VENTILATORY RESPONSES IN THE OBSTRUCTIVE SLEEP APNEA SYNDROME

阻塞性睡眠呼吸暂停综合征（OSAS）是儿童发病的重要原因。 对这种常见而重要的疾病的病理生理学知之甚少。 我们假设患有OSAS的儿童在他们的呼吸驱动和/或唤醒反应中存在异常，这有助于上气道阻塞。 现已发表的初步数据显示，患有OSAS的儿童对高碳酸血症的唤醒反应迟钝。 在方案的第二部分中，测试了对吸气阻力负荷（IRL）的唤醒和唤醒反应。 OSAS组患儿的唤醒负荷明显高于对照组（23 ± 8vs 15 ± 7 cmH 2 O/L/s，P < 0.05）。 OSAS患者快速眼动期觉醒阈值高于非快速眼动期（P < 0.001），而正常人快速眼动期觉醒阈值低于非快速眼动期（P < 0.005）。 在对照组中评价对IRL的通气反应。 IRL即刻（IRL为15 cm H2O/L/min时为基线的56 ± 17%，P < 0.001）和IRL 3分钟后（67 ± 23%，P < 0.005）潮气量均显著减少。 占空比增加。 我们的结论是，儿童阻塞性睡眠呼吸暂停综合征有受损的唤醒反应IRL。 正常儿童在睡眠中对IRL只有部分代偿。 然而，唤醒发生在IRL导致气体交换异常之前。 儿童的反应与成人不同。 我们推测对IRL的异常唤醒反应可能在儿童阻塞性睡眠呼吸暂停的病理生理学中起作用。

The obstructive sleep apnea syndrome (OSAS) is a significant cause of morbidity in children. Little is known about the pathophysiology of this common and important disease. We hypothesized that children with OSAS have abnormalities in their ventilatory drive and/or arousal responses, which contribute to upper airway obstruction. Initial data, which have now been published, showed that children with OSAS have blunted arousal responses to hyercapnia. In the second part of the protocol, arousal and ventilatory responses to inspiratory resistance loading (IRL) were tested. Children with OSAS aroused at a higher load than controls (23 + 8 vs 15 + 7 cm H2O/L/s, P < 0.05). Patients with OSAS had higher arousal thresholds during rapid eye movement (REM) vs nonREM sleep (P < 0.001), whereas normal subjects had lower arousal thresholds during REM (P < 0.005). Ventilatory responses to IRL were evaluated in the controls. There was a marked decrease in tidal volume both immediately (56 + 17% of baseline at an IRL of 15 cm H2O/L/min, P < 0.001) and after 3 minutes of IRL (67 + 23%, P < 0.005). The duty cycle increased. We conclude that children with OSAS have impaired arousal responses to IRL. Normal children have only partial ventilatory compensation for IRL during sleep. However, arousal occurs before IRL results in gas exchange abnormalities. The response in children differs from adults. We speculate that abnormal arousal responses to IRL may play a role in the pathophysiology of childhood obstructive sleep apnea.