TOPICAL OROPHARYNGEAL ANESTHESIA IN PATIENTS WITH OBSTRUCTIVE SLEEP-APNEA

Topical oropharyngeal anesthesia (TOPA) increases obstructive sleep ap nea (OSA) frequency in both normal subjects and loud snorers. The effe cts of TOPA in established OSA were assessed in six male patients with a mean age (+/- SEM) of 50 +/- 5.3 yr. Following an acclimatization n ight, each subject underwent two overnight sleep studies, randomly ass igned to TOPA (10% lidocaine spray and 0.25% bupivocaine gargle) and c ontrol (C) (saline placebo). Patients demonstrated sleep efficiencies of 93 +/- 2.9% (mean +/- SEM) during C and 88 +/- 2.9% during TOPA. Ov erall apnea-hypopnea (AH) frequency, using inductance plethysmography, showed little change: 21.2 +/- 3.6 on C versus 25.1 +/- 3.5 events/h on TOPA nights (p = 0.12). There was no significant increase in AH dur ation with TOPA, and oxygen desaturation (greater than or equal to 4%) frequency was similar: 21.1 +/- 3.9 per hour during TOPA versus 23.6 a 5.9 during C. However, obstructive AHs showed a change in thoracoabd ominal motion from C to TOPA nights, with an increase in events with a bdominal paradox from 3.1 +/- 1.1 to 10.3 +/- 3.1 per hour (p = 0.03), and a reduction in events with ribcage paradox from 13.1 +/- 1.6 to 8 .2 +/- 2.4 per hour (p = 0.08). Central and mixed AHs demonstrated sim ilar frequencies on both nights. These data support an impairment of u pper airway (UA) protective reflexes among patients with OSA.