Continuous Positive Airway Pressure and Acetazolamide to Treat Sleep Apnea Syndrome Patients at Altitude

Continuous Positive Airway Pressure (CPAP) and Acetazolamide for Treatment of Patients With the Obstructive Sleep Apnea Syndrome at Altitude

The purpose of the study is to investigate the effect of nasal continuous positive airway pressure in combination with acetazolamide as a treatment for sleep related breathing disturbances in patients with the obstructive sleep apnea syndrome living at low altitude during a sojourn at moderate altitude.

Inclusion Criteria:

• Obstructive sleep apnea syndrome, successfully on CPAP therapy
• Residence at low altitude (< 800 m)
• Obstructive apnea/hypopnea index >20/h and a complaint of excessive daytime sleepiness before introduction of CPAP therapy
• > 15 oxygen desaturations/h (> 3% dips) during an ambulatory nocturnal pulse oximetry performed at the end of a 4-night period without CPAP

Exclusion Criteria:

• Sleep disorders other than OSA
• More than mild cardiovascular disease, unstable cardiovascular disease
• Any lung disease, pulmonary hypertension
• Chronic rhinitis
• Treatment with drugs that affect respiratory center drive (benzodiazepines or other sedatives or sleep inducing drugs, morphine or codeine derivates), stimulants (modafinil, methylphenidate, theophylline)
• Internal, neurologic or psychiatric disease that interfere with sleep quality
• Previous intolerance to moderate or low altitude (< 2600 m)
• Exposure to altitudes > 1500m for > 1 day within the last 4 weeks before the study