Basics
Description
- Sleep-disordered breathing encompasses a range of breathing disorders occurring during sleep. These conditions include primary snoring (PS), respiratory events related to arousals (RERA), and obstructive sleep apnea syndrome (OSAS).
- Obstructive apnea is defined as the cessation of airflow at the nose and mouth despite respiratory effort, associated with some gas exchange abnormality and/or loss of regular sleep patterns.
PHYSIOLOGY
- OSAS may be subdivided into mild, moderate, and severe forms.
- Many children with OSAS exhibit partial airway obstruction. This is known as obstructive hypoventilation or hypopnea and is more commonly seen in children than is complete obstruction.
- OSAS is distinct from central apnea (cessation of airflow that is not accompanied by respiratory effort), which indicates brain immaturity or dysfunction.
- Upper airway resistance syndrome is a respiratory disorder characterized by partial airway obstruction and arousals leading to sleep fragmentation and is not associated with gas exchange abnormalities.
- Central apnea up to 20 seconds may be a normal finding in premature or newborn infants during the 1st month of life.
- Periodic breathing: 3 or more episodes of central apnea lasting at least 3 seconds each, separated by <20 seconds. Periodic breathing may be found in the newborn; however, it should not exceed >4% of sleep time (from a sleep study) and is not associated with bradycardia or hypoxemia.
Risk Factors
- In infants, OSAS is uncommon; however, it may exist with craniofacial anomalies, neurologic disorders associated with low muscle tone, laryngomalacia or tracheomalacia, and gastroesophageal reflux.
- Impaired arousal mechanisms also contribute to abnormalities seen in OSAS.
- In older children, OSAS may be associated with obesity. This form may resemble the adult type of OSAS.
- PS or habitual snoring implies snoring that does not lead to abnormalities in gas exchange or sleep fragmentation; however, 20 " �50% of children with habitual snoring may have OSAS.
Genetics
- Several genetic disorders with associated craniofacial anomalies, hypotonia, and obesity may lead to OSAS. These include the following:
- Pierre Robin syndrome
- Treacher Collins syndrome
- Down syndrome
- Mucopolysaccharide disorders
- Arnold-Chiari malformations
- Prader-Willi syndrome
- Hereditary neuromuscular disorders
Commonly Associated Conditions
- Adenotonsillar hypertrophy
- Craniofacial anomalies including midfacial hypoplasia and mandibular hypoplasia
- Laryngomalacia
- Neurologic and neuromuscular disorders that cause hypotonia may underlie poor ventilation during sleep.
- Gastroesophageal reflux
- Obesity
- Metabolic disorders
- Allergic rhinitis, nasal septum deviation, nasal polyps
- Sedatives, seizure medications, and anesthesia
Diagnosis
History
- Nocturnal symptoms include difficulty breathing when asleep, snoring, apnea, and restless sleep with frequent arousals.
- Daytime symptoms: excessive sleepiness, frequent upper respiratory/ear infections, conductive hearing loss, mouth breathing, poor appetite, and a hyponasal voice
- Other concerns: attention-deficit/hyperactivity disorder (ADHD), gastroesophageal reflux, poor school performance, and headaches (especially in the morning and upon awakening)
- OSAS rarely produces these symptoms acutely but tends to occur over weeks to months.
- Parents may notice that symptoms worsen with upper respiratory infections.
- The possibility of sleep-disordered breathing or a primary sleep disorder should be considered in children evaluated for ADHD.
Physical Exam
- Assessment of the child 's growth. In severe cases of OSAS, failure to thrive has been reported.
- Obesity remains a risk factor, especially in older children.
- Assessment of tonsillar size
- Presence of mouth breathing, hyponasal speech, adenoidal facies, midfacial hypoplasia, retrognathia, micrognathia, or other craniofacial anomalies may be present at times and may suggest the diagnosis.
- Nasal obstruction due to polyps, nasal septum deviation, turbinate hypertrophy, or congestion
- Tongue size
- Mobility and elevation of the soft palate; hard palate integrity
- In extreme cases, cardiac involvement may lead to cor pulmonale and heart failure. Examination may suggest signs of pulmonary hypertension or congestive heart failure, such as an increased second heart sound.
- A neurologic examination to evaluate general muscle strength, tone, and developmental status, especially in infants and children who do not improve after adenotonsillectomy
Alert
Normal-sized tonsils do not exclude OSAS. � �
Diagnostic Tests & Interpretation
Lab
- Polysomnography
- The gold standard for the diagnosis of OSAS is nocturnal polysomnography to differentiate the type of sleep apnea and to assess severity.
- Polysomnography is an 8 " �10-hour-long multichannel study performed in a controlled setting to assess respiratory and/or sleep abnormalities.
- Indices such as oxygenation, ventilation, apnea index (AI), apnea " �hypopnea index (AHI), arousal index, arousal awakening index, and periodic limb movements index are determined along with sleep efficiency and sleep stages.
- Monitoring includes electroencephalogram, electrooculogram, electromyogram, arterial oxygen saturation, end tidal CO2 tension, airflow, respiratory effort, and electrocardiogram.
- Normative respiratory and sleep variables for children have recently been published and include an AHI of <1 being normal.
- Scoring for pediatric polysomnography differs from that of adults. This includes using 2 respiratory cycles to define both obstructive apnea and central apnea or 2 respiratory cycles associated with a 30% decline in airflow and a >4% decline in oxygen level to define hypopnea. Lower AHI values are considered significant in children compared with adults.
- Other studies
- Validated questionnaires are helpful to screen for OSAS in the office.
- Routine blood work is generally noncontributory; in severe forms, polycythemia, hypercarbia, and elevated bicarbonate may be noted.
- Evaluation for gastroesophageal reflux may include pH monitoring during sleep, barium swallow, or radionuclide studies (milk scan).
- Home testing is not approved for use in children with suspected OSAS.
Imaging
- Lateral neck x-ray is easy to perform to assess adenoid and tonsillar size as well as patency of the nasopharyngeal airway.
- Nocturnal audio- and videotaping, as well as abbreviated nap polysomnography, are useful studies if the results are positive but generally have a poor negative predictive value.
- Upper airway endoscopy as well as bronchoscopy may be performed to evaluate anatomic or dynamic causes for airway obstruction (pharyngeal hypotonia, pharyngeal stenosis, laryngotracheomalacia, vocal cord polyps, papilloma).
- Head or neck computed tomography or magnetic resonance imaging (MRI) should be considered for complex craniofacial anomalies. If central apnea is noted, then MRI studies should also evaluate the brainstem to evaluate for an Arnold-Chiari malformation.
- In severe cases of OSAS, a cardiac evaluation, including electrocardiogram, chest x-ray, and echocardiogram, may be indicated.
Differential Diagnosis
- PS or habitual snoring
- Upper airway resistance syndrome: This condition is associated with sleep fragmentation and daytime sleepiness.
- Obesity " �hypoventilation syndrome: a variant of OSAS
- Central apnea and periodic breathing
- Congenital central hypoventilation syndrome
- Other causes of excessive daytime sleepiness include the following:
- Disorganized home environment, emotional stress
- Substance abuse/drug intoxication: psychotropic medications, antihistamines, anticonvulsants, narcotics
- Narcolepsy: Onset typically around adolescence, but cataplexy may occur later and delay the diagnosis.
- Epilepsy: absence spells of unresponsiveness, electroencephalogram changes
- Causes of obstructive apnea include any cause of lymphoidal hypertrophy in the upper airway (allergies, viral/bacterial tonsillitis, neoplasm, epiglottitis, retropharyngeal abscess), chronic phenytoin exposure, and excessive storage material in upper airway submucosa.
- Causes of abnormal laxity of upper airway soft tissues: Down syndrome, acute polyneuropathy (Guillain-Barre syndrome), chronic neuromuscular disease, Prader-Willi syndrome, myasthenia gravis
- Causes of abnormal control/coordination of upper airway musculature: almost any cause of diffuse CNS dysfunction, including cerebral palsy and acquired lesions of the CNS such as stroke and head trauma
- Causes of central apnea: beyond infancy, most commonly due to drugs that suppress ventilatory drive; in premature infants, may be due to nonspecific immaturity of neural ventilatory control mechanism; sepsis, seizures, brainstem compression, brain tumors, Arnold-Chiari type 2 (although increasingly seen with type 1)
- Gastroesophageal reflux may potentiate central apnea and should be investigated.
- Androgen steroids may cause central apnea in adults.
Treatment
Initial Stabilization
- Severe cases may require urgent intervention.
- Severe cases of upper airway obstruction are usually diagnosed during polysomnography or during procedures involving sedation or anesthesia.
- Ensure adequate ventilation and oxygenation, with quick assessment of the cause.
- Temporary relief of the obstruction should be undertaken by an experienced team.
- Transfer to an intensive care unit where the airway can be monitored carefully
- Following relief of airway obstruction, pulmonary and airway edema, as well as copious secretion production, may develop.
- Modalities of care should include placement of a nasopharyngeal airway, noninvasive ventilation with continuous positive airway pressure/bilevel positive airway pressure (CPAP/BiPAP), or placement of an endotracheal tube for mechanical ventilation.
- Risk factors for postoperative complications in children with OSAS include age <3 years, severe OSAS, pulmonary hypertension, obesity, prematurity, failure to thrive, craniofacial or neuromuscular disorders, and/or upper respiratory tract infection.
General Measures
- In most cases, adenotonsillectomy is 1st-line therapy. However, some patients continue to have significant postoperative OSAS that requires further evaluation.
- Noninvasive ventilatory support with CPAP or BiPAP may be helpful.
- Intranasal steroids and leukotriene modifiers have been shown to have a positive effect in children with mild sleep apnea. Duration of use and long-term outcomes remain unclear.
- In complicated cases, when craniofacial malformations are involved, surgical procedures such as tongue reduction, uvulopalatopharyngoplasty, or mandibular or maxillary advancement may be indicated.
- When there is evidence of gastroesophageal reflux, treatment with acid-suppression agents and chalasia precautions are indicated.
- Weight loss may be useful in obese children.
- Laser surgery and dental appliances may be useful in adults with mild OSAS, but there is no experience with these approaches in children.
- In extreme cases, a tracheostomy may be indicated, especially when significant craniofacial abnormalities exist.
Alert
Treatment of gastroesophageal reflux in infants with obstructive apnea may be helpful even in the absence of obvious symptoms of reflux. � �
Ongoing Care
Complications
Complications are due to chronic hypoxemia, hypercarbia, acidosis, as well as impaired sleep and include the following: � �
- Pulmonary hypertension, later cor pulmonale (rare)
- Systemic hypertension has been reported in adults and a few pediatric cases.
- Congestive heart failure; arrhythmias are common in adults with underlying coronary artery disease.
- Neurodevelopmental complications: daytime somnolence, poor school performance, hyperactivity, and social withdrawal
- Poor growth and failure to thrive
- Postanesthesia respiratory failure and death have been reported in children with OSAS.
Follow-up
- Clinical improvement is expected soon after adenotonsillectomy. In children <1 year of age with severe forms of OSAS, underlying craniofacial anomalies, or neurologic disorders, repeat overnight polysomnography is indicated 6 " �8 weeks after surgery.
- Regrowth of adenoid tissue may occur months to years after adenoidectomy. Therefore, if clinical symptoms, such as snoring, difficulty breathing while asleep, or a decline in school performance recur, a reevaluation is indicated.
Additional Reading
- American Academy of Sleep Medicine. International Classification of Sleep Disorders. 2nd ed. Westchester, IL: American Academy of Sleep Medicine; 2005:56 " �60.
- American Sleep Apnea Association. http://www.sleepapnea.org.
- D 'Andrea � �LA. Diagnostic studies in the assessment of pediatric sleep-disordered breathing: techniques and indications. Pediatr Clin North Am. 2004;51(1):169 " �186. � �[View Abstract]
- Marcus � �CL, Brooks � �LJ, Draper � �KA, et al. Diagnosis and management of childhood obstructive sleep apnea syndrome. Pediatrics. 2012;130(3):576 " �584. � �[View Abstract]
- Pandit � �C, Fitzgerald � �DA. Respiratory problems in children with Down syndrome. J Paediatr Child Health. 2011;48(3):E147 " �E152. � �[View Abstract]
- Rosen � �CL. Obstructive sleep apnea syndrome in children: controversies in diagnosis and treatment. Pediatr Clin North Am. 2004;51(1):153 " �167. � �[View Abstract]
- Witmans � �M, Young � �R. Update on pediatric sleep disordered breathing. Pediatr Clin North Am. 2011;58(3):571 " �589. � �[View Abstract]
Codes
ICD09
- 780.57 Unspecified sleep apnea
- 327.23 Obstructive sleep apnea (adult)(pediatric)
- 327.26 Sleep related hypoventilation/hypoxemia in conditions classifiable elsewhere
- 327.27 Central sleep apnea in conditions classified elsewhere
ICD10
- G47.30 Sleep apnea, unspecified
- G47.33 Obstructive sleep apnea (adult) (pediatric)
- G47.36 Sleep related hypoventilation in conditions classd elswhr
- G47.31 Primary central sleep apnea
SNOMED
- 73430006 Sleep apnea (disorder)
- 78275009 Obstructive sleep apnea syndrome (disorder)
- 89911000119102 Sleep related hypoventilation or hypoxemia (disorder)
- 9741000119101 Primary central sleep apnea (disorder)
FAQ
- Q: Can my child still have OSAS after adenotonsillectomy?
- A: Yes. At times, the adenoid tissue can grow back again. In addition, some cases of OSAS are related to a small upper airway that is restricted by anatomic or neurologic conditions. In these cases, adenotonsillectomy will not always resolve OSAS.
- Q: Does OSAS cause neurologic problems?
- A: Several studies suggest neurocognitive deficits in children with OSAS. The most common findings include reduced school performance and ADHD.