Forced vital capacity and not central chemoreflex predicts maximal hyperoxic breath-hold duration in elite apneists

2017 ◽  
Vol 242 ◽  
pp. 8-11 ◽  
Author(s):  
Anthony R. Bain ◽  
Otto F. Barak ◽  
Ryan L. Hoiland ◽  
Ivan Drvis ◽  
Damian M. Bailey ◽  
...  
2001 ◽  
Vol 91 (5) ◽  
pp. 2173-2181 ◽  
Author(s):  
Hye-Won Shin ◽  
Christine M. Rose-Gottron ◽  
Federico Perez ◽  
Dan M. Cooper ◽  
Archie F. Wilson ◽  
...  

Currently accepted techniques utilize the plateau concentration of nitric oxide (NO) at a constant exhalation flow rate to characterize NO exchange, which cannot sufficiently distinguish airway and alveolar sources. Using nonlinear least squares regression and a two-compartment model, we recently described a new technique (Tsoukias et al. J Appl Physiol 91: 477–487, 2001), which utilizes a preexpiratory breath hold followed by a decreasing flow rate maneuver, to estimate three flow-independent NO parameters: maximum flux of NO from the airways ( J NO,max, pl/s), diffusing capacity of NO in the airways ( D NO,air, pl · s−1 · ppb−1), and steady-state alveolar concentration (Calv,ss, ppb). In healthy adults ( n = 10), the optimal breath-hold time was 20 s, and the mean (95% intramaneuver, intrasubject, and intrapopulation confidence interval) J NO,max, D NO,air, and Calv,ss are 640 (26, 20, and 15%) pl/s, 4.2 (168, 87, and 37%) pl · s−1 · ppb−1, and 2.5 (81, 59, and 21%) ppb, respectively. J NO,maxcan be estimated with the greatest certainty, and the variability of all the parameters within the population of healthy adults is significant. There is no correlation between the flow-independent NO parameters and forced vital capacity or the ratio of forced expiratory volume in 1 s to forced vital capacity. With the use of these parameters, the two-compartment model can accurately predict experimentally measured plateau NO concentrations at a constant flow rate. We conclude that this new technique is simple to perform and can simultaneously characterize airway and alveolar NO exchange in healthy adults with the use of a single breathing maneuver.


2020 ◽  
Vol 63 (8) ◽  
pp. 2597-2608
Author(s):  
Emily N. Snell ◽  
Laura W. Plexico ◽  
Aurora J. Weaver ◽  
Mary J. Sandage

Purpose The purpose of this preliminary study was to identify a vocal task that could be used as a clinical indicator of the vocal aptitude or vocal fitness required for vocally demanding occupations in a manner similar to that of the anaerobic power tests commonly used in exercise science. Performance outcomes for vocal tasks that require rapid acceleration and high force production may be useful as an indirect indicator of muscle fiber complement and bioenergetic fitness of the larynx, an organ that is difficult to study directly. Method Sixteen women (age range: 19–24 years, M age = 22 years) were consented for participation and completed the following performance measures: forced vital capacity, three adapted vocal function tasks, and the horizontal sprint test. Results Using a within-participant correlational analyses, results indicated a positive relationship between the rate of the last second of a laryngeal diadochokinesis task that was produced at a high fundamental frequency/high sound level and anaerobic power. Forced vital capacity was not correlated with any of the vocal function tasks. Conclusions These preliminary results indicate that aspects of the laryngeal diadochokinesis task produced at a high fundamental frequency and high sound level may be useful as an ecologically valid measure of vocal power ability. Quantification of vocal power ability may be useful as a vocal fitness assessment or as an outcome measure for voice rehabilitation and habilitation for patients with vocally demanding jobs.


Pneumologie ◽  
2017 ◽  
Vol 71 (S 01) ◽  
pp. S1-S125
Author(s):  
U Costabel ◽  
C Albera ◽  
KU Kirchgaessler ◽  
F Gilberg ◽  
U Petzinger ◽  
...  

2020 ◽  
Vol 91 (7) ◽  
pp. 578-585
Author(s):  
Victory C. Madu ◽  
Heather Carnahan ◽  
Robert Brown ◽  
Kerri-Ann Ennis ◽  
Kaitlyn S. Tymko ◽  
...  

PURPOSE: This study was intended to determine the effect of skin cooling on breath-hold duration and predicted emergency air supply duration during immersion.METHODS: While wearing a helicopter transport suit with a dive mask, 12 subjects (29 ± 10 yr, 78 ± 14 kg, 177 ± 7 cm, 2 women) were studied in 8 and 20°C water. Subjects performed a maximum breath-hold, then breathed for 90 s (through a mouthpiece connected to room air) in five skin-exposure conditions. The first trial was out of water for Control (suit zipped, hood on, mask off). Four submersion conditions included exposure of the: Partial Face (hood and mask on); Face (hood on, mask off); Head (hood and mask off); and Whole Body (suit unzipped, hood and mask off).RESULTS: Decreasing temperature and increasing skin exposure reduced breath-hold time (to as low as 10 ± 4 s), generally increased minute ventilation (up to 40 ± 15 L · min−1), and decreased predicted endurance time (PET) of a 55-L helicopter underwater emergency breathing apparatus. In 8°C water, PET decreased from 2 min 39 s (Partial Face) to 1 min 11 s (Whole Body).CONCLUSION: The most significant factor increasing breath-hold and predicted survival time was zipping up the suit. Face masks and suit hoods increased thermal comfort. Therefore, wearing the suits zipped with hoods on and, if possible, donning the dive mask prior to crashing, may increase survivability. The results have important applications for the education and preparation of helicopter occupants. Thermal protective suits and dive masks should be provided.Madu VC, Carnahan H, Brown R, Ennis K-A, Tymko KS, Hurrie DMG, McDonald GK, Cornish SM, Giesbrecht GG. Skin cooling on breath-hold duration and predicted emergency air supply duration during immersion. Aerosp Med Hum Perform. 2020; 91(7):578–585.


2021 ◽  
pp. 021849232110100
Author(s):  
Neetika Katiyar ◽  
Sandeep Negi ◽  
Sunder Lal Negi ◽  
Goverdhan Dutt Puri ◽  
Shyam Kumar Singh Thingnam

Background Pulmonary complications after cardiac surgery are very common and lead to an increased incidence of post-operative morbidity and mortality. Several factors, either modifiable or non-modifiable, may contribute to the associated unfavorable consequences related to pulmonary function. This study was aimed to investigate the degree of alteration and factors influencing pulmonary function (forced expiratory volume in one second (FEV1) and forced vital capacity), on third, fifth, and seventh post-operative days following cardiac surgery. Methods This study was executed in 71 patients who underwent on-pump cardiac surgery. Pulmonary function was assessed before surgery and on the third, fifth, and seventh post-operative days. Data including surgical details, information about risk factors, and assessment of pulmonary function were obtained. Results The FEV1 and forced vital capacity were significantly impaired on post-operative days 3, 5, and 7 compared to pre-operative values. The reduction in FEV1 was 41%, 29%, and 16% and in forced vital capacity was 42%, 29%, and 19% consecutively on post-operative days 3, 5, and 7. Multivariate analysis was done to detect the factors influencing post-operative FEV1 and forced vital capacity. Discussion This study observed a significant impairment in FEV1 and forced vital capacity, which did not completely recover by the seventh post-operative day. Different factors affecting post-operative FEV1 and forced vital capacity were pre-operative FEV1, age ≥60, less body surface area, lower pre-operative chest expansion at the axillary level, and having more duration of cardiopulmonary bypass during surgery. Presence of these factors enhances the chance of developing post-operative pulmonary complications.


2021 ◽  
Vol 22 (sup1) ◽  
pp. 14-21
Author(s):  
Gabriela M. Stegmann ◽  
Shira Hahn ◽  
Cayla J. Duncan ◽  
Seward B. Rutkove ◽  
Julie Liss ◽  
...  

2020 ◽  
Vol 7 (1) ◽  
pp. e000598
Author(s):  
Michael T Durheim ◽  
Anna-Maria Hoffmann-Vold ◽  
Tomas M Eagan ◽  
Arnt-Ove Hovden ◽  
May Brit Lund ◽  
...  

IntroductionIdiopathic pulmonary fibrosis (IPF) and systemic sclerosis-associated interstitial lung disease (SSc-ILD) are fibrotic ILDs with divergent disease populations. Little is known about health-related quality of life (HRQL) in SSc-ILD relative to IPF.MethodsWe used the Kings Brief Interstitial Lung Disease Questionnaire (K-BILD) to compare HRQL in a cross-sectional study of 57 patients with IPF and 29 patients with SSc-ILD. Analysis of covariance was used to adjust for age, gender and lung function.ResultsThe unadjusted mean K-BILD score was 63.1 (95% CI 57.1 to 69.1) among patients with SSc-ILD, as compared with 54.7 (51.8–57.5) among those with IPF (p=0.005). However, this difference in HRQL was attenuated after adjustment for age, gender and lung function. In a multivariable model, only forced vital capacity was associated with K-BILD scores. K-BILD scores were correlated with both forced vital capacity and with other relevant HRQL measures, regardless of ILD diagnosis.DiscussionPatients with SSc-ILD may have better ILD-specific quality of life than patients with IPF, but this difference appears to be driven primarily by better lung function. These results underscore the impact of lung function on HRQL in fibrotic ILD and the utility of K-BILD to assess HRQL in SSc-ILD.


Rheumatology ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 250-255
Author(s):  
Takashi Nawata ◽  
Yuichiro Shirai ◽  
Mikito Suzuki ◽  
Masataka Kuwana

Abstract Objective To investigate the potential contribution of accessory respiratory muscle atrophy to the decline of forced vital capacity (FVC) in patients with SSc-associated interstitial lung disease (ILD). Methods This single-centre, retrospective study enrolled 36 patients with SSc-ILD who underwent serial pulmonary function tests and chest high-resolution CT (HRCT) simultaneously at an interval of 1–3 years. The total extent of ILD and chest wall muscle area at the level of the ninth thoracic vertebra on CT images were evaluated by two independent evaluators blinded to the patient information. Changes in the FVC, ILD extent, and chest wall muscle area between the two measurements were assessed in terms of their correlations. Multiple regression analysis was conducted to identify the independent contributors to FVC decline. Results Interval changes in FVC and total ILD extent were variable among patients, whereas chest wall muscle area decreased significantly with time (P=0.0008). The FVC change was negatively correlated with the change in ILD extent (r=−0.48, P=0.003) and was positively correlated with the change in the chest wall muscle area (r = 0.53, P=0.001). Multivariate analysis revealed that changes in total ILD extent and chest wall muscle area were independent contributors to FVC decline. Conclusion In patients with SSc-ILD, FVC decline is attributable not only to the progression of ILD but also to the atrophy of accessory respiratory muscles. Our findings call attention to the interpretation of FVC changes in patients with SSc-ILD.


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