Exercise-induced bronchoconstriction: a survey of diagnostic practice in the United Kingdom

Background: Exercise-induced bronchoconstriction (EIB) is an important and common cause of exertional dyspnoea. International guidelines recommend objective testing using indirect bronchial challenge and advocate mannitol, exercise challenge test (ECT), or eucapnic voluntary hyperpnoea (EVH). Each test should be performed using a validated method in order to ensure diagnostic accuracy. Aim: To identify current diagnostic practices in EIB and adherence to guidelines. Methods: A survey of diagnostic practice in hospitals with ‘Association for Respiratory Technology and Physiology’ accreditation. Forty-three hospitals were identified. First line bronchial challenge and standard operating procedure (SOP) documents were requested. Results: Twenty-nine of the 40 hospitals replying currently offer tests for EIB. Of these 48% offered mannitol challenge, 45% ECT, 3% full cardiopulmonary exercise testing and 3% histamine challenge. ECT SOPs were received from nine centres, none of which adhered to full recommendations for medication abstinence. All ECT SOPs used heart rate to measure exercise intensity, and a majority (89%) adhered to exercise intensity guidelines. Environmental conditions (inspired air temp and relative humidity%) are considered in 22%, and 33% adhere to recommended post-exercise lung function testing regimen. Criteria for a diagnosis of EIB varied between hospitals, with 56% of ECT SOPs specifying a fall of ≥10% as diagnostic. Conclusion: Two thirds of UK hospitals offer an indirect BCT for diagnosis of EIB. However, there is limited adherence to ECT guidelines and consequent significant variation in practice.