RT Journal Article
SR Electronic
T1 CPAP Decreases Lung Hyperinflation in Patients With Stable COPD
JF Respiratory Care
FD American Association for Respiratory Care
SP 1164
OP 1169
DO 10.4187/respcare.01092
VO 56
IS 8
A1 Agnaldo J Lopes
A1 Flávio POS Nery
A1 Felipe C Sousa
A1 Fernando S Guimarães
A1 Cristina M Dias
A1 Juliana F Oliveira
A1 Sara LS Menezes
YR 2011
UL http://rc.rcjournal.com/content/56/8/1164.abstract
AB BACKGROUND: Dynamic hyperinflation, caused by expiratory flow limitation, markedly increases resting end-expiratory lung volume (functional residual capacity) in many COPD patients. OBJECTIVE: To determine the impact and duration of impact of CPAP on hyperinflation and airway resistance in patients with stable COPD. METHODS: In a case series, 21 patients underwent CPAP at 8 cm H2O for 15 min, then whole-body plethysmography immediately after, and at 15 and 30 min after CPAP. RESULTS: The cohort's mean ± SD age was 70 ± 9 y, and the mean FEV1 was 41 ± 8% of predicted. Residual volume, functional residual capacity, total lung capacity, the ratio of residual volume to total lung capacity, and airway resistance decreased after CPAP and did not significantly change at 15 min (P < .001), but returned to baseline at 30 min. CONCLUSIONS: In patients with severe to very severe stable COPD, CPAP reduces lung volumes and airway resistance for 15 min, but the lung volumes return to baseline by 30 min.