Somnofluoroscopy, computed tomography, and cephalometry in the assessment of the airway in obstructive sleep apnoea.

BACKGROUND: Assessments of the upper airways in patients with the obstructive sleep apnoea syndrome are usually carried out on awake patients who are upright. The dynamics of the airway in a patient who is asleep and lying down may be different. METHODS: Somnofluoroscopy, computed tomography of the upper airway, and cephalometry were carried out in 11 patients with the obstructive sleep apnoea syndrome (10 male; mean (SD) age 53 (10) years) to examine the airway while they were awake and asleep. RESULTS: At somnofluoroscopy 10 patients were in stage 2 sleep and only one in REM sleep. At least five obstructive events were visualised by lateral fluoroscopy in each patient. Imaging allowed observation of the dynamics of airway collapse, which began in the oropharynx in all cases, progressing to the hypopharynx in 10 cases and to the laryngopharynx in five. At fluoroscopy the soft palate was seen to hook up during airway occlusion in 10 patients, thereby increasing its cross sectional area. It was then sucked down into the hypopharynx. Somnofluoroscopic and cephalometric findings agreed, eight of the 10 patients with hypopharyngeal collapse shown by somnofluoroscopy having an inferiorly placed hyoid bone according to cephalometry (distance from the mandibular plane to the hyoid bone (MP-H distance) increased); the one patient with no hypopharyngeal collapse had a normal MP-H. By contrast, six of the 11 patients had a normal or supranormal hypopharyngeal cross sectional area of the airway on the computed tomogram. CONCLUSIONS: Somnofluoroscopy allows examination of the dynamics of airway closure in this disorder and shows the important role of the soft palate in acting as a plug in the oropharynx. Dynamic studies are required to determine the pattern of pharyngeal obstruction in obstructive sleep apnoea.

[1]  A C Bryan,et al.  Upper airway morphology in patients with idiopathic obstructive sleep apnea. , 2015, The American review of respiratory disease.

[2]  R. Blanks,et al.  Cephalometric analysis for diagnosis and treatment of obstructive sleep apnea , 1988, The Laryngoscope.

[3]  J. Remmers,et al.  Pathogenesis of upper airway occlusion during sleep. , 1978, Journal of applied physiology: respiratory, environmental and exercise physiology.

[4]  P. L. Smith,et al.  CT demonstration of pharyngeal narrowing in adult obstructive sleep apnea. , 1983, AJR. American journal of roentgenology.

[5]  S A Shea,et al.  Pharyngeal size and shape during wakefulness and sleep in patients with obstructive sleep apnoea. , 1989, The Quarterly journal of medicine.

[6]  J. Stauffer,et al.  Pharyngeal size and resistance in obstructive sleep apnea. , 1987, The American review of respiratory disease.

[7]  M Partinen,et al.  Obstructive sleep apnea and cephalometric roentgenograms. The role of anatomic upper airway abnormalities in the definition of abnormal breathing during sleep. , 1988, Chest.

[8]  N J Douglas,et al.  The sleep hypopnea syndrome. , 1988, The American review of respiratory disease.

[9]  C. Guilleminault,et al.  Obstructive sleep apnea and cephalometric roentgenograms. , 1984, The American review of respiratory disease.

[10]  J. Stauffer,et al.  Morphology of the uvula in obstructive sleep apnea. , 1989, The American review of respiratory disease.

[11]  J. Shepard,et al.  Evaluation of the upper airway by computerized tomography in patients undergoing uvulopalatopharyngoplasty for obstructive sleep apnea. , 1989, The American review of respiratory disease.

[12]  M Partinen,et al.  Women and the obstructive sleep apnea syndrome. , 1988, Chest.

[13]  T. Smith,et al.  Sleep apnea syndrome: diagnosis of upper airway obstruction by fluoroscopy. , 1978, The Journal of pediatrics.

[14]  P. Suratt,et al.  Fluoroscopic and computed tomographic features of the pharyngeal airway in obstructive sleep apnea. , 2015, The American review of respiratory disease.

[15]  N. Zamel,et al.  Pharyngeal size in snorers, nonsnorers, and patients with obstructive sleep apnea. , 1986, The New England journal of medicine.

[16]  E. Bleecker,et al.  Computerized Tomography in Obstructive Sleep Apnea , 1983 .

[17]  R. Cartwright,et al.  Sleep position training as treatment for sleep apnea syndrome: a preliminary study. , 1985, Sleep.

[18]  C. Guilleminault,et al.  Obstructive sleep apnea: Electromyographic and fiberoptic studies , 1978, Experimental Neurology.

[19]  Remmers Je,et al.  Pathogenesis of upper airway occlusion during sleep , 1978 .

[20]  K G van Houwelingen,et al.  Sleep Apnoea Syndromes , 1979, The Lancet.

[21]  C. Guilleminault,et al.  Cephalometric analyses and flow-volume loops in obstructive sleep apnea patients. , 1983, Sleep.

[22]  J R Galvin,et al.  Cine CT demonstration of nonfixed upper airway obstruction. , 1986, AJR. American journal of roentgenology.

[23]  N. Zamel,et al.  Pharyngeal compliance in snoring subjects with and without obstructive sleep apnea. , 2015, The American review of respiratory disease.

[24]  Suratt Pm,et al.  Inspiratory activation of the masseter. , 1990 .

[25]  E. Wolpert.  A Manual of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects. , 1969 .