Feeding difficulties are frequent comorbid conditions in infants and children with both acute and chronic illnesses and can alert the clinician to an underlying condition. In fact, feeding problems can precede the diagnosis of cerebral palsy in 60% of children with both cerebral palsy and oromotor dysfunction.¹ Decreased oral intake can lead to nutritional deficiencies, failure to thrive, and dehydration. The ability of infants and children to feed and grow relies on safe oromotor coordination, endurance while feeding, adequate caloric intake, an appropriate food source, and positive feedback with respect to the feeding experience. Although poor feeding may be associated with many other pediatric illnesses, by far the most common feeding-related issues are gastroesophageal reflux (GER) and gastroesophageal reflux disease (GERD). Dysphagia and feeding aversion are two other distinct feeding-related diagnoses that will be addressed. Complications related to feeding aversion and to aspiration are also often concomitant diagnoses in medically complex children.

Dysphagia, or difficulty swallowing, is the term often used to refer to a swallowing abnormality, which frequently leads to an effect on eating. Swallowing can be divided into three phases: oral, pharyngeal, and esophageal. Problems at any stage of swallowing can affect eating to some degree. During the oral phase, an infant forms a bolus of fluid after creating suction with the lips, tongue, and palate. The bolus is then moved to the posterior pharynx. Infants older than 3 to 4 months and children are able to complete the oral phase of swallowing with more mature tongue movements and are able to move boluses of food of different consistencies by chewing and tongue movements. The oral phase depends on normal oral anatomy, normal sensation and sensory feedback, strong sucking (in infants), and normal oral muscular function (in children).

The pharyngeal phase of swallowing is an involuntary action that is initiated when the bolus touches the posterior pharyngeal wall. During this phase, respiration ceases as the vocal cords close, the larynx elevates, and the upper esophageal sphincter relaxes to allow the bolus to enter the esophagus. In children with poor oral muscular coordination, early entry of the bolus into the pharynx before vocal cord closure may allow aspiration into the trachea. Similarly, delay in relaxation of the upper esophageal sphincter allows food to pool above or penetrate the larynx and increases the risk for aspiration when the vocal cords open again.

The involuntary esophageal phase of swallowing requires normal esophageal mucosa, caliber, and motility to allow the bolus to enter the stomach. Esophageal inflammation, stricture, dysmotility, and obstruction can all contribute to dysphagia.

Abnormalities in swallowing are most common in premature infants and children with neurologic abnormalities or airway anomalies, such as laryngeal clefts, vocal cord palsy, and tracheoesophageal fistula. Disorders of swallowing in children differ from those in adults because of the anatomic relationships of airway structures in children and variations in neurologic maturity. The most common disorders of swallowing in infants relate to immature sucking, inefficient sucking, and difficulty coordinating the suck-swallow-breathe rhythm. Less commonly, incoordination of swallowing may be due to an anatomic or neuromuscular abnormality that impairs one or several phases of swallowing. Swallowing incoordination may cause aspiration into the respiratory tract and lead to acute pneumonitis or pneumonia or to nonspecific airway inflammation. In many children, chronic aspiration can also lead to poor nutritional intake and feeding aversion.

Although most children who aspirate have neurodevelopmental delay or airway anomalies, aspiration can occur as an isolated phenomenon in neurologically normal infants. Two studies of term infants presenting with swallowing dysfunction suggest that the prognosis is excellent, with most babies showing improvement in swallowing by 3 to 9 months and more than 77% successfully exclusively feeding orally by 37 months.^2,3 Theories about the cause of isolated dysphagia in healthy infants include delayed neuromuscular coordination and esophageal dysmotility.^2,3

CLINICAL PRESENTATION

The most common symptoms associated with dysphagia are coughing, choking, and “blue” spells with feeding. Blue spells may be actual hypoxic events caused by impaired minute ventilation or aspiration of oral contents into the airway, and may be more marked in children who already have underlying cardiorespiratory compromise (e.g. congenital heart disease, bronchopulmonary dysplasia). Parents or caregivers may also report stridor, wheezing, and vomiting. Symptoms may vary in severity and quality depending on the feeding position, feed consistency, and type of feeding apparatus. The symptoms may occur exclusively during feeding (e.g. blue spells, choking, or sputtering), linger after completion of feeding (e.g. cough or stridor), or persist between feedings (increased secretions, wheeze). Some children have a history of pneumonia or a previous diagnosis of reactive airways disease, which may really reflect a previous aspiration event or chronic aspiration. A chest radiograph may show a focal infiltrate or chronic changes.

A larger proportion of children than adults aspirate silently without associated symptoms or evidence of protective cough. Silent aspiration is also more common in patients who aspirate more than once during a swallow.⁴ It should be considered in children with an anatomic or neuromuscular disorder, a report of slow feeding, chronic respiratory symptoms, or recurrent pneumonia.

Children with cleft palate or cardiorespiratory illnesses (e.g. chronic lung disease, congenital heart disease, or acute infectious respiratory illnesses) may become tachypneic, cyanotic, or diaphoretic and may have difficulty coordinating the suck-swallow-breathe cycle. These infants may suffer a significant reduction in minute ventilation while swallowing that leads to hypoxia. Infants with cleft palate need extra assistance with control of the flow of liquid into the pharynx to prevent aspiration and may have difficulty organizing the swallow at the end of the oral phase.

Healthy infants with recent lower respiratory tract infections, such as bronchiolitis, may also be at increased risk for laryngeal penetration, tracheal penetration, and aspiration into the lower airways. These abnormalities can normalize within 2 to 4 weeks after the infection.⁵ Infants with underlying dysphagia may experience worsening of their swallowing dysfunction and a further increase in their risk for aspiration.

DIFFERENTIAL DIAGNOSIS

The symptoms and signs that suggest dysphagia warrant consideration of the underlying abnormalities that may contribute to the disorder, including esophageal dysmotility, GERD, and anatomic, sensory, or motor abnormalities of the oropharynx.

DIAGNOSTIC EVALUATION

Clinical assessment of feeding is a bedside evaluation that is performed by an experienced occupational therapist or speech-language pathologist. It involves observation and assessment of tone, feeding position, sucking, tongue and jaw movements, bolus formation, and bolus manipulation. Observation of changes in respiratory status (coughing, choking, increased secretions, increased adventitious sounds on auscultation) is also important. In addition, assessment includes an evaluation with various food thicknesses and textures, depending on the age of the child. Clinical assessment should be considered for any child with an underlying condition that predisposes to dysphagia and aspiration or a child who exhibits unexplained respiratory symptoms, evidence of recurrent pneumonia, or difficulty feeding. Children with feeding aversion behavior may also benefit from clinical assessment. Clinical assessment is important for evaluation of the caregiver-infant feeding relationship and feeding safety and serves as a guide for the need for additional diagnostic testing (e.g. videofluoroscopic feeding study [VFS]). Clinical assessment of swallowing of liquids and solids at the bedside has a sensitivity of 90% and a specificity of 56% for risk for aspiration⁶ and is therefore a useful screening test to determine the need for radiographic evaluation.

VFS is considered the gold standard for assessment of feeding function. Radiographic contrast material is mixed with foodstuff of variable consistency (age appropriate) to visualize its dynamic passage from the mouth to the stomach. The nature and severity of specific abnormalities of function can be identified, including inefficient bolus formation, abnormal movement of the bolus to the posterior pharynx, pooling above the larynx, penetration of the bolus into the trachea, or direct aspiration into the lungs. There is a relationship between the severity of laryngeal penetration and aspiration risk, particularly with thin liquids. Eighty-five percent of children with evidence of deep laryngeal penetration on VFS also aspirate thin liquids on VFS.⁷ Swallowing appears to become more dysfunctional after multiple swallows in infants, thus suggesting that longer assessments with videofluoroscopy are most useful. VFS is also an excellent tool to evaluate the effect of changes in posture and texture on the safety of feeds in order to devise an optimal feeding plan for a child with dysphagia.

Because VFS requires radiation exposure, alternatives have been explored, including fiberoptic endoscopic evaluation of swallowing (FEES). This method allows direct visualization of baseline swallowing, as well as observation of swallowing with liquid or solid boluses. In one study of FEES in children who also underwent VFS, there was 100% agreement between the results of both modalities.⁸ FEES has the added benefit of enabling assessment of baseline swallowing without requiring the introduction of oral liquids or solids in high-risk children.

Salivagrams and milk scans are both nuclear medicine tests that have been used to assess swallowing and the presence of aspiration. Drawbacks to nuclear scintigraphy in the assessment of swallowing include the inability to assess tracheal penetration, making these tests situationally useful rather than first-line investigations of dysphagia. Similarly, bronchoscopy can detect lipid-laden macrophages, making aspiration of food contents into the airways highly likely, but it cannot distinguish between dysphagia and GER as a cause of aspiration.

Delineation of the swallowing disorder directs the clinician toward necessary feeding interventions or limitations. It may also help identify or clarify a condition for which dysphagia is only part of the clinical picture.

MANAGEMENT

The goal of management is to establish safe feeding regimens that improve the efficiency and enjoyment of feeding. Children with oromotor incoordination may benefit from an ongoing oral stimulation therapeutic program led by a speech pathologist or occupational therapist. It is vital to maintain positive oral experiences and reassess the safety of oral feeding clinically and radiographically, particularly in infants and young children, because there is a potential for improvement and maturation of the swallow mechanism. Without ongoing oral stimulation, feeding aversion may develop in children whose dysphagia improves.

Intervention for children who aspirate depends on which food consistency, if any, is found to be safe. Foods that are associated with aspiration are restricted. Children who are safe only with pureed consistencies often require another method of feeding to receive adequate fluids. Depending on the cause of dysphagia and the likelihood of improvement, nasogastric or gastrostomy tube feedings are indicated. Children who are found to aspirate all consistencies require admission to the hospital to establish tube feeding and to either teach parents how to administer nasogastric feeding or arrange for insertion of a gastrostomy tube.

Multiple factors can influence the enjoyment of eating and lead to food refusal in infants and children. Chronic discomfort from abnormal gastrointestinal motility, chronic esophagitis, chronic aspiration, sensory abnormalities, and force-feeding can all lead to feeding aversion, decreased oral intake, and poor nutrition and growth.⁹ Stressed feeder–child interactions around mealtime can also influence and exacerbate aversion behavior. Feeding aversion is particularly important in the inpatient setting for children who have prolonged illness. One study suggests that feeding refusal in children may stem from visceral hyperalgesia, often as a result of previous painful experiences such as prolonged neonatal care, multiple painful procedures, and chronic gastritis and esophagitis.¹⁰

DIAGNOSTIC EVALUATION

Evaluation of feeding aversion requires a thorough review of a child’s health, feeding, growth, and development. It is important to identify experiences that may have contributed to traumatically-acquired feeding disorders. Parental reports and direct or videotaped mealtime observation are also helpful to evaluate feeding behavior and identify feeder–child interaction problems.¹¹ Feeding questionnaires and structured observation tools are also available to assist in the evaluation of feeding aversion.¹¹