Sleep Studies

Down Syndrome Center at UPMC Children’s Hospital of Pittsburgh

An interview with Pediatric Sleep Medicine specialist Sangeeta Chakravorty, MD, Dip. ABSM, of the Pediatric Sleep Program at UPMC Children’s Hospital of Pittsburgh.

Released: 3/13/14


Dr. Vellody: Welcome back everyone to the Down Syndrome Center of Western Pennsylvania podcast. I am your host, Dr. Kishore Vellody. Today, we are joined by Dr. Sangeeta Chakravorty who is our Pediatric Sleep Medicine specialist at the Children’s Hospital of Pittsburgh. Dr. Chakravorty, it’s great to have you join us today. Could we start off with hearing a little bit about your training background?

Dr. Chakravorty: Sure! I trained as a neurologist in Buffalo New York. My training background was actually in adult neurology. Then I did a sub-specialty training fellowship in sleep disorder medicine at Emory University in Atlanta. I have been in Pittsburgh for the last 12 years but I have been specifically interested in pediatric sleep for the last 7 years and that is how long I have been here at Children’s.

Dr. Vellody: Great. Well thanks again for joining us on the podcast. As you might imagine, we’re hoping you can give us some information on sleep apnea and sleep studies today. Sleep apnea is known to be extremely common in kids with Down syndrome so this information will be very useful to our families. Before we get too far ahead, can you give us some background on what sleep apnea is?

Dr. Chakravorty: Sleep apnea is the process by which breathing pauses during sleep. Apnea means the absence of breath going in or out – the airway closes up during sleep. During that time, our muscles are particularly vulnerable to being more limp and being more relaxed and gravity narrows down the air passages. If there is collapse of the upper airway, which is like a muscular tube, then air can neither enter nor exit. If that happens that is called an apnea. Usually the brain compensates and awakens the individual after an apneic pause so that breathing is restored, which is the recovery phase after apnea. For example, if you sigh and hold your breath, that is considered an apnea – but that is normal. If this happens in sleep more often than we like then we term it pathological. There are several types of apnea as well. The first is called obstructive apnea where the air passage really narrows down and closes up. The lungs and the heart sense that and it increases the respiratory muscle effort to breath. That is termed obstruction. There is another type of apnea called a central apnea where the airway might close up or narrow down but there is no stimulus to breathe. The abdomen and chest stay calm and quiet for a few seconds until the brain triggers a recovery breath.

Dr. Vellody: Thanks for that overview. Since obstructive sleep apnea is so much more common in children with Down syndrome, I’d like to spend the remainder of the podcast talking about that. Can you give our families some idea of what symptoms may be present in a child with sleep apnea?

Dr. Chakravorty: Sure, if you hear your child snore at night habitually more than two or three times per week, the snoring could be soft or loud, that is a sign that your child is potentially at risk for obstructive sleep apnea. Not everyone who snores has obstructive apnea, but they might develop it at a later time. If your child has already developed obstructive apnea, then the snoring might include a crescendo pattern. By that I mean, it might get louder over time, and there may actually be pauses in the breathing that you might hear. For example, it might sound like this [sound]. I don’t know if you could get that but that was an obstructive pause followed by a recovery breath and a long expiration. If you hear that happen periodically at night that is a sign that your child might have obstructive apnea. During the day time the child might be more irritable, might be a little cranky, may have nasal congestion, and have mouth breathing that you can observe during the day or at night time. He might wake up with a dry mouth. Some children who have obstructive apnea might have night sweats and some children might also lose control of their bladder at nighttime. The child could also be very restless, toss and turn and even moan and groan at times. Sometimes, you might have nighttime coughing that might occur after a lot of snores. Those are some of the signs that we encounter commonly in clinic.

Dr. Vellody: Thanks. So, if a parent notices these issues, I would typically recommend a sleep study. However, some families wonder if sleep apnea is really that important to diagnose and treat. What are the possible complications of untreated sleep apnea?

Dr. Chakravorty: If sleep apnea is untreated, it can definitely impair the quality of the child’s sleep. It might impact the quantity of the child’s sleep. Sleep deprivation in children can be a trigger for learning, memory and mood problems in the daytime. It can also make the child cranky and irritable. It might affect how they perform at school and it might make them tired during the day. Some children, as opposed to getting tired, may develop hyperactivity and inattention and may mimic ADHD-type symptoms during the daytime. So these are some of the more immediate, short-term effects. Over the long-term, untreated obstructive sleep apnea can lead to cardio-respiratory problems. In adults, it has shown to be a risk factor for hypertension and heart disease. It has also been associated with obesity and metabolic syndrome in some individuals. In very rare cases, it can be associated with increased pressure in the pulmonary blood vessels, called pulmonary hypertension. In very young children, untreated obstructive sleep apnea can affect their appetite, their growth, how their facial skull features develop. That is one of the reasons why we like to recognize it and treat it early.

Dr. Vellody: Well, those are obviously issues that a parent would want to avoid for the child, if possible. What should a parent do next if they notice the signs of sleep apnea you told us about?

Dr. Chakravorty: If you suspect that your child is not breathing correctly, do bring it to the attention of your primary pediatrician or to a specialist/ medical professional whom you encounter and explain your suspicions to them. They will ask you some questions including a sleep history. Getting an accurate history is one part of making the diagnosis. The second part is some form of clinical testing to confirm the diagnosis. This could be of two types – you could have an x-ray for example of the lateral neck area and look at the soft tissue enlargement of the adenoids and tonsils. These are lymph tissues that sit at the entrance to the mouth at the back of the throat. They commonly enlarge in children between the ages of 2 and 8. Even though the size may not appear very large on the clinical examination, or if you just look at it with the naked eye, it can have a functional impact because of the size when the child is sleeping. The child’s clinical symptoms will give you some diagnosis. Another way to test it to perform an overnight sleep study, which is considered the gold standard for testing based on the recommendations of the American Academy of Pediatrics.

Dr. Vellody: Great. Sangeeta, as you know, the American Academy of Pediatrics updated the healthcare guidelines for children with Down syndrome in 2011. In that update, they recommended that all children with Down syndrome have an overnight sleep study by the age of 4 years because sleep apnea is so common in this population. Why is that?

Dr. Chakravorty: Down syndrome represents a special population of children who have such predictable craniofacial features that predispose them for a higher incidence of obstructive sleep apnea compared with the general population. Their stature, slightly flatter noses, the size of the tongue as well as their low tone all lead to a higher risk of sleep apnea. There actually are guidelines because the sooner you diagnose and treat this, the better the long term impact and outcome in terms of learning, school performance as well as eventual facial development. That is one of the reasons these guidelines were included.

Dr. Vellody: Okay, so with these new guidelines, all of our families will likely be bringing their children for sleep studies. Could you please walk us through the process from scheduling to the study itself?

Dr. Chakravorty: When a family makes an appointment to have their child undergo a sleep test we would like them to understand all of the process steps that are involved. Normally you would schedule a study overnight which means you bring the child one evening after dinner and a change of clothes for the night. You are usually assigned a private bedroom with an attached bathroom. There is a bed for the child and some sleeping arrangement for the accompanying parent who comes in with the child.

Essentially, we want to replicate the atmosphere of sleep that the child has at home so you can bring their favorite toy, their blanket – you can bring a comfort object that the child usually sleeps with. Usually we want the child to have had their dinner and to be comfortable and ready to go to bed when they come to the lab. In addition to the bedroom atmosphere, there is a technician who is going to assist you through the night. The technologist is going to place certain sensors on the child’s body which do not involve any needles, injury or pain but they are stuck to the child and have to last overnight. Some labs use a form of electric paste to hold the electrodes and sensors in place, some use a form of glue that has to be dried and is held with tape.

What do we measure during the sleep study? We measure the child’s brain waves, their eye movements, heart rate, blood pressure, oxygen levels, and carbon dioxide levels. We look at how the air is entering and leaving the nose and measure snoring. We also look at how the chest wall and their belly move. These are measured using wires, plastic tubes which are called cannulas. For example, a plastic tube might slide under the child’s nose to measure the air going in and out. There will be an elastic belt that will go around the child’s chest and belly. There may be some wires on their legs because we do look at leg movements also. These wires have to last the whole night so we want them to be stuck to the child pretty securely. If they move or if the wires come loose, you can buzz and request the technician to come fix the problem. Or if the child needs to get up to use the restroom or something, the technician can assist the parent. And in this manner, the child sleeps for at least 7-8 hours. They get woken up the next morning and the technician will remove all the equipment and you can leave, your child is free to go home. That is what happens during an overnight sleep study. The term polysomnogram is sometimes used, abbreviated PSG, and it simply means we are measuring a bunch of signals during sleep.

Dr. Vellody: Thanks for walking us through that process. It sounds like there are quite a lot of leads and wires. Now, children with Down syndrome tend to have significant facial sensitivities. How in the world do you get them to keep all these wires in place?

Dr. Chakravorty: We are very patient with the children. The technicians are really very skilled. We have one technician to one child and family assigned. Most of the time when a child with Down Syndrome comes in for a sleep study, you have their undivided attention. We really do a good job trying to secure things to the child’s face, with their permission, with tape, latex-free tape if necessary. We try to use other types of softer material to make it as comfortable as possible for the child and the family. Sometimes if the cannula slips or the sensors come loose, the technician will reenter the room with the parent’s permission to attach them again. We try to get as accurate a signal as possible and do our best.

Dr. Vellody: That’s good to know. Now, besides the technicians who are specially trained to work with children, are there any other differences in the sleep studies being done at a Children’s hospital as opposed to, say, a community hospital?

Dr. Chakravorty: Yes there certainly are some differences. In general, between the ages of 0-12 years, there are certain specific pediatric guidelines and criteria which differ slightly from adult criteria. Our pediatric sleep lab really does a good job of doing and performing the tests in accordance with these guidelines from the American Academy of Sleep Medicine. One of the fundamental differences between adult labs and pediatric specialty labs is that adult labs do not require overnight, continuous carbon dioxide monitoring whereas pediatric specialty labs are mandated to do so. That provides very valuable information that is otherwise missed in some adult situations because children have a higher tendency to retain CO2¬ ¬and unless we measure that, the test is thorough or complete.

Dr. Vellody: Thanks. I think that’s a point that a lot of families are not aware of. There really is a difference between getting a study done at Children’s versus getting it done at another place. Well, after a sleep study is completed and all of that information is analyzed, we usually get a report from your sleep lab in a couple weeks that tells us if there is significant sleep apnea. What are typically the next steps based on those findings?

Dr. Chakravorty: That is a good question but it depends on the results of the study. Obstructive sleep apnea can be classified based on the severity into mild, moderate or severe. Based on what has happened to the child before and what the other comorbidities are [which means what are the other medical conditions that a child with Down Syndrome may have in addition to obstructive sleep apnea] – all of these determine the sort of treatment. In general, if it is very mild and there is simple snoring we may tend to watch and wait for a few more months until apnea develops to wait to treat. Sometimes when there is mild sleep apnea, which means there are breathing pauses say between 1-5 times per hour of sleep, which is the term we use to calculate the index of severity. In that case we may prefer that child be evaluated by Ear Nose and Throat Surgery to take a look at the adenoids and tonsils. Sometimes a simple adenoidectomy and/or a tonsillectomy, which means removal of these tissues, can be curative in a subgroup of children, but not always - especially if they have Down Syndrome and have other issues. If the child has severe sleep apnea then we definitely prefer that a multidisciplinary team get involved that would include a lung specialist and an ENT surgeon to comprehensively assess the child and determine other forms of surgical treatment.

Dr. Vellody: And are there any options besides surgical options?

Dr. Chakravorty: There is a form of non-surgical therapy which is available for treatment of obstructive sleep apnea. It is called CPAP and stands for continuous positive airway pressure. Effectively, through a mask and machine that is connected to the mask, the machine acts like a blower and blows in room air which is slightly pressurized into the child’s nose to help splint the air passage open. In this manner there is no narrowing of the airway and the continuous smooth flow of air supports breathing during sleep. In such a manner that there is less awakening, less arousal and the oxygen levels of the child are maintained at a stable value. This is sometimes challenging in children with Down syndrome because they cannot understand why they need to wear the apparatus. It is also challenging in some adults because it a very commonly used treatment in adult obstructive sleep apnea but we do successfully use this form of treatment in a large group of children, including those with Trisomy 21who do very well once they wear this apparatus through the night. Its non-surgical advantage is a great advantage and I would encourage families to consider this option if they have exhausted surgical options.

Dr. Vellody: Excellent. Thanks for that summary. That actually is all the time we have for our podcast today. I want to thank you Dr. Chakravorty for joining me today and sharing your expertise?

Dr. Chakravorty: Thanks Dr. Vellody! It has been my pleasure. I hope the families can benefit from some of this information.

Dr. Vellody: I’m sure they will. Thanks again. And thanks as always to you, our listeners, for tuning in. Be sure to keep watching for our next podcasts. Until then . . . bye bye!

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