Bianchi Roberto, Gigliotti Francesco, Romagnoli Isabella, Lanini Barbara, Castellani Carla, Grazzini Michela, Scano Giorgio
Fondazione Don C. Gnocchi IRCCS, Via Imprunetana 124, 50020 Pozzolatico, Florence, Italy.
Chest. 2004 Feb;125(2):459-65. doi: 10.1378/chest.125.2.459.
Pursed-lip breathing (PLB) is a strategy often spontaneously employed by patients with COPD during distress situations. Whether and to what extent PLB affects operational lung volume is not known. Also, conflicting reports deal with PLB capability of decreasing breathlessness.
Twenty-two patients with mild-to-severe COPD were studied. Volumes of chest wall (CW) compartments (rib cage [RC] and abdomen) were assessed using an optoelectronic plethysmograph. Dyspnea was assessed by a modified Borg scale.
Compared to spontaneous breathing, patients with PLB exhibited a significant reduction (mean +/- SD) in end-expiratory volume of the CW (VCW) [VCWee; - 0.33 +/- 0.24 L, p < 0.000004], and a significant increase in end-inspiratory VCW (VCWei; + 0.32 +/- 0.43 L, p < 0.003). The decrease in VCWee, mostly due to the decrease in end-expiratory volume of the abdomen (VAbee) [- 0.25 +/- 0.21 L, p < 0.00002], related to baseline FEV(1) (p < 0.02) and to the increase in expiratory time (TE) [r(2) = 0.49, p < 0.0003] and total time of the respiratory cycle (TTOT) [r(2) = 0.35, p < 0.004], but not to baseline functional residual capacity (FRC). Increase in tidal volume (VT) of the chest wall (+ 0.65 +/- 0.48 L, p < 0.000004) was shared between VT of the abdomen (0.31 +/- 0.23 L, p < 0.000004) and VT of the rib cage (+ 0.33 +/- 0.29 L, p < 0.00003). Borg score decreased with PLB (p < 0.04). In a stepwise multiple regression analysis, decrease in VCWee accounted for 27% of the variability in Borg score at 99% confidence level (p < 0.008).
Changes in VCWee related to baseline airway obstruction but not to hyperinflation (FRC). By lengthening of TE and TTOT, PLB decreases VCWee and reduces breathlessness.
缩唇呼吸（PLB）是慢性阻塞性肺疾病（COPD）患者在不适情况下常自发采用的一种策略。PLB是否以及在多大程度上影响有效肺容积尚不清楚。此外，关于PLB减轻呼吸困难能力的报道相互矛盾。
对22例轻至重度COPD患者进行了研究。使用光电体积描记法评估胸壁（CW）各腔室（胸廓[RC]和腹部）的容积。采用改良的Borg量表评估呼吸困难程度。
与自主呼吸相比，采用PLB的患者呼气末胸壁容积（VCW）[VCWee；-0.33±0.24L，p<0.000004]显著降低，吸气末VCW（VCWei；+0.32±0.43L，p<0.003）显著增加。VCWee的降低主要归因于腹部呼气末容积（VAbee）的减少[-0.25±0.21L，p<0.00002]，与基线第1秒用力呼气容积（FEV(1)）相关（p<0.02），与呼气时间（TE）的增加[r(2)=0.49，p<0.0003]和呼吸周期总时间（TTOT）的增加[r(2)=0.35，p<0.004]相关，但与基线功能残气量（FRC）无关。胸壁潮气量（VT）的增加（+0.65±0.48L，p<0.000004）由腹部VT（0.31±0.23L，p<0.000004）和胸廓VT（+0.33±0.29L，p<0.00003）共同构成。采用PLB时Borg评分降低（p<0.04）。在逐步多元回归分析中，VCWee的降低在99%置信水平下占Borg评分变异性的27%（p<0.008）。
VCWee的变化与基线气道阻塞有关，而与肺过度充气（FRC）无关。通过延长TE和TTOT，PLB可降低VCWee并减轻呼吸困难。
