RESUMEN
Cross-sectional imaging has long been employed to examine swallowing in both the sagittal and axial planes. However, data regarding temporal swallow measures in the upright and supine positions are sparse, and none have employed the MBS impairment profile (MBSImP). We report temporal swallow measures, physiologic variables, and swallow safety of upright and supine swallowing in healthy subjects using videofluoroscopy (VFS). Twenty healthy subjects ages 21-40 underwent VFS study upright and supine. Subjects were viewed in the sagittal plane and swallowed 5 mL liquid and pudding barium. Oral transit time, pharyngeal delay time, pharyngeal response time, pharyngeal transit time, and total swallow duration were measured. Penetration/aspiration scores and 14 MBSImP variables were analyzed in both positions. All subjects completed swallows supine, although one aspirated on one liquid bolus. Temporal measures of swallowing were similar for pudding upright and supine. Pharyngeal phase swallow measures were longer for liquids in supine. MBSImP physiologic measures revealed a pharyngeal delay in both positions. Although Pen/Asp range was higher supine, more subjects penetrated upright. Temporal measures were increased for liquids in supine. Although Pen/Asp range was higher in supine, more subjects penetrated upright. These results provide support for cross-sectional supine imaging of swallowing for pudding, but perhaps not thin liquids for dysphagic patients. Slightly thicker liquids might prove reliable in supine without compromising swallow safety. Future research should examine swallow physiology in both positions in dysphagic and older healthy subjects.