The Quarterly Consultis a quarterly supplement to the Bulletin highlighting pediatric clinical expertise. If you have an item of interest to include in the Quarterly Consult, contact Dr. Steve Dassel at 206-625-7373, mailbox 8588.
By Steve Dassel, MD
I talked with Dr. Maida Chen, associate director of the Pediatric Sleep Disorders Clinic at Seattle Children's Hospital and assistant professor at the University of Washington. Maida received her undergraduate and medical degrees from Northwestern University; she completed her residency at Rush University Medical Center and fellowship at Children's Hospital Los Angeles in pulmonary medicine and sleep physiology.
Q: What is the history of the Pediatric Sleep Disorders Center at Seattle Children's?
A: It started in 2002 as a one-bed sleep lab, and has grown into a four-bed lab located in Bellevue. We can also do inpatient studies on the Seattle campus, and we have clinics in Everett and Olympia. Currently, all beds are filled seven nights a week, and we can see patients within a month. Dr. Yemi Kifle, a board certified sleep specialist, is the center's director.
Q: What are examples of urgent cases?
A: An urgent case could be any child, and especially any infant, who has struggled to breathe at night with witnessed apneas and gasping. Any sleep difficulties that severely affect daytime quality of life are also priority cases.
Q: How many pediatric sleep labs are there in the country?
A: While there are many fully accredited sleep centers in the United States, only a handful are dedicated exclusively to pediatrics. There are about 30 fully accredited pediatric-specific sleep labs in the country. Ours is the only one in the Washington, Alaska, Montana and Idaho region. Many adult labs will not study children, especially younger children.
Q: What are some of the issues you deal with in the sleep clinic?
A: Concerns about diseases related to obstructive sleep apnea syndrome (OSAS), also called sleep-disordered breathing, are the most common. This includes primary snoring and upper airways resistance syndrome (UARS). Other issues are insomnias, both primary (such as circadian rhythm abnormalities) and secondary (such as behavioral sleep onset association disorders); the hypersomnias such as narcolepsy; and sleep movement disorders such as head-banging, restless legs syndrome, benign nocturnal limb pain of children (growing pains) and periodic limb movements. We also see many children with academic and behavioral problems who may have an occult sleep disorder contributing to the severity of their daytime dysfunctions. We also evaluate some medical disorders that have significant subjective sleep complaints, such as autism.
Q: What are some of the criteria for doing a sleep study on your patients?
A: We usually recommend an overnight sleep study any time we're seeking objective information about a child's actual sleep. The most common indication is when the clinical history and physical exam suggest any degree of upper airway obstruction leading to sleep-disordered breathing. This includes a history of snoring, even without observed apneas. I recommend that every child who snores should have a full sleep study because studies have shown that it's hard for a provider or parent to tell if a snoring child is actually having apneic, hypopneic (partial apneic) or hypoventilation episodes. In addition, should that child proceed with adenotonsillectomy, it's important to know the degree of gas exchange abnormalities associated with sleep-disordered breathing for better perioperative care. This stance is supported by the American Academy of Pediatrics. Signs and symptoms of sleep-disordered breathing include snoring, open-mouth or audible breathing, restless sleep, frequent arousals, gasping, sweating and frequent position changes.
Q: Are there other criteria for a sleep study?
A: Other indications include frequent and possibly abnormal limb movements or other body movements during sleep, any frequent nocturnal arousals, resistant parasomnias (which can be triggered by occult sleep disorders), persistent enuresis, and unexplained daytime sleepiness or dysfunction, including academic and behavioral problems. For example, we don't need a sleep study to diagnose night terrors, and we don't need to capture the actual event in a sleep study, but the etiology of a night terror may be an underlying sleep disorder such as obstruction.
Kids who have difficulty concentrating in school, even if they have a diagnosis of ADHD, may have sleep issues if they have associated sleep symptoms such as obstruction, restlessness or frequent limb movements.
Children who have Down syndrome, neuromuscular diseases such as Duchenne's muscular dystrophy, or primary neurological problems such as Prader-Willi syndrome, Arnold-Chiari malformations, and myelomeningocele, should also have sleep studies to evaluate their adequacy of oxygenation and ventilation.
Obesity is another indication; obese children have a much higher prevalence of sleep-disordered breathing. One study showed that 46% of obese children will have abnormal sleep studies consistent with some degree of OSAS, and many of them are not overtly symptomatic.
Q: What about sleep studies in kids who have difficulty getting to sleep or staying asleep?
A: There are many reasons why children may have difficulty initiating or maintaining sleep. A sleep study can be useful if disorders such as restless legs syndrome or periodic limb movement are suspected. The former can present with a child complaining of odd sensations in the legs that prevent sleep onset. If a child is having difficulty maintaining sleep, ruling out occult obstructive apneas as a cause for arousal is also important.
Q: What should be our criteria for referring to sleep clinic?
A: Frankly, any subjective complaint about a child's sleep that the referring pediatrician cannot quickly resolve. Sleep disorders, and particularly OSAS, is probably way underdiagnosed in children. But even with purely behavioral problems, a sleep study may be necessary to convince the parents that there is nothing physiologically wrong with their child, allowing them to pursue a behavioral approach without worrying that they're missing a medical illness.
Q: How much does a sleep study cost?
A: A diagnostic sleep study usually costs about $3000.
Q: Is this often covered by insurance?
A: It's almost always covered by insurance.
Q: Let's spend the last part of our discussion talking about treatments for these disorders, such as OSAS. What works and what doesn't work?
A: The most definitive and curative procedure is adenotonsillectomy, which can resolve OSAS in about 80% of children. Nonsurgical options such as using continuous positive airway pressure (CPAP) or bi-level positive airway pressure (BiPAP) are becoming more common and better tolerated. We have over 500 children in the community using CPAP or BiPAP. The least invasive measure is getting good control of rhinitis/sinusitis, usually with topical nasal steroids. Measures such as positioning, special pillows, nasal strips, mandibular positioning devices, and many herbal medications are not usually effective as long-term solutions.
Q: What about treating restless legs syndrome or periodic limb movements?
A: First, we rule out iron deficiency by checking the serum ferritin level. We will often give children with periodic limb movements 3mg/kg/day of supplemental iron if their ferritin is below 50. A low ferritin level even in the presence of a normal hematocrit can be associated with an increased amount of limb movements. We also make sure there is no associated renal failure. After that, there are times when we will treat with things such as Neurontin, or dopa agonists, such as Mirapex.
Q: And the insomnias?
A: Certainly a behavioral approach is the most important. We work with our child psychiatrists and psychologists here. If there is a circadian rhythm abnormality, melatonin can be useful as a chronic medication with supervision. I do not recommend Benadryl and certainly not chloral hydrate.
Q: Why not Benadryl?
A: It is over-the-counter, and therefore too easy for parents to over-medicate on a chronic basis without getting to the root of the problem. Children also generally develop a tolerance to it.
Q: How about night terrors?
A: It's important to determine whether an occult sleep disorder such as OSAS is triggering these events. Techniques such as scheduled awakenings can be effective. It's also important to counsel parents to not wake the child, who may then develop a learned habit of needing parents to go back to sleep. When those interventions have been done appropriately, very rarely we will try a medication, usually benzodiazepine. But this is a rare situation.
A: If the diagnosis is narcolepsy, stimulant medication is effective. Usually we use Provigil. In children who have excessive daytime sleepiness related to other untreated sleep disorders, the first treatment is to treat the underlying cause, such as using CPAP for OSAS.
Q: Finally, do you have any normative data that we can use in the office?
A: Yes, the usual number of hours of sleep needed in 24 hours are as follows:
- Newborns to infants: 16 to 20 hours
- Toddlers: 12 to 16 hours
- School-age children: 10 to 12 hours
- Preteens: 9 to 10 hours
- Adolescents: 8 to 10 hours
- Adults: 7 to 9 hours
Time needed to fall asleep: Toddlers and young children may need up to 30 minutes to fall asleep, while adolescents and adults usually take less than 20 minutes.
Newborns may arouse as frequently as every one to two hours, giving them upwards of 10 to 12 awakenings at night! Fortunately, toddlers awaken only three to five times per night. This number of natural awakenings persists through adulthood. Awakenings naturally occur with sleep state transition (i.e., going from dream sleep into lighter sleep). However, assuming the child or adult has the ability to fall back asleep easily after these natural arousals, most people do not remember them the next day.