Sleep Disorders Center, Pulmonary Division, University Hospital of Zurich, Zurich; Center for Human Integrative Physiology, University of Zurich, Zurich.
Center for Human Integrative Physiology, University of Zurich, Zurich.
Chest. 2012 Jan;141(1):131-138. doi: 10.1378/chest.11-0375. Epub 2011 Jun 9.
Many patients with obstructive sleep apnea syndrome (OSA) are unable or unwilling to use continuous positive airway pressure (CPAP) therapy when traveling to the mountains for work or recreation even though they risk pronounced hypoxemia and exacerbation of sleep apnea. Because the treatment of OSA at altitude has not been established, we tested the hypothesis that acetazolamide improves hypoxemia, sleep, and breathing disturbances in otherwise untreated patients with OSA at altitude.
Forty-five patients with OSA on long-term CPAP, median age 64 years, living at < 600 m underwent a placebo-controlled, double-blind, crossover trial randomized for the sequence of drug and altitude exposure (490 m, 1,860 m, and 2,590 m). Patients spent two 3-day periods at altitude and a 2-week wash-out period at < 600 m. At altitude, patients discontinued CPAP and received acetazolamide 2 × 250 mg daily or placebo. Polysomnography, vigilance, and symptoms were evaluated.
At 490 m, off CPAP, median nocturnal oxygen saturation was 93%, and the apnea/hypopnea index was 51.2/h. On placebo at 1,860 m and 2,590 m, the corresponding values were 89% and 85% and 63.6/h and 86.2/h, respectively (P < .01 vs 490 m, both instances). On acetazolamide at 1,860 m and 2,590 m, oxygen saturation was higher (91% and 88%) and apnea/hypopnea indices were lower (48.0/h and 61.4/h) than on placebo (P < .01 all instances). Acetazolamide reduced nocturnal transcutaneous Pco(2), improved sleep efficiency and subjective insomnia, and prevented excessive BP elevations at altitude.
In patients with OSA discontinuing CPAP during an altitude sojourn, acetazolamide improves oxygenation, breathing disturbances, and sleep quality by stimulating ventilation. Therefore, patients with OSA may benefit from acetazolamide at altitude if CPAP therapy is not feasible.
ClinicalTrials.gov; No.: NCT00714740; URL: www.clinicaltrials.gov.
许多阻塞性睡眠呼吸暂停综合征（OSA）患者在出差或旅行到山区时无法或不愿使用持续气道正压通气（CPAP）疗法，尽管他们有明显的低氧血症和睡眠呼吸暂停加重的风险。由于在高海拔地区治疗 OSA 尚未得到证实，我们检验了以下假设：乙酰唑胺可改善未经治疗的 OSA 患者在高海拔地区的低氧血症、睡眠和呼吸紊乱。
45 例长期接受 CPAP 治疗的 OSA 患者（中位年龄 64 岁，生活在<600m 处）进行了安慰剂对照、双盲、交叉试验，随机分为药物和海拔暴露的顺序（490m、1860m 和 2590m）。患者在海拔高度处度过了两个为期 3 天的时期，并在<600m 处度过了两周的洗脱期。在海拔高度处，患者停止使用 CPAP，并接受乙酰唑胺 2×250mg 每日或安慰剂治疗。评估了多导睡眠图、警觉性和症状。
在 490m 处，停用 CPAP 时，夜间氧饱和度中位数为 93%，呼吸暂停/低通气指数为 51.2/h。在 1860m 和 2590m 处使用安慰剂时，相应值分别为 89%和 85%和 63.6/h 和 86.2/h（均 P<0.01 与 490m 比较）。在 1860m 和 2590m 处使用乙酰唑胺时，氧饱和度较高（91%和 88%），呼吸暂停/低通气指数较低（48.0/h 和 61.4/h），与安慰剂相比差异有统计学意义（均 P<0.01）。乙酰唑胺降低了夜间经皮 Pco2，改善了睡眠效率和主观失眠，并防止了在高海拔地区血压过度升高。
在中断 CPAP 治疗期间，在高原地区逗留的 OSA 患者中，乙酰唑胺通过刺激通气来改善氧合、呼吸紊乱和睡眠质量。因此，如果 CPAP 治疗不可行，OSA 患者可能会从高海拔地区的乙酰唑胺治疗中受益。
ClinicalTrials.gov；编号：NCT00714740；网址：www.clinicaltrials.gov。
