0457 An Effective Mode To Predict Severity Of Obstructive Sleep Apnea: Dynamic Change Of Aerospace Detected By Submental Ultrasonography

We previously reported that manually-operated submental ultrasonography (US) could be used to identify patients with severe obstructive sleep apnea (OSA). The present study aimed to test the accuracy of machine-held submental US to identify patients with of different severity. 13 heathy volunteers [apnea-hypopnea index (AHI)<5/hr] and 51 OSA patients (AHI>5/hr) were enrolled. The pharynx was scanned for 4 seconds through hypoid bone to mandibular plane with 5-MHz convex transducers while the participants were awake and at supine position with total 84 frames of US-images obtained. Transverse diameter of pharyngeal aerospace was measured for three times for tidal breathing and Müller's Maneuver (MM). The dynamic change was defined as percentage of pharyngeal diameters shortening from the diameters upon expiration during tidal breathing to that during MM. The dynamic change was compared between OSA of different severity while multivariate logistic regression was applied to identify independent predictors. Thereafter, these independent predictors were used to estimate the probability of OSA of different severity, which was tested using the area under the receiver operating characteristic (AUROC) curve. Among 64 participants, 68.9% male, the median age was 46 y/o [interquartile range (IQR), 17.5] and body mass index (BMI) was 26.8 Kg/m2 (6.7). The AHI was 0.4/hr (0.5) and 22/hr (31.6) in volunteers and OSA patients, respectively. The age (r=0.485, p<0.001), BMI (r=0.628, p<0.001), median pharyngeal diameter at MM (r=0.387, p=0.0016) and median dynamic change (r=0.622, p<0.001) were correlated with AHI. The Stepwise logistic analysis identified the median dynamic change as independent predictor for no-mild [odds ratio (OR), 1.148], moderate (1.070) and severe (1.037) OSA. The AUROC of BMI and median diameters for identifying the no-mild, moderate, severe OSA was 0.893, 0.849, 0.667, respectively. Using BMI and median dynamic change of pharyngeal diameter as the indicators, the machine-held submental US could be applied to identify patients with OSA of different severity with good accuracy. AmCad BioMed Corporation, Ultrasound Images from Lung and Airway Collection and Development(106-S-C12) from Chin-Ling Center in Taiwan