RT Journal Article
SR Electronic
T1 Time constant of respiratory muscle relaxation in patients with cystic fibrosis
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P1973
VO 44
IS Suppl 58
A1 Theodore Dassios
A1 Athanasios Kaditis
A1 Anna Katelari
A1 George Chrousos
A1 Stavros Doudounakis
A1 Gabriel Dimitriou
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/P1973.abstract
AB Background: Patients with cystic fibrosis (CF) are at increased risk of respiratory muscle fatigue and respiratory failure, secondary to lower airway obstruction and malnutrition. Testing for respiratory muscle fatigue involves complex methodology and the physical presence of the patient in a research facility. The time constant of respiratory muscle relaxation (τ) is a simple bedside test which can be alternatively used to assess CF patients for respiratory muscle fatigue.Measures: For this cross-sectional study, we measured body mass index z-score (BMI), upper arm muscle area (UAMA), Forced Expiratory Volume in 1 second z-score (FEV1), Forced Vital Capacity z-score (FVC), maximal inspiratory pressure (Pimax), τ after maximal inspiration (τ-Pimax), maximal expiratory pressure (Pemax) and τ after maximal expiration (τ-Pemax).Results: Fifty-three CF patients [median age 14 years (interquartile range: 11-19.5)] and 53 age- and sex-matched healthy controls [14 years (11-19.5)]were recruited.Pimax and Pemax did not differ significantly between patients and controls.Median (IQR) τ-Pimax in CF subjects [253(188-406)] was significantly increased compared to median (IQR) τ-Pimax in controls [117(81-185); p<0.001]. Median (IQR) τ-Pemax in CF subjects [232 (105-344)] was significantly increased compared to median (IQR) τ-Pemax in controls [101 (78-143); p<0.001]. τ-Pimax was significantly related to FEV1 (r=-0.205, p=0.031) and FVC (r=-0.294, p=0.002) but not to BMI or UAMA.Conclusions: Our findings suggest that CF patients are predisposed to respiratory muscle fatigue as described by slow respiratory muscle relaxation, which is significantly associated with severity of spirometric abnormalities.