American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Nov 2003
Randomized Controlled Trial Clinical TrialReduction of sleep-disordered breathing after physostigmine.
The cholinesterase inhibitor physostigmine (PHYS) was investigated in a double-blind, placebo-controlled, randomized, crossover trial of 10 male patients with moderate to severe obstructive sleep apnea. PHYS (0.12 microg/minute/kg, 7-hour infusion) reduced mean apnea/hypopnea index (AHI) by 13.6 (95% confidence interval [CI], 2.2-25.1) corresponding to 21.4% (95% CI, -5.5 to 47.9) and increased minimum SaO2 by 8.7% (95% CI, -0.3 to 17.7) corresponding to 23.2% (95% CI, 4.8-41.3). During the last third of the night, coinciding with predicted plasma concentration steady state, non-REM sleep AHI decreased by 19.2 (95% CI, 0.1-38.3) or 14.9% (95% CI, -43.6 to 77.7) and REM AHI by 33.8 (95% CI, 13.7-54.0) or 67.5% (95% CI, 49.7-85.3). ⋯ Moreover, resting (early-night placebo heart rate) was positively correlated with proportional reduction of REM apnea index (r = 0.69, p < 0.02). Body mass index was negatively correlated with reduction of REM AHI (r = 0.77, p < 0.02). This, predominantly REM-related, reduction of obstructive sleep apnea after PHYS may provide a new treatment option if the effects are maintained in long-term studies.
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Am. J. Respir. Crit. Care Med. · Nov 2003
Randomized Controlled Trial Clinical TrialBenefits of supplemental oxygen in exercise training in nonhypoxemic chronic obstructive pulmonary disease patients.
Supplemental oxygen improves exercise tolerance of normoxemic and hypoxemic chronic obstructive pulmonary disease (COPD) patients. We determined whether nonhypoxemic COPD patients undergoing exercise training while breathing supplemental oxygen achieve higher intensity and therefore improve exercise capacity more than patients breathing air. A double-blinded trial was performed involving 29 nonhypoxemic patients (67 years, exercise SaO2 > 88%) with COPD (FEV1 = 36% predicted). ⋯ After training, endurance in constant work rate tests increased more in the oxygen-trained group (14.5 minutes) than in the air-trained group (10.5 minutes) (p < 0.05). At isotime, the breathing rate decreased four breaths per minute in the oxygen-trained group and one breath per minute in the air-trained group (p = 0.001). We conclude that supplemental oxygen provided during high-intensity training yields higher training intensity and evidence of gains in exercise tolerance in laboratory testing.