Goldstein R S, De Rosie J A, Avendano M A, Dolmage T E
Department of Medicine, University of Toronto, Ontario, Canada.
Chest. 1991 Feb;99(2):408-15. doi: 10.1378/chest.99.2.408.
Intermittent positive pressure ventilation reduces inspiratory muscle electromyographic activity among patients with restrictive ventilatory failure. It has therefore been suggested that the reduction of energy expenditure at night could result in improved inspiratory muscle function during the day. Reported successes with nocturnal ventilation have not included measurements of inspiratory muscle endurance. We therefore electively ventilated six (five female, one male) patients (mean +/- SD) aged 36 +/- 13 years in whom respiratory failure (room air PaCO2, 60 +/- 13 mm Hg; PaO2, 44 +/- 11 mm Hg; SaO2, 75 +/- 12 percent) was consequent on restrictive ventilatory disease (vital capacity, 25 +/- 7 percent predicted; FEV1/FVC, 81 +/- 12 percent; total lung capacity, 40 +/- 5 percent predicted; MIPRV -42 +/- 10 cm H2O; MEP, 81 +/- 28 cm H2O). Positive pressure ventilation was administered with a customized closely fitting nasal mask attached to a volume-cycled pressure-limited ventilator. Full respiratory polysomnographic measurements as well as arterial blood gases, pulmonary function, distance walked in six minutes, and inspiratory muscle endurance were measured at baseline and after 3 and 14 months of ventilation. Ventilation improved saturation (baseline on O2; SWS 87 +/- 10, REM 79 +/- 14, ventilator on R/A; SWS 90 +/- 6, REM 89 +/- 5 percent) and transcutaneous Pco2 (baseline on O2; SWS 85 +/- 26, REM 94 +/- 39, ventilator on R/A; SWS 53 +/- 9, REM 58 +/- 9 mm Hg). During ventilation, the quantity and distribution of sleep was similar to that observed prior to ventilation. Daytime gas exchange improved as did the six-minute walking test (initial test = 429 +/- 120 m, three months after ventilation = 567 +/- 121 m), both of these improvements being sustained at 14 months. Inspiratory muscle endurance measured using a pressure threshold load (mean mouth pressure = 45 percent MIPRV) improved from 7.1 +/- 3.4 minutes at baseline to 14.8 +/- 7.6 minutes at 3 months, an improvement sustained at 14 months. There was no change in measured lung volumes or respiratory muscle strength. We conclude that the improvement in nocturnal gas exchange, daytime functioning, and arterial blood gases resulting from nocturnal positive pressure ventilation is associated with an increase in inspiratory muscle endurance sustained at 14 months.
间歇性正压通气可降低限制性通气衰竭患者吸气肌的肌电图活动。因此，有人提出夜间能量消耗的减少可能会导致白天吸气肌功能的改善。已报道的夜间通气成功案例中并未包括吸气肌耐力的测量。因此，我们选择性地对6例（5例女性，1例男性）年龄为36±13岁的患者进行通气，这些患者因限制性通气疾病导致呼吸衰竭（室内空气时PaCO₂为60±13mmHg；PaO₂为44±11mmHg；SaO₂为75±12%）（肺活量为预测值的25±7%；FEV₁/FVC为81±12%；肺总量为预测值的40±5%；最大吸气压为-42±10cmH₂O；最大呼气压为81±28cmH₂O）。使用定制的紧密贴合的鼻面罩连接到容量切换压力限制呼吸机进行正压通气。在基线以及通气3个月和14个月后，测量了完整的呼吸多导睡眠图、动脉血气、肺功能、6分钟步行距离和吸气肌耐力。通气改善了饱和度（吸氧时基线；慢波睡眠时为87±10%，快速眼动睡眠时为79±14%，呼吸机辅助呼吸时；慢波睡眠时为90±6%，快速眼动睡眠时为89±5%）和经皮Pco₂（吸氧时基线；慢波睡眠时为85±26mmHg，快速眼动睡眠时为94±39mmHg，呼吸机辅助呼吸时；慢波睡眠时为53±9mmHg，快速眼动睡眠时为58±9mmHg）。通气期间，睡眠的数量和分布与通气前观察到的相似。白天气体交换得到改善，6分钟步行试验也有所改善（初始试验为429±120m，通气3个月后为567±121m），这两项改善在14个月时均得以维持。使用压力阈值负荷（平均口腔压力为最大吸气压的45%）测量的吸气肌耐力从基线时的7.1±3.4分钟改善到3个月时的14.8±7.6分钟，并在14个月时维持改善。测量的肺容积或呼吸肌力量没有变化。我们得出结论，夜间正压通气导致的夜间气体交换、白天功能和动脉血气的改善与吸气肌耐力增加有关，且这种增加在14个月时得以维持。
