eMedicine Specialties > Pediatrics: General Medicine > Pulmonology

Obstructive Sleep Apnea Syndrome

Timothy D Murphy, MD, Assistant Professor, Department of Pediatrics, Division of Pulmonology, University of Pittsburgh; Consulting Staff, Division of Pulmonology, Children's Hospital of Pittsburgh
Andrew J Lipton, MD, MPH and TM, Staff Pediatric Pulmonologist, Assistant Professor of Pediatrics, Department of Pediatrics, Walter Reed Army Medical Center; David Gozal, MD, Vice-Chairman of Research and Director, Kosair Children's Hospital Comprehensive Sleep Medicine Center, Professor, Department of Pediatrics, University of Louisville

Updated: Feb 27, 2009

Introduction

Background

Obstructive sleep apnea (OSA) syndrome was described more than a century ago; however, obstructive sleep apnea in children was first described in the 1970s. Obstructive sleep apnea is a common but underdiagnosed condition in children that may lead to substantial morbidity if left untreated. The mechanisms of obstruction, adverse effects of obstructive sleep apnea, diagnostic criteria, and recommended treatment options are different in children than in adults. Important recent advances in the understanding of the underlying pathophysiological mechanisms of obstructive sleep apnea in children have been coupled with improved approaches to the diagnosis and management of obstructive sleep apnea.

Pathophysiology

Snoring and obstructive apnea are symptoms of increased upper airway resistance. The ability to maintain upper airway patency during the normal respiratory cycle is the result of a delicate equilibrium between the forces that promote airway closure and dilation. This "balance of forces" concept was initially proposed by 2 independent groups and reflects the current line of thought regarding the underlying pathophysiological mechanisms that result in the clinical spectrum of obstructive apnea. The 4 major predisposing factors for upper airway obstruction include anatomic narrowing, abnormal mechanical linkage between airway dilating muscles and airway walls, muscle weakness, and abnormal neural regulation.

Anatomic narrowing

At any point in life, a smaller cross-sectional area of the upper airway is associated with decreased ability to maintain upper airway patency. In adults, the upper airway behaves as predicted by the Starling resistor model. According to this model, under conditions of flow limitation, maximal inspiratory flow is determined by the pressure changes upstream (nasal) to a collapsible site of the upper airway, and flow is independent of downstream (tracheal) pressure generated by the diaphragm. Pressures at which the airway collapses have been termed critical closing pressures, or P_crit. In other words, in the presence of a collapsible segment of the upper airway, such as the pharyngeal introitus, the overall resistance to airflow proximal to that segment is the major factor responsible for occlusion of the collapsible segment. This model explains why, for example, snoring and obstructive apnea worsen during a common cold (increased nasal-upstream resistance).

The validity of this model was also confirmed in children, and, interestingly, the collapsibility of the upper airway in children was reduced when compared with that of adults. As predicted by the Starling resistor model, the collapsible segment of the upper airway in children displayed less negative (higher and, therefore, more collapsible) pressures in children with obstructive sleep apnea. Components that affect the upstream segment pressures or increase P_crit are of major consequence to the ability to maintain airway patency. For example, a viral cold or allergic rhinitis that induces increased secretion in the nasal passages and mucosal swelling is associated with increased nasal resistance to airflow. Not surprisingly, the magnitude of snoring and the severity of obstructive apnea are increased during periods in which the upstream segment pressure has been adversely affected.

The contribution of the various anatomical nasopharyngeal structures to P_crit and the interactions between these structures that lead to upper airway patency or obstruction during sleep are of obvious importance in increasing the understanding of the pathophysiology of obstructive sleep apnea in children. For most children, enlargement of the tonsils and/or adenoid is the proximate cause for the development of obstructive sleep apnea.

The static pressure and/or area relationships of the passive pharynx were endoscopically measured in 14 children with obstructive sleep apnea and in 13 healthy children under general anesthesia with complete paralysis.¹ Children with obstructive sleep apnea closed their airways at the level of enlarged adenoids and tonsils at low positive pressures, whereas healthy children required subatmospheric pressures to induce upper airway closure. The cross-sectional area of the narrowest segment was significantly smaller in children with obstructive sleep apnea and particularly involved the retropalatal and retroglossal segments. Thus, both congenital and acquired anatomic factors clearly play a significant role in the pathogenesis of pediatric obstructive sleep apnea.

Abnormal mechanical linkage between airway dilating muscles and airway walls

Malposition or malinsertion of specific dilating muscles is likely to have major consequences on the mechanical dilating efficiency. Therefore, even if a major weakness is not present, the mechanical disadvantage imposed by muscle shortening or by displacement of the muscle insertion on the pharyngeal wall undoubtedly results in diminished ability to stiffen the airway, thus leading to increased collapsibility or elevation of P_crit.

Control of the upper airway size and stiffness depends on the relative and rhythmic contraction of a host of paired muscles, which include the palatal, pterygoid, tensor palatini, genioglossus, geniohyoid, and sternohyoid muscles. These muscles tend to promote a patent pharyngeal lumen and receive phasic activation in synchrony with phrenic nerve activation. Upon contraction, these muscles promote motion of soft palate, mandible, tongue, and hyoid bone. Although the coordinated action of these muscles during the respiratory cycle has yet to be deciphered, a reasonable generalization is that inspiratory muscle output stiffens the pharynx and related structures and enlarges the lumen.

The optimal activity of these muscles depends on their anatomic arrangement; for example, airway patency is compromised during increased neck flexion by changing the points of attachment of muscles acting on the hyoid bone, such that the resulting vector of their forces may be nullified. The activity of pharyngeal muscles greatly depends on various factors within the CNS and, more particularly, on the brainstem respiratory network. Wakefulness conveys a supervisory function that ensures airway patency, and sedative agents, which compromise genioglossal muscle activity, may result in significant upper airway compromise.

Mechanoreceptor-mediated and chemoreceptor-mediated genioglossal activity is critical for maintenance of upper airway patency in healthy and micrognathic infants. Changes in genioglossal activity during transitions, from oral to nasal breathing and relative to P_crit, suggest that genioglossus activation is critical for airway patency in micrognathic infants.

Muscle weakness

Little evidence suggests that intrinsic muscle weakness is a major contributor to upper airway dysfunction in conditions other than those associated with neuromuscular disorders. However, in neuromuscular disorders, upper airway obstruction is frequently observed during sleep, further reinforcing the validity of the balance-of-pressures concept.

Abnormal neural regulation

Abnormal respiratory control does not appear to play a significant role in upper airway obstruction during sleep in children with obstructive sleep apnea. The ventilatory response to hyperoxic hypercapnic challenge in children and adolescents with obstructive sleep apnea was similar to that measured in age-matched and sex-matched control children.² Similarly, no differences were found in the ventilatory response to isocapnic hypoxia. Blunting in central chemosensitivity was reported in some children with obstructive sleep apnea undergoing surgery; however, despite such reports, central chemosensitivity during sleep was similar in children with obstructive sleep apnea and matched controls. However, arousal to hypercapnia was blunted, suggesting that subtle alterations in the central chemosensitive arousal network may have occurred in these children.

These subtle changes have been further substantiated by examining the ventilatory response to repeated hypercapnia, whereby reciprocal changes in respiratory frequency and tidal volume occur. In addition, children with obstructive sleep apnea demonstrate impaired arousal responses to inspiratory loads during rapid eye movement (REM) and non-REM sleep compared with control children. Neural responses to hypoxia and hypercarbia have not been well studied in children with obstructive sleep apnea and underlying syndromes.

In addition to the aforementioned considerations, diminished laryngeal reflexes to mechanoreceptor and chemoreceptor stimulation, with reduced afferent inputs into central neural regions underlying inspiratory inputs, can be present. For example, chemoreceptor stimuli, such as increased PaCO₂ or decreased PaO₂, stimulate the airway, dilating muscles in a preferential mode (ie, upper airway musculature is more stimulated than the diaphragm).

This preferential recruitment tends to correct an imbalance of forces acting on the airway and, therefore, maintains airway patency. Similarly, stimuli that result from suction pressures in the nose, pharynx, or larynx rapidly stimulate the activity of upper airway dilators. This effect is also preferential to the upper airway, causing some degree of diaphragmatic inhibition and, thus, compensating for increases in upstream resistance. The function of these upper airway receptors in children with adenotonsillar hypertrophy with and without obstructive sleep apnea is not known.

Summary

Several potential mechanisms in the maintenance of upper airway patency during sleep and wakefulness have been identified. Each of these mechanisms, or a combination thereof, plays a role in the causation of respiratory compromise in the healthy child or in children with clinical problems that predispose to obstructive sleep apnea. A systematic approach to identification and modification of these mechanisms may lead to improvement in therapeutic approaches and avoidance of unnecessary morbidity in these patients. For many pediatric patients, the cause of the obstructive sleep apnea is enlargement of the tonsils and/or adenoid; and when other resistors to airflow are present, removal of the tonsils and adenoid may still prove adequate to relieve the obstruction.

Frequency

United States

Precise prevalence figures for obstructive sleep apnea in children are currently unavailable. Estimates from limited field studies suggest that as many as 2% of all children may be affected; however, the prevalence of snoring in the general pediatric population is much higher and has been estimated at 8-27%.

Mortality/Morbidity

Despite the misleadingly benign clinical presentation, the pathological consequences of obstructive sleep apnea in children may be severe, and some pathological consequences are still being uncovered. These morbidities can be divided as the corollary of the 4 immediate consequences of upper airway obstruction during sleep, which include sleep fragmentation, increased work of breathing, alveolar hypoventilation, and intermittent hypoxemia. Other consequences are related to more than one factor.

• Sleep fragmentation
  • Experimental fragmentation of the sleep of healthy adults may be achieved with auditory stimuli–inducing arousals. Subjects who were awakened at various intervals during the night demonstrated performance decrements and increased sleepiness on the following day.³ This was also true when EEG arousals, rather than behavioral arousals, were induced.
  • The physiological and behavioral effects of partial and total sleep loss due to obstructive sleep apnea in adults have been extensively investigated. Daytime tiredness or fatigue is a common symptom, although sleepiness, which is a subjective notion, may not be directly reported. Significant deterioration in functions that require concentration or dexterity, as well as automatic behavior with retrograde amnesia, disorientation, and morning confusion, have all been reported in patients with sleep fragmentation and has led to the term sleep drunkenness. In addition, personality changes and abnormal behavioral outbursts follow sleep fragmentation. Aggressiveness, irritability, anxiety attacks, and depression may occur.
  • Sleep fragmentation in adults affects neuropsychological and cognitive performance. No evidence suggests such impairments are absent in children, and such deleterious effects may be worse, given that the child's brain is undergoing active developmental changes. Reports of decreased intellectual function in children with tonsillar and adenoidal hypertrophy date from 1889 when Hill reported on "some causes of backwardness and stupidity in children." Schooling problems have been repeatedly reported in case studies of children with obstructive sleep apnea and, in fact, may underlie more extensive behavioral disturbances, such as restlessness, aggressive behavior, excessive daytime sleepiness, and poor test performances.
  • The neurocognitive and behavioral consequences of disrupted sleep architecture and hypoxemia caused by sleep-disordered breathing in children with obstructive sleep apnea have only recently been defined by appropriate scientific methodology in the pediatric population. However, some studies have documented that children with sleep disorders tend to have behavioral problems similar to those observed in children with attention deficit hyperactivity disorder (ADHD). A survey study of 782 children recently documented daytime sleepiness, hyperactivity, and aggressive behavior in children who snore.⁴ Inverse correlations between memory and learning performance and the severity of obstructive sleep apnea were also found, and other studies have clearly demonstrated significant improvements in school performance after treatment of obstructive sleep apnea.
  • In a study of 19 preschool-aged children with obstructive sleep apnea, prior to tonsillectomy and adenoidectomy (T&A), cognitive scores were significantly lower in children with obstructive sleep apnea versus control subjects.⁵ Following T&A, the scores of the children with obstructive sleep apnea improved compared with preoperative scores and did not differ from those of the matched controls. This underscores the importance of diagnosis and treatment, insofar as the cognitive impairments of children, unlike adults, take place in the developing brain.
  • Sleep deprivation, sleep disruption, and intermittent hypoxia independently may be sufficient to cause daytime effects in vulnerable children. Preliminary evidence suggests that, if left untreated, sleep-disordered breathing may impose long-term decrements in academic performance and the combination of 2 or more of these factors can result in particularly impaired daytime functioning.
  • Although empirical awareness of the deleterious consequences of obstructive sleep apnea on neurocognitive function and behavior is well established, the scientific foundation for the causal mechanisms underlying such detrimental effect on intellectual function has yet to be determined. This endeavor is currently a major focus of research programs.
• Increased work of breathing
  • A major cardiovascular consequence of obstructive sleep apnea in adults is arterial hypertension. Although the pathophysiological mechanisms of elevation in arterial tension are still under debate, intermittent arousal, hypoxemia, and increases in cardiac afterload during the obstructive apneic event apparently lead to enhanced sympathoadrenal discharge and heightened sympathetic tone, even during waking hours. Significant alterations in autonomic nervous system tone have been documented in children with obstructive sleep apnea, and modest diurnal elevations in arterial blood pressure have also been reported.
  • Sleep-disordered breathing is associated with higher systolic blood pressures in children aged 5-12 years and supports the use of an apnea hypopnea index (AHI) threshold of 5 for initiating treatment.⁶ The long-term effects of this process in childhood and the effect on adult health are unknown.
  • A prominent clinical manifestation of increased work of breathing in children with obstructive sleep apnea is failure to thrive (FTT). Indeed, reports from the early 1980s found more than a 50% prevalence of FTT in patients with pediatric obstructive sleep apnea, and significant catch-up growth patterns have recently been reported after T&A, even in children with obesity and obstructive sleep apnea. The causes of poor growth include anorexia and dysphagia due to tonsillar and adenoid hypertrophy, diminished or altered patterns of nocturnal growth hormone secretion, hypoxemia, acidosis, and increased work of breathing during sleep.
  • In one study, a substantial reduction in resting energy expenditure was reported after adenotonsillectomy in children with obstructive sleep apnea and FTT with concomitant gains in body weight.⁷ Another study demonstrated significant recovery in the insulin growth factor 1 axis.⁸ These findings suggest that an important factor that mediates FTT in pediatric obstructive sleep apnea involves the combination of increased energy expenditure caused by increased respiratory effort and disruption of the pathways of the growth hormone somatomedin.
• Alveolar hypoventilation
  • Intermittent hypercapnia frequently occurs among patients with various respiratory disorders, becomes more prominent or sustained during sleep, and is minimal or absent during wakefulness.
  • Children with obstructive sleep apnea who snore exhibit classic intermittent alveolar hypoventilation, which is elicited by increased upper airway resistance, concurrent with diminished or insufficient compensatory mechanisms developing during sleep.
  • In adults with obstructive sleep apnea, blunted ventilatory drive to hypercapnia during wakefulness develops and may potentially contribute to the pathophysiology of upper airway obstruction.
  • In contrast, waking and sleeping ventilatory responses to hypercapnia in children with obstructive sleep apnea are similar to those measured in healthy children. However, arousal responses are attenuated during sleep, suggesting that long-standing interactions between sleep and upper airway resistance in these children primarily affect arousal mechanisms during sleep. Another potential contribution of alveolar hypoventilation and hypercapnia during sleep may relate to exacerbation of the effect of intermittent hypoxia on the vasomotor tone of the pulmonary circulation.
• Intermittent hypoxemia
  • A serious consequence of intermittent hypoxia is elevation of pulmonary artery pressure due to pulmonary vasoconstriction, such that chronic intermittent nocturnal hypoxemia leads to development of pulmonary hypertension and cor pulmonale. In 27 pediatric patients with moderate-to-severe obstructive sleep apnea, radionuclide assessment of right ventricular function revealed reduced ejection fraction in 37% of these children and wall motion abnormality in 45%.⁹ Another potentially serious consequence of intermittent hypoxia may involve its long-term deleterious effects on neuronal and intellectual function. Indeed, in a study on an animal model developed in the coauthor's laboratory, intermittent hypoxia was associated with significant increases in neuronal apoptosis and reduced functionality within brain regions that mediate learning and memory.
  • Because the peak age for obstructive sleep apnea coincides with that of a critical period for brain development, delayed diagnosis and treatment of obstructive sleep apnea possibly imposes a greater burden on vulnerable brain structures and ultimately hampers the overall neurocognitive potential of children with obstructive sleep apnea.
  • Neurobehavioral disturbances and diminished learning capabilities, stunted growth, altered respiratory load response patterns, and pulmonary hypertension are major consequences of obstructive sleep apnea in childhood. Early diagnosis and prevention of such morbidities are fundamental aspects of adequate pediatric care in the community.
• Inflammation
  • The association of inflammation with obstructive sleep apnea in relation to this schema is uncertain.
  • Markers of systemic inflammation such as interleukin (IL)-6¹⁰ and C-reactive protein¹¹ are elevated in obstructive sleep apnea and decrease following T&A, suggesting that the elevation was due to the obstructive sleep apnea.
  • An increased inflammatory response may be associated with infectious diseases associated with tonsillar and adenoidal hypertrophy; thus, the issue of cause and effect can be difficult to ascertain.

Race

The current evidence assigns a particularly higher risk for obstructive sleep apnea among black children compared with white children. However, the high frequency of obstructive sleep apnea among adult Asian populations indicates that the anthropometric characteristics of the craniofacial structures in this racial group also predispose for higher obstructive sleep apnea rates in children. The frequency of obstructive sleep apnea in Hispanic children is equal to that of white children.

Sex

The prevalence of snoring and obstructive sleep apnea among prepubertal children does not differ based on sex. In older adolescents, a male preponderance emerges that essentially reflects the typical male predominance observed in the adult population.

Age

The peak prevalence is in children aged 2-8 years (coinciding with adenotonsillar lymphatic tissue growth). Preterm babies are at risk for more obstructive events while supine but are still at a lower risk of death from sudden infant death syndrome.

Clinical

History

The clinical presentation of a child with obstructive sleep apnea (OSA) syndrome is nonspecific and requires increased awareness by the primary care physician. Indeed, the medical history is usually normal, unless the pathophysiology of sleep-associated airway obstruction is related to one of the various conditions delineated in Causes.

Clinical findings of tonsillar enlargement or obesity should prompt questioning regarding snoring. Family history of snoring, allergies, and exposure to environmental tobacco smoke are all strongly related to snoring. In the otherwise healthy child, parents principally report snoring during sleep. History of loud snoring 3 or more nights per week should increase suspicion of obstructive sleep apnea.

Parents occasionally comment on breathing difficulties during sleep (eg, gasps or heroic snorts), unusual sleeping positions, morning headaches, daytime fatigue, irritability, poor growth and weight gain, and behavioral problems. Nevertheless, even in cases in which a sleep specialist conducts the diagnostic interview, the accuracy of obstructive sleep apnea prediction is poor and does not exceed a sensitivity and specificity of 50-60%, particularly in distinguishing obstructive sleep apnea from benign snoring.

Physical

Physical examination findings are generally normal while awake, with the exception of findings related to the predisposing conditions noted (see Causes). Plot a growth chart, including a height-adjusted, weight-adjusted, and age-adjusted body mass index in order to identify obesity or failure to thrive (FTT). Carefully examine the nasal passages for mucosal swelling, cobblestone pattern of the mucosa, polyps, and reduced nasal airflow. Carefully evaluate the size and position of tonsils and uvula, particularly noting hypertrophy or malformation. Unfortunately, although tonsillar hypertrophy may contribute to the severity of obstructive sleep apnea, the data available to date have not established a clear relationship between tonsillar size and frequency or severity of apneic events. Furthermore, although more prevalent in patients with obstructive sleep apnea, tonsillar hypertrophy is also common in healthy children without obstructive sleep apnea, with a prevalence as high as57%.

Document the width and height of the hard palate, as well as the overall appearance of the soft palate, looking for evidence of cleft or pharyngeal narrowing or compression.

Although not extensively evaluated in children, the Mallampati classification may help quantify the degree of oropharyngeal anatomical obstruction. This classification is based on the structures visualized with maximal mouth opening and the tongue extended. The classes are determined by the visible structures. In class I, the soft palate, fauces, uvula, and pillars are visible. In class II, the soft palate, fauces, and a portion of uvula are visible. In class III, the soft palate and base of uvula are visible. In class IV, only the hard palate is visible. The higher the Mallampati classification, the greater the likelihood of oropharyngeal obstruction, and the greater the risk of persistent obstruction following tonsillectomy and adenoidectomy (T&A).¹²

The relative position of the chin with respect to the maxilla is helpful in the identification of mild micrognathia or retrognathia.

Cardiac examination may reveal the presence of a prominent pulmonic second heart sound suggestive of pulmonary hypertension.

No other distinctive findings are usually present unless one of the medical conditions is present.

Causes

Medical conditions associated with obstructive sleep apnea in children include the following:

• Tonsillar and adenoid hypertrophy
• Achondroplasia, Crouzon syndrome, and Apert syndrome
• Neuromuscular disorders (eg, Duchenne muscular dystrophy, spinal muscular atrophy)
• Myelomeningocele
• Obesity
• Pierre Robin sequence
• Cerebral palsy
• Down syndrome
• Sickle cell diseases
• Choanal stenosis
• Hypothyroidism
• Klippel-Feil syndrome and Hallermann-Streiff syndrome
• Mucopolysaccharidosis
• Osteopetrosis
• Oropharyngeal papillomatosis
• Beckwith-Wiedemann syndrome
• Pfeiffer syndrome, Prader-Willi syndrome, and Treacher-Collins syndrome

Differential Diagnoses

Other Problems to Be Considered

Primary snoring
Upper airway resistance syndrome
Other sleep disorders

Workup

Laboratory Studies

Polysomnography (PSG) is the study of choice in obstructive sleep apnea (OSA) and measures the following:

• Sleep state (>2 EEG leads)
• Electrooculogram (right and left)
• Submental electromyelogram (EMG)
• Airflow at nose and mouth (thermistor, capnography, or mask and pneumotachygraph)
• Chest and abdominal wall motion (impedance or inductance plethysmography)
• Electrocardiogram (preferably with R-R interval derivation technology)
• Pulse oximetry (including a pulse waveform channel)
• End-tidal carbon dioxide (sidestream or mainstream infrared sensor)
• Video camera monitor with sound montage (analog or digital)
• Transcutaneous oxygen and carbon dioxide tensions (in infants and children <8 y)

The following sleep study parameters are under investigation:

• Nasal pressure–flow measurements
• Esophageal manometry
• Continuous noninvasive blood pressure monitoring
• Autonomic nervous system tone using finger tonometry

PSG, continuously monitored by appropriately trained technical personnel, may be difficult to arrange due to relative unavailability, with long waiting periods between referral and testing times. For these reasons, attempts have recently been made to evaluate the role of outpatient overnight studies to provide more accessible and practical approaches to the diagnosis of pediatric obstructive sleep apnea. However, these outpatient studies are not well validated yet or covered by third party payers and, thus, remain largely available only as research tools.

The results of initial studies indicate that, although home audio tape recordings appear relatively insensitive, oximetry trend analysis with or without additional measures may provide a useful alternative in establishing the definitive cases that require intervention. However, despite high specificity, home oximetry has low sensitivity, and children with negative findings on studies still require complete nocturnal polysomnography.

Compared with the adult literature, the available normative data for sleep and cardiorespiratory parameters are rather sparse in the pediatric literature, such that most pediatric sleep laboratories use individually established reference ranges rather than referring to an authoritative text. Nevertheless, the general consensus criteria for a normal finding on sleep study are presented in the following table and have been derived from the published literature on this subject and the authors' experience.

Reference range parameters for sleep gas exchange and gas exchange in children are as follows:

• Sleep latency - More than 10 minutes
• Total sleep time (TST) - More than 5.5 hours
• Percentage of rapid eye movement (REM) sleep - More than 15% of TST
• Percentage of stage 3-4 non-REM sleep - More than 25% of TST
• Respiratory arousal index (number per hour of TST) - Less than 5
• Periodic leg movements (number per hour of TST) - Less than 1
• Apnea index (number per hour of TST) - Less than 1
• Hypopnea index (nasal/esophageal pressure catheter; number per hour of TST) - Less than 3
• Nadir oxygen saturation - More than 92%
• Mean oxygen saturation - More than 95%
• Desaturation index (>4% for 5 s; number per hour of TST) - Less than 5
• Highest carbon dioxide level - 52 mm Hg
• Carbon dioxide level of more than 45 mm Hg - Less than 20% of TST

The adult criteria usually used around the world for the diagnosis of obstructive sleep apnea do not apply to children. In fact, the finding of 10-15 obstructive apneic events per hour of sleep, which represents mild obstructive sleep apnea in an adult patient in whom treatment may not even be contemplated, represents a sleep-related respiratory disturbance corresponding to a severely affected child definitely in need of therapeutic intervention. Thus, an apnea hypopnea index (AHI) of more than 5 events per hour clearly represents an indication for treatment in children. An AHI of fewer than 3 events per hour does not require any intervention, and, in children with an AHI of more than 3 but fewer than 5 events per hour, the benefit of treatment remains to be determined.

Imaging Studies

Assessment of tonsillar size usually does not require any type of imaging; however, lateral neck radiographs can be used to determine adenoid size. Although MRI can provide very detailed images of soft tissues and bony structures underlying the nasopharynx, such images are not usually required, except in cases of suspected aberrant anatomy.

Other diagnostic studies may be warranted to evaluate for complications of obstructive sleep apnea or to better assess the contribution of an underlying condition. In patients with severe obstructive sleep apnea, electrocardiography and echocardiography are particularly important to assess for pulmonary hypertension and cor pulmonale.

Other Tests

Currently, the only available tool for definitive diagnosis of obstructive sleep apnea is an overnight polysomnographic evaluation in the sleep laboratory. An overnight polysomnographic study usually includes multiple channels that aim to monitor sleep state, as well as cardiac and respiratory parameters (see Media file 2).

Procedures

Nasopharyngoscopy or direct laryngoscopy and bronchoscopy may be required to determine anatomy prior to contemplated otolaryngologic surgery.

Treatment

Medical Care

• Medical therapy
  • In general, medical therapy is of limited value in the typical pediatric patient with obstructive sleep apnea (OSA).
  • Antihistamine or antimuscarinic therapy may lead to relief in cases of nasal congestion, although sustained benefit is uncertain. For allergic rhinitis or conditions associated with decreased nasal airflow, efforts to improve nasal patency may be beneficial.
  • An oral leukotriene modifier may eliminate residual obstructive sleep apnea following surgery, and these agents may have a role in improving clinical outcomes without surgery. Although systemic steroids do not improve obstructive sleep apnea, topical budesonide used for 6 weeks has been demonstrated to lead to a sustained improvement in mild obstructive sleep apnea. Such preparations are unproven as therapy for severe obstructive sleep apnea. Topical therapy as a primary treatment for obstructive sleep apnea remains largely investigational.
• Positive-pressure ventilation
  • In recent years, positive-pressure ventilation administered via a noninvasive interface (nasal mask) has become a safe, efficient, and viable alternative to further surgery or tracheotomy in children and infants with unresolved obstructive sleep apnea after tonsillectomy and adenoidectomy (T&A).
  • An important distinction must be made between continuous positive airway pressure (CPAP) and bilevel (or biphasic) positive airway pressure (BiPAP).
    • In CPAP, airway pressure is maintained above atmospheric pressure throughout the respiratory cycle.
    • In BiPAP, pressure is delivered during the inspiratory cycle; exhalation then occurs at either atmospheric pressure or at a preset positive airway pressure, such that differences between inspiratory and expiratory pressures are usually greater than 10 cm H₂ O. The BiPAP device may be set to control ventilation entirely (control mode), to deliver breaths only when triggered by a threshold negative pressure or nasal flow generated by the patient (assist mode), or both (assist/control mode).
    • Because CPAP does not involve a respiratory phase change in pressure, no control or assist modes are available.
  • Another important aspect of these interventions involves the patient-machine interface. The use of nasal prongs, nasal masks, or facemasks requires individualized case-by-case consideration. However, when a silicone mask is selected, particular care to ensure that the mask fits snugly and is comfortable to the patient is essential for ensuring successful intervention. Pediatric masks are currently available in several sizes and for particular clinical conditions, such as craniofacial syndromes. Custom-made masks can be ordered to fit the facial contours.
  • Inappropriately fit masks inevitably leak, and efforts to seal these leaks frequently result in pressure sores on the bridge of the nose. Bubble-cushioned masks have been developed and sometimes palliate the severity of the air leak while adding to the patient's comfort. In addition, air leaks are more frequently directed upward and may irritate the conjunctiva, leading to increased lacrimation and eye discomfort. Tolerance of CPAP or BiPAP may be greatly increased by devoting a period of time to condition the patient to use the mask during waking hours, particularly in young or developmentally delayed patients.
  • Pay attention to the mask manifold to ensure that no pressure vectors are generated. Multiple techniques may be used to secure the mask and primarily include Velcro, elastic straps, or a tissue cap. Again, the importance of the patient's comfort cannot be overemphasized. Finally, implement adequate parental training and behavioral techniques designed to improve the acceptance and tolerance to these devices in order to increase patient and family compliance. Over the last decade, CPAP has been increasingly used in children as a successful alternative to upper airway surgery or tracheotomy. However, midfacial hypoplasia may develop with long-term use, particularly in children with neuromuscular weakness. In other situations, temporary palliation using supplemental oxygen may be implemented until surgery, provided that sufficient attention is given to the possibility that severe hypercapnia may develop.

Surgical Care

• Tonsillectomy and adenoidectomy
  • Although obstructive sleep apnea has multiple etiologies in children, once the diagnosis of obstructive sleep apnea has been established and its severity assessed, T&A is usually the first line of treatment. Tonsillotomy, rather than tonsillectomy, has been recently advocated as equally effective with less postoperative morbidity. Most of these surgical procedures can be performed safely on an outpatient basis.
  • Notwithstanding the surgery being planned, carefully consider the existence of risk factors for perioperative morbidity and adverse outcomes in the surgical planning. Children with severe obstructive sleep apnea, children younger than 2 years, and children with craniofacial syndromes or other conditions that contribute to the pathophysiology of obstructive sleep apnea are at a higher risk for surgical complications. For example, in children with severe obstructive sleep apnea, the existence of pulmonary hypertension and right ventricular dysfunction has been linked to the onset of cardiac arrhythmias during the process of anesthesia induction. Thus, preoperative echocardiographic assessment is indicated in these patients.
  • Similarly, for all of the risk categories mentioned above, an obtunded patient in whom the anesthetic effects on upper airway tone and reflexes are still compromised has a high risk of postsurgical upper airway obstruction. Finally, the development of idiopathic pulmonary edema following the relief of upper airway obstruction has also been noted. Therefore, in this high-risk group of patients, pursue overnight cardiorespiratory monitoring in the intensive care unit.
• Other surgical procedures: Additional surgical options may include uvulopharyngopalatoplasty, epiglottoplasty, and mandibular advancement procedures. However, most facilities lack extensive experience with these procedures in children, and the overall outcomes from these interventions have not been appropriately documented in the pediatric population. Extensive surgical intervention in the upper airway of the child may lead to decreased oral-motor functioning (ie, increased risk of aspiration) and, thus, multiple long-term complications. Therefore, seriously consider nonsurgical alternatives before recommending additional surgery.
• Tracheotomy: In the past, when surgery did not relieve the degree of sleep-associated respiratory disturbance, a tracheotomy was frequently performed. Currently, this alternative is rarely needed because of the development of noninvasive approaches to maintain upper airway patency during sleep.
• Bariatric surgery: Although bariatric surgery is primarily performed in patients who are obese, the associated weight loss may be of value in reducing obstructive sleep apnea because obesity predicts a lower success rate in treatment of obstructive sleep apnea by T&A. The effects of weight loss surgery on health problems associated with morbid obesity include decreases in severity or incidence of obstructive sleep apnea, diabetes, asthma, hypertension, infertility, arthritis, heart disease, reflux, stress incontinence, and pseudotumor cerebri.

Consultations

• For the otherwise healthy child with enlarged tonsils and adenoids, consultation with a pediatric sleep specialist and referral to a pediatric sleep laboratory for diagnosis are usually sufficient.
• When findings support the existence of obstructive sleep apnea, refer the patient to a pediatric otolaryngologist for T&A and take appropriate perioperative and postoperative precautions in higher-risk groups. When obesity is present, refer the patient to a nutritional interventional program. Similarly, pursue echocardiography and input from a pediatric cardiologist when pulmonary hypertension is clinically suspected.
• When craniofacial syndromes or neuromuscular disorders are the major cause of obstructive sleep apnea, a multidisciplinary approach is mandatory for improved outcomes.

Diet

• Introduce an appropriate diet in patients who are obese to facilitate weight reduction.
• Weight reduction is most successful with the aid of a nutritionist or an established weight reduction program. However, such programs have a low success rate, and surgical intervention for severe obesity is increasingly considered in older children.
• Although bariatric surgery is primarily thought of as a treatment option for adults, it is increasingly considered in adolescents (see Surgical Care).

Medication

Preliminary studies suggest an oral leukotriene modifier therapy may reduce the severity of obstructive sleep apnea (OSA); however, this intervention is currently considered investigational. Intranasal budesonide used for 6 weeks has been demonstrated to lead to a sustained improvement in mild obstructive sleep apnea but is unproven as therapy for severe obstructive sleep apnea.¹³

Follow-up

Further Outpatient Care

• In most otherwise healthy children with obstructive sleep apnea (OSA), tonsillectomy and adenoidectomy (T&A) results in complete resolution of the problem, and a postsurgical evaluation in the sleep laboratory is usually not recommended. However, residual mild sleep-disordered breathing is found in more than one third of these patients after T&A, particularly those included in the high-risk category. Thus, T&A alone may not suffice, and polysomnographic evaluation 6-8 weeks after T&A may confirm the need for additional treatment, including the use of intranasal steroids and oral leukotriene modifier therapy or continuous positive airway pressure (CPAP) and/or bilevel positive airway pressure (BiPAP).
• Patients treated with noninvasive ventilation require close follow-up by a pediatric pulmonologist and may periodically require a repeat polysomnographic evaluation. Treat patients who are found to have significant hypoxemia during polysomnography as soon as possible with overnight supplemental oxygen until T&A can be performed. Carefully assess the patient when using oxygen because of the rare possibility that significant hypercapnia may develop during the night.

Deterrence/Prevention

• Although no specific prevention has been reported, a high index of suspicion in patients with predisposing conditions or suggestive history is necessary for early detection. The need for increased awareness of and screening for obstructive sleep apnea among primary care providers is significant. History obtained during preventive health visits should include questions regarding snoring (frequency, quality), obvious nocturnal airway obstruction or apnea, restless sleep, mouth breathing, daytime inattention, hyperactivity or hypersomnolence, and family history of obstructive sleep apnea. Loud snoring 3 or more nights per week warrants further investigation.
• Obesity is increasing in children; 16-33% of children and adolescents are obese. Primary care providers should provide basic weight loss information and support and readily refer patients to a pediatric weight loss program. A pediatric sleep disorders clinic should work closely with a weight loss program and can be a portal of entry for a patient into such care systems.

Complications

• Complications of obstructive sleep apnea are discussed in detail in Mortality/Morbidity. Complications include deficits in neurocognitive function, failure to thrive (FTT), alterations in autonomic tone, modest elevations in arterial blood pressure, pulmonary hypertension, and cor pulmonale.
• Children with obstructive sleep apnea have an increased prevalence of night terrors and other parasomnias.

Prognosis

• In children with enlarged tonsils and adenoids that lead to obstructive sleep apnea, a T&A usually results in complete cure, although no definitive studies have clearly demonstrated this issue.
• The outcome of patients who require extensive surgical management obviously depends on the severity of the condition that leads to upper airway compromise. With the emergence of noninvasive ventilation as an alternative option for these children, upper airway obstruction during sleep can be conservatively and successfully managed in most children.
• In children with FTT, treatment of obstructive sleep apnea leads to resolution of the somatic growth disturbance. Similarly, pulmonary hypertension resolves. Although major improvements in neurobehavioral outcomes are expected, data are currently insufficient to support a complete recovery in some of the cognitive abilities affected by obstructive sleep apnea.

Patient Education

• Compliance issues are of particular importance in patients treated with noninvasive ventilation. Weight loss through an appropriate program of diet and exercise is clearly beneficial for patients with obstructive sleep apnea who are obese.
• For excellent patient education resources, visit eMedicine's Sleep Disorders Center. Also, see eMedicine's patient education article Disorders That Disrupt Sleep (Parasomnias).

Miscellaneous

Medicolegal Pitfalls

• Refer patients in whom obstructive sleep apnea (OSA) is diagnosed following polysomnography for appropriate therapy. Failure to make an appropriate referral could result in legal action if a patient were to develop complications that could be attributed to obstructive sleep apnea, such as cor pulmonale.

Special Concerns

• Please see Sleep Apnea for additional reading.

Multimedia

Media file 1: Medical complications associated with obstructive sleep apnea in children.

Media file 2: Compressed overnight polysomnography tracing of a 6-year-old boy who snores, showing multiple events of obstructive apnea (green-shaded areas) associated with oxyhemoglobin desaturation (yellow-shaded areas) and EEG arousals (red-shaded areas).

Media file 3: Parameters monitored during an overnight pediatric sleep study.

Media file 4: Normal parameters for sleep gas exchange and gas exchange in children.

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Keywords

obstructive sleep apnea syndrome, OSA, sleep apnea, sleep-induced apnea, snoring, increased upper airway resistance, upper airway obstruction, anatomic narrowing, abnormal mechanical linkage between airway dilating muscles and airway walls, muscle weakness, abnormal neural regulation, sleep fragmentation, increased work of breathing, alveolar hypoventilation, intermittent hypoxemia, adenotonsillar hypertrophy, tonsillectomy and adenoidectomy, T&A, daytime tiredness, fatigue, sleep drunkenness, respiratory disorders, achondroplasia, Crouzon syndrome, Apert syndrome, Duchenne muscular dystrophy, spinal muscular atrophy, myelomeningocele, obesity, Pierre Robin sequence, cerebral palsy, Down syndrome, sickle cell disease, choanal stenosis, hypothyroidism, Klippel-Feil syndrome, Hallerman-Streiff syndrome, mucopolysaccharidosis, osteopetrosis, oropharyngeal papillomatosis, Beckwith-Wiedemann syndrome, Pfeiffer syndrome, Prader-Willi syndrome, Treacher-Collins syndrome 

Contributor Information and Disclosures

Author

Timothy D Murphy, MD, Assistant Professor, Department of Pediatrics, Division of Pulmonology, University of Pittsburgh; Consulting Staff, Division of Pulmonology, Children's Hospital of Pittsburgh
Disclosure: Nothing to disclose.

Coauthor(s)

Andrew J Lipton, MD, MPH and TM, Staff Pediatric Pulmonologist, Assistant Professor of Pediatrics, Department of Pediatrics, Walter Reed Army Medical Center
Andrew J Lipton, MD, MPH and TM is a member of the following medical societies: American Academy of Pediatrics, American College of Chest Physicians, and American Thoracic Society
Disclosure: Nothing to disclose.

David Gozal, MD, Vice-Chairman of Research and Director, Kosair Children's Hospital Comprehensive Sleep Medicine Center, Professor, Department of Pediatrics, University of Louisville
David Gozal, MD is a member of the following medical societies: Society for Pediatric Research
Disclosure: Nothing to disclose.

Medical Editor

Thomas Scanlin, MD, Chief, Division of Pediatric Pulmonary & Cystic Fibrosis, Assistant Professor, Department of Pediatrics, Robert Wood Johnson University Medical Group
Thomas Scanlin, MD is a member of the following medical societies: American Thoracic Society and Society for Pediatric Research
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

Heidi Connolly, MD, Associate Professor of Pediatrics and Psychiatry, University of Rochester; Director, Pediatric Sleep Medicine Services, Strong Sleep Disorders Center
Heidi Connolly, MD is a member of the following medical societies: American Academy of Pediatrics, American Thoracic Society, and Society of Critical Care Medicine
Disclosure: Nothing to disclose.

CME Editor

Mary E Cataletto, MD, Associate Director, Division of Pediatric Pulmonology, Winthrop University Hospital; Professor of Clinical Pediatrics, State University of New York at Stony Brook; Director of Children's Sleep Services, Winthrop University Hospital
Mary E Cataletto, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Chest Physicians
Disclosure: Shering Plough Pharmaceuticals Honoraria Consulting

Chief Editor

Michael R Bye, MD, Professor of Clinical Pediatrics, Division of Pulmonary Medicine, Columbia University College of Physicians and Surgeons; Attending Physician, Pediatric Pulmonary Medicine, Morgan Stanley Children's Hospital of New York Presbyterian, Columbia University Medical Center
Michael R Bye, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Chest Physicians, and American Thoracic Society
Disclosure: Merck Honoraria Speaking and teaching

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