Clinical trial NCT00714740: Treatment of Patients With the Obstructive Sleep Apnea Syndrome at Altitude
Official title: Treatment of Patients With the Obstructive Sleep Apnea Syndrome at Altitude
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Obstructive Sleep Apnea Syndrome
Keywords: apnea, sleep, altitude, hypoxia
Lead sponsor: University of Zurich
Sponsor class: OTHER
First posted: 2008-07-14
Enrollment: 49
Sex: ALL
Minimum age (years): 20
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: 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


Eligibility criteria: 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

Primary outcomes:
measure: sleep disordered breathing, sleep structure, vigilance, subjective sleep quality acute mountain sickness
timeFrame: during treatment while at altitude
Secondary outcomes:
measure: blood pressure endothelial function
timeFrame: during treatment while at altitude
Other outcomes:
Locations:
city: Zurich
country: Switzerland
facility: Pulmonary Division, University Hospital Zurich
Study officials:
affiliation: Pulmonary Division, University Hospital Zurich, Switzerland
name: Konrad E Bloch, MD
role: STUDY_DIRECTOR
References:
citation: Nussbaumer-Ochsner Y, Latshang TD, Ulrich S, Kohler M, Thurnheer R, Bloch KE. Patients with obstructive sleep apnea syndrome benefit from acetazolamide during an altitude sojourn: a randomized, placebo-controlled, double-blind trial. Chest. 2012 Jan;141(1):131-138. doi: 10.1378/chest.11-0375. Epub 2011 Jun 9.
citation: Ulrich S, Nussbaumer-Ochsner Y, Vasic I, Hasler E, Latshang TD, Kohler M, Muehlemann T, Wolf M, Bloch KE. Cerebral oxygenation in patients with OSA: effects of hypoxia at altitude and impact of acetazolamide. Chest. 2014 Aug;146(2):299-308. doi: 10.1378/chest.13-2967.
citation: Stadelmann K, Latshang TD, Nussbaumer-Ochsner Y, Tarokh L, Ulrich S, Kohler M, Bloch KE, Achermann P. Impact of acetazolamide and CPAP on cortical activity in obstructive sleep apnea patients. PLoS One. 2014 Apr 7;9(4):e93931. doi: 10.1371/journal.pone.0093931. eCollection 2014.