ABSTRACT: Obstructive sleep apnea (OSA) has a high prevalence in the pediatric population and is associated with significant morbidity, both physical and in the realms of development, cognition, behavior, and school performance. Certain subgroups of children are more susceptible to the development of OSA. Although adenotonsillectomy—the most common treatment for childhood OSA—improves symptoms in the majority of patients, a number of children respond less favorably. Positive airway pressure (PAP) is the second most common treatment for childhood OSA. Success in achieving adherence to PAP often requires a stepwise, multidisciplinary approach with close follow-up to address and quickly resolve any problems that arise.
Obstructive sleep apnea (OSA) in children and adolescents is much more prevalent than most practitioners realize: it is found in 1% to 4% of children.1 Moreover, the incidence of pediatric OSA appears to be on the upswing, probably because of the notable increase in childhood and adolescent obesity over the past decade.2 The peak incidence of OSA is seen in children between 3 and 6 years of age,3 around the time that the tonsils and the adenoids reach their maximum size relative to the dimensions of the upper airway. In young children, OSA is equally common in boys and girls, but following the onset of puberty, it is more common in boys.
In this article, I discuss the effects of OSA in children and provide concrete guidance on diagnosing the disorder and ensuring that treatment is as effective as possible.
THE SPECTRUM OF PEDIATRIC OSA
The muscles of the upper airway relax during sleep, leading to a narrowing of its caliber. In addition, the negative pressure generated during inspiration causes the soft tissue of the upper airway to collapse inward. Varying degrees of obstruction can result. With mild obstruction, the only manifestation may be snoring. As the degree of obstruction increases, so does the work of breathing. This tends to result in an increased number of arousals. Arousals in the setting of airflow that remains greater than 50% of baseline constitute what is known as upper airway resistance syndrome. Reductions of airflow to less than 50% of baseline for 2 breath cycles, accompanied by arousal and/or desaturation, are called "hypopneas"; and reductions to less than 10% of baseline are termed "apneas."
Children with obstructed breathing during sleep are less likely to have arousals than are adults. It is not unusual for children—especially younger children—to present instead with obstructive hypoventilation, in which persistent obstruction and decreased airflow lead to carbon dioxide retention and hypoxemia that can persist for minutes without causing an arousal (which might prompt a change in body position, leading to resolution of the obstruction).
CAUSES OF OSA IN CHILDREN
Pediatric OSA is caused by the interaction of many different factors that together result in a critical degree of narrowing and ultimate collapse of the upper airway. Among these are anatomical factors, conditions that result in inflammation of the soft tissue of the upper airway, and reduced baseline central muscle tone of various etiologies4 (Table 1). OSA is also typically worse in the supine position and during rapid eye movement (REM) sleep, when almost all muscle tone except for that of the eye muscles and diaphragm is lost. The large number of possible contributory factors explains why the approach to the treatment of OSA varies from one child to the next.