Characterization of postoperative edema following laser-assisted uvulopalatoplasty using MRI and polysomnography: implications for the outpatient treatment of obstructive sleep apnea syndrome

Laser-assisted uvulopalatoplasty (LAUP) has been introduced as an alternative to uvuloplatopharyngoplasty for the treatment of snoring. Despite limited study, the use of this procedure has been expanded to include patients with obstructive sleep apnea syndrome. Although the potential cost-savings of performing sleep apnea surgery on an outpatient basis are self-evident, concern exists regarding the safety of this practice. In an effort to characterize the risk of performing LAUP on an outpatient basis, eight patients with mild or no sleep apnea were identified and intensively studied before and after the first stage of LAUP to cure snoring. Assessment included preoperative magnetic resonance imaging (MRI) scans, polysomnography, and videoendoscopy. Each of these diagnostic studies was then repeated between 48 and 72 hours after LAUP. Complete polysomnographic data were available for seven of the eight patients. The mean ( +/- SD) preoperative respiratory disturbance index (RDI) was 11.3 +/- 10.9, and the mean oxygen saturation nadir (LSAT) was 87.7 +/- 6.2% (n = 7). The mean airway cross-sectional area at the palate (by MRI) was 49.8 +/- 22.8 mm2 (n = 8). After LAUP, the mean RDI nearly doubled to 21.7 +/- 9.9 (P > .1). The apnea index increased fourfold from 3.3 +/- 3.5 to 14.8 +/- 10.9 (P < .03). The mean LSAT remained stable at 87.4 +/- 4.1% (P > .5). The cross-sectional area of the airway decreased to a mean of 47.9 +/- 22.4 mm2 (P > .5). These data suggest that LAUP may temporarily worsen obstructive sleep apnea. Although the clinical significance of this degree of worsening is uncertain, it would be prudent to consider perioperative use of nasal continuous positive airway pressure in patients with more than mild obstructive sleep apnea who undergo ambulatory LAUP.

Prolonged confusion with nocturnal wandering arising from NREM and REM sleep: a case report

A 51-year-old man with Machado-Joseph disease had a 3-year history of prolonged confusion following nightly nocturnal wandering. Polysomnography with videotape monitoring revealed 19- to 120-minute sleepwalking episodes emerging from non-rapid eye movement (NREM) sleep and occasionally from rapid eye movement (REM) sleep, followed by 22-47 minutes of prolonged confusion and disorientation. The patient also had a periodic limb movement disorder and obstructive sleep apnea syndrome. Excessive daytime sleepiness was evident by results from the Epworth Sleepiness Scale and Multiple Sleep Latency Test. A sleep-deprived electroencephalogram (EEG) and a polysomnogram with an expanded EEG montage before and during these episodes revealed no epileptiform activity. A contrast-enhanced brain magnetic resonance imaging (MRI) scan demonstrated findings consistent only with Machado-Joseph disease. The patient improved with a combination of temazepam and carbidopa-levodopa.

Load detection in subjects with sleep-induced upper airway obstruction

Respiratory flow-resistive load detection in obese patients has been shown to be impaired. We tested the hypothesis that there is no difference in inspiratory flow-resistive load detection measured in nonobese obstructive sleep apnea patients, nonobese snorers, and normal control subjects. Eleven male obstructive sleep apnea patients and seven male snorers were investigated and compared with 10 normal male control subjects. Severely obese patients (body mass index, BMI > 35 kg/m2) were excluded. Patients were investigated by nocturnal polysomnography with measurement of esophageal pressure (Pes). Awake pulmonary function tests were performed before the investigation. Airway resistance (Raw) and lung volumes were measured with plethysmography. Resistive loads were investigated according to Tapper and associates (13) and Killian and associates (12). Resistances were applied for the duration of one inspiratory cycle and a minimum of two breaths allowed between each resistive load. Six different resistances plus background shams were presented 10 times in random order. Flow, pressure, and subject response were recorded with a calibrated multichannel recorder. Subjects signaled detected changes of inspiratory resistance with a hand-held signaling device. The probability of detecting a particular resistance was calculated as the ratio of correct identification to the number of presentations (i.e., 10). The resistance corresponding to a 0.5 probability of detection was determined. The Weber fraction (wf) calculated as delta R/R(apparatus) +Raw. There were no differences between nonobese subjects and controls in terms of resistive load detection.