Spahija Jadranka, de Marchie Michel, Grassino Alejandro
School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada.
Chest. 2005 Aug;128(2):640-50. doi: 10.1378/chest.128.2.640.
To investigate the effect of volitional pursed-lips breathing (PLB) on breathing pattern, respiratory mechanics, operational lung volumes, and dyspnea in patients with COPD.
Eight COPD patients (6 male and 2 female) with a mean (+/-SD) age of 58 +/- 11 years and a mean FEV1 of 1.34 +/- 0.44 L (50 +/- 21% predicted).
Wearing a tight-fitting transparent facemask, patients breathed for 8 min each, with and without PLB at rest and during constant-work-rate bicycle exercise (60% of maximum).
PLB promoted a slower and deeper breathing pattern both at rest and during exercise. Whereas patients had no dyspnea with or without PLB at rest, during exercise dyspnea was variably affected by PLB across patients. Changes in the individual dyspnea scores with PLB during exercise were significantly correlated with changes in the end-expiratory lung volume (EELV) values estimated from inspiratory capacity maneuvers (as a percentage of total lung capacity; r2 = 0.82, p = 0.002) and with changes in the mean inspiratory ratio of pleural pressure to the maximal static inspiratory pressure-generating capacity (PcapI) [r2 = 0.84; p = 0.001], measured using an esophageal balloon, where PcapI was determined over the range of inspiratory lung volumes and adjusted for flow.
PLB can have a variable effect on dyspnea when performed volitionally during exercise by patients with COPD. The effect of PLB on dyspnea is related to the combined change that it promotes in the tidal volume and EELV and their impact on the available capacity of the respiratory muscles to meet the demands placed on them in terms of pressure generation.
探讨自主缩唇呼吸（PLB）对慢性阻塞性肺疾病（COPD）患者呼吸模式、呼吸力学、有效肺容积和呼吸困难的影响。
8例COPD患者（6例男性，2例女性），平均（±标准差）年龄58±11岁，平均第1秒用力呼气容积（FEV1）为1.34±0.44L（占预计值的50±21%）。
患者佩戴贴合面部的透明面罩，分别在静息状态和恒定功率自行车运动（最大运动强度的60%）时进行8分钟的呼吸，一次有PLB，一次无PLB。
PLB使静息和运动时的呼吸模式更慢且更深。静息时，无论有无PLB患者均无呼吸困难，但运动时，不同患者的呼吸困难受PLB的影响各异。运动时PLB导致的个体呼吸困难评分变化与通过吸气容量动作估算的呼气末肺容积（EELV）值变化（占肺总量的百分比；r2 = 0.82，p = 0.002）以及与使用食管气囊测量的胸膜压力与最大静态吸气压力产生能力（PcapI）的平均吸气比值变化显著相关[r2 = 0.84；p = 0.001]，其中PcapI是在吸气肺容积范围内测定并根据流量进行调整的。
COPD患者在运动时自主进行PLB，对呼吸困难的影响可能因人而异。PLB对呼吸困难的影响与它所促进的潮气量和EELV的联合变化及其对呼吸肌满足压力产生需求的可用能力的影响有关。
