Aspiration and Swallowing Disorders

Key Points

  • The first priority in evaluating children with aerodigestive disorders is to ensure a safe airway.

  • The coordination of breathing and swallowing is crucial to survival, because both functions share the pharynx as a common conduit.

  • The four phases of swallowing are the 1) oral preparatory, 2) oral, 3) pharyngeal, and 4) esophageal phases.

  • The characteristics of dysphagia are defined by the anatomic site of impairment: nose and nasopharynx, oral cavity and oral pharynx, hypopharynx and larynx, and trachea and esophagus.

  • Swallowing must allow for sufficient nutritional and fluid intake for optimal growth and development.

  • Videofluoroscopic swallow studies and flexible endoscopic evaluation of swallowing are commonly used evaluation tools to assess the pharyngeal phase of swallowing.

  • Dysphagia management may include feeding modifications, supplemental nutrition, oral motor and swallowing therapies, and alternative feeding routes.

Swallowing involves multiple, highly integrated and partially overlapping actions; however, for discussion purposes, it is frequently separated into three phases— oral, pharyngeal, and esophageal . During the oral phase, food is processed into a swallow-ready ball known as a bolus and is then transported to the back of the mouth. In infants, the oral phase is limited to suction of fluid from a nipple. In children approximately 6 months of age and older, the oral phase may be further partitioned to include the oral preparatory phase, during which solid foods are masticated and prepared for the oral phase. The pharyngeal phase comprises a series of complex and interrelated events that direct and propel boluses through the pharynx into the esophagus while simultaneously protecting the airway. During this phase of swallowing, the velum rises and approximates the pharyngeal walls, breathing stops, the larynx rises, the vocal folds adduct, and the base of the tongue and pharyngeal muscles propel the bolus through a relaxed upper esophageal sphincter. The act of swallowing results in mechanical closure of the airway and cessation of breathing. The esophageal phase begins when the bolus enters the esophagus and ends when it passes into the stomach.

Typical swallowing maturation involves transformation from the primitive sucking and swallowing reflexes used during infancy into the mature and volitional functions of biting, chewing, and bolus formation necessary for the safe and adequate delivery of nutrients in older children and adults. Appropriate adjustments to growth and developmental changes of the aerodigestive system and changes in airway protective responses are essential to competent postnatal maturation processes. Changes in the anatomic relationships of the oral cavity, pharynx, and larynx occur throughout the first few years of life and are well described. In addition, neurodevelopmental, cognitive, and sensory inputs modulate deglutitive function and consequently may influence the maturation process.

Competent deglutition, or swallowing, is crucial to survival. Two primary functions of swallowing are to direct oral secretions, liquids, and food from the mouth to the stomach while protecting the airway and to provide sufficient amounts of nutrients and fluids for children to grow and develop optimally. Appropriate adjustments to growth and increases in nutritional needs are crucial to successful postnatal deglutition. Because breathing and swallowing share common conduits, such as the oral cavity and pharynx, their functions are intertwined.

Dysphagia, or swallowing dysfunction, may be caused by any condition that interferes with the integrity of the structures that comprise the aerodigestive tract or their coordination. Congenital or acquired structural or anatomic anomalies may cause airway and swallowing defects. This chapter focuses on the evaluation of infants and children with suspected dysphagia and the associated primary aerodigestive tract anomalies. Management approaches to swallowing and airway-related problems are reviewed.

Evaluation of Infants and Young Children with Suspected Dysphagia

Clinical or Bedside Evaluation

Evaluation of all children with feeding and swallowing difficulties begins with taking a thorough history and performing a physical examination. Children with anatomic anomalies are at increased risk for dysphagia when the underlying conditions interfere with the structural integrity of the oropharynx or the complex coordination of neuromuscular and airway processes involved in deglutition. Consequently, the focus of the clinical evaluation is the selection of diagnostic tests to determine the nature and extent of the swallowing impairments and to guide management decisions. Children who present with structural anomalies as one component of a complex medical history or syndrome (e.g., bronchopulmonary dysplasia or Smith-Lemli-Opitz syndrome) may require other specialized evaluations such as direct laryngoscopy and bronchoscopy to determine the impact of the associated comorbidities on swallowing.

Instrumental Evaluation

When the clinical evaluation identifies swallowing problems without obvious physical manifestations, an instrumental evaluation is typically recommended. The structures involved in swallowing may be visualized by radiologic procedures, such as an upper gastrointestinal (UGI) series and videofluoroscopic swallow studies (VFSS), and/or endoscopic procedures, such as flexible endoscopic evaluation of swallowing (FEES). Evaluation by a UGI series, VFSS, and FEES may establish a diagnosis of dysphagia by identifying a specific pathophysiology; however, these tests may fail to detect aspiration even in children who aspirate, particularly when aspiration is episodic. Therefore negative findings for aspiration should be interpreted with caution.

Upper Gastrointestinal Series

UGI series may provide important information for children with anatomic anomalies, particularly when the anomaly is distal to the oropharynx. UGI study allows for assessment of the anatomy and physiology of the esophagus, stomach, and duodenum and identifies gastrointestinal (GI) obstructions and malrotation. In addition, it serves as a screen of oropharyngeal structure and function. Liquid barium may be administered orally or by nasogastric tube, depending on the specific diagnostic questions and whether the child is at risk for aspiration secondary to swallowing dysfunction.

Videofluoroscopic Swallow Study

VFSS, sometimes referred to as a modified barium swallow study, images the structures of the oral cavity, pharynx, and cervical esophagus during deglutition. It is useful to evaluate children suspected to have oropharyngeal dysphagia and as a screening test for GI structures distal to the cervical esophagus. The goals of VFSS are to provide information that helps to 1) determine whether anatomic or structural abnormalities are present; 2) ascertain whether coordination of the structures and functions of the upper aerodigestive tract supports safe and efficient bolus passage; and 3) identify strategies that enhance the safety and efficiency of feeding. During VFSS, children ingest liquids and/or foods impregnated with barium contrast material to simulate functional feeding as closely as possible. Consequently, children must be ready, willing, and able to cooperate with VFSS.

Flexible Endoscopic Evaluation of Swallowing

FEES is an extension of the routine flexible fiberoptic nasopharyngolaryngoscopy examination, and it can be used to evaluate the structures and functions of the nasopharynx, oropharynx, and larynx during phonation, spontaneous swallows, and swallows of liquids and foods. FEES may be particularly useful in nonoral feeders, those unable to cooperate with VFSS, in children with vocal fold dysfunction, or in those with questionable ability to handle their secretions.

FEES may provide sensory information when the endoscope touches adjacent mucosa or structures. FEES plus sensory air pulse testing (FEES-ST) allows standardized evaluation of responsiveness to sensory input (calibrated air pulses administered endoscopically). Studies have demonstrated the utility of FEES-ST for the evaluation and treatment of children with specific diagnostic conditions (e.g., type I laryngeal clefts) and during preoperative evaluations for pediatric airway reconstruction. Elevated thresholds of laryngopharyngeal sensation have been documented in children with clinical diagnoses of recurrent pneumonia, neurologic disorders, and gastroesophageal reflux disease (GERD). Table 30-1 outlines the utility of using VFSS and FEES based on the anatomic or structural condition.

TABLE 30-1

Anatomic Locations, Conditions, Phases of Swallowing Dysfunction, and Utility of Videofluoroscopic Swallow Studies and Flexible Endoscopic Evaluation of Swallowing

Anatomic Location Anatomic or Structural Condition potential phase of swallowing impairment Indication for VFSS Indication for FEES
Oral Pharyngeal Esophageal
Nose and nasopharynx Midface hypoplasia Yes Yes ± ±
Piriform aperture stenosis Yes Yes ± ±
Deviated septum Yes Yes No No
Encephalocele Yes Yes No No
Tumor Yes Yes No No
Choanal atresia Yes Yes No No
Adenoid hypertrophy Yes Yes No No
Oral cavity and oropharynx Cleft lip/palate Yes No No
Micrognathia or retrognathia Yes Yes ± ±
Macroglossia Yes Yes ± ±
Tumor Yes Yes ± ±
Hypopharynx and larynx Vallecular cyst Yes No No
Laryngomalacia Yes ± ±
Vocal fold paralysis/paresis Yes Yes Yes
Laryngeal web Yes ± ±
Posterior laryngeal cleft Yes Yes Yes Yes
Subglottic stenosis Yes S ± ±
Subglottic hemangioma Yes S ± ±
Trachea and esophagus GERD S Yes ± No
Eosinophilic esophagitis S Yes ± No
Vascular ring Yes ± No
Tracheal stenosis Yes ± No
Tracheomalacia Yes ± No
Tracheoesophageal fistula Yes ± No

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Jul 15, 2019 | Posted by in OTOLARYNGOLOGY | Comments Off on Aspiration and Swallowing Disorders

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