Bernoulli Effect Producing Maneuver-Induced Pharyngeal Narrowing in Patients with Obstructive Sleep Apnea Syndrome

Abstract

We developed a new method to evaluate dynamic narrowing of the pharynx induced by the Bernoulli effect producing maneuver (BEPM) of forced inspiration through the nose with the mouth closed in patients with obstructive sleep apnea syndrome (OSAS) using computer-assisted analysis of nasopharyngoscopic images. There was a significant correlation between the narrowing rate of the pharyngeal images obtained by nasopharyngoscopy during BEPM and the apnea index measured by single-night polysomnography. It is suggested that in addition to static pharyngeal narrowing, dynamic narrowing of the pharynx also contributes to the pathophysiology of OSAS. The pharyngeal narrowing rate during BEPM at a cut-off value of 50% combined with the body mass index (BMI) at a cut-off value of 25 kg/m² yielded a sensitivity of 93%, but a specificity of only 67% in differentiating simple snoring from OSAS. It is suggested that the pharyngeal narrowing rate during BEPM combined with the BMI is a promising index for predicting OSAS and that nasopharyngoscopy during BEPM could be a good OSAS screening method.