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Exercise-induced bronchoconstriction (EIB) describes acute airway narrowing that occurs as a result of exercise. EIB occurs in a substantial proportion of patients with asthma, but may also occur in individuals without known asthma.To provide clinicians with practical guidance, a multidisciplinary panel of stakeholders was convened to review the pathogenesis of EIB and to develop evidence-based guidelines for the diagnosis and treatment of EIB. The evidence was appraised and recommendations were formulated using the Grading of Recommendations, Assessment, Development, and Evaluation approach.Recommendations for the treatment of EIB were developed. The quality of evidence supporting the recommendations was variable, ranging from low to high. A strong recommendation was made for using a short-acting β(2)-agonist before exercise in all patients with EIB. For patients who continue to have symptoms of EIB despite the administration of a short-acting β(2)-agonist before exercise, strong recommendations were made for a daily inhaled corticosteroid, a daily leukotriene receptor antagonist, or a mast cell stabilizing agent before exercise.The recommendations in this Guideline reflect the currently available evidence. New clinical research data will necessitate a revision and update in the future.

We studied, separately, the effects of the histamine antagonist, fexofenadine hydrochloride, and the leukotriene antagonist, montelukast sodium, and their placebos on airway sensitivity to and recovery from inhaled mannitol in subjects with asthma. Two 180-mg doses of fexofenadine were taken over 14 h, and three 10-mg doses of montelukast over 36 h, with the last dose 5 h before challenge. Fexofenadine reduced sensitivity to mannitol and the PD(15) was (mean [95% confidence interval] 138 [95, 201]) mg versus placebo (51 [25, 106] mg) (p < 0.001). The final percent reduction in FEV(1) with fexofenadine was 20.8 +/- 5.4% and not different from placebo (20.1 +/- 5.3%) (p = 0.7); however, recovery was slower with fexofenadine compared with placebo (p < 0.001). By contrast, montelukast had no effect on sensitivity to mannitol and the PD(15) was 71 [36, 144] mg versus placebo (87 [51, 148] mg (p = 0.35). The total dose of mannitol delivered and the final percent reduction in FEV(1) with montelukast were 171 +/- 142 mg and 21 +/- 4% and for placebo were 182 +/- 144 mg and 20 +/- 5% (p = 0.35, p = 0.59, respectively). However, recovery of FEV(1) to baseline was faster with montelukast, with the area under the percent reduction FEV(1)-versus-time curve reduced (220 +/- 121% change.min) compared with placebo (513 +/- 182% change.min) (p < 0.001). We conclude that whereas histamine is important for the initial airway response, leukotrienes are important in sustaining the airway response to inhaled mannitol.

To determine predictors for failed reduction of inhaled corticosteroids (ICS), in 50 subjects with well-controlled asthma (age 43.7 [18–69]; 22 males) taking a median dose of 1,000 μ g ICS/d (100–3,600 μ g/d), ICS were halved every 8 wk. Airway hyperresponsiveness (AHR) to a bronchial provocation test (BPT) with histamine was measured at baseline. AHR to BPT with mannitol, spirometry, exhaled nitric oxide (eNO), and, in 31 subjects, sputum inflammatory cells were measured at baseline and at monthly intervals. Thirty-nine subjects suffered an asthma exacerbation. Seven subjects were successfully weaned off ICS. Using a Kaplan– Meier survival analysis, the significant predictors of a failure of ICS reduction were being hyperresponsive to both histamine and mannitol at baseline (p = 0.039), and being hyperresponsive to mannitol during the dose-reduction phase of the study (p = 0.02). Subjects older than 40 yr of age tended to be at greater risk of ICS reduction failure (p = 0.059). Response to mannitol and p...

Nedocromil sodium inhibits the response to exercise-induced asthma (EIA). Mannitol given as a powder by inhalation is an osmotic stimulus that identifies EIA. We studied the acute effect of nedocromil on airway responsiveness to mannitol in 24 asthmatic subjects. After a control day, nedocromil (8 mg) or its placebo was administered randomized, double blind, 10 min before a challenge with progressively increasing doses of mannitol. Nedocromil inhibited the response to mannitol and there was a significant increase in the dose of mannitol required to cause a 15% reduction in FEV(1) (PD(15)) after nedocromil 409 (316,503) mg compared with placebo 156 (106,229) mg (p0.001). In the presence of nedocromil 12 subjects no longer recorded a 15% decrease in FEV(1) in response to mannitol. The remaining 12 required a significantly greater dose of mannitol to achieve a 15% decrease in FEV(1) after nedocromil. Following nedocromil, a plateau in responsiveness to mannitol was observed in 14 subjects. Nedocromil significantly inhibits the responsiveness to inhaled mannitol in asthmatic subjects.

Bronchiectasis is a disease characterized by hypersecretion and retention of mucus requiring physical and pharmacologic treatment. Recently we reported that inhalation of dry powder mannitol markedly increases mucociliary clearance (MCC) in asthmatic and in healthy subjects (Daviskas, E., S. D. Anderson, J. D. Brannan, H. K. Chan, S. Eberl, and G. Bautovich. 1997. Inhalation of dry-powder mannitol increases mucociliary clearance. Eur. Respir. J. 10:2449-2454). In this study we investigated the effect of mannitol on MCC in patients with bronchiectasis. Eleven patients 40 to 62 yr of age inhaled mannitol (approximately 300 mg) from a Dinkihaler. MCC was measured over 90 min, in the supine position, on three occasions involving: mannitol or control or baseline, using a radioaerosol technique. On the control day patients reproduced the breathing maneuvers and the number of coughs induced by the mannitol. Mannitol significantly increased MCC over the 75 min from the start of the intervention compared with control and baseline in the whole right lung, central, and intermediate region. Mean (+/- SEM) clearance with mannitol was 34.0 +/- 5.0% versus 17.4 +/- 3.8% with control and 11.7 +/- 4.4% with baseline in the whole right lung (p0.0001). The mean number of coughs induced by mannitol was 49 +/- 11. In conclusion, inhalation of dry powder mannitol increased clearance of mucus and thus has the potential to benefit patients with bronchiectasis.

We investigated airway responsiveness to mannitol, a new hyperosmolar challenge, in persons hyperresponsive to airway drying. We studied 36 asthmatic subjects, 18 to 40 yr of age, responsive to exercise (n = 23) and eucapnic hyperventilation (n = 28) defined by a 10% fall in FEV1. Fifteen subjects performed both challenges. All subjects performed a challenge with dry powder mannitol, encapsulated and delivered via a Dinkihaler until a 15% decrease in FEV1 was documented or a cumulative dose of 635 mg was delivered. All subjects responsive to eucapnic hyperventilation and all but one subject responsive to exercise were responsive to mannitol. Sixty-nine percent of subjects had a positive response to mannitol after less than 155 mg (6 capsules) and 94% less than 320 mg (10 capsules). The provoking dose of mannitol required to cause a 15% fall in FEV1 (PD15) was related to the severity of the response to exercise (Pearson's correlation coefficient [rp] = 0.68, p < 0.01) and eucapnic hyperventilation (rp = 0.68, p < 0.01) in subjects who were not taking inhaled corticosteroids. The mean (+/- SD) maximum percent fall in FEV1 after mannitol was 24.4 +/- 6.2% and recovery to bronchodilator occurred within 10 min in most subjects. The mannitol test is simple, inexpensive, faster to perform than hyperpnea with dry air and could become an office-based test. Further studies are now required to determine the sensitivity of mannitol to identify exercise-induced asthma in a random population.

We developed a bronchial provocation test (BPT) with a dry powder preparation of mannitol. The mannitol was inhaled from gelatin capsules containing 5, 10, 20, or 40 mg to a cumulative dose of 635 mg, and was delivered via an inhalator, Halermatic, or Dinkihaler device. We studied the airway sensitivity to inhaled mannitol, the repeatability of the response, and the recovery after challenge in 43 asthmatic subjects 18 to 39 yr of age who had a 20% decrease in FEV1 in response to inhaling a 4.5% NaCl. We compared this with the airway response to methacholine in 25 subjects. The geometric mean (GM) for the dose of dry mannitol required to reduce the FEV1 by 15% of the baseline value (PD15) was 64 mg, with a 95% confidence interval (CI) of 45 to 91. Subjects responsive to mannitol had a PD20 to metacholine of < 7.8 mumol, with a GM of 0.7 mumol (CI: 0.4 to 1.2). For the first of two challenges to mannitol the PD15 was 59 mg (CI: 36 to 97) and for the second the PD15 was 58 mg (CI: 35 to 94) p = 0.91 (n = 23). Spontaneous recovery to within 5% of baseline occurred within 60 min and within 10 min after 0.5 mg terbutaline sulfate was inhaled. Arterial oxygen saturation (SaO2) remained at 93% or above during mannitol challenge. Subjects tolerated the inhalation of the mannitol well. A dry powder preparation of mannitol may be suitable to develop for bronchial provocation testing.

Bronchial provocation tests provide objective criteria for asthma and exercise-induced bronchoconstriction (EIB) and were recommended to justify the use of inhaled beta2-agonists by athletes at the Winter Olympics 2002. Eucapnic voluntary hyperpnea (EVH) was one test recommended to identify EIB. Provocation with EVH requires a special dry gas mixture limiting its availability. Provocation tests with osmotic aerosols require less expensive equipment that is easily portable. We assessed the sensitivity of a challenge with mannitol to identify responsiveness to EVH in 50 elite summer sport athletes who were unselected if they had respiratory symptoms. Asthma was previously diagnosed by a doctor in 27 subjects, and 21 subjects were currently under treatment for EIB or asthma. The mean predicted FEV1 was 103.6 +/- 10.8%, FVC was 99 +/- 13.3%, and mean forced expiratory flow during the middle half of the FVC was 104 +/- 22.7%. A total of 25 subjects were positive to EVH challenge (mean percentage of fall in FEV1 was 25.4 +/- 15% SD), and 26 subjects had a positive mannitol challenge (geometric mean [95% confidence interval] provoking dose causing a 10% fall in forced expiratory volume in one second [PD10] was 202 mg [134, 300], with 24 of the subjects positive to both challenges). Mannitol had a sensitivity of 96% and specificity of 92% to identify a positive response to EVH and, as such, could be used as an alternative to EVH to identify EIB.