Nishida Katsufumi, Lanspa Michael J, Cloward Tom V, Weaver Lindell K, Brown Samuel M, Bell James E, Grissom Colin K
1 Division of Pulmonary and Critical Care Medicine, University of Utah School of Medicine, Salt Lake City and.
2 Division of Pulmonary and Critical Care Medicine.
Ann Am Thorac Soc. 2015 Jul;12(7):1072-8. doi: 10.1513/AnnalsATS.201411-506OC.
In acute ascent to altitude, untreated obstructive sleep apnea (OSA) is often replaced with central sleep apnea (CSA). In patients with obstructive sleep apnea who travel to altitude, it is unknown whether their home positive airway pressure (PAP) settings are sufficient to treat their obstructive sleep apnea, or altitude-associated central sleep apnea.
Ten participants with positive airway pressure-treated obstructive sleep apnea, who reside at 1,320 m altitude, underwent polysomnography on their home positive airway pressure settings at 1,320 m and at a simulated altitude of 2,750 m in a hypobaric chamber. Six of the participants were subsequently studied without positive airway pressure at 2,750 m.
At 1,320 m, all participants' sleep apnea was controlled with positive airway pressure on home settings; at 2,750, no participants' sleep apnea was controlled. At higher altitude, the apnea-hypopnea index was higher (11 vs. 2 events/h; P < 0.01), mostly due to hypopneas (10.5 vs. 2 events/h; P < 0.01). Mean oxygen saturations were lower (88 vs. 93%; P < 0.01) and total sleep time was diminished (349 vs. 393 min; P = 0.03). Four of six participants without positive airway pressure at 2,750 m required supplemental oxygen to prevent sustained oxygen saturation (as determined by pulse oximetry) less than 80%. Positive airway pressure also was associated with reduced central sleep apnea (0 vs. 1; P = 0.03), improved sleep time (358 vs. 292 min; P = 0.06), and improved sleep efficiency (78 vs. 63%; P = 0.04).
Acute altitude exposure in patients with obstructive sleep apnea treated with positive airway pressure is associated with hypoxemia, decreased sleep time, and increased frequency of hypopneas compared with baseline altitude. Application of positive airway pressure at altitude is associated with decreased central sleep apnea and increased sleep efficiency.
在急性登高至高原时，未经治疗的阻塞性睡眠呼吸暂停（OSA）常被中枢性睡眠呼吸暂停（CSA）取代。对于前往高原的阻塞性睡眠呼吸暂停患者，其在家中的气道正压通气（PAP）设置是否足以治疗其阻塞性睡眠呼吸暂停或与高原相关的中枢性睡眠呼吸暂停尚不清楚。
10名接受气道正压通气治疗的阻塞性睡眠呼吸暂停参与者，居住在海拔1320米处，在海拔1320米时按照其在家中的气道正压通气设置进行多导睡眠图监测，并在低压舱中模拟海拔2750米时进行监测。其中6名参与者随后在海拔2750米时不使用气道正压通气进行研究。
在海拔1320米时，所有参与者的睡眠呼吸暂停在家中设置的气道正压通气下得到控制；在海拔2750米时，没有参与者的睡眠呼吸暂停得到控制。在更高海拔时，呼吸暂停低通气指数更高（11次/小时对2次/小时；P<0.01），主要是由于低通气（10.5次/小时对2次/小时；P<0.01）。平均血氧饱和度更低（88%对93%；P<0.01），总睡眠时间减少（349分钟对393分钟；P=0.03）。在海拔2750米时不使用气道正压通气的6名参与者中有4名需要补充氧气以防止持续血氧饱和度（通过脉搏血氧饱和度测定）低于80%。气道正压通气还与中枢性睡眠呼吸暂停减少（0次对1次；P=0.03）、睡眠时间改善（358分钟对292分钟；P=0.06）和睡眠效率提高（78%对63%；P=0.04）相关。
与基线海拔相比，接受气道正压通气治疗的阻塞性睡眠呼吸暂停患者急性暴露于高原与低氧血症、睡眠时间减少和低通气频率增加有关。在高原应用气道正压通气与中枢性睡眠呼吸暂停减少和睡眠效率提高有关。
