Assessment of fitness to dive in candidates with possible asthma – a pilot study

Background and Objective: Fitness to SCUBA dive in individuals with asthma has been much debated. A clinical algorithm for assessment of fitness to dive in individuals with possible asthma was developed based on national guidelines, and tested in clinical practice. Methods: All patients with possible asthma referred to Hvidovre Hospital, DK, for assessment of fitness to dive over a 5-year period (2013-17) were included. Fitness to dive was assessed by case history, spirometry and mannitol challenge test. All patients with ≥ 10% decline in FEV1 (any point during the challenge test) were offered stepping-up anti-asthma therapy and re-challenge after at least 3 months. Patients with less than 10% decline in FEV1 after administration of the max. dose of mannitol at the latest challenge were classified as fit for SCUBA-diving. Results: The study cohort compromised 41 patients (24 men; mean age 33 years, range 10 – 69 years), of whom 71% and 63%, respectively, were treated with rescue bronchodilator and inhaled corticosteroid. After the first mannitol challenge test, 21 patients were classified as fit to dive. After adjustment of anti-asthma therapy and re-challenge test, an additional seven patients were classified as being fit to dive. So, overall 28 (68%) of the referred patients were finally assessed as fit to dive using this clinical algorithm. Conclusion: Using a clinical algorithm with mannitol challenge for assessment of fitness to dive in patients with possible asthma allowing re-challenge testing after stepping-up asthma therapy increased the proportion of individuals classified as fit for recreational SCUBA diving.