No abstract

This study was designed to investigate the significance of bolus types and volumes, delivery methods and swallowing instructions on lung volume at swallowing initiation in normal subjects in a single experiment using a multifactorial approach. Our broad range goal was to determine optimal lung volume range associated with swallowing initiation to provide training targets for dysphagic patients with disordered respiratory-swallow coordination. Our hypothesis was that swallows would be initiated within a limited range of quiet breathing lung volumes regardless of bolus volume, consistency or task. Results confirmed this hypothesis and revealed that swallows were initiated at mean lung volume = 244 ml). Cued swallows were initiated at lower quiet breathing volumes than un-cued swallows (cued = 201 ml; un-cued = 367 ml). Water boluses were initiated at slightly higher quiet breathing volumes than solids. Data suggest that swallows occur within a restricted range of lung volumes with variation due to instructions, bolus type and other experimental variables.

Reducing fluoroscopic pulse rate, a method used to reduce radiation exposure from Modified Barium Swallow Studies (MBSSs), decreases the number of images available from which to judge swallowing impairment. It is necessary to understand the impact of pulse rate reduction on judgments of swallowing impairment and, consequentially, treatment recommendations. This preliminary study explored differences in standardized MBSS measurements (Modified Barium Swallow Impairment Profile (MBSImP™©) and Penetration Aspiration Scale (PAS) scores) between two pulse rates: 30 and simulated 15 pulses per second (pps). Two reliable speech-language pathologists (SLPs) scored all 5 MBSSs. Five SLPs reported treatment recommendations based on those scores. Differences in judgments of swallowing impairment were found between 30 and simulated 15pps in all 5 MBSSs. These differences were in six physiological swallowing components: initiation of pharyngeal swallow, anterior hyoid excursion, epiglottic movement, pharyngeal contraction, pharyngeal-esophageal segment opening and tongue base retraction. Differences in treatment recommendations were found between 30 and simulated 15pps in all 5 MBSSs. These findings suggest that there are differences in both judgment of swallowing impairment and treatment recommendations when pulse rates are reduced from 30pps to 15pps to minimize radiation exposure.

The Modified Barium Swallow Impairment Profile (MBSImP™©) is a standardized method for the assessment of swallowing physiology from videofluoroscopic imaging used by teams of speech-language pathologists (SLPs) and radiologists during modified barium swallowing studies (MBSS). The approach is grounded in research and motivated by patient need toward minimizing wide variation in clinical practice and equivocal swallowing assessment findings when attempting to compare assessment results across the continuum of care and between clinical settings. Various methods of scoring are used, which are dependent upon the nature and purpose of the clinical or research question. The MBSImP™© initiated with an National Institute of Health [NIH] supported study has been field tested for 13 years. The standardized method aims to enhance the validity and reliability of swallowing metrics, improve transparency and reproducibility of clinical and research MBSS practices, as well as to optimize patient safety, comfort, expectations, and outcomes. The physiologic study of swallowing impairment using the MBSImP™© has become a program of research that strategically includes a data science initiative using a global registry of quality, safety and outcome metrics.

Purpose Guidelines and preventive measures have been established to limit radiation exposure time during modified barium swallow studies (MBSS) but multiple variables may influence exam duration. This study examines the influence of clinician experience, medical diagnosis category, swallowing impairment severity and use of a standardized protocol on fluoroscopy time. Methods A retrospective review was completed on 739 MBSSs performed on 612 patients (342 males/270 females; age range = 18 to 96 years) completed in one year at the Medical University of South Carolina with IRB approval. All studies were completed by speech-language pathologists trained in the data collection protocol, interpretation, and scoring of the MBSImP™©. Medical diagnosis category, swallowing impairment severity (MBSImP™© score), clinician experience, and fluoroscopy time were the variables recorded for analysis. Results Fluoroscopy time was not significantly associated with medical diagnosis category (p=0.10). The severity of the MBSImP©™ Oral Total and Pharyngeal Total resulted in statistically significant increases in fluoroscopy time (p<0.05). Studies by novice clinicians had longer exposure times when compared to experienced clinicians (p=0.037). Average radiation exposure time using the MBSImP©™ approach was 2.9 minutes, with a 95% confidence interval of 2.8 minutes to 3.0 minutes, which was well within the range of exposure times reported in the literature. Conclusions This study provides preliminary information regarding the impact of medical diagnosis category, swallowing impairment severity and clinician experience on fluoroscopy time. These findings also suggest that a thorough, standardized protocol for MBSSs did not cause unnecessary radiation exposure time during the MBSS.