Petrof B J, Kimoff R J, Levy R D, Cosio M G, Gottfried S B
Department of Medicine, Montreal General Hospital, Quebec, Canada.
Am Rev Respir Dis. 1991 May;143(5 Pt 1):928-35. doi: 10.1164/ajrccm/143.5_Pt_1.928.
Patients with chronic respiratory insufficiency due to severe chronic obstructive pulmonary disease (COPD) and presumed respiratory muscle fatigue may benefit from therapeutic maneuvers aimed at reducing the magnitude of inspiratory muscle effort. Recent work has demonstrated that continuous positive airway pressure (CPAP) can significantly reduce inspiratory effort and work of breathing in COPD patients with acute respiratory failure. Accordingly it was reasoned that prolonged CPAP administration may similarly reduce the work of breathing in stable COPD patients with chronic respiratory insufficiency, thereby allowing recovery from respiratory muscle fatigue. The purpose of this study was to determine the feasibility of employing nasal CPAP during sleep as a means of implementing this approach to reducing inspiratory muscle effort in such patients. Standard polysomnographic parameters were recorded during nocturnal administration of nasal CPAP in eight stable patients with severe COPD (FEV1 = 26.7 +/- 3.9% of predicted). Esophageal pressure, diaphragmatic (EMGdi) and parasternal intercostal (EMGic) electromyographic activity, arterial oxyhemoglobin saturation (SaO2), and transcutaneous PCO2 (PtcCO2) were also measured. Breathing pattern was determined by respiratory inductive plethysmography. In each patient an optimum level of nasal CPAP could be determined that produced consistent reductions in indices of inspiratory muscle effort without changing tidal volume or breathing frequency. Highly significant reductions in the tidal excursions of esophageal pressure and the pressure-time integral for the inspiratory muscles occurred at the optimum CPAP level in all patients. EMGdi and EMGic were similarly reduced. SaO2 and PtcCO2 were unaffected by CPAP. These results indicate that nasal CPAP can effectively reduce inspiratory muscle effort during sleep in patients with severe COPD.(ABSTRACT TRUNCATED AT 250 WORDS)
患有严重慢性阻塞性肺疾病（COPD）导致慢性呼吸功能不全且推测存在呼吸肌疲劳的患者，可能会从旨在降低吸气肌用力程度的治疗措施中获益。最近的研究表明，持续气道正压通气（CPAP）可显著降低急性呼吸衰竭的COPD患者的吸气用力和呼吸功。因此，有理由认为，长期给予CPAP可能同样会降低慢性呼吸功能不全的稳定期COPD患者的呼吸功，从而使呼吸肌疲劳得以恢复。本研究的目的是确定在睡眠期间使用鼻CPAP作为降低此类患者吸气肌用力的一种方法的可行性。在8例重度COPD稳定期患者（FEV1 = 预测值的26.7 +/- 3.9%）夜间给予鼻CPAP期间，记录了标准的多导睡眠图参数。还测量了食管压力、膈肌（EMGdi）和胸骨旁肋间肌（EMGic）的肌电图活动、动脉血氧血红蛋白饱和度（SaO2）和经皮二氧化碳分压（PtcCO2）。通过呼吸感应体积描记法确定呼吸模式。在每位患者中，均可确定一个最佳鼻CPAP水平，该水平可使吸气肌用力指标持续降低，而不改变潮气量或呼吸频率。在所有患者中，最佳CPAP水平下食管压力的潮气量变化和吸气肌的压力-时间积分均显著降低。EMGdi和EMGic也有类似降低。SaO2和PtcCO2不受CPAP影响。这些结果表明，鼻CPAP可有效降低重度COPD患者睡眠期间的吸气肌用力。（摘要截短至250字）
