Children with developmental disabilities frequently have problems related to feeding and nutrition that pediatricians are first to evaluate and treat. This article offers a conceptual framework for understanding feeding and nutrition problems in children with disabilities, provides the pediatrician with the necessary tools to evaluate these problems, and reviews treatment options. The overarching goal of treatment is to provide adequate calories and nutrients in the safest and most pleasurable manner.
SURVEILLANCE OF GROWTH AND NUTRITIONAL STATUS
An important part of routine health-care maintenance for all children is the surveillance of growth and nutritional status. This includes growth measurements1 and charting against normal standards.2 Normal growth is a marker for health, while abnormal growth suggests medical illness, malnutrition, or a psychosocial problem. While this is also true for children with disabilities, two problems make the interpretation of growth more difficult. The first is obtaining reliable measures may be difficult, and the second is reference standards may not be appropriate.
Head circumference, height or length, and weight are routinely used to monitor growth in children. Head circumference is easily and reliably measured. The measurement of weight is generally straightforward as well, using standard infant and pediatric/adult scales. However, larger children with disabilities may be difficult to weigh if they are too large for the infant scale but are unable to stand independently for a standard scale. A bed scale or wheelchair scale may be used to weigh these children. Most pediatric offices will not have such a scale. One reliable method is to weigh the caregiver and the child and then subtract the weight of the caregiver. Once children get too large for this method, an accurate weight cannot easily be obtained in the office setting« Weight then may need to be obtained at a local hospital or developmental center.
Reliable measures of height or length in children with physical disabilities are often impossible to obtain due to scoliosis, fixed joint contractures, involuntary muscle spasms, and poor cooperation due to cognitive deficits.3,4 Alternate measures to height or length, and the segmental measurement of upper arm length and lower leg length, have been investigated in children with cerebral palsy4,5 and are now used in studies of growth.6,7 Recently, clinically useful formulas for estimating stature from these measurements and from knee height have been developed for children with cerebral palsy.8 The easiest segmental measurement to obtain is tibial length. With both the knee and ankle at 90° angles, the tibial length is measured from the medial joint line of the knee to the inferior rim of the medial malleolus using a flexible steel tape. In children with cerebral palsy, an estimate of stature then can be calculated from this measurement (tibial length (TL) formula: estimated stature = 3.26 × (TL) + 30.8) for use on standard growth charts, or the tibial length can be plotted on specialized growth charts designed for that purpose.4 Arm span can be used as a proxy for length in children with meningomyelocele.9
Even after reliable estimates of weight and stature have been obtained, the interpretation of the plotted data and the diagnosis of malnutrition in children with disabilities is often unclear. The application of standards based on normally active children to children with less muscle and bone density due to physical inactivity may not be appropriate.10 Specialized growth charts have been developed for many populations of children with developmental disabilities, including Down syndrome,11 Prader-Willi syndrome,12 De Lange's syndrome,13 and meningomyelocele. Other measures that can be extremely useful are triceps and subscapular skinfold thickness. The use of skinfold thicknesses to determine energy reserves also has been proven useful.5,14 Standards are available,15 and this may be a helpful adjunct, especially in those groups of children for whom specialized growth charts do not exist.
NORMAL FEEDING DEVELOPMENT
The process of "learning to eat" is complex. The development of feeding is a progression of physiologic tasks and behaviors gradually learned in a social context. Feeding begins as a brainstem-mediated reflex in the infant, manifested by the suck-swallowbreathe triad.16,17 Neurophysiologic control of feeding involves peripheral afferents, peripheral efferente, the medullary swallowing centers, and eventually suprabulbar inputs. Gradually, feeding evolves from a purely reflexive behavior to a largely voluntary process with only the pharyngeal and esophageal phases of swallowing remaining under reflex control. This process has been termed "encephalization."18 Through feeding experience, different sensory inputs are extended past the brainstem to tlie midbrain, cerebellum, thalamus, and the cerebral cortex. These interpret the sensory input and exert volitional control on the brainstem motor centers. As a result, the older infant and young can evaluate the physical character of food, manipulate it appropriately, and voluntarily ingest it.18 Feeding experiences that occur multiple times each day are crucial to acquisition of feeding skills. While the process proceeds smoothly in most children, developmental disabilities can disrupt normal neurologic maturation, the learning of feeding skills, and the feeding relationship.
Learning to eat occurs in the context of a relationship with a primary caregiver. The biopsychosocial model offers an excellent way to conceptualize the multiple interacting variables of feeding development and problems.19 Sometimes a mismatch between parental expectations and the child's attributes leads to difficulties with feeding. In addition, external supports, such as family, and stressors, such as financial problems, can impact on feeding interaction.
FEEDING PROBLEMS IN CHILDREN WITH DISABILITIES
Specific child factors that contribute to feeding disorders are outlined in Table 1. Anatomical problems such as cleft palate, choanal atresia, or tracheoesophageal fistula have a significant effect on feeding, often in the first days of life, and frequently are found in certain genetic syndromes associated with developmental disabilities. Sensory-perceptual abnormalities, while difficult to quantify, also can contribute to feeding problems. These can manifest as either hypersensitivity, as in a child who gags at the slightest touch of his or her tongue, or hyposensitivity, as in a child who drools and requires an increased stimulus, such as large bolus size, in order to initiate swallowing.
Motor dysfunction leads to various difficulties that can affect feeding. First, many children with motor impairment have poor head and trunk control and are unable to sit upright and align their bodies correctly for eating. In addition, fine-motor impairment, coupled with limited mobility, may make it difficult for children to bring food to their mouths. This impairs the physical act of feeding and may exacerbate sensory abnormalities by contributing to oral hypersensitivity. Overall, these motor impairments render a child dependent on others for his or her feeding. This implies that communication must take place to convey hunger, satiety, food preferences, etc.
Often children with motor dysfunction have specific dysfunction of the oral motor mechanism. These children may have pathologic oral reflexes, such as an uncontrolled tonic bite that causes them to bite down on the spoon without being able to let go or a tongue thrust that pushes food out of the mouth. They may be unable to keep food in the mouth due to tongue thrust or poor mouth closure. They may have difficulty initiating a swallow or may spill oral contents posteriorly into the pharynx before a swallow. In addition, pharyngeal clearance of a bolus may be poor, leading to pharyngeal pooling. Oral motor dysfunction can lead to drooling, spillage of foodstuffs, prolonged feeding times (because each mouthful may be painstakingly slow), laryngeal penetration, and aspiration, and may be one of the most important factors contributing to feeding problems, malnutrition, and respiratory symptoms.
Medical problems often have a large impact on feeding through their effects on appetite, energy needs, and oral-motor function. These problems are important to identify because treatment is often straightforward and helpful. Constipation is probably the most common medical problem in children with disabilities. It negatively affects the appetite, probably slows gastric emptying, and exacerbates gastroesophageal reflux. Chronic lung disease increases energy needs and complicates the coordination of feeding and breathing, particularly in young infants.17 Gastroesophageal reflux is another common problem that causes the loss of nutrients from vomiting and can cause anorexia. It can lead to esophagitis, pain, and possibly esophageal stricture. Malnutrition itself, while generally a result of feeding problems, also can contribute to the perpetuation of the problem by decreasing appetite and strength, and causing behavioral apathy. Other medical problems that can affect feeding include seizures, chronic infections, and congenital heart disease.
A child's temperament can contribute to feeding problems. Fussy, irritable babies, babies who are intense and cry a great deal, and those who have irregular activity patterns can be difficult to feed. In addition, some children can learn food aversion. For example, a child with chronic lung disease of prematurity who requires frequent intubation and oral suctioning may learn that oral sensations are unpleasant. This child may become aversive to any kind of stimulation around the mouth and may refuse oral feedings. These children may be difficult to treat. Specific attachment or interactional disorders can play an important role in feeding problems. This can occur secondary to chronic institutionalization and separation of the child from the parent(s), as well as to specific parental emotional difficulties.
FACTORS CONTRIBUTING TO FEEDING PROBLEMS IN CHILDREN WITH DISABILITIES
EVALUATION OF FEEDING PROBLEMS
Evaluation of a child with feeding disorders should begin in the pediatrician's office. You will often need help. The following disciplines can offer needed consultation: nutritionists, speech pathologists, occupational therapists, physical therapists, social workers, psychologists, radiologists, neurologists, and gastroenterologists. A pediatrician, nutritionist, and feeding specialist (speech pathologist, occupational therapist, or nurse) often can perform a thorough initial evaluation. The evaluation of children with feeding problems is outlined in Table 2.
The first step is nutritional anthropometry; the methodology for this is discussed earlier in this article. At a minimum, each child should be measured for weight, height or length (or segmental length as proxy), and triceps skinfold. The purpose is to identify a target weight for the child's stature and quantify malnutrition. The child's height-age should be determined from the standard NCHS growth charts2 or from the specialized growth chart corresponding to the child's condition. The height-age is the age at which the child's height is at the 50th percentile. The child's ideal body weight is defined as the 50th percentile weight for the height-age. This method will overestimate the ideal weight20 of some children with motor impairment, and the 10th or 25th percentile weight for height-age may be more appropriate. The degree of malnutrition can be quantified by expressing the child's actual weight as a percentage of the ideal. Mild, moderate, and severe malnutrition are defined as actual weights <90%, 85%, or 75% of ideal body weight respectively. This can help in deciding between initial inpatient or outpatient management and provides a target weight.
The Evaluation of Children With Feeding Problems
Evaluation of dietary intake and comparison with recommended standards is performed next. The estimation of dietary intake is straightforward when children are primarily on liquid diets and can be undertaken by the pediatrician. Older children with a more varied diet may require the assistance of a dietician. The estimation of caloric needs also may be difficult because recommended daily allowances (RDA) are based on normally growing, active children.21 While appropriate for some children with developmental disabilities, they may not be appropriate for others, especially motor-impaired children with cerebral palsy. Krick et al20 have proposed an empirically derived formula for the calculation of energy needs for children with cerebral palsy.
The pediatric history and physical examination can identify acute or chronic problems that make eating difficult. Most medical problems described above can be diagnosed clinically with selected laboratory tests. A radiograph of the abdomen occasionally can help determine the extent of constipation and confirm success of treatment. A radiograph of the hand and wrist can help determine skeletal age and the presence of rickets or osteomalacia. An EEG can help identify subtle seizures or subclinical/nonconvulsive status epilepticus. The diagnosis of gastroesophageal reflux often can be made clinically. However, pH probes, technetium milk scans, radionuclide gastric emptying studies, or esophagogastroduodenoscopy with biopsy should be used when the diagnosis is in doubt. Other important laboratory tests include complete blood cell count, alkaline phosphatase, calcium, phosphorus, vitamin D, albumin, total protein, prealbumin, liver function tests, and anticonvulsant levels.
Someone should watch the child eat. The clinical feeding evaluation involves observing the child being fed by his or her caregiver and feeding the child directly. This assesses position, normal or pathologic reflexes, oral-motor function, sensory factors, interactional/social factors, temperament, and behavior. Foods with different textures and different modes of delivery (eg spoon, cup, or bottle) can be presented. This evaluation often is done by an occupational therapist, speech therapist, or nurse. Seating evaluation by physical and occupational therapy is especially important in the child who is unable to sit independently. Some children, particularly those who have chronic aspiration and recurrent pulmonary infections, require a radiographic study of feeding. Videofluoroscopy or a modified barium swallow enables the clinician to visualize the oral, pharyngeal, and esophageal phases of swallowing. The texture of the barium and the child's positioning can be modified to evaluate swallowing. The study should be undertaken with a feeding specialist skilled in the procedure and an experienced radiologist. Table 3 outlines some details regarding videofluoroscopy.
The social factors in feeding are as important as motor function. Successful feeding gives caregivers a sense of self-worth. However, feeding can become a battleground. Feeding times can be extreme, as some families spend 6 or more hours a day feeding their child, which leaves little time for anything else. The physician should ask how feeding affects the family and assess enjoyment and quality of life issues both for the child and the family. The impact that feeding can have on a family's quality of life should not be underestimated.
TREATMENT OF FEEDING PROBLEMS
Once feeding problems have been identified, treatment can proceed logically. The primary issue is management of malnutrition. Usually caloric intake must be increased. The first step involves adding nutritional snacks, encouraging increased intake during mealtimes, or adding a high-calorie dietary supplement. Often this greatly affects intake and nutritional status. However, sometimes the child's oral-motor efficiency limits the volume that can be ingested in any given period. This, coupled with time constraints of caregivers, may limit the success of this intervention. Other dietary techniques include increasing caloric density and altering food textures to facilitate functional feeding. Thickening fluids to make them more viscous may enhance a child's ability to ingest them. If these dietary measures are unable to overcome the child's capacity for fcod intake or if oral feeding leads to recurrent respiratory problems, gastrostomy tube placement should be considered.
Adequate treatment of existing medical problems is imperative for the overall success of feeding. Seizure control must be optimal. Gastroesophageal reflux must be treated medically or surgically. Chronic pulmonary infections and wheezing must be managed medically. Constipation must be managed as well- Positioning and postural support involves providing the child with an appropriate seating system so that the child's body is properly aligned for feeding. Oral-motor treatment by feeding specialists may have a positive effect on feeding abilities.22 Behavioral, environmental, and social problems must be addressed.
The need for a gastrostomy arises when a child is unable to safely ingest adequate calories to meet his or her energy needs. Indications for gastrostomy placement include duration of nasogastric feeds for more than 2 months, protracted feeding times, recurrent aspiration pneumonias, malnutrition and food refusal, and the failure of more conservative treatment. The decision to place a gastrostomy is collaborative, involving both professionals and parents. Discussions regarding gastrostomies ideally are begun well in anticipation of the actual need. Families often benefit from talking to other families of children with gastrostomies.
Several options are available once the decision is made to proceed with supplemental tube feedings. Nasogastric feeding is often the first step. This is a fairly safe way to provide extra calories for days, weeks, or even months. However, the unsightliness, discomfort, and risk of nasal and esophageal irritation from nasogastric tubes make them undesirable for longterm use. The Stamm surgical gastrostomy is the time-honored method for placement of a permanent feeding tube. This procedure is often performed with an antireflux procedure, or fundoplication, in children with developmental disabilities. However, the routine practice of fundoplication when gastrostomy is performed in neurologically impaired patients has been questioned,23 and fundoplication is being reserved only for those with significant gastroesophageal reflux unresponsive to medical management. Because preoperative testing does not predict which patients will ultimately develop reflux with gastrostomy feedings, a pragmatic way to assess the need for fundoplication is to administer a clinical trial of nasogastric feedings for 2 weeks. Patients who tolerate this trial are likely to tolerate gastrostomy feedings without fundoplication, while those who have reflux that cannot be controlled medically should have an antireflux procedure. Children who tolerate a 2-week nasogastric trial are referred for placement of a percutaneous endoscopic gastrostomy. This procedure is a safe and effective way to place gastrostomies in children. 2^ Other options for select patients include gastroduodenostomy or jejunostomy, particularly for children with significant reflux who cannot tolerate the fundoplication procedure.
Radiographic Study of Feeding (Vldeofluoroscopy)
Once the gastrostomy is placed, feedings can be intermittent boluses or a continuous drip. The latter can be infused overnight. Many children can, and should, continue to eat orally after gastrostomy placement. Oral feedings can be given for pleasure and to enhance quality of life without the pressure of having to feed the child a prescribed amount. Even if prone to aspiration, most children can tolerate at least small amounts of oral feedings for pleasure. The need for a gastrostomy may be temporary if a time-limited medical problem (eg, chronic lung disease in a premature infant) is the major reason for a gastrostomy. Underlying neurologic disabilities usually require a permanent gastrostomy.
The most important aspect of feeding disorders is follow-up to assess efficacy of treatment and adjust the feeding program for optimal outcomes. This is especially true following gastrostomy placement. A major risk following gastrostomy placement is obesity because many severely impaired children have energy needs far below the RDA for age. Useful empiric formulas for the estimation of caloric needs have been developed for children with disabilities,20 but careful monitoring is still imperative.
SUMMARY AND CONCLUSIONS
Feeding is a complex physiologic process that is further complicated by social and cultural influences. Feeding development, although dependent on structural integrity and neurologic maturation, is a learned progression of behaviors influenced by sensory motor development and experience. Children learn how to eat. Children with developmental disabilities frequently develop problems with feeding that can lead to malnutrition and respiratory symptoms. Feeding disorders are often the result of multiple interacting variables that have disrupted feeding development and the feeding relationship. The pediatrician who has a solid understanding of these variables can understand the problems, sort out the contributing causes, and intervene effectively.
The author thanks Barbara Fortsch and Brenda Koonce, CPS, for their assistance in preparing the manuscript.
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FACTORS CONTRIBUTING TO FEEDING PROBLEMS IN CHILDREN WITH DISABILITIES
The Evaluation of Children With Feeding Problems
Radiographic Study of Feeding (Vldeofluoroscopy)