Responding to Pediatric CPAP Problems

The difficulties of prescribing CPAP to pediatric patients are slowly being addressed as new equipment and tailored treatments are developed.

By Regina Patrick, RPSGT

Using information from 2003 and 2004, the National Health and Nutrition Examination Survey (NHANES)¹ found that 19% of children and 17% of teens are obese—about four times the prevalence of obesity from just 40 years ago when only 4% of both children and teens suffered from the condition. The increasing prevalence of obesity may be partly responsible for the increased prevalence of obstructive sleep apnea (OSA) now noted in children. While OSA affects an estimated 1% to 10% of all children,² obese children have 10 times the prevalence³ of OSA compared to their nonobese counterparts. As a result of the increased prevalence of OSA in children, sleep disorders centers are treating more and more pediatric patients. However, because OSA treatment has been primarily adult-focused, treating pediatric OSA patients can be a challenge.

In OSA, a child stops breathing for brief moments during sleep due to an obstruction in the upper airway. Problems that affect the patency of the upper airway, such as craniofacial abnormalities, neuromuscular problems, or an excessive amount of pharyngeal tissue, increase the risk of a child having OSA. Most children with OSA have enlarged tonsils and/or adenoids. Removing the tonsils and adenoids (ie, adenotonsillectomy) resolves OSA in 85% to 95%⁴ of children, but OSA often persists in obese children after the surgery.⁵ In such a case, a physician may use continuous positive airway pressure (CPAP) or bilevel positive airway pressure treatment to counteract residual upper airway obstruction. A physician also might use CPAP/bilevel to treat apnea in children who are not candidates for corrective surgery for craniofacial abnormalities or to treat apnea in children with neuromuscular problems.

In adults, CPAP/bilevel is the most effective treatment for OSA, but several factors make this treatment more problematic for children, including properly diagnosing OSA in a child, prescribing the right equipment, and dealing with treatment-induced adverse effects and noncompliance issues.

Diagnosing Pediatric OSA
Diagnosing pediatric OSA can be difficult since the criteria used to diagnose the condition in adults do not adequately detect the disorder in a child. Criteria for diagnosing an adult with OSA⁶ are five or more episodes of apnea (cessation of breathing) per hour of sleep with each episode lasting 10 or more seconds and one or more of the following: frequent arousals often with quick, gasping, deep breaths on the restoration of breathing; oxygen desaturation down to 89% or lower during an apneic event; and/or bradytachycardia (slowing of heart rate during an apneic event followed by a dramatic increase on restoration of breathing). Children with OSA, on the other hand, commonly have fewer than five apneic episodes per hour during sleep; frequently have apneic episodes of a shorter duration than 10 seconds; and often do not have arousals on the restoration of breathing. As well, their oxygen desaturation during apneic events falls more rapidly than it would in an adult.

With these factors in mind, scientists have adopted slightly different criteria for diagnosing OSA in children. In a child, an apneic event consists of at least two missed breaths rather than 10 seconds, and a child will have one or both of the following: 1 to 1.5 apneic events per hour of sleep (rather than 5 events/hour of sleep) and/or desaturation down to 92% (rather than 89%) or lower during an event.² By compensating for aspects of pediatric respiration that differ from respiration in adults, these changes allow for more effective diagnosis of OSA in a child.

Prescribing the Right Equipment
Once it is determined that a child has OSA, treating the disorder effectively can be hampered by the limited amount of pediatric CPAP/bilevel equipment available. As a solution, sleep centers often prescribe to children nasal masks and headgear designed for “small” or “petite” adults (ie, “off-label” use). For older children and teens, this solution may work well. For smaller, younger children, however, this solution can be inadequate at best and useless at worst. Adult small and petite sizes may still be too large to properly cover a child’s nose, thereby allowing leaks to occur. Nasal pillows are sometimes a good alternative, but small adult-sized nasal pillows may still be too large to fit into the nostrils of a small child. Even if a nasal mask or nasal pillows fit correctly, ill-fitting headgear can counteract their usefulness. Headgear that is too large does not allow a snug fit for the mask or nasal pillows. Furthermore, headgear straps can be difficult for the smaller, less agile hands of a child to manipulate, making it difficult for a child to correct leaks.

Despite the knowledge that adult equipment is ill suited for pediatric patients, there has been a somewhat slow response in the development of pediatric CPAP/bilevel  equipment. Some of the slow reaction could be credited to the lack of awareness by medical equipment manufacturers of the needs of pediatric OSA patients (since this group of patients is a relatively small market) and/or the difficulty in obtaining pediatric subjects for clinical, safety, or efficacy research studies. Another explanation could lie within the difficult process involved in getting US Food and Drug Administration (FDA) approval for pediatric medical equipment.

Obtaining FDA approval can be a particularly complicated process. For example, despite availability of data from off-label use of CPAP/bilevel equipment in children, the FDA does not allow off-label data to be used in its considerations for approval. Addi-tionally, the FDA requires a manufacturer to develop a noninvasive ventilator for pediatric use first that passes the FDA approval process before approving a pediatric nasal mask or headgear for use in the United States. Because of the strict rules involved in approving pediatric medical devices, only one pediatric noninvasive ventilator and mask system⁷ has received FDA approval to be sold in the United States at this time.

Most children will use CPAP/bilevel equipment temporarily to treat OSA before adenotonsillectomy or before having corrective surgery. In cases where surgery is not an option or has not fully alleviated OSA, however, a child may have to use CPAP/bilevel long-term. Until recently, scientists were not sure whether long-term use of CPAP/bilevel treatment could cause any adverse effects in children. One long-term effect is now coming to light.

Adverse Effect
In 2000, Li et al⁸ were the first to report a case of midface hypoplasia (underdevelopment of maxilla bone) in an obese 15-year-old boy who had been using a nasal mask since the age of 5 years. At 5 years old, the patient had had a normal facial structure. During a retitration study at 15 years old, physicians noted a “squashed” appearance (ie, hypoplasia) around the nose where the patient placed the mask. Li et al believe that repeated pressure from the nasal mask may have altered the normal growth pattern of the maxilla bone.

Bones in the midface area (eg, the maxilla, nasal bone, and the zygomatic bone  or cheekbone) are very malleable during childhood. Ortho-dontists take advantage of this malleable quality by using devices (eg, splint) to push against certain areas on a bone to slowly change its orientation, thereby correcting bite problems in a child. However, the malleability of the facial bones also makes it possible for a nasal mask to push the bones inward if the mask is used for a prolonged time.

Italian researchers Villa et al⁹ in 2002 were the first to report successfully treating midface hypoplasia induced by a nasal mask. The patient was a 7-year-old girl who had been using bilevel positive airway pressure treatment since she was an infant. The researchers referred her to an orthodontist on noting hypoplasia. The orthodontist treated the patient with a Delaire mask, which is used to treat midface hypoplasia in other disorders (eg, Down syndrome, Crouzon syndrome). The mask pushes the maxilla bone forward. Since the patient needed bilevel therapy, the researchers modified the Delaire mask so that it could be screwed onto the nasal mask. The screws allowed the distance between the Delaire and bilevel masks to be adjusted so that the nasal mask’s pressure on the patient’s face was minimized, but it still fit the nasal area snugly enough to prevent leaks. After 10 months of treatment, the patient’s facial structure was virtually restored to normal.

In their studies, both Li and Villa suggest that regular examinations of the maxilla might be needed to more quickly identify and treat the adverse effect of midface hypoplasia in children who need to use long-term CPAP/bilevel therapy. It may be especially critical to examine children younger than 12 years old since most facial bone growth takes place until approximately 12 years of age.

Dealing With Noncompliance
Even if a child is correctly diagnosed and prescribed properly fitting CPAP/bilevel equipment, the effectiveness of the treatment can be undermined by noncompliance.  Children (especially older children) might not want to comply with treatment due to the “weirdness” of having to wear the mask and headgear. Noncompliance in children more often results from discomfort caused by mask usage (eg, claustrophobia, sores on the bridge of the nose, nasal dryness, eye dryness, or soreness on the head caused by headstraps, etc). Desensitization to lessen claustrophobia or to acclimate a child to the feel of the mask and headgear early in the treatment can lessen later noncompliance. Treating dry eyes, dry nasal passages, pressure sores, etc through the use of products specially designed for these purposes also can increase compliance.

The degree of a child’s compliance is often tied to the compliance of the parents to treatment. Parents might not comply with treatment if they do not fully understand OSA; its consequences in a child (eg, inattention, restlessness, excessive sleepiness, poor school performance); or the importance of CPAP/bilevel treatment in countering the effects of OSA. Patient education material aimed at both parent and child can be used to counteract this possibility.

Tailoring Pediatric Treatment
Children are an emerging population in OSA treatment as childhood obesity rates climb. In the past, children were treated as “miniature adults.” Adult criteria were used for diagnosing OSA in a child, and adult equipment was used to treat it. Many children as a result who had the disorder were wrongly not diagnosed with OSA, or they were ineffectively treated with ill-fitting equipment. To address the needs of pediatric OSA patients, sleep medicine has changed its criteria for diagnosis and treatment to adapt to the unique characteristics of childhood respiration. Additionally, sleep medicine is making adaptations in treatment plans to accommodate the effect of continual growth in a child. For example, sleep specialists suggest that a child should ideally have a restudy every 6 to 12 months after therapy begins since frequent changes in fat distribution, facial structure, or head size can result in a need to keep adjusting CPAP/bilevel pressure. Some medical device manufacturers have begun addressing the need of providing pediatric CPAP/bilevel equipment. Changes such as these are improving the quality of pediatric OSA treatment. As the needs of children with OSA are more effectively addressed, an increased number of children can be spared a struggle with the consequences of OSA.

Regina Patrick, RPSGT, is a contributing writer for Sleep Review.

REFERENCES
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6. International Classification of Sleep Disorders: Diagnostic and Coding Manual. Revised. Chicago: American Academy of Sleep Medicine; 2001:52–58.

7. US Department of Health and Human Services, Public Health Service, Food and Drug Administration. Pre-Market Approval Letter, April 7, 2006. Available at: [removed]www.fda.gov/cdrh/pdf6/K060105.pdf[/removed] Accessed September12, 2006.

8. Li KK, Riley RW, Guilleminault C. An unreported risk in the use of home nasal continuous positive airway pressure and home nasal ventilation in children: mid-face hypoplasia. Chest. 2000;117:916–918.

9. Villa MP, Pagani J, Ambrosio R, Ronchetti R, Bernkopf E. Mid-face hypoplasia after long-term nasal ventilation. Am J Resp Crit Care Med. 2002;166: 1142-1143.