ABSTRACT
BACKGROUND: Asthma may be regarded as a contraindication to scuba diving. PURPOSE: A clinical algorithm to assess fitness to dive among individuals with asthma was developed and tested prospectively in clinical practice. STUDY DESIGN: Cohort study. METHODS: All patients with possible asthma referred to Hvidovre Hospital, Denmark, for assessment of fitness to dive over a 5-year period (2013-2017) were included. Fitness to dive was assessed by case history, spirometry and mannitol challenge test. All patients with ≥10% decline in forced expiratory volume in 1 s (FEV1) (at any point during the challenge test) were offered step-up asthma therapy and rechallenge after at least 3 months. Patients with <10% decline in FEV1 after administration of a maximum dose of mannitol at the latest challenge were classified as having no medical contraindications to scuba diving. RESULTS: The study cohort comprised 41 patients (24 men; mean age 33 years), of whom 71% and 63% of men and women, respectively, were treated with rescue bronchodilator and inhaled corticosteroid. After the first mannitol challenge test, 21 patients were classified as having no medical contraindications to scuba diving, of whom 16 were currently prescribed asthma medication. After step-up asthma therapy and rechallenge test, an additional seven patients were classified as having no medical contraindications to scuba diving. Overall, using this clinical algorithm, 28 (68%) of the referred patients were finally assessed as having no medical contraindications to scuba diving. CONCLUSION: Using a clinical algorithm with mannitol challenge to assess fitness to dive among patients with possible asthma and allowing a rechallenge test after step-up asthma therapy increased the proportion of individuals classified as having no medical contraindications to scuba diving. However, as this algorithm has so far not been evaluated against actual scuba diving safety, further studies are clearly needed before it can be implemented with confidence for use in clinical practice. CLINICAL RELEVANCE: An algorithm to assess fitness for scuba diving among individuals with possible asthma using bronchial challenge test, with the option of step-up asthma therapy and rechallenge for reassessment, has been developed for clinical use.
ABSTRACT
To investigate predictors of accelerated decline in forced expiratory volume in 1 s (FEV1) in individuals with preexisting airflow limitation (AL). Participants in the Health2006 baseline study aged ≥ 35 with FEV1/ forced vital capacity (FVC) < lower limit of normal (LLN) were invited for a 10-year follow-up. At both examinations, data were obtained on demographics, spirometry, fitness level, allergy, and exhaled nitric oxide. We used multiple regression modeling to predict the annual decline in FEV1, reported as regression coefficients ( R) and 95% confidence intervals (CIs). A total of 123 (43% of those invited) participated in the follow-up examination, where more had exercise-induced dyspnea but fewer had asthma symptoms. Being female ( R = -29.8 ml, CI: -39.7 to -19.8), diagnosed with asthma ( R = -13.7, CI: -20.4 to -7.0) or atopic dermatitis ( R = -29.0, CI: -39.7 to -18.4), and having current asthma symptoms or nightly respiratory symptoms ( R = -22.1, CI: -31.9 to -12.4 and R = -14.3, CI: -19.9 to -8.7, respectively) were significantly associated with a steeper decline in FEV1. Although to a smaller extent, a steeper decline was also predicted by age, baseline FEV1, waist/hip-ratio, and number of pack-years smoked. In individuals with preexisting AL, being female and having ever or current respiratory symptoms were associated with an accelerated annual decline in FEV1.
