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CPAP pressure requirements for obstructive sleep apnea patients at varying altitudes.

STUDY OBJECTIVES
This study was performed to determine whether the obstructive sleep apnea patient who requires a certain CPAP pressure at one altitude requires the same or a different CPAP pressure at a different altitude.


PARTICIPANTS
7 mountain residents with OSA, comfortably using CPAP and planning to travel to lower altitude.


DESIGN AND SETTING
Participants used a ResMed Autoset autotitrating CPAP unit for at least 3 days at their home and at each of their lower travel destinations.


MEASUREMENTS
Nightly CPAP 95th percentile pressure, median CPAP pressure and AHI were recorded.


RESULTS
At high altitude, 7400 ft. to 10,100 ft (2255 m to 3080 m), average CPAP 95th percentile pressure was 9.43 (+/- 0.12) cm H2O. At low altitude, sea level to 2800 ft. (0-853m), average CPAP 95th percentile pressure was 9.54 (+/- 0.13) cm H2O, P = 0.18. At high altitude, median CPAP pressure was 7.00 (+/- 0.10) cm H2O vs. 7.21 (+/- 0.14) cm. H20 at low altitude, P = 0.54. Three patients had a slight decrease in required pressure at low elevation, 4 had a slight increase.


INTERVENTIONS
N/A.


CONCLUSIONS
For obstructive sleep apnea patients living at altitude, changes in elevation between 10,100 ft (3075 m) and sea level do not significantly alter absolute CPAP pressure requirements.