Modified Barium Swallow Study
Many caregivers and patients use the terms Modified Barium Swallow and Barium Swallow interchangeably. While both procedures are radiological diagnostic tests used to diagnose swallowing problems, rationale for the tests, the procedures, and the counter indications clearly differentiate these two tests.
The Modified Barium Swallow Study is a therapeutic diagnostic test jointly conducted by a speech-language pathologist and a radiologist to examine the oropharyngeal swallowing function, quantify the risk of aspiration and objectively determine which swallowing strategies and diet textures increase the efficiency and safety of the swallow. The test requires a patient to sit upright in a special chair that fits up against the radio graphic table or stand in place for approximately 10 minutes. No specific diet restrictions are necessary to prepare the patient prior to the test although, the speech-language pathologist may make specific recommendations such as NPO (nothing by mouth) or thickened liquids only, prior to the test to protect the patient from aspiration. A fluoroscopic video is recorded to detail the physiology and function of the oral and pharyngeal musculature during the swallow as the events occur very rapidly (i.e.1-2 sec.). The test starts with very small quantities (3ccs.5ccs.and 10ccs.) of thin and thickened liquid barium. If no aspiration is noted, the test systematically progresses to quantities and consistencies that would be typical during a meal. Aspiration is defined as food or liquid material passing through the vocal folds into the trachea. Care is taken to minimize the amount of aspiration. If aspiration is detected, therapeutic strategies are performed to eliminate aspiration and facilitate safe and efficient swallowing. The patient's response to aspirated materials (e.g. no cough, strong effective cough or weak nonproductive cough) is also an important diagnostic indicator that can be measured during this test. Not all patients that aspirate show symptoms at bedside. Patients that silently aspirate (i.e. no spontaneous cough response) can only be accurately diagnosed by completion of the Modified Barium Swallow test. Although not everyone that aspirates develops aspiration pneumonia, patients that are non-ambulatory, immunocompromised or have underlying pulmonary compromise are at highest risk of complications from aspiration.
THE IMPACT OF ASPIRATION ON THE LUNGS
All instances of aspiration are not equal. The effect of aspiration on the lungs and on health depends upon at least 5 different features.
Acid: When a child aspirates refluxed food that has been mixed with stomach acid (i.e., aspirated coming up) it is more likely to cause an aspiration pneumonia or damage the lungs than food or formula that is more alkaline (i.e., aspirated going down).
Fat: Food or liquid containing fat molecules (i.e. milk, yogurt, meat broth) is more dangerous to the lungs, and may trigger pneumonia faster, than food or liquid that has is composed primarily of water (i.e. fruits, vegetables, grains). This is because the lungs are used to handling water in the air we breathe and can release it more easily than a fat which is foreign to the lungs.
Amount: There are estimates that our lungs can handle aspiration of 10-20% of what we swallow. Children often aspirate small amounts when they are learning to eat by mouth. If this is a very small amount of a safe food, the aspiration is less likely to trigger an aspiration pneumonia. If larger amounts are aspirated, or if smaller amounts are aspirated every time the child swallows, it is more dangerous.
Bacteria: The mouth itself plays host to colonies of bacteria. The number and type of bacteria depend a great deal on dental health and oral hygiene. When the mouth is kept clean through regular brushing of the teeth or wiping of the gums, bacterial growth is kept to a minimum. When a child resists oral care, bacterial growth multiplies. Children can develop cavities and gum inflammation which further increase bacterial growth. If the child is on medication to reduce mucous and other secretions, the bacteria in the existing saliva becomes more concentrated. If the child aspirates saliva, alone or mixed with small amounts of food or liquid, the bacteria will be carried into the lungs. An aspiration pneumonia can result from a bacterial infection.
Health: The overall state of the child's health and wellness, and specifically the health of the lungs plays a major role. This is the guiding principle we use in understanding who gets sick when a group of people are exposed to a virus. Our bodies are full of bacteria and viruses that float around the environment we live in. We tend to get sick when our overall health is poor, when we are fatigued, under stress, or lack control over our lives. Many young children have very healthy lungs. Aspiration may not initially cause a pneumonia. However, with constant aspiration, the lungs may become weaker or more vulnerable. At some point aspiration begins to cause a severe pneumonia because the lungs are no longer strong enough to stay well. Chronic aspiration pneumonia may result. Infants and children who have already experienced lung damage because of prematurity, respiratory distress syndrome, or broncho-pulmonary dysplasia are more vulnerable to aspiration than children who start out with strong, healthy lungs. Some parents are told that they shouldn't worry about coughing during a meal because children aren't aspirating unless they have gotten a pneumonia. This simply isn't true. Even if slight aspiration isn't causing a pneumonia today, we need to think about the potential impact in the future. It is important for many children who aren't eating or children who cough and choke at lot at mealtimes to have a modified barium swallow study done to rule out aspiration.
STRUGGLING TO EAT
The struggle to eat contributes to aspiration and to feeding aversion. The ability to suck and swallow safely is build on a foundation of sensory skills, motor skills, and comfortable coordination of swallowing and breathing. When one or more of these skills is missing or compromised, eating can be frightening, uncomfortable, or take an excessive amount of effort. If a child is already taking some food and liquid orally, look carefully for signs of aversion or physical struggle. Know that when the child must struggle to eat, the risk of aspiration increases. Prior to scheduling a swallowing study look carefully at specific foods that the child is eating. List foods that are easiest, and those that are the most difficult. Look at the texture, thickness, and taste of these foods. Try to find patterns in the foods and liquids the child handles well, and those that cause trouble. Eliminate all foods from oral feedings that have caused difficulty. Increase the types of foods that the child handles more
PREPARING FOR A SWALLOWING STUDY
SELECTING A HOSPITAL
Parents and therapists are consumers of medical services. The selection of a hospital and physician for a swallowing study is an important purchase. Parents and referring therapists should discuss the following questions with their doctor and with the staff of the hospital.
Is a speech-language pathologist with a background in swallowing (i.e. dysphagia) part of the evaluation team? Physicians often ask only whether the child is aspirating or not. When a therapist is involved in the evaluation, a stronger focus is placed on therapeutic questions related to the child's positioning, food amount and consistency. This provides more information that will help develop an appropriate therapy program for the child.
Does the swallowing team do a modified barium swallow procedure? Standard barium swallow studies use a large amount of food or liquid. If the child aspirates, the study is often discontinued immediately. A modified barium procedure uses only a small amount of food or liquid, and the evaluation usually compares different consistencies of liquid and puree. This is important because some children have trouble with some consistencies but not others. A child may be able to swallow very small amounts at a time, but aspirate on larger amounts.
Does the radiology suite have a special chair or seating system so that a baby or young child can be carefully positioned in sitting? Some hospitals don't have appropriate equipment for infants and children who cannot sit unsupported. They may choose to do a swallowing study with the child lying down, or the child may be strapped into an adult chair. When a child is not positioned well for a swallowing study, information on the swallow is useless. We want to know how the child swallows in supported sitting with good alignment of the body, neck, and head.
How does the radiologist handle the situation if the child is upset and starts to cry or scream? We hope that children will cooperate during the test, but sometimes the equipment and strange situation is frightening. Children often cry or protest about eating under these conditions. It is important to look for a radiologist who is willing to take time with children, and will stop the study if the child continues to cry. Some physicians feel that the study is more important than the child. They use an open mouth as an opportunity to pour liquid into the mouth of a screaming child. The child may struggle and be forcibly held down as the mouth is pried open to take a squirt of liquid. Any information gotten from this type of study is totally useless and meaningless! No parent or therapist would feed children when they were screaming. When children are evaluated in this negative environment, they may loose their trust in adults who feed them, and increase their aversion to eating.
Providing Physical and Emotional Support During the Swallowing Study.
Quiet, organizing music can be played for the child before and during the study to assist with calming. A favorite toy can accompany the child, and parents can be present to do the actual feeding. A child-size chair with appropriate head supports should be used for positioning. Soft pillows or rolled towels can be added to make sure that the child is comfortable and seated with good head support with the chin tucked slightly down toward the chest. In many settings parents can bring the child's favorite liquid and food. When a child is resistant to changes in taste, familiarization with the taste of barium in the food can be done in therapy prior to scheduling a study. Small amounts of thin liquid, thickened liquid, and puree consistency food can be offered to compare ability to swallow different consistencies.
ASKING THE RIGHT QUESTIONS
A swallowing study can tell us so much more than simply whether the child is aspirating or not. Each study should be centered around a set of questions that have been prioritized. In order to reduce a child's exposure to radiation, there may not be time to address all of the questions. What are the most important questions for this child, at this time?
Is there a delay in the swallow with any consistency? A delayed swallow indicates that the child may be at risk for aspiration even when aspiration does not occur during the swallowing study.
Is swallowing ability influenced by the consistency of the food or liquid? Are there differences between thin vs. thicker liquids? Are there differences between thick liquids and pureed consistency? This information can help identify the consistency that promotes the coordinated and safe swallow.
Is swallowing ability influenced by the amount of the food or liquid? Is there a difference in swallowing skill when a single swallow of food or liquid is compared with 2 or 3 consecutive swallows? Some children are very safe when they take a few swallows and then have a short pause. A child can do very well with small sips, but may aspirate when drinking multiple consecutive suck-swallows.
Is swallowing ability influenced by the timing of the meal? Is there a difference between the beginning of a feeding and the end? Some children do very well at the beginning of a meal, but the swallow deteriorates as they get tired. If the child typically does better at the beginning of a meal, and begins to have more trouble after 20 minutes, you can ask the therapist and radiologist to set up the swallowing study in two parts. They would evaluate the swallow at the beginning of a meal, and would then stop filming as the parent continued to feed the child a regular meal for another 20 minutes. At the time when the child begins to fatigue with eating, they would again video the swallow. Other children are poorly coordinated at the beginning of a meal, but improve their eating abilities as the rhythm of the meal continues. These children also benefit from testing at two different points in the meal.
Once it is determined that your child is for sure aspirating an important decision needs to be made as to what type of feeding tube you want to have placed.