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Timing and driving components of the breathing strategy in children with cystic fibrosis during exercise.
Pediatr Pulmonol 2005; 40(5):449-56PP

Abstract

The aim of this study was twofold: first, to determine the breathing strategies of children with cystic fibrosis (CF) during exercise, and secondly, to see if there was a correlation with lung function parameters. We determined the tension-time index of the inspiratory muscles (T(T0.1)) during exercise in nine children with CF, who were compared with nine healthy children with a similar age distribution. T(T0.1) was determined as followed T(T0.1) = P0.1/PImax . T(I)/T(TOT), where P0.1 is mouth occlusion pressure, PImax is maximal inspiratory pressure, and T(I)/T(TOT) is the duty cycle. CF children showed a significant decrease of their forced expiratory volume in 1 sec (FEV1), forced vital capacity (FCV), and FEV1/FVC, whereas the residual volume to total lung capacity ratio (RV/TLC) ratio and functional residual capacity (FRC) were significantly increased (P < 0.001). Children with CF showed mild malnutrition assessed by actual weight expressed by percentage of ideal weight for height, age, and gender (weight/height ratio; 82.3 +/- 3.6%). Children with CF showed a significant reduction in their PImax (69.3 +/- 4.2 vs. 93.8 +/- 7 cmH2O). We found a negative linear correlation between PImax and weight/height only in children with CF (r = 0.9, P < 0.001). During exercise, P(0.1), P0.1/PImax, and T(T0.1) were significantly higher, for a same percent maximal oxygen uptake in children with CF. On the contrary, T(I)/T(TOT) ratio was significantly lower in children with CF compared with healthy children. At maximal exercise, children with CF showed a T(T0.1) = 0.16 vs. 0.14 in healthy children (P < 0.001). We observed at maximal exercise that P0.1/PImax increased as FEV1/FVC decreased (r = -0.90, P < 0.001), and increased as RV/TLC increased (r = 0.92, P < 0.001) only in children with CF. Inversely, T(I)/T(TOT) decreased as FEV1/FVC decreased (r = 0.89, P < 0.001), and T(I)/T(TOT) decreased as RV/TLC increased (r = -0.94, P < 0.001). These results suggest that children with CF adopted a breathing strategy during exercise in limiting the increase of the duty cycle. Two determinants of this strategy were degrees of airway obstruction and hyperinflation.

Authors+Show Affiliations

EA 3300-APS et Conduites Motrices: Adaptations et Réadaptations, Université Picardie Jules Verne, Amiens, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16163725

Citation

Keochkerian, D, et al. "Timing and Driving Components of the Breathing Strategy in Children With Cystic Fibrosis During Exercise." Pediatric Pulmonology, vol. 40, no. 5, 2005, pp. 449-56.
Keochkerian D, Chlif M, Delanaud S, et al. Timing and driving components of the breathing strategy in children with cystic fibrosis during exercise. Pediatr Pulmonol. 2005;40(5):449-56.
Keochkerian, D., Chlif, M., Delanaud, S., Gauthier, R., Maingourd, Y., & Ahmaidi, S. (2005). Timing and driving components of the breathing strategy in children with cystic fibrosis during exercise. Pediatric Pulmonology, 40(5), pp. 449-56.
Keochkerian D, et al. Timing and Driving Components of the Breathing Strategy in Children With Cystic Fibrosis During Exercise. Pediatr Pulmonol. 2005;40(5):449-56. PubMed PMID: 16163725.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Timing and driving components of the breathing strategy in children with cystic fibrosis during exercise. AU - Keochkerian,D, AU - Chlif,M, AU - Delanaud,S, AU - Gauthier,R, AU - Maingourd,Y, AU - Ahmaidi,S, PY - 2005/9/16/pubmed PY - 2006/3/17/medline PY - 2005/9/16/entrez SP - 449 EP - 56 JF - Pediatric pulmonology JO - Pediatr. Pulmonol. VL - 40 IS - 5 N2 - The aim of this study was twofold: first, to determine the breathing strategies of children with cystic fibrosis (CF) during exercise, and secondly, to see if there was a correlation with lung function parameters. We determined the tension-time index of the inspiratory muscles (T(T0.1)) during exercise in nine children with CF, who were compared with nine healthy children with a similar age distribution. T(T0.1) was determined as followed T(T0.1) = P0.1/PImax . T(I)/T(TOT), where P0.1 is mouth occlusion pressure, PImax is maximal inspiratory pressure, and T(I)/T(TOT) is the duty cycle. CF children showed a significant decrease of their forced expiratory volume in 1 sec (FEV1), forced vital capacity (FCV), and FEV1/FVC, whereas the residual volume to total lung capacity ratio (RV/TLC) ratio and functional residual capacity (FRC) were significantly increased (P < 0.001). Children with CF showed mild malnutrition assessed by actual weight expressed by percentage of ideal weight for height, age, and gender (weight/height ratio; 82.3 +/- 3.6%). Children with CF showed a significant reduction in their PImax (69.3 +/- 4.2 vs. 93.8 +/- 7 cmH2O). We found a negative linear correlation between PImax and weight/height only in children with CF (r = 0.9, P < 0.001). During exercise, P(0.1), P0.1/PImax, and T(T0.1) were significantly higher, for a same percent maximal oxygen uptake in children with CF. On the contrary, T(I)/T(TOT) ratio was significantly lower in children with CF compared with healthy children. At maximal exercise, children with CF showed a T(T0.1) = 0.16 vs. 0.14 in healthy children (P < 0.001). We observed at maximal exercise that P0.1/PImax increased as FEV1/FVC decreased (r = -0.90, P < 0.001), and increased as RV/TLC increased (r = 0.92, P < 0.001) only in children with CF. Inversely, T(I)/T(TOT) decreased as FEV1/FVC decreased (r = 0.89, P < 0.001), and T(I)/T(TOT) decreased as RV/TLC increased (r = -0.94, P < 0.001). These results suggest that children with CF adopted a breathing strategy during exercise in limiting the increase of the duty cycle. Two determinants of this strategy were degrees of airway obstruction and hyperinflation. SN - 8755-6863 UR - https://www.unboundmedicine.com/medline/citation/16163725/Timing_and_driving_components_of_the_breathing_strategy_in_children_with_cystic_fibrosis_during_exercise_ L2 - https://doi.org/10.1002/ppul.20266 DB - PRIME DP - Unbound Medicine ER -