoracic Society recommends formal post exercise spirometric testing in patients with suspected exercise-induced bronchoconstriction (EIB). In those patients with confirmed EIB, pre-exercise use of an inhaled short-acting beta-agonist (SABA) is still the mainstay. The panel also recommends using mast cell stabilizers or anticholinergic medications in patients who don’t respond well to SABA’s. For patients using SABA’s every day, the panel recommends adding a daily controller medication (inhaled corticosteroids [ICS] or leukotriene receptor antagonists), but recommends against the use of long-acting beta-agonists (LABA’s). (LOE = 5)
Parsons JP, Hallstrand TS, Mastronarde JG, et al, for the American Thoracic Society Subcommittee on Exercise-induced Bronchoconstriction. An official American Thoracic Society clinical practice guideline: exercise-induced bronchoconstriction. Am J Respir Crit Care Med 2013;187(9):1016-1027.
Study design: practice guideline
The American Thoracic Society assembled a panel of content and methodologic experts (many with ties to industry) — but nobody representing patients or societal perspectives — to develop guidelines for managing patients with EIB. Librarians systematically searched multiple databases for relevant research. Panel members reviewed the search results, evaluated the quality of the research, and generated recommendations. The panel recommends (expert opinion) that the diagnosis of EIB should NOT be based on symptoms, but on spirometric changes after exercise. Pharmacologic treatment: A systematic review of 8 clinical trials that demonstrated patients using pre-exercise SABAs showed significantly less spirometric decline after exercise than patients using placebo. Additionally, 2 clinical trials evaluating LABAs found a higher rate of treatment failure with LABAs. Several other trials and meta-analyses exist, but these included patients also using inhaled corticosteroids. A systematic review of 6 clinical trials of daily ICS reported that patients using steroids had modestly less spirometric decline after exercise than those using placebo. However, another systematic review of 4 trials found pre-exercise ICS was no better than placebo. The panel also summarized systematic reviews of randomized trials of several other classes of medications (daily leukotriene receptor antagonists, mast cell stabilizers, antihistamines, and short-acting inhaled anticholinergic medication). For all except antihistamines, the active medication was modestly better than placebo. Although pre-exercise antihistamines were no better than placebo, the panel felt they might be helpful in allergic patients. Nonpharmacologic treatment: A systematic review of several randomized trials of warm-up periods (interval, low-intensity continuous, high-intensity, or combination) before exercise reported that patients doing interval and combination warm-up periods had modestly less postexercise spirometric decline than patients not doing a formal warm up. One randomized trial of limited quality and 2 nonrandomized trials provided weak evidence of modest benefit to warming or humidifying the air (with a face mask or scarf) during exercise. Although the panel identified limited quality research on sodium restriction, fish oil supplementation, and ascorbic acid for patients interested in dietary modification to control symptoms, the panel basically said “it couldn’t hurt.”
Henry C. Barry, MD, MS
Michigan State University
East Lansing, MI