Effect of Sleeping Position on Upper Airway Patency in Obstructive Sleep Apnea Is Determined by the Pharyngeal Structure Causing Collapse. Marques Melania,Genta Pedro R,Sands Scott A,Azarbazin Ali,de Melo Camila,Taranto-Montemurro Luigi,White David P,Wellman Andrew Sleep Objectives:In some patients, obstructive sleep apnea (OSA) can be resolved with improvement in pharyngeal patency by sleeping lateral rather than supine, possibly as gravitational effects on the tongue are relieved. Here we tested the hypothesis that the improvement in pharyngeal patency depends on the anatomical structure causing collapse, with patients with tongue-related obstruction and epiglottic collapse exhibiting preferential improvements. Methods:Twenty-four OSA patients underwent upper airway endoscopy during natural sleep to determine the pharyngeal structure associated with obstruction, with simultaneous recordings of airflow and pharyngeal pressure. Patients were grouped into three categories based on supine endoscopy: Tongue-related obstruction (posteriorly located tongue, N = 10), non-tongue related obstruction (collapse due to the palate or lateral walls, N = 8), and epiglottic collapse (N = 6). Improvement in pharyngeal obstruction was quantified using the change in peak inspiratory airflow and minute ventilation lateral versus supine. Results:Contrary to our hypothesis, patients with tongue-related obstruction showed no improvement in airflow, and the tongue remained posteriorly located while lateral. Patients without tongue involvement showed modest improvement in airflow (peak flow increased 0.07 L/s and ventilation increased 1.5 L/min). Epiglottic collapse was virtually abolished with lateral positioning and ventilation increased by 45% compared to supine position. Conclusions:Improvement in pharyngeal patency with sleeping position is structure specific, with profound improvements seen in patients with epiglottic collapse, modest effects in those without tongue involvement and-unexpectedly-no effect in those with tongue-related obstruction. Our data refute the notion that the tongue falls back into the airway during sleep via gravitational influences. 10.1093/sleep/zsx005

Swallowing physiology and pathophysiology. Logemann J A Otolaryngologic clinics of North America Many disturbances in oropharyngeal physiology can result in aspiration. Poor tongue movement in chewing or in the oral swallow can cause food to fall into the pharynx and into the open airway before swallowing. A delay in triggering the pharyngeal swallow can result in food falling into the airway during the delay when the airway is open. Reduced peristalsis in the pharynx, whether unilateral or bilateral, will cause residue in the pharynx after the swallow that can fall or be inhaled into the airway. Reduced laryngeal elevation causes food to catch at the top of the airway. This residual food is then easily aspirated during the inhalation after the swallow. Reduced laryngeal closure may result in food penetrating the larynx during the pharyngeal swallow. Cricopharyngeal dysfunction can result in material remaining in the pyriform sinus, with aspiration of material into the airway after the swallow. Aspiration may also occur because food returns or is refluxed from the stomach or esophagus back into the pharynx. Each of these causes of aspiration can occur in a variety of patients, including those with neurologic impairment or structural damage. Each of these causes of aspiration has a different treatment. Thus, accurate and in-depth evaluation of swallowing anatomy and physiology in the oral-pharyngeal region as well as in the esophagus is necessary in successful re-establishment of oral nutrition in the dysphagic patient. Currently, such thorough evaluation requires radiographic graphic techniques, that is, videofluoroscopy and often manometry as well.