Dysphagia Assessment (Bedside, MBSS, FEES, PAS)

Screen vs. Clinical Evaluation vs. Instrumental Exam

• 3-oz (90 mL) water swallow test: drink 90 mL of water without stopping; coughing, choking or a wet voice during or up to a minute after is a fail. In one study of 3,000 patients with FEES as the reference, sensitivity for aspiration was about 96% but specificity was only about 49%. Passing predicts tolerance of thin liquids well; failing over-refers about half of patients (Suiter & Leder, 2008).
• Yale Swallow Protocol: a brief cognitive screen and oral-mechanism check, then the 3-oz water swallow. It rests on the same water challenge, so expect the same trade-off (few aspirators missed, many false positives). In a blinded comparison, nurses trained with a short module administered it in close agreement with SLPs (Warner et al., 2014).
• Estimates vary with population and method. A pass supports starting oral intake; a fail means referral, not a diagnosis. No screen or CSE rules out silent aspiration.
• Timing after stroke: the 2019 AHA/ASA guideline supports a dysphagia screen before the patient takes any food, drink or oral medication (Powers et al., 2019).

Clinical Bedside/Swallow Evaluation (CSE)

Components:

• Case history: Medical diagnoses, medications, NPO status, weight changes, pneumonia history
• Oral mechanism exam: Strength, range, symmetry, sensation of oral structures (CN assessment)
• Cognitive/language screen: Alertness, orientation, ability to follow commands
• Trial swallows: Various consistencies, observe oral control, timing, laryngeal elevation, cough/throat clear
• Cervical auscultation: Stethoscope on lateral neck to listen for swallow sounds (adjunct, not diagnostic)

CSE Limitations:

• Cannot visualize pharyngeal phase: cannot detect silent aspiration
• Cannot assess pharyngeal residue, penetration, or aspiration definitively
• Sensitivity for aspiration is limited, and published estimates vary widely with population and method; in one blinded study, the bedside evaluation identified only 42% of patients who aspirated on videofluoroscopy (Splaingard et al., 1988)
• Best used to identify signs of dysphagia and decide whether instrumental assessment is needed; instrumental assessment recommended when aspiration is suspected

Modified Barium Swallow Study (MBSS / VFSS)

• One of the two main instrumental exams, with FEES; neither is a single gold standard, because each shows parts of the swallow the other misses
• Real-time fluoroscopic imaging of the oral, pharyngeal, and upper esophageal phases
• Patient ingests barium-containing foods/liquids of various consistencies
• SLP directs the study; radiologist provides fluoroscopy
• Visualizes oral, pharyngeal, and upper esophageal phases

What MBSS Shows:

• Bolus formation and transit
• Oral residue and premature spillage
• Vallecular and pyriform sinus residue
• Penetration and aspiration (timing relative to swallow)
• Effectiveness of compensatory strategies (tested in real-time)
• Epiglottic deflection, hyolaryngeal excursion, UES opening

MBSS Standardized Protocol (MBSImP):

• 17 physiologic components scored on ordinal scales
• Provides objective, reliable scoring framework
• Components include: lip closure, tongue control, bolus transport, laryngeal elevation, pharyngeal contraction, UES opening, etc.

Fiberoptic Endoscopic Evaluation of Swallowing (FEES)

• Flexible endoscope passed transnasally to view pharynx/larynx from above
• Visualizes pharyngeal and laryngeal structures before and after the swallow
• Material below the vocal folds may be observed after the swallow, supporting identification of aspiration even without a cough
• Whiteout during the swallow (the pharynx closes around the endoscope tip at the height of the swallow and blanks the view)
• Can be done at bedside: portable; no radiation
• Excellent for assessing secretion management, vocal fold function, velopharyngeal closure

FEES Advantages over MBSS:

• Portable (ICU, bedside, nursing home)
• No radiation exposure
• Can assess secretions
• Repeated trials without radiation concern
• Views laryngeal anatomy directly

FEES Limitations:

• Cannot view oral phase or esophageal phase
• Whiteout during swallow: obscures aspiration occurring during the swallow; events before or after may be visible
• Cannot assess UES opening or bolus transit timing as precisely

Penetration-Aspiration Scale (PAS)

When to Refer for Instrumental Assessment

• Suspected silent aspiration (history of pneumonia, weak cough, neurological diagnosis)
• CSE findings are equivocal
• Need to evaluate effectiveness of compensatory strategies
• Persistent dysphagia despite treatment
• Pre-/post-surgical evaluation
• Failure to progress with current diet recommendations

Sources to Know

• ASHA Practice Portal: Adult Dysphagia
• ASHA: Videofluoroscopic Swallow Study
• ASHA: Flexible Endoscopic Evaluation of Swallowing
• Rosenbek et al. (1996). A penetration-aspiration scale. Dysphagia
• Robbins et al. (1999). Differentiation of normal and abnormal airway protection during swallowing using the Penetration-Aspiration Scale. Dysphagia
• Splaingard et al. (1988). Aspiration in rehabilitation patients: videofluoroscopy vs bedside clinical assessment. Arch Phys Med Rehabil
• Martin-Harris et al. (2008). MBS measurement tool for swallow impairment (MBSImP): establishing a standard. Dysphagia
• Langmore, Schatz & Olsen (1988). Fiberoptic endoscopic examination of swallowing safety: a new procedure. Dysphagia
• Powers et al. (2019). Guidelines for the early management of acute ischemic stroke: 2019 update. Stroke
• Suiter & Leder (2008). Clinical utility of the 3-ounce water swallow test. Dysphagia
• Logemann, J. A. (1998). Evaluation and Treatment of Swallowing Disorders (2nd ed.). Pro-Ed.
• Warner et al. (2014). Comparing accuracy of the Yale swallow protocol when administered by registered nurses and speech-language pathologists. J Clin Nurs

Reviewed: 2026-09