Clinical Evaluation of Swallowing

The clinical evaluation of swallowing is the initial step in the diagnostic process (American Speech-Language-Hearing Association, 2019). The purpose of this evaluation includes:

  • diagnose a suspected swallowing dysfunction
  • identify site or which phase of the swallowing function may be affected
  • identify severity and prognosis of the swallowing dysfunction
  • refer to additional healthcare professionals or medical specialists
  • determine whether further objective instrumental assessment is required
  • develop a management plan for oral, pharyngeal, and/or laryngeal dysfunction (Ongkasuwan & Chiou, 2018)

The clinical evaluation of swallowing is comprised of a collection of measures, each providing a unique contribution to a comprehensive understanding of a swallowing problem (McCullough & Martino, 2013).

The components of a clinical evaluation of swallowing include assessment of:

  • oral motor structure and function
  • cranial nerves involved in swallowing
  • feeding and swallowing
  • suspected pharyngeal phase difficulties
  • trials of conservative strategies or techniques
  • information from instrumental evaluation if available
  • results of additional diagnostic tests such as chest x-rays and upper gastrointestinal series

A clinical physical examination by physician(s), (e.g. general pediatrician, otolaryngologist, gastroenterologist, pulmonologist) of systems involved should be part of a comprehensive clinical evaluation.

The clinical evaluation of swallowing assessment should mirror the natural environment as much as possible. Elements from the natural environment to consider during assessment include: familiarity and responsiveness with the feeder, liquid and food choices, positioning, and typical equipment. Trials of conservative strategies or techniques include facilitating increased responsiveness, introducing novel liquids or foods, including consistency modifications, achieving improved positioning, and trialing new equipment.

Validated methods are recommended for interpreting and reporting results of all clinical feeding and swallowing assessments. The following measures are recommended:

  1. Australian Therapy Outcome Measures (AusTOMs) for Speech Pathology Swallowing Scale© (Perry & Skeat, 2005)
  2. Functional Oral Intake Scale (FOIS) Pediatric (Dodrill & Gosa, Pediatric Dysphagia: Physiology, Assessment, and Management, 2015); (Yi & Shin, 2019)
  3. Safe Individualized Nipple Competence, (SINC©) (Alberta Health Services, 2019)
  4. Positive Oral Experiences Training Initiative (POETrI)

A clinical evaluation of swallowing cannot conclusively demonstrate anatomical problems, functional problems, or aspiration events nor does it reliably diagnose oropharyngeal dysphagia and aspiration (Duncan, Mitchell, Larson, & Rosen, 2018). Clinical evaluation of swallowing is open to subjective interpretation. It is a particularly ineffective diagnostic tool for infants and children experiencing silent aspiration, which has been estimated to involve 60-100% of aspiration cases (Weir, McMahon, Taylor, & Chang, 2011). For infants and children with concerns related to aspiration, or swallowing function, instrumental assessments of swallowing are recommended (Arvedson J. , 2008).

When to consider instrumental evaluations of swallowing:

  • concerns related to aspiration or swallowing function to assess laryngeal integrity
  • concerns related to oral and pharyngeal phase disorders
  • preoperative evaluation, e.g. pre-surgical baseline
  • additional information to support the course of management
  • evaluate the effect of compensatory and treatment strategies (The Speech Pathology Association of Australia, 2012)

Contraindications to instrumental evaluations of swallowing:

  • infant or child is drowsy, agitated, or unable to cooperate with the exam
  • child has an intercurrent illness, e.g. viral bronchiolitis, which may be predicted to temporarily impact swallowing
  • child is physiologically unstable
  • additional information will not change the course of management

Instrumental evaluation is conducted following a clinical evaluation when further information is needed to determine the presence, nature and extent of the swallowing disorder. It assesses swallowing structures, physiology, and biomechanics, and examines motor and sensory function. Instrumental evaluation goes beyond describing the presence or absence of aspiration; instrumental evaluation can also help to determine if swallow safety can be improved by modifying food textures, liquid consistencies, nipple flow rate, bite sizes, modified or specialty bottles, and/or positioning (Martin-Harris, Carson, Pinto, & Lefton-Greif, 2020).

Instrumental evaluations of swallowing are not necessarily conclusive. Instrumental techniques cannot irrefutably exclude aspiration given the time dependent nature of the evaluations and the situational nature of aspiration. These limitations should be taken into consideration when estimating the results of the evaluations. 

The reliability of instrumental evaluations can be increased by adopting tools that decrease procedural variability and increase the quantification of oropharyngeal swallow physiology. 

The most commonly used instrumental assessments of swallowing include the Videofluoroscopic Swallowing Study (VFSS) and Fiberoptic Endoscopic Evaluation of Swallowing (FEES).

Videofluoroscopic Swallowing Study (VFSS) or Modified Barium Swallow (MBS)

VFSS allows for the assessment of the swallow in all of the swallowing stages (Dodrill & Gosa, Pediatric Dysphagia: Physiology, Assessment, and Management, 2015). During this study, the patient is presented with barium-infused liquid and food, and videofluoroscopic monitoring is used to document integrity of laryngeal and pharyngeal structures, oral and pharyngeal phases of the swallow, swallowing disturbances, and airway protection (Bülow, 2012); (Arvedson & Lefton-Greif, 2017). VFSS also verifies success of modifications to increase swallowing safety. See Table 2 and Table Table 3.


Table 2: When to Consider VFSS

When to Consider VFSS

Contraindications of VFSS

  • Patient cooperation is maximized
  • Some exposure to oral intake – a minimal amount is necessary to obtain enough diagnostic information from the study
  • Fatigue with feeding
  • Potential for medical complications or potential for compromised pulmonary function (suboptimal endurance)
  • Child is NPO 
  • Child is refusing feeding with evident aversive behaviours, and has minimal oral intake


Table 3: Advantages and Disadvantages of VFSS

Advantages of VFSS

Disadvantages of VFSS

  • Defines oral and pharyngeal stages of swallowing
  • Provides dynamic imaging of oral, pharyngeal, and upper esophageal phases of swallowing
  • Non-intrusive (although, for some the confined space may be considered intrusive)
  • Assesses various consistencies
  • Provides ongoing view of airway protection during sequential swallows
  • Verifies outcomes of modifications
  • Must accept some oral intake
  • Does not provide comprehensive examination of esophageal structure and function
  • Radiation exposure (limits duration and repeatability)
  • Barium alters the taste and texture of liquids and foods
  • Operator dependent and open to subjective interpretation
  • Staff and scheduling requirements
  • Cannot assess an exclusively breastfed baby

(Logemann, 1998)

Image Acquisition Rate

When considering image acquisition rate, it is important to consider three components: fluoroscopy rate, pulse rate and frame rate. These three components should be compared to ensure that the necessary questions are answered while limiting unnecessary radiation exposure (Steele, 2015). 

A full study is always recommended. Partial information may lead to erroneous assumptions about a child’s swallow function resulting in unnecessary radiation exposure and compromised patient care (Bohilha, et al., 2013); (Bohilha, et al., 2013); (Cohen, 2009).

Refer to: Role Descriptors and Tasks within Full Scope - for discipline specific roles with VFSS

Fiberoptic Endoscopic Evaluation of Swallowing (FEES)

FEES provides images of the anatomical structures involved in swallow physiology, which identifies structural and physiological swallowing impairments, as well as an assessment of aspiration risk (Willging, 2018). See Table 4 and Table 5.


Table 4: When to Consider FEES

When to Consider FEES

Contraindications of FEES

  • Clinical signs of aspiration during the clinical evaluation for bottle or breastfeeding
  • Poor or questionable secretion management
  • Stertor
  • Stridor
  • Suspected laryngeal abnormality
  • Fatigue with feeding
  • Considering initiation of oral intake
  • Assess progress or change
  • Inability to tolerate or pass a nasogastric tube
  • Anatomic conditions such as choanal atresia and nasal or pharyngeal stenosis


Table 5: Advantages and Disadvantages of FEES

Advantages of FEES

Disadvantages of FEES

  • It is possible to complete if non-oral or limited oral intake
  • Assesses secretion management
  • Visualizes pharyngeal and laryngeal anatomy
  • Visualizes the vocal cords
  • Assesses various consistencies
  • Position of patient is flexible and not critical to results 
  • Assesses swallow while breastfeeding 
  • Portable and accessible
  • No limitations on time and repeatability
  • No taste alteration of liquids or solids (can use favourite foods)
  • No radiation exposure or risk of aspirating barium
  • Useful for biofeedback
  • Intrusive
  • Actual swallow is obscured (white out)
  • Cannot assess esophageal phase
  • Operator dependent and open to subjective interpretation

(Arvedson, Brodsky, & Lefton-Grief, 2020)

Refer to: Role Descriptors and Tasks within Full Scope - for discipline specific roles with FEES

Instrumental Evaluation of Swallowing Considerations

VFSS and FEES exams can be complementary and augmentative. Both tests provide information about modifications that can be made to enhance swallow safety and allow an infant or child to continue eating by mouth. In the case of frequent interval testing, FEES can be repeated as often as necessary. With FEES, there is no radiation exposure. VFSS, on the other hand, introduces radiation exposure and risk of barium aspiration, which has been shown to deleteriously impact health (Leder & Karas, 2000); (Sitton, et al., 2011).

Normal FEES and VFSS do not always exclude aspiration – just as normal outcomes from a clinical examination does not always exclude silent aspiration. An aspiration event can be situational, and the degree of impairment and level of risk may not be adequately captured at the time of the instrumental evaluation. Further complicating the assessment and interpretation of swallowing dysfunction is limited evidence describing the effect of aspiration on the lungs of children. The quality and type of aspiration that can or cannot be safely tolerated by the lungs has not yet been clearly defined (Tanaka, et al., 2019).

Validated methods are recommended to mitigate subjective interpretation of FEES and VFSS by standardizing the method of training and administration, analyzing impairment, and reporting results (Martin-Harris, Carson, Pinto, & Lefton-Greif, 2020).

VFSS: Tools recommended for the quantification of oropharyngeal swallow physiology include:

a. Penetration Aspiration Scale (Rosenbek, Robbins, Roecker, Coyle, & Woods, 1996)
BaByVFSSImP© (Martin-Harris, Carson, Pinto, & Lefton-Greif, 2020)

FEES: Tools recommended for the quantification of swallow physiology and secretion management include:

a. Penetration Aspiration Scale (Rosenbek, Robbins, Roecker, Coyle, & Woods, 1996)
b. Secretion Rating Scale (Murray, Langmore, Ginsberg, & Dostie, 1996)

It is important that test fluids match prescribed fluids in terms of viscosity, volume, dose, and method of administration as they apply to all feeding and swallowing assessments.

Refer to: The International Dysphagia Diet Standardisation Initiative (IDDSI)

When penetration/aspiration and residue are reported in isolation and as the only outcomes in instrumental evaluations it: 

  • minimizes the complexity of the swallowing mechanism
  • does not sufficiently capture degree of impairment and level of risk
  • does not provide information to maximize function 
  • does not guide treatment

Results of instrumental assessments are reviewed in the context of findings from the clinical assessment.

Total or supplementary non-oral nutrition may be recommended when an infant or child is assessed to be unable to safely swallow any liquid or food, or when dysphagia compromises their ability to obtain adequate nutrition and/or hydration orally (College of Audiologists and Speech-Language Pathologists of Ontario, 2007). 

The physician, along with the other members of the interdisciplinary team, is responsible to discuss with the parents the possibility of proceeding with non-oral nutrition for the infant or child, and the risks and benefits associated with non-oral nutrition (College of Audiologists and Speech-Language Pathologists of Ontario, 2007).

Indications for non-oral nutrition include optimization of nutrition and/or hydration, and limiting the occurrence of aspiration (although not shown to effectively prevent aspiration pneumonia) (College of Audiologists and Speech-Language Pathologists of Ontario, 2007).