We studied the effects of almitrine, acetazolamide, and placebo on the hypoxic ventilatory response (HVR), sleep periodic breathing, and arterial oxygen saturation (Sa(O2)) in 4 healthy climbers. In a laboratory on Denali (Mt. McKinley) at 4,400 m (P(B) = 440 mm Hg), we used a double-blind, randomized, three-way crossover design. The HVR was measured during the waking state. Periodic breathing and SA(O2)% were measured during 3-h sleep studies. Almitrine and acetazolamide both increased Sa(O2)% during sleep, although almitrine increased periodic breathing, whereas acetazolamide decreased periodic breathing. The HVR (ΔV̇E/ΔSa(O2)%) was doubled with almitrine (p < 0.05), but unchanged with acetazolamide. The HVR was positively related to periodic breathing (p < 0.05). We conclude that periodic breathing during sleep at high altitude is related to the hypoxic ventilatory response, and that acetazolamide is a superior agent to almitrine for ameliorating periodic breathing.
|Original language||English (US)|
|Number of pages||11|
|Journal||American Review of Respiratory Disease|
|Issue number||4 I|
|State||Published - Jun 12 1987|
All Science Journal Classification (ASJC) codes
- Pulmonary and Respiratory Medicine