Amelioration of sleep apnea by salicylate-induced hyperventilation.
It is well documented that upper airway (UAW) muscle activity is augmented in response to increased respiratory drive, the overall effect being an improvement in UAW patency. We have recently shown that salicylate-induced ventilatory stimulation increased UAW muscle electrical activity and decreased UAW resistance and collapsibility in anesthetized dogs. In the present study, we evaluated the effect of respiratory stimulation produced by high therapeutic doses of aspirin on sleep in nine patients with previously diagnosed sleep apnea. A control, all-night, polysomnographic sleep study, including oximetry and ventilatory monitoring by inductive plethysmography, was compared with a second study undertaken after patients ingested 8 to 10 g of aspirin over a period of 4 to 5 h. Aspirin ingestion resulted in high therapeutic salicylate serum levels (33 +/- 2.5 mg/dl, mean +/- SE) the following morning and was associated with marked ventilatory stimulation. Mean sleep duration and the relative partitioning of sleep stages were not affected by aspirin. However, aspirin-induced hyperventilation was associated with a significant non-rapid decrease in periodic breathing and the frequency of both obstructive and mixed apneas in all non-rapid eye movement (REM) sleep stages. The total number of apneas over the whole night was reduced in all subjects and on average fell from a control rate of 42 +/- 7 to 28 +/- 7 apneas/h (p less than 0.01). Similarly, the mean duration of apneas fell from 23 +/- 2 to 20 +/- 1 s (p less than 0.05), and the overall time spent in apneas decreased from 17 +/- 3 to 10 +/- 3 min/h (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)