High Prevalence of Exercise-Induced Stridor During Parkrun
Total Page:16
File Type:pdf, Size:1020Kb
BMJ Open Resp Res: first published as 10.1136/bmjresp-2020-000618 on 30 September 2020. Downloaded from Respiratory research High prevalence of exercise- induced stridor during Parkrun: a cross- sectional field-basedevaluation Joe Sails,1 James H Hull,2,3 Hayden Allen,1 Liam Darville,1 Emil S Walsted,1,2,4 Oliver J Price 1,5 To cite: Sails J, Hull JH, ABSTRACT Key messages Allen H, et al. High prevalence Background and objective The differential diagnosis of exercise- induced stridor for exercise-associa ted breathlessness is broad, during Parkrun: a cross- however, when a young athletic individual presents with What is the key question? sectional field- based respiratory symptoms, they are most often prescribed ► To use a novel sound- based approach to assess- evaluation. BMJ Open Resp Res inhaler therapy for presumed exercise- induced asthma ment to evaluate and characterise abnormal breath- 2020;7:e000618. doi:10.1136/ (EIA). The purpose of this study was therefore to use a ing sounds in a large cohort of recreationally active bmjresp-2020-000618 novel sound- based approach to assessment to evaluate individuals. ► Additional material is the prevalence of exertional respiratory symptoms and What is the bottom line? published online only. To view characterise abnormal breathing sounds in a large cohort The most common audible sign, detected in approx- please visit the journal online ► of recreationally active individuals. imately 1 in 10 individuals, was inspiratory stridor, a (http:// dx. doi. org/ 10. 1136/ Methods Cross-sectional field-based evaluation of bmjresp- 2020- 000618). characteristic feature of upper airway closure occur- individuals completing Parkrun. ring during exercise. Phase 1 Prerace, clinical assessment and baseline Received 20 April 2020 spirometry were conducted. At peak exercise and Why read on? Revised 31 July 2020 immediately postrace, breathing was monitored This study demonstrates the potential value of field- copyright. Accepted 18 August 2020 ► continuously using a smartphone. Recordings were based smartphone audio recordings as a simple analysed retrospectively and coded for signs of the screening modality or adjunctive tool to aid the as- predominant respiratory noise. sessing clinician in an office-based setting to guide Phase 2 A subpopulation that reported symptoms with clinical workup and inform subsequent diagnostic at least one audible sign of respiratory dysfunction was referral. randomly selected and invited to attend the laboratory on a separate occasion to undergo objective clinical workup to confirm or refute EIA. body of evidence indicating a poor associ- Results Forty-eight participants (22.6%) had at least ation between the presence of exertional http://bmjopenrespres.bmj.com/ © Author(s) (or their one audible sign of respiratory dysfunction; inspiratory employer(s)) 2020. Re- use respiratory symptoms and objective evidence stridor (9.9%), expiratory wheeze (3.3%), combined 3 4 permitted under CC BY- NC. No of EIA. stridor+wheeze (3.3%), cough (6.1%). Over one- third of commercial re- use. See rights The limited predictive value of symptoms, and permissions. Published by the cohort (38.2%) were classified as symptomatic. Ten BMJ. individuals attended a follow- up appointment, however, in this context, is likely explained by the presence of conditions that can act to mimic 1Clinical Exercise and only one had objective evidence of EIA. Respiratory Physiology Conclusions The most common audible sign, detected in EIA. In this respect, closure of the laryn- Research Group, Carnegie approximately 1 in 10 individuals, was inspiratory stridor, geal inlet (upper airway) during exercise—a School of Sport, Leeds a characteristic feature of upper airway closure occurring condition termed exercise- induced laryngeal Beckett University, Leeds, UK during exercise. Further work is now required to further 2 obstruction (EILO) is recognised to precipi- Department of Respiratory validate the precision and feasibility of this diagnostic tate breathlessness and wheeze.5 6 EILO is a Medicine, Royal Brompton approach in cohorts reporting exertional breathing on October 1, 2021 by guest. Protected Hospital, London, UK common condition, affecting between 5% difficulty. 7 3Institute of Sport, Exercise and 7% in adolescents, with a higher prev- and Health (ISEH), University alence in athletes and military personnel College London, London, UK 8 9 4 (15%–35%), but can also exist as a comorbid Department of Respiratory INTRODUCTION phenomenon in approximately one in four Medicine, Bispebjerg Hospital, 10 11 Copenhagen, Denmark The differential diagnosis for exercise- patients with asthma. 5Leeds Institute of Medical associated breathlessness with wheeze is A key difference between EILO and EIA Research at St. James’, broad,1 however, when a young athletic is the nature and quality of the respiratory University of Leeds, Leeds, UK individual reports this problem, they are sound that develops during exercise. Specif- Correspondence to most often prescribed inhaler therapy for ically, EILO is typically associated with an Dr Oliver J Price; a presumed diagnosis of exercise- induced inspiratory phase stridor, that is present o. price@ leedsbeckett. ac. uk asthma (EIA).2 This is despite a substantial during exercise, whereas in contrast, EIA can Sails J, et al. BMJ Open Resp Res 2020;7:e000618. doi:10.1136/bmjresp-2020-000618 1 BMJ Open Resp Res: first published as 10.1136/bmjresp-2020-000618 on 30 September 2020. Downloaded from Open access be associated with expiratory wheeze, often maximal in Patient and public involvement the postexercise period. Thus, a unique but mandatory Patients were not involved in the design of this study. requirement, in the assessment of patients who report exertional breathlessness, is the ability to evaluate respi- ratory sounds during exercise (ie, not simply in the clinic Experimental design room). The study was conducted as a cross-sectional field- based The gold- standard method to confirm a diagnosis of evaluation of individuals completing Parkrun across EILO is the continuous laryngoscopy during exercise test Northern England between 2017 and 2019. Phase 1. (CLE)12, a technique that involves flexible nasendoscopy, Prerace, preparticipation health screening, clinical assess- to allow visualisation of the laryngeal structures during ment and baseline spirometry were conducted prior to laboratory- based exercise. Although the feasibility of completing a 5 km time- trial run. At peak exercise and this approach is well established, CLE is currently only immediately postrace, breathing was self-recorded by available at specialist centres across Europe and requires the participant and analysed, retrospectively (figure 1). expensive comprehensive setup and expertise, and thus Phase 2. A subpopulation that reported symptoms and at least one audible sign of respiratory dysfunction was deemed impractical for field-based assessment. Alterna- randomly selected and invited to attend the laboratory tive detection methods used in this setting have included on a separate occasion to undergo objective clinical evaluating the origin of respiratory sounds by auscul- workup to confirm or refute EIA. tating the neck and chest, during exercise. Previously, a high prevalence of inspiratory stridor has been reported when employing sound-based stethoscope assessment PHASE 1 during exercise challenge testing in athletes screened for Clinical assessment and baseline lung function 13 EIA. Respiratory symptoms were assessed via completion of The purpose of this study was therefore to use a novel the Allergy Questionnaire for Athletes (AQUA) (AQUA sound- based approach to assess and evaluate the prev- score: 0–30) and Dyspnoea-12 (D-12 score:1–36). The alence of exertional respiratory symptoms and char- AQUA has previously been validated to evaluate allergic acterise abnormal breathing sounds in a large cohort and respiratory symptoms in athletes15 16—whereas of recreationally active individuals. Due to the typical D-12 quantifies the physical and affective components copyright. features associated with upper and lower airway obstruc- of breathlessness.17 A combined positive AQUA score tion during exercise (ie, high- pitched stridor or ‘whistle’ ≥5 and D-12 score ≥1 was used to confirm symptomatic on inspiration and expiratory wheeze, respectively), we status. Lung function was assessed by maximal forced hypothesised that self-recorded audio using smartphones flow- volume spirometry with established reference values could offer utility as a screening modality to guide clin- employed in accordance with international guidelines.18 ical workup and inform subsequent diagnostic referral. Audio-recordings and sound analysis Breathing sounds during exercise were self- recorded by http://bmjopenrespres.bmj.com/ METHODS the participant using an in- built audio- recording appli- Study population cation on a smartphone. At the start of the race, partic- Two hundred and twenty recreational runners (men: ipants launched the application in preparation to begin n=100) currently meeting the American College of recording at peak exercise (ie, approaching and crossing Sports Medicine physical activity recommendations were the finish line) and immediately postrace for 15 min or enrolled into the study.14 All were non- smokers and free until resting tidal breathing had resumed. To optimise from respiratory, cardiovascular, metabolic and psychi- signal- to- noise ratio (ie, minimise distortion and back- atric disease