Pediatric Sleep-Disordered Breathing

Are Healthcare Practitioners Recognizing the Signs?

Ann C. Halbower, MD and Keith Cavanaugh, MD

Last week, D.H., a 17-year-old young lady with Trisomy 21, attended her first visit to the sleep clinic at Children's Hospital Colorado. Her mom, who works in education at Denver public schools, brought her daughter in because she had been diagnosed with severe pulmonary hypertension.

D.H. had recently been hospitalized with pneumonia, and it was noted that she snored severely, gasping for air, dropping her oxygen saturations into the 60 percent range. After her recovery from the pneumonia, a sleep study demonstrated severe obstructive sleep apnea, with severe hypoxemia, and an echocardiogram confirmed her pulmonary hypertension.

D.H. is very obese, and her mother stated that her weight gain took off years ago in the 4th grade. She always snored, and often gasped, gagged or slept in an upright position, but her mother did not know that it was important to bring this up to her doctor, nor did she understand that the symptoms could be dangerous. Her primary care practitioner always checked her daughter’s thyroid function, and her echocardiograms were followed until her atrial septal defect closed in childhood. But there was no mention of the high risk of sleep apnea in children with trisomy 21,[1;2] especially those who are obese, and no discussion of the symptoms of sleep disorders was done during her well child visits.

Diagnosis of childhood sleep-disordered breathing (SDB)

Childhood sleep-disordered breathing (SDB) is associated with a multitude of health problems that are still not recognized in their relationship to sleep disorders. Children with SDB present with behavior problems,[3;4]*, deficits of general intelligence,[5;6], learning and memory deficits,[7] cardiovascular markers for risk of atherosclerosis and metabolic syndrome,[8]** and poor quality of life.[9]*

Obesity is a large risk factor for SDB. Although that association is more notable in the adolescent, we are seeing increasing numbers of pre-teen overweight children with SDB. Pediatricians are aware of the link between SDB and large tonsils and adenoids, however, many practitioners are not aware of the increased incidence of sleep apnea in kids with midface hypoplasia (as seen in Down Syndrome), craniofacial disorders, dental misalignment or nasal obstruction.

Another symptom of SDB that frequently leads to a misdiagnosis (or co-diagnosis) of attention deficit hyperactivity disorder is the irritability and hyperactivity that associates with the airway obstruction and sleep fragmentation in SDB. Adults with obstructive sleep apnea are usually sleepy and at risk of automobile accidents as they fall asleep at the wheel, but sleepy young children can present with a constellation of symptoms that include belligerence, hyperactivity, mood disorders and depression. Nighttime symptoms of SDB include snoring; however, some children don’t snore. They may demonstrate labored breathing such as paradoxical rib and abdominal movements, arching of the neck, gasping for breath, diaphoresis or abrupt awakenings with coughing and gagging. Cyanosis in sleep is rarely reported.

The physical exam of children with SDB may be helpful in steering the practitioner to the diagnosis. Children with SDB may present with large tonsils, nasal obstruction from swollen turbinates or enlarged adenoids, allergic shiners, open-mouth breathing, failure to thrive and sleepiness or fatigue. It is not infrequent, however, to find thin children without adenotonsillar hypertrophy with significant sleep apnea. A careful look at the pharyngeal space (low palate, narrow pharynx, high arched palate, retro-positioned mandible and cross bite) as well as the nose for septal deviation or enlarged turbinates might hint toward a risk of airflow limitation during sleep.[10]

The risk of missing a diagnosis of sleep apnea is the long-term impact of intermittent hypoxemia and sleep fragmentation on the developing child. In addition to the associated complications discussed above, children used to present with severe pulmonary hypertension after years of unrecognized sleep apnea symptoms,[11] and that finding is getting less common with caretaker education. But unfortunately, with the combination of SDB, obesity and altitude, D.H. was severely impacted.

Unrecognized SDB has resulted in poor school performance,[12] a finding that could permanently alter a child’s potential. Obese children with sleep apnea show cardiovascular risk profiles that indicate risk of future myocardial infarction, metabolic syndrome or stroke.[8] Finally, our lab reported the concerning finding of altered metabolites in the neurons of the hippocampus and frontal lobes in children with SDB,[13] areas of the brain responsible for memory and cognitive function. These school-aged children with sleep apnea and obesity also showed severe deficits of IQ levels.

SDB in children

The diagnosis and management of SDB in children follows different rules than those for adults, and sleep studies should be performed in pediatric sleep centers where the standard equipment is designed for the diagnosis of childhood SDB.

For instance, children with SDB might exhibit prolonged airflow limitation with elevated carbon dioxide, despite near-normal oxygen saturations.[14] This situation does not meet the criteria for obstructive sleep apnea events as seen in adults and requires a carbon dioxide monitor, frequently not found in adult sleep laboratories.

Prolonged airflow limitation increases the work of breathing and nighttime arousals causing daytime fatigue, and it is important to understand that this common form of pediatric SDB is not detected by overnight oximetry studies or limited channel sleep studies done by some centers. A sleep study using a polysomnogram with a CO2 monitor is the gold-standard diagnostic tool, as it measures gas exchange, sleep fragmentation, cardiac involvement and even work of breathing if certain tools are available.

A pediatric sleep center using polysomnography has the advantage of kid-sized equipment, kid-trained personnel and a child-friendly environment. This environment is imperative should the ultimate decision for treatment lead to non-surgical approaches such as nasal mask positive pressure (CPAP or PAP). Children benefit from a teaching and training environment that is mindful of childhood fears, patient with introduction of devices and able to educate parents in the techniques available for success with PAP adherence.[15]

Our patient, D.H., was started on nasal positive airway pressure since the risk of surgery was deemed too high for her at the time. Her mother reported that after treatment, she suddenly had more energy to walk, she brightened and improved in school focus, and her pulmonary hypertension was beginning to show signs of improvement. Her mother noted that she wished she had known the importance of the symptoms her daughter had demonstrated for years.

Treatment of childhood SDB improves function, including neuropsychological deficits. Recent studies demonstrated improvement, and even reversal of the diagnosis of ADHD in children who were treated for SDB.[3;4] Pulmonary hypertension can reverse with treatment,[16] as can growth improvement[17] and improvement of markers of cardiovascular risk, especially in obese children.[8]

If children sent for treatment for SDB do not improve in symptoms such as excessive daytime sleepiness, a referral to a pediatric sleep specialist is warranted.

The differential diagnosis includes narcolepsy, a disorder that commonly occurs but is frequently misdiagnosed as a psychological disorder, or as a variant of normal, for years. The symptoms of narcolepsy in children may just be excessive sleepiness out of the range of normal, such as a seven-year old who still needs a nap daily after school or who falls asleep in unusual places. Other symptoms associated with narcolepsy, such as weakness or drop attacks caused by cataplexy, may not be present until adolescence.

A second common disorder causing excessive sleepiness in adolescents is sleep phase delay, a circadian rhythm disorder that leads to missed morning classes at school, school failure, with common links to mood disorders. Teens with sleep phase delay are frequently labeled as lazy or willful, while they actually suffer from a treatable disorder. Disorders resulting in excessive daytime sleepiness include those, plus sleep-related seizures, central nervous system abnormalities and many more differential diagnoses. These require diagnostic tools and management strategies available in a pediatric sleep-disorders center.

Sleep disorders such as SDB may permanently modify a child’s health and cognitive potential, especially if the disorder is not recognized early in life. Early diagnosis and treatment should be the standard of care in order to protect children from brain or cardiovascular injury, until proven otherwise. This case underscores the importance of including a screen for symptoms of SDB in the routine well-child check up.

References

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