Resting Respiratory Resistance in Female Teenage Athletes With and Without Exercise-Induced Laryngeal Obstruction.

OBJECTIVE: Exercise-induced laryngeal obstruction (EILO) occurs with paradoxical vocal fold motion or supraglottic collapse during moderate to vigorous exercise. Previously, Gallena et al (2015) reported lower-than-normal inspiratory (Ri) and expiratory (Re) resistances during resting tidal breathing (RTB) in female teenage athletes with EILO. This study aimed to replicate that unexpected result. METHOD: The Airflow Perturbation Device measured Ri and Re during three 1-minute trials of RTB in 16 teenage female athletes with EILO and 16 sex-, age-, and height-matched controls. Multiple linear regression examined group, age, height, and weight as predictors of Ri and Re. RESULTS: Ri and Re tended to be lower in the EILO group than the control group [Ri: F(1,30) = 3.58, P = 0.068, d = 0.686; Re: F(1,30) = 3.28, P = 0.080, d = 0.640], but there was no statistically significant difference in the overall effect [F(2,29) = 1.75, P = 0.192]. After one outlier for Re from the EILO group and her matched control were removed, the overall difference was statistically significant, F(2,27) = 3.38, P = 0.049, with Re primarily contributing to the difference [Ri: F(1,28) = 3.66, P = 0.066, d = 0.719; Re: F(1,28) = 5.69, P = 0.024, d = 0.899]. CONCLUSION: These results did not replicate the robust differences found previously between Ri and Re during RTB in teenage girls with and without EILO, but the results trended in the same direction and met criterion for statistical significance once an outlier was removed from analysis. Overall, the observation that resting respiratory resistances were lower in most teenage girls with EILO suggests that reduced tone of the laryngeal and/or lower airways may predispose young athletes to EILO.

Short-Term Intensive Therapy and Outcomes for Athletes With Paradoxical Vocal Fold Motion Disorder.

Purpose The aim of the study was to develop a treatment for athletes with paradoxical vocal fold motion disorder (PVFMD) based on exercise physiology and learning theory principles and administer it over a preestablished time frame. Method A prospective, repeated-measures, within-subject group design was used. Eleven adolescent/teen athletes diagnosed with PVFMD via laryngoscopy received short-term intensive (STI) therapy. Eight of the athletes returned for extended follow-up. Changes in postexercise inspiratory ( R i) and expiratory ( R e) resistances and Modified Borg Dyspnea Scale (MBDS) ratings collected at baseline were compared immediately posttreatment and at extended follow-up. Dyspnea Index scores were collected at baseline and at extended follow-up. Two no-treatment control athletes with PVFMD participated in two exercise challenges-baseline and 6 weeks later. Results Immediately after STI therapy, athletes attained significant improvement in R i, R e, and MBDS ratings. These changes were maintained at extended follow-up as well as a significant change in Dyspnea Index scores. The 2 control athletes who were reassessed 6 weeks after baseline experienced negative changes in postexercise R i and MBDS ratings. Conclusion STI therapy that incorporated individuality, specificity, and variable practice effectively changed outcome measures posttreatment with further improvement observed at extended follow-up. These results provide preliminary evidence for STI therapy for PVFMD.

A Rapid, Handheld Device to Assess Respiratory Resistance: Clinical and Normative Evidence.

INTRODUCTION: Following reports of respiratory symptoms among service members returning from deployment to South West Asia (SWA), an expert panel recommended pre-deployment spirometry be used to assess disease burden. Unfortunately, testing with spirometry is high cost and time-consuming. The airflow perturbation device (APD) is a handheld monitor that rapidly measures respiratory resistance (APD-Rr) and has promising but limited clinical data. Its speed and portability make it ideally suited for large volume pre-deployment screening. We conducted a pilot study to assess APD performance characteristics and develop normative values. MATERIALS AND METHODS: We prospectively enrolled subjects and derived reference equations for the APD from those without respiratory symptoms, pulmonary disease, or tobacco exposure. APD testing was conducted by medical technicians who received a 10-min in-service on its use. A subset of subjects performed spirometry and impulse oscillometry (iOS), administered by trained respiratory therapists. APD measures were compared with spirometry and iOS. RESULTS: The total study population included 199 subjects (55.8% males, body mass index 27.7 ± 6.0 kg/m2, age 49.9 ± 18.7 yr). Across the three APD trials, mean inspiratory (APD-Ri), expiratory (APD-Re), and average (APD-Ravg) resistances were 3.30 ± 1.0, 3.69 ± 1.2, and 3.50 ± 1.1 cm H2O/L/s. Reference equations were derived from 142 clinically normal volunteers. Height, weight, and body mass index were independently associated with APD-Ri, APD-Re, and APD-Ravg and were combined with age and gender in linear regression models. APD-Ri, APD-Re, and APD-Ravg were significantly inversely correlated with FEV1 (r = -0.39 to -0.42), FVC (r = -0.37 to -0.40), and FEF25-75 (r = -0.31 to -0.35) and positively correlated with R5 (r = 0.61-0.62), R20 (r = 0.50-0.52), X5 (r = -0.57 to -0.59), and FRES (r = 0.42-0.43). Bland-Altman plots showed that the APD-Rr closely approximates iOS when resistance is normal. CONCLUSION: Rapid testing was achieved with minimal training required, and reference equations were constructed. APD-Rr correlated moderately with iOS and weakly with spirometry. More testing is required to determine whether the APD has value for pre- and post-deployment respiratory assessment.

The Effect of Exercise on Respiratory Resistance in Athletes With and Without Paradoxical Vocal Fold Motion Disorder.

PURPOSE: An investigational, portable instrument was used to assess inspiratory (R(i)) and expiratory (R(e)) resistances during resting tidal breathing (RTB), postexercise breathing (PEB), and recovery breathing (RB) in athletes with and without paradoxical vocal fold motion disorder (PVFMD). METHOD: Prospective, controlled, repeated measures within-subject and between-groups design. Twenty-four teenage female athletes, 12 with and 12 without PVFMD, breathed into the Airflow Perturbation Device for baseline measures of respiratory resistance and for two successive 1-min trials after treadmill running for up to 12 min. Exercise duration and dyspnea ratings were collected and compared across groups. RESULTS: Athletes with PVFMD had lower than control R(i) and R(e) values during RTB that significantly increased at PEB and decreased during RB. Control athletes' R(e) decreased significantly from RTB to PEB but not from PEB to RB, whereas R(i) did not change from RTB to PEB but decreased from PEB to RB. Athletes without PVFMD ran longer, providing lower dyspnea ratings. CONCLUSION: Immediately following exercise, athletes with PVFMD experienced increased respiratory resistance that affected their exercise performance. The difference in resting respiratory resistances between groups is intriguing and could point to anatomical differences or neural adaptation in teenagers with PVFMD. The Airflow Perturbation Device appears to be a clinically feasible tool that can provide insight into PVFMD and objective data for tracking treatment progress.

Test-retest reliability of respiratory resistance measured with the airflow perturbation device.

PURPOSE: In this study, the authors aimed to determine reliability of the airflow perturbation device (APD) to measure respiratory resistance within and across sessions during resting tidal (RTB) and postexercise breathing in healthy athletes, and during RTB across trials within a session in athletes with paradoxical vocal fold motion (PVFM) disorder. METHOD: Prospective, repeated-measures design. The APD measured respiratory resistance during 3 baseline assessments in 24 teenage female athletes, 12 with and 12 without PVFM. Control athletes provided data at rest and following a customized exercise challenge during each of 3 sessions. Intraclass correlation coefficient (ICC) analysis assessed strength of relationships, and repeated-measures analysis of variance assessed differences across trials and sessions. RESULTS: ICC analyses confirmed strong correlations across RTB trials for inspiratory, expiratory, and mean respiratory resistance in both groups. Inspiratory resistance decreased ~5% between sessions for control participants; expiratory and mean respiratory resistances were stable. Data from control athletes across sessions and following rigorous exercise were strongly correlated when taken at comparable intervals. CONCLUSIONS: APD-measured respiratory resistance, including separate assessments for the inspiratory and expiratory phases, has strong test-retest reliability during RTB and after exercising. This suggests that the APD is a useful measurement tool for the assessment of airway function in patients suspected of having PVFM.

Validity of a new respiratory resistance measurement device to detect glottal area change.

OBJECTIVE: To determine the correlation between respiratory resistance (Rr) values measured with the Airflow Perturbation Device (APD) to laryngoscopic images of glottal area (GA) in feigned paradoxical vocal fold motion (PVFM), also known as vocal cord dysfunction. HYPOTHESIS: There is a strong inverse relationship between Rr and GA such that laryngeal constriction can be detected and quantified by APD-measured Rr. STUDY DESIGN: Prospective, single subject study. METHODS: A healthy adult feigned breathing that was characteristic of PVFM. Rr and GA were simultaneously recorded, synchronized, and analyzed for three complete breathing cycles with significant glottal constriction occurring during inspiration. RESULTS: Cross-correlation analysis revealed a strong negative correlation (-0.824) between GA and Rr during feigned PVFM breathing such that Rr increased when GA decreased. CONCLUSION: APD-measured Rr appears to be a viable noninvasive method for diagnostic screening and monitoring of treatment outcomes for individuals presenting with dyspnea related to PVFM.