Togeiro Sonia Maria Guimarães Pereira, Fontes Francisco Hora
Instituto do Sono, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
J Bras Pneumol. 2010 Jun;36 Suppl 2:47-52. doi: 10.1590/s1806-37132010001400013.
Sleep hypoventilation is seen in patients with neuromuscular disease, as well as in those with obesity hypoventilation syndrome (OHS), which is defined as the combination of obesity, chronic hypercapnia, and hypoxemia during wakefulness that is aggravated during sleep. In 90% of cases, OHS is accompanied by obstructive sleep apnea. The diagnosis of OHS is based on hypoventilation and pulmonary hypertension that cannot be explained by alterations in pulmonary function. The mortality of patients with OHS is greater than is that of obese patients without hypoventilation. The principal neuromuscular diseases associated with OHS are the muscular dystrophies. The progression to chronic respiratory failure results from respiratory muscle weakness and impaired airway secretion clearance, causing atelectasis and pneumonia. With a decrease of greater than 50% in respiratory muscle strength, there is a reduction in VC. Cough peak flow < 160 L/min is associated with impaired airway secretion clearance, and values near 270 L/min indicate the need for assisted cough techniques. Obstructive sleep apnea usually worsens sleep hypoventilation. Noninvasive ventilation during sleep can improve survival, symptoms, and hypoventilation during wakefulness, as well as being able to improve pulmonary function in patients with neuromuscular disease. Patients with OHS can require oxygen therapy.
睡眠低通气见于神经肌肉疾病患者以及肥胖低通气综合征（OHS）患者，肥胖低通气综合征定义为肥胖、慢性高碳酸血症以及清醒时低氧血症，且在睡眠期间病情加重。在90%的病例中，OHS伴有阻塞性睡眠呼吸暂停。OHS的诊断基于低通气和无法用肺功能改变解释的肺动脉高压。OHS患者的死亡率高于无低通气的肥胖患者。与OHS相关的主要神经肌肉疾病是肌肉萎缩症。进展为慢性呼吸衰竭是由呼吸肌无力和气道分泌物清除受损导致肺不张和肺炎引起的。呼吸肌力量下降超过50%时，肺活量会降低。咳嗽峰流速<160 L/分钟与气道分泌物清除受损有关，接近270 L/分钟的值表明需要辅助咳嗽技术。阻塞性睡眠呼吸暂停通常会加重睡眠低通气。睡眠期间无创通气可提高生存率、改善症状以及清醒时的低通气情况，还能改善神经肌肉疾病患者的肺功能。OHS患者可能需要氧疗。
