Degree Of Obstructive Sleep Apnea Research Articles

Alternatives to tracheostomy in infants and children with obstructive sleep apnea

Purpose: Since 1989, 70 children have been treated surgically with varying degrees of obstructive sleep apnea (OSA). Of these, 29 patients had completely failed conventional medical and surgical treatment and were considered tracheostomy (T) candidates, whereas five had previously undergone T for severe OSA as infants and did not respond to standard decannulation protocols. The preoperative diagnoses were cerebral palsy (n = 5), Down's syndrome (n = 5), hemifacial microsomia (n = 4), Pierre Robin sequence (n = 6), and a mixed group of craniofacial disorders (n = 14). The patients ranged in age from 2.5 weeks to ≥18 months (mean, 7.32 years). Preoperatively, four patients were on ventilators and one suffered a cardiac arrest, attesting to the severity of OSA. Methods: To enlarge the caliber of the airway, each patient underwent an aggressive surgical treatment protocol. All sites of upper airway obstruction were treated simultaneously by a combination of craniofacial skeletal expansion and soft-tissue reduction. Results: Tracheostomy was avoided in 90.4% of patients. Temporary or “permanent T” were required in three patients (9.6%). One patient with cerebral palsy had recurrent OSA and died. A second patient with severe laryngotracheomalacia and retrognathia who did not respond to apnea surgery underwent a tracheostomy and ultimately died of pulmonary causes. Four patients (7.8%) required supplemental home oxygen or continuous positive airway pressure. The average preoperative respiratory disturbance index, defined as the average number of apneic and hypopneic events per hour of sleep, dropped from 25.9 to 4.4 after surgery. The average lowest recorded oxygen saturation during overnight polysomnography rose from 61% to 92% after surgery. Of the five patients with permanent T, four had thus far been decannulated. Complications occurred in 10 patients, 50% of which were related to minor problems with mandibular distraction devices. Conclusion: Our results confirm the efficacy of an aggresive surgical approach to the treatment of OSA in children, avoiding the necessity for tracheostomy or permitting decannulation of permanent T in the majority of cases.

Efficacy of a Herbst mandibular advancement device in obstructive sleep apnea.

Treatment options for obstructive sleep apnea (OSA) may involve potential side effects or discomfort; nasal continuous positive airway pressure (CPAP) may not be tolerated by 25% of patients. We therefore sought to determine the efficacy of mandibular advancement as a treatment for OSA, and to investigate whether clinical and radiographic parameters can predict the response to this treatment. Sixteen male and 3 female subjects with documented OSA who had failed or been unable to tolerate nasal CPAP underwent baseline polysomnography and cephalometry, and were then fitted with a removable Herbst appliance to achieve forward mandibular advancement during sleep. All subjects then underwent a second cephalometric evaluation and polysomnography with the appliance in place. Fourteen of 15 subjects demonstrated significant improvement in the degree of OSA, based on the apnea-hypopnia index (AHI) (34.7 +/- 5.3 to 12.9 +/- 2.4 events/h, p < 0.002). Comparison of pre- and posttreatment cephalometric values revealed no significant change in the posterior airway space (PAS) despite a reduction in mean AHI. There was a significant decrease in the mandible-hyoid distance (MP-H) with treatment for the group as a whole. When the study population was evaluated on the basis of a successful response to mandibular advancement (posttreatment AHI < 10), the baseline MP-H was found to be significantly shorter in the responders than in nonresponders. MP-H after mandibular advancement was likewise shorter in responders than in nonresponders. In addition, the soft palate length (PNS-P) showed a significantly greater shortening in responders after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of hypoxemia in patients with sleep disorders using saturation impairment time.

A method of recording cumulative nocturnal oxygen desaturation was utilized to develop a quantitative index of nocturnal hypoxemia (SIT index) to provide reference values and distributional properties for apneic and nonapneic sleep-disordered patients. The SIT indices were compared in patients with varying degrees of obstructive sleep apnea (OSA) as determined by traditional methods of counting apneas and hypopneas. We studied 298 patients who were divided into five groups based on the presence and frequency of apnea or sleep-related respiratory deterioration. SIT indices for patient groups and individual patients were compared with the respiratory disturbance index (apneas + hypopneas x 60/total sleep time = RDI) using scatter plots, Kruskal-Wallis analysis of variance, and Mann-Whitney U tests. The OSA and non-respiratory-impaired patient groups had mean SIT values that were significantly different (p < 0.05). Subjects with severe apnea differed (p < 0.05) from subjects with mild and moderate apnea at SIT index thresholds < baseline, < 90, < 80, and < 70% SaO2, but subjects with mild and moderate apnea did not differ statistically from each other at any threshold. In individual patients with similar RDI values, considerable variation in SIT index can be seen, and the reverse is also true. This suggests that using both RDI and SIT may provide complementary information in assessing the severity of OSA.

Treatment of Snoring and Obstructive Sleep Apnea with a Dental Orthosis

A dental orthosis, designed to increase the size of the upper airway by advancing the mandible, was used in 68 patients to treat snoring and varying degrees of obstructive sleep apnea. The orthosis increased the posterior airway space, as assessed by lateral cephalograms. Seven months (range 2 to 25) after beginning use, 75 percent of patients were using the orthosis regularly. Snoring, by report, was improved in all patients but one (p less than 0.001) and was eliminated in 42 percent (95 percent confidence interval 30 to 55 percent). Sleep quality and sleepiness were also reported improved. Apneas and hypopneas, measured before and after use in 20 patients with obstructive sleep apnea, were reduced from an average of 47 to 20 events per hour (p less than 0.001). Oxygenation and sleep disturbance were also improved. Apnea-hypopnea frequency was reduced with treatment to less than 20/h in 13 patients. Residual frequencies greater than 20/h were associated with higher initial frequencies of apneas and hypopneas. Side effects of orthosis use were minor, and no serious complications were observed. The dental orthosis is an effective treatment for the symptom of snoring and can also effectively treat obstructive sleep apnea of moderate severity.

Obstructive Sleep Apnea in Premenopausal Women: A Comparison with Men and with Postmenopausal Women

Because obstructive sleep apnea (OSA) is unusual in premenopausal women, we describe ten women with this syndrome and compare them to 13 postmenopausal women and with 32 men with OSA. Two premenopausal women had structural abnormalities of their pharynx, and the remaining eight were significantly more obese than men with OSA. In these eight patients, there was no relationship between pulse flow resistance and the degree of OSA in contrast to significant relationships in postmenopausal women, and men. Hypercapnia occurred in three premenopausal women, no postmenopausal women and in two men. We conclude that premenopausal women with OSA are more likely than men and postmenopausal women to have structural abnormalities of their upper airway, to be extremely obese, and to be hypercapneic, and that OSA occurs in them independent of their upper airway dimensions.

Physiological determinants of nocturnal arterial oxygenation in patients with obstructive sleep apnea.

Among patients with similar degrees of obstructive sleep apnea (OSA) there is considerable variability in the degree of associated nocturnal hypoxemia. The factors responsible for this variability have not been clearly defined. Therefore we studied 44 patients with OSA to identify the physiological determinants of nocturnal arterial O2 saturation (SaO2). All patients underwent pulmonary function testing, arterial blood gas analysis, and overnight polysomnography. Mean nocturnal SaO2 ranged from 96 to 66% and apnea-hypopnea index from 11 to 128 per hour of sleep. Several anthropometric, respiratory physiological, and polysomnographic variables that could be expected to influence nocturnal SaO2 were entered into a stepwise multiple linear regression analysis, with mean nocturnal SaO2 as the dependent variable. Three variables [awake supine arterial PO2 (PaO2), expiratory reserve volume, and percentage of sleep time spent in apnea] were found to correlate strongly with mean nocturnal SaO2 (multiple R, 0.854; P less than 0.0001) and accounted for 73% of its variability among patients. Body weight, other lung volumes, and airflow rates influenced awake PaO2 and expiratory reserve volume but had no independent influence on nocturnal SaO2. In a further group of 15 patients with OSA a high correlation was obtained between measured nocturnal SaO2 and that predicted by the model (r = 0.87; P less than 0.001). We conclude that derangements of pulmonary mechanics and awake PaO2 (generally attributable to obesity and diffuse airway obstruction) are of major importance in establishing the severity of nocturnal hypoxemia in patients with OSA.

Nonhypersomnolent patients with obstructive sleep apnea.

Until recently, snoring had been considered both a medical enigma and a psychosocial problem. Snoring is now considered to be an acoustic phenomenon produced by vibration of the soft palate and the tonsillar pillars. We describe 20 patients with a clinical complaint of excessive snoring who were referred to rule out obstructive sleep apnea. All patients were without symptoms of daytime sleepiness and failure of the right heart. Twenty subjects were studied, 18 of whom were males. All subjects were monitored for one full night in the Sleep Laboratory. The apnea rate ranged from 9.0 to 94.0 incidents an hour with a mean of 30.0. Eight of the 20 subjects had obstructive episodes longer than 1 minute and three others had episodes longer than 55 seconds. Hypersomnolence, long thought to be a cardinal symptom, is not present in all patients with an ostensibly significant degree of obstructive sleep apnea.