Clinical Evaluation of Swallowing

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

Table 3: Advantages and Disadvantages of VFSS

(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

Table 5: Advantages and Disadvantages of FEES

(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)
b. 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.