Arán X, Félez M A, Gea J, Orozco-Levi M, Sauleda J, Broquetas J M
Servei de Pneumologia, Hospital del Mar-IMIM, Universitat Autònoma de Barcelona.
Arch Bronconeumol. 1999 Oct;35(9):440-5. doi: 10.1016/s0300-2896(15)30040-5.
During nighttime episodes of obstructive apnea in patients with sleep apnea-hypopnea syndrome (SAHS), repeated and progressive inspiratory efforts are made. Such intense nighttime activity can have a deleterious effect on daytime function of respiratory muscles.
The objective of this study was to evaluate daytime respiratory muscle function in a group of SAHS patients before and after two months of treatment with nighttime continuous positive airway pressure (CPAP).
We enrolled 12 patients with SAHS and 10 normal subjects (control group). To evaluate respiratory muscle strength we measured maximum esophageal pressure (Pesmax), transdiaphragmatic pressure (Pdimax) and inspiratory pressure in the mouth (PM). Respiratory muscle resistance was assessed using peak pressure in the mouth (PMPeak), time of tolerance (Tlim) and maximum inspiratory pressure-time index (PTimax). We also analyzed the nighttime function of respiratory muscles during apneic episodes in 10 of the 12 SAHS patients. We propose and define an index of nighttime respiratory muscle activity (RMian) as the product of the tension-time index for the diaphragm observed at the end of nighttime apneic episodes (TTdiapnea) and the apnea-hypopnea index (AHI).
Respiratory muscle strength was similar in the two groups and no changes were observed in SAHS patients after treatment with nighttime CPAP. However, tolerance was lower in SAHS patients (PMpeak--30%, Tlim--31% and PTimax--49%). Two months of nighttime CPAP normalized all three variables in these patients. MRian was related to percent improvement in PMpeak after treatment with nighttime CPAP in SAHS patients (r = 0.66, p < 0.04).
SAHS has an adverse effect on the daytime endurance of respiratory muscles that is proportional to the increase of nighttime mechanical muscle activity. The application of nighttime CPAP is restorative, probably because it allows respiratory muscles to rest.
在睡眠呼吸暂停低通气综合征（SAHS）患者的夜间阻塞性呼吸暂停发作期间，会反复进行渐进性吸气努力。这种强烈的夜间活动会对呼吸肌的日间功能产生有害影响。
本研究的目的是评估一组SAHS患者在夜间持续气道正压通气（CPAP）治疗两个月前后的日间呼吸肌功能。
我们纳入了12例SAHS患者和10名正常受试者（对照组）。为评估呼吸肌力量，我们测量了最大食管压力（Pesmax）、跨膈压（Pdimax）和口腔吸气压力（PM）。使用口腔峰值压力（PMPeak）、耐受时间（Tlim）和最大吸气压力 - 时间指数（PTimax）评估呼吸肌阻力。我们还分析了12例SAHS患者中10例在呼吸暂停发作期间的夜间呼吸肌功能。我们提出并定义夜间呼吸肌活动指数（RMian），其为夜间呼吸暂停发作末期观察到的膈肌张力 - 时间指数（TTdiapnea）与呼吸暂停低通气指数（AHI）的乘积。
两组的呼吸肌力量相似，SAHS患者在夜间CPAP治疗后未观察到变化。然而，SAHS患者的耐受性较低（PMpeak降低30%，Tlim降低31%，PTimax降低49%）。两个月的夜间CPAP使这些患者的所有三个变量恢复正常。在SAHS患者中，MRian与夜间CPAP治疗后PMpeak的改善百分比相关（r = 0.66，p < 0.04）。
SAHS对呼吸肌的日间耐力有不良影响，且与夜间机械性肌肉活动的增加成正比。夜间CPAP的应用具有恢复作用，可能是因为它使呼吸肌得以休息。
