REVERSAL OF CENTRAL SLEEP-APNEA WITH OXYGEN

Objective: To examine the effect of oxygen on apneas and sleep quality in patients with frequent central apneas during sleep. Design/subject s: Prospective intervention study of 20 consecutive patients with pred ominant central apnea identified from 570 patients referred for suspec ted sleep apnea syndrome. Sixteen patients had congestive heart failur e and seven of them had a previous stroke. Three of the remaining four patients without heart failure had experienced a previous stroke, and one was being treated with morphine. Setting: The Department of Pulmo nary Medicine at Umea (Sweden) University Hospital. Interventions: The patients were investigated for one night receiving nasal oxygen and o ne night without it. Measurements: Overnight polysomnography with tran scutaneous Pco(2) and arterial blood gases. Results: Central apneas oc curred during Cheyne-Stokes respiration in 18 of 20 patients and two p atients had idiopathic central apneas. Without oxygen, the median numb er of all central apneas and hypopneas was 33.5 (range, 8.0 to 52.0) p er hour of sleep, These episodes decreased to 5.0 (range, 0.0 to 31.0) (p<0.01) during oxygen therapy. In 17 of 20 patients, the frequency o f central apneas was reduced by more than 50%. Central apneas were red uced by oxygen irrespective of the presence or absence of heart failur e or Cheyne-Stokes respiration. The arousal frequency was reduced duri ng oxygen treatment. Daytime sleepiness, difficulty falling asleep, sn oring, and self-scored awakenings were reduced in seven patients who w ere given nocturnal oxygen at home. Obstructive and mixed apneas were unaffected by oxygen. Conclusions: Oxygen effectively reduces central sleep apnea in eucapnic patients.