By Carole L. Marcus, MD

OSA (obstructive sleep apnea) is estimated to occur in 1 percent to 3 percent of otherwise healthy preschool children.1,2 The peak prevalence is at two to six years of age, but it can be seen in neonates to adolescents. It is thought to occur equally among boys and girls, and can result in significant morbidity and mortality.

ETIOLOGY

OSA in children is usually due to large tonsils and adenoids. There is no relation, however, between tonsils and adenoid size and the degree of OSA. This is probably due to the combined effects of muscle tone, pharyngeal size and adenotonsillar hypertrophy. Some children with huge tonsils are asymptomatic, whereas others with small tonsils have severe OSA. High risk groups include children with craniofacial anomalies, cerebral palsy, muscular dystrophy and Down syndrome. Children with OSA are not usually obese, but OSA does occur frequently in morbidly obese children and adolescents.

SYMPTOMS

The presence of OSA cannot be determined by history and physical examination alone. Most children present with a history of snoring and difficulty breathing during sleep. The child sleeps restlessly, and may adopt bizarre sleeping positions. Enuresis is common. The child’s appearance during sleep can be so alarming that parents often continually stimulate or reposition the child throughout the night. Despite this, many parents do not volunteer a history of their child’s sleep symptoms unless specifically asked.

During wakefulness, the child breathes normally. There is often a family history of snoring or OSA. Physical examination is usually normal, though the child may have an adenoidal facies, and mouthbreathing is common.

DIAGNOSIS

The American Thoracic Society recently published guidelines for pediatric polysomnography.3 In our practice, approximately 40 percent of children referred for suspected OSA have negative sleep studies. We therefore strongly recommend polysomnography in all children with suspected OSA.

Age-appropriate criteria should be used in interpreting sleep studies.4 During sleep, normal children have fewer obstructive apneas than adults, and the apneas are of shorter duration. They also have higher SaO2 values. Cortical arousals are less common, and sleep architecture is usually preserved. Some children have a pattern of persistent, partial airway obstruction associated with hypercapnia, rather than cyclic, discrete obstructive apneas, termed obstructive hypoventilation.

TREATMENT

Tonsillectomy and adenoidectomy (T&A) cures most children. Since OSA results from the upper airway components’ relative size and structure rather than the tonsils’ and adenoids’ absolute size, both tonsils and adenoids should be removed. T&A should also be the exclusive initial OSA treatment in children with others predisposing factors.

Though considered to be minor surgery, T&A can be associated with significant complications. Therefore, snoring without OSA is not an indication for surgery. Postoperative complications in children with OSA include upper airway edema, pulmonary edema and respiratory failure, in addition to the usual risks of T&A. OSA may not resolve fully until six to eight weeks postoperatively.

Occasionally, children present with severe OSA requiring emergency hospital admission. Sedative drugs may aggravate OSA, thus should be avoided. Supplemental oxygen should not be administered without simultaneous monitoring of PCO2, as it may precipitate respiratory failure. Nasopharyngeal tubes can be placed to bypass the obstruction pending definitive treatment, but vigilant nursing is necessary, as the tubes frequently clog with mucus.

While the FDA has not approved a CPAP machine specifically for children, it is commonly prescribed because CPAP delivered by nasal mask can be used effectively in the population. Care must be used in choosing an appropriate mask size. We have found that most children under the care of experienced practitioners will tolerate CPAP well, if they have motivated families. CPAP requirements vary with age and upper airway structure growth, so sleep studies should be repeated every six to 12 months.

Obese patients should be encouraged to lose weight. In patients with craniofacial anomalies, specific surgery can sometimes be performed. Lip-tongue adhesion procedures, for example can help patients with Pierre Robin sequence. Some patients benefit from UVPP. These days, tracteostomy is rarely required.

PROGNOSIS

Most children experience a dramatic resolution of their symptoms following T&A, though the natural course and long-term prognosis of pediatric OSA are not known. It is possible that children with treated OSA are at risk for recurrence during adulthood.

References

  1. Ali NJ, Pitson DJ, Strading JR. Snoring, sleep disturbance and behaviour in 4 to 5 years olds. Arch Dis Child. 1993; 68:360-366.
  2. Gislason T, Benediktsdottir. Snoring, apneic episodes and nocturnal hypoxemia among children 6 months to 6 years old. CHEST. 1995;107:963-966.
  3. American Thoracic Society. Standards and indications for cardiopulmonary sleep studies in children. Am J Respir Crit Care Med. 1996; 153:866-878.
  4. Marcus CL, Omlin KJ, Basinski DJ, et al. Normal polysomnographic values for children and adolescents. AM Rev Resp Dis. 1992; 146:1235-1239.

Dr. Marcus is medical director of the pediatric sleep laboratory at The John Hopkins Pediatric Sleep and Breathing Disorders Center, and a member of the ASAA Medical and Research Advisory Committee.

The ASAA can help you help your patients. For brochures, reprints of their newsletters and other informational materials, write to them at 1425 K St. NW Ste. 302, Washington, DC 20005 (202) 293-3650

Sleep Tracks, Advance for Managers of Respiratory Care, September, 1996.