Changes in pulmonary function and feasibility of portable continuous laryngoscopy during maximal uphill running

Objective To evaluate changes in pulmonary function and feasibility of portable continuous laryngoscopy during maximal uphill running. Methods Healthy volunteers participated in an uphill race. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were obtained before and 5 and 10 min after finishing the race. Capillary blood lactate concentration ([BLa-]) and Borg score for perceived exertion were registered immediately after the race. One participant wore a portable video-laryngoscope during the race, and the video was assessed for technical performance. Results Twenty adult subjects participated with a mean (SD) age of 40.2 (9.7) years. Mean (SD) race duration and post-exercise [BLa-] was 13.9 (2.3) min and 10.7 (2.1) mmol/L, respectively, and the median (range) Borg score for perceived exertion was 9 (5–10). Mean percentage change (95% CI) 5 and 10 min post-exercise in FEV1 were 6.9 (3.7 to 10.2) % and 5.9 (2.7 to 9.0) %, respectively, and in FVC 5.2 (2.3 to 8.1) % and 4.7 (1.6 to 7.9) %, respectively. The recorded video of the larynx was of good quality. Conclusions Maximal aerobic field exercise induced bronchodilatation in the majority of the healthy non-asthmatic participants. It is feasible to perform continuous video-laryngoscopy during heavy uphill exercise.publishedVersio

Exercise inducible laryngeal obstruction: diagnostics and management

Obstruction of the central airways is an important cause of exercise-induced inspiratory symptoms (EIIS) in young and otherwise healthy individuals. This is a large, heterogeneous and vastly understudied group of patients. The symptoms are too often confused with those of asthma. Laryngoscopy performed as symptoms evolve during increasing exercise is pivotal, since the larynx plays an important role in symptomatology for the majority. Abnormalities vary between patients, and laryngoscopic findings are important for correct treatment and handling. The simplistic view that all EIIS is due to vocal cord dysfunction [VCD] still hampers science and patient management. Causal mechanisms are poorly understood. Most treatment options are based on weak evidence, but most patients seem to benefit from individualised information and guidance. The place of surgery has not been settled, but supraglottoplasty may cure well-defined severe cases. A systematic clinical approach, more and better research and randomised controlled treatment trials are of utmost importance in this field of respiratory medicine.publishedVersio

Exercise related respiratory problems in the young—Is it exercise-induced bronchoconstriction or laryngeal obstruction?

Complaints of breathlessness during heavy exercise is common in children and adolescents, and represent expressions of a subjective feeling that may be difficult to verify and to link with specific diagnoses through objective tests. Exercise-induced asthma and exercise-induced laryngeal obstruction are two common medical causes of breathing difficulities in children and adolescents that can be challenging to distinguish between, based only on the complaints presented by patients. However, by applying a systematic clinical approach that includes rational use of tests, both conditions can usually be diagnosed reliably. In this invited mini-review, we suggest an approach we find feasible in our everyday clinical work.publishedVersio

Conundrums in the breathless athlete; exercise-induced laryngeal obstruction or asthma?

Purpose: Exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) are the two disorders commonly considered when athletes complain of exertional dyspnea. They are highly different but often confused. We aimed to address this diagnostic challenge and its consequences in elite athletes. Methods: We included all athletes competing at national or international level, referred to our institution for workup for EILO during 2013–2016. We diagnosed EILO from video-recorded laryngoscopy performed during maximal cardiopulmonary treadmill exercise (CLE test). Symptoms and previous diagnostic evaluations were obtained from referral letters and chart reviews. Results: Exercise-induced laryngeal obstruction was diagnosed in 73/101 referred athletes, of whom 70/73 had moderate/severe supraglottic obstruction and 3/73 had primarily glottic obstruction with only minor supraglottic involvement. Of the 73 athletes with EILO, we were able to identify objective tests for asthma in 55 participants, of whom 22 had findings supporting asthma. However, 58/73 had used asthma therapy at some time previously, with current use in 28. Only three reported that asthma medication had improved their exercise-related breathing problems, two of whom with tests confirming asthma. Treatment for EILO improved breathing problems in all but four. Conclusions: Objective testing verified EILO in most of the referred athletes. EILO coexisting with asthma was common, and large proportions had used asthma medication; however, few reported effect on exercise-related breathing problems. Unexplained persistent exertional dyspnea must not lead to indiscriminate escalation of asthma treatment, but instead incite investigation for EILO, either as a co-morbidity or as a differential diagnosis.publishedVersio

Exercise-induced laryngeal obstruction (EILO) in athletes: a narrative review by a subgroup of the IOC Consensus on 'acute respiratory illness in the athlete'

Exercise-induced laryngeal obstruction (EILO) is caused by paradoxical inspiratory adduction of laryngeal structures during exercise. EILO is an important cause of upper airway dysfunction in young individuals and athletes, can impair exercise performance and mimic lower airway dysfunction, such as asthma and/or exercise-induced bronchoconstriction. Over the past two decades, there has been considerable progress in the recognition and assessment of EILO in sports medicine. EILO is a highly prevalent cause of unexplained dyspnoea and wheeze in athletes. The preferred diagnostic approach is continuous visualisation of the larynx (via laryngoscopy) during high-intensity exercise. Recent data suggest that EILO consists of different subtypes, possibly caused via different mechanisms. Several therapeutic interventions for EILO are now in widespread use, but to date, no randomised clinical trials have been performed to assess their efficacy or inform robust management strategies. The aim of this review is to provide a state-of-the-art overview of EILO and guidance for clinicians evaluating and treating suspected cases of EILO in athletes. Specifically, this review examines the pathophysiology of EILO, outlines a diagnostic approach and presents current therapeutic algorithms. The key unmet needs and future priorities for research in this area are also covered.publishedVersio

Development of lung diffusion to adulthood following extremely preterm birth

Background: Gas exchange in extremely preterm (EP) infants must take place in fetal lungs. Childhood lung diffusing capacity of the lung for carbon monoxide (DLCO) is reduced; however, longitudinal development has not been investigated. We describe the growth of DLCO and its subcomponents to adulthood in EP compared with term-born subjects. Methods: Two area-based cohorts born at gestational age ≤28 weeks or birthweight ≤1000 g in 1982–1985 (n=48) and 1991–1992 (n=35) were examined twice, at ages 18 and 25 years and 10 and 18 years, respectively, and compared with matched term-born controls. Single-breath DLCO was measured at two oxygen pressures, with subcomponents (membrane diffusion (DM) and pulmonary capillary blood volume (VC)) calculated using the Roughton–Forster equation. Results: Age-, sex- and height-standardised transfer coefficients for carbon monoxide (KCO) and DLCO were reduced in EP compared with term-born subjects, and remained so during puberty and early adulthood (p-values for all time-points and both cohorts ≤0.04), whereas alveolar volume (VA) was similar. Development occurred in parallel to term-born controls, with no signs of pubertal catch-up growth nor decline at age 25 years (p-values for lack of parallelism within cohorts 0.99, 0.65, 0.71, 0.94 and 0.44 for z-DLCO, z-VA, z-KCO, DM and VC, respectively). Split by membrane and blood volume components, findings were less clear; however, membrane diffusion seemed most affected. Conclusions: Pulmonary diffusing capacity was reduced in EP compared with term-born subjects, and development from childhood to adulthood tracked in parallel to term-born subjects, with no signs of catch-up growth nor decline at age 25 years.publishedVersio

Clinical responses following inspiratory muscle training in exercise-induced laryngeal obstruction

Purpose Exercise-induced laryngeal obstruction (EILO) is relatively common in young people. Treatment rests on poor evidence; however, inspiratory muscle training (IMT) has been proposed a promising strategy. We aimed to assess laryngeal outcomes shortly after IMT, and to compare self-reported symptoms with a control group 4–6 years later. Methods Two groups were retrospectively identified from the EILO-register at Haukeland University Hospital, Norway; one group had received only information and breathing advice (IBA), and another additionally IMT (IBA + IMT). At diagnosis, all participants performed continuous laryngoscopy during exercise (CLE), with findings split by glottic and supraglottic scores, and completed a questionnaire mapping exercise-related symptoms. After 2–4 weeks, the IBA + IMT-group was re-evaluated with CLE-test. After 4–6 years, both groups were re-assessed with a questionnaire. Results We identified 116 eligible patients from the EILO-register. Response rates after 4–6 years were 23/58 (40%) and 32/58 (55%) in the IBA and IBA + IMT-group, respectively. At diagnosis, both groups rated symptoms similarly, but laryngeal scores were higher in the IBA + IMT-group (P = 0.003). After 2–4 weeks, 23/32 in the IBA + IMT-group reported symptom improvements, associated with a decrease of mainly glottic scores (1.7–0.3; P < 0.001), contrasting unchanged scores in the 9/32 without symptom improvements. After 4–6 years, exercise-related symptoms and activity levels had decreased to similar levels in both groups, with no added benefit from IMT; however, full symptom resolution was reported by only 8/55 participants. Conclusion Self-reported EILO symptoms had improved after 4–6 years, irrespective of initial treatment. Full symptom resolution was rare, suggesting individual follow-up should be offered.publishedVersio

Predicting physical activity in a national cohort of children born extremely preterm

Predicting physical activity in a national cohort of children born extremely preterm. Objectives: To compare physical activity among school-aged children born extremely preterm or with extremely low birthweight (EP/ELBW) to term-born children, and to identify early predictors for physical inactivity in the EP/ELBW-children. Methods: A national cohort born during 1999–2000 at gestational age < 28 weeks or birthweight <1000 g and term-born controls were assessed. EP/ELBW-children without neurodevelopmental disabilities were labeled “healthy”. At five years, we examined the EP/ELBW-children's motor, mental and intellectual functioning using the Movement Assessment Battery for Children (MABC), The Strength and Difficulties Questionnaire (SDQ) and The Wechsler Preschool and Primary Scale of Intelligence-revised. At 11 years, the parents reported their children's physical activity (PA) in questionnaires. Results: Information was obtained from 231/372 EP/ELBW and 57/61 term-born children. At 11 years, EP/ELBW-children had fewer exercise events per week, were less engaged in team sports, had lower endurance, lower sports proficiency, and were less vigorous during PA than term-born children (p < 0.05). Low sports proficiency in the healthy EP/ELBW-children at 11 years was predicted (odds ratio; 95% confidence interval) by abnormal MABC-score (3.0; 1.0 to 8.7), and abnormal SDQ-score (4.0; 1.6 to 10.0) at 5 years. Lower endurance at PA was predicted by abnormal MABC-score (2.6; 1.0 to 6.6), abnormal SDQ-score (3.0; 1.4 to 6.5), and borderline intellectual functioning (4.2; 1.8 to 10.1). Conclusions: Eleven-year-old EP/ELBW-children were less physically active than term-born. In healthy EP/ELBW-children, impaired motor coordination, borderline intellectual functioning and behavioral problems at 5 years of age predicted unfavorable PA habits at 11 years.publishedVersio

Impaired Lung Function in Extremely Preterm-Born Adults in Their Fourth Decade of Life

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Reliability of maximum oxygen uptake in cardiopulmonary exercise testing with continuous laryngoscopy

Aims: A cardiopulmonary exercise test (CPET) is the gold standard to evaluate symptom-limiting exercise intolerance, while continuous laryngoscopy performed during exercise (CLE) is required to diagnose exercise-induced laryngeal obstruction. Combining CPET with CLE would save time and resources; however, the CPET data may be distorted by the extra equipment. We therefore aimed to study whether CPET with CLE influences peak oxygen uptake (V′O2peak) and other gas exchange parameters when compared to a regular CPET. Methods: Forty healthy athletes without exercise-related breathing problems, 15–35 years of age, performed CPET to peak exercise with and without an added CLE set-up, in randomised order 2–4 days apart, applying an identical computerised treadmill protocol. Results: At peak exercise, the mean difference (95% confidence interval) between CPET with and without extra CLE set-up for V′O2peak, respiratory exchange ratio (RER), minute ventilation (V′E) and heart rate (HR) was 0.2 (−0.4 to 0.8) mL·kg−1·min−1, 0.01(−0.007 to 0.027) units, 2.6 (−1.3 to 6.5) L·min−1 and 1.4 (−0.8 to 3.5) beats·min−1, respectively. Agreement (95% limits of agreement) for V′O2peak, RER and V′E was 0.2 (±3.7) mL·kg−1·min−1, 0.01 (±0.10) units and 2.6 (±24.0) L·min−1, respectively. No systematic or proportional bias was found except for the completed distance, which was 49 m (95% CI 16 to 82 m) longer during CPET. Conclusion: Parameters of gas exchange, including V′O2peak and RER, obtained from a maximal CPET performed with the extra CLE set-up can be used interchangeably with data obtained from standard CPET, thus preventing unnecessary additional testing.publishedVersio