Treatment of Patients With the Obstructive Sleep Apnea Syndrome at Altitude

Treatment of Patients With the Obstructive Sleep Apnea Syndrome at Altitude

The purpose of the study is to investigate the effect of 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 (<800m)
• 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 or recently diagnosed (within the last 6 months) cardiovascular disease such as arterial hypertension, coronary artery or cerebrovascular 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 (<2600m).
• Exposure to altitudes >1500m for >1 day within the last 4 weeks before the study