Our understanding of the nature and consequences of upper-airway obstruction in adults during sleep has evolved considerably over the past two decades. Sleep apnea — defined as repeated episodes of obstructive apnea and hypopnea during sleep, together with daytime sleepiness or altered cardiopulmonary function — is common.1 Epidemiologic studies estimate that the condition affects 2 to 4 percent of middle-aged adults.2 Only a small portion of the cases in this group of adults have been diagnosed; this is related to insufficient awareness of sleep apnea among physicians and the public at large.3 Definitions The manifestations of upper-airway closure during sleep . . .

Obstructive Sleep Apnea

This paper, which has been reviewed and approved by the Board of Directors of the American Sleep Disorders Association, provides the background for the Standards of Practice Committee's parameters for the practice of sleep medicine in North America. The intent of this paper is to provide an overview of the surgical treatment of obstructive sleep apnea syndrome, to provide the basis for the American Sleep Disorders Association's practice parameters on this subject and to share our findings of metanalysis of previously published studies regarding uvulopalatopharyngoplasty. We searched MEDLINE from January 1966 through April 1993, with an update in February 1995, to provide a review of the application of surgical modifications of the upper airway to treat adults with obstructive sleep apnea syndrome. Operations to treat obstructive sleep apnea syndrome include nasal septal reconstruction; uvulopalatopharyngoplasty; uvulopalatopharyngoglossoplasty; laser midline glossectomy; lingualplasty; inferior sagittal mandibular osteotomy and genioglossal advancement, with hyoid myotomy and suspension (the entire process is referred to as GAHM); maxillomandibular osteotomy and advancement, and tracheotomy. Papers included in metanalysis provided preoperative and postoperative polysomnographic data on at least nine patients treated with uvulopalatopharyngoplasty for their obstructive sleep apnea. Analysis of the uvulopalatopharyngoplasty papers revealed that this procedure is, at best, effective in treating less than 50% of patients with obstructive sleep apnea syndrome. The site of pharyngeal narrowing or collapse, although identified by different and unvalidated methods, has a marked effect on the probability of success of uvulopalatopharyngoplasty. Patients who achieve a favorable response with uvulopalatopharyngoplasty tend to have less severe obstructive sleep apnea than those who do not. For patients who demonstrate retrolingual narrowing or collapse, other surgical modifications have been described, such as lingualplasty, GAHM, and maxillomandibular osteotomy and advancement. The studies to support the use of the surgical treatment of obstructive sleep apnea syndrome contain biases related to small sample size, limited follow-up and patient selection.

The Efficacy of Surgical Modifications of the Upper Airway in Adults With Obstructive Sleep Apnea Syndrome

Objective: To identify physical findings that can be standardized to predict the presence and the severity of obstructive sleep apnea (OSA).

Study Design: One hundred seventy-two patients who answered questionnaires with responses that suggested they might have OSA were included in this prospective study.

Methods: All patients underwent a physical examination and polysomnography. The physical examination included the measurement of four parameters used by anesthesiologists to identify patients likely to have difficult intubation to determine if these same parameters predict OSA. We recorded modified Mallampati grade (MMP), tonsil size, and body mass index (BMI) and measured thyroid-mental distance (TMD) and hyoid-mental distance (HMD) in the study population.

Results: When the physical findings were correlated singly with the respiratory disturbance index (RDI), we found that MMP (P < .001), tonsil size grading (P = .008), and BMI (P = .003) were reliable predictors of OSA. A greater correlation with OSA emerged when an “OSA score” was formulated by factoring the MMP, tonsil grade, and BMI grade (RDI = 7.816 × MMP + 3.988 × Tonsil Size + 4.675 × BMI − 7.544). A high score was not only predictive of OSA but also correlated well with OSA severity. Neither HMD nor TMD correlated with the severity of RDI.

Conclusions: An OSA score may help identify those patients who should have a full sleep evaluation.

Clinical Predictors of Obstructive Sleep Apnea

Pulmonary Complications of Obesity

https://journal.chestnet.org/article/S0012-3692(15)41968-3/pdf

Effects of Obesity on Respiratory Resistance

Multiple methods have been used to study the structure and physiological behavior of the upper airway (UA) in patients with obstructive sleep apnea (OSA). Valuable information may be obtained from the physiologic measurement of pressure and resistance along the UA, as well as from imaging techniques that include: direct or fiberoptic visualization, cephalometric roentgenograms, fluoroscopy, acoustic reflection, computerized tomography, and magnetic resonance imaging. This review summarizes the information that each of these methods has contributed to our understanding of the UA. The results obtained with these different methodologies have generally been complementary with structural narrowing being identified in the majority of patients with OSA. This narrowing is usually focal and located in the velopharyngeal or retropalatal segment of the UA. This is also the predominant site of initial UA collapse. Although obesity with enlargement of soft tissue structures is considered the predominant mechanism leading to UA narrowing, abnormal craniofacial development on a genetic or developmental basis plays an important contributory role.

Evaluation of the upper airway in patients with obstructive sleep apnea.

apnea/hypopnea index (AHI) > 10/h, was significantly more frequent (60% vs 32%, 2 < 0.0001) and severe (mean SE, 25 26/h vs 12 19/h, p < 0.0001) in men than in women. Men had significantly larger NC than women, but the difference became much less pronounced when we normalized NC to body height (0.24 0.02 vs 0.23 0.03, p < 0.0001). Men had significantly higher AHI than women even after controlling for age, body mass index (BMI), and neck/height ratio (NHR); analysis of covariance showed that mean AHI was 24.4 0.4 in men vs 14.8 0.7 in women (p < 0.0001). This difference persisted even when we matched men and women for NHR and BMI. Finally, multiple regression analysis revealed the following: (1) NHR was the most significant predictor of AHI, accounting for 19% of the variability; and (2) the slope of AHI vs NHR was significantly higher in men than in women. Conclusions: We conclude the following: (1) the frequency and severity of sleep apnea in the sleep clinic population is greater in men than women, and (2) factors other than NC, age, and BMI must contribute to these gender differences. (CHEST 2003; 123:1544 –1550)

Victor Hoffstein

Papers

Evaluation of the upper airway in patients with obstructive sleep apnea.

The Role of Neck Circumference