Pediatric Obstructive Sleep Apnea




Screening for obstructive sleep apnea (OSA) with in-laboratory polysomnography is recommended for children with sleep disordered breathing. Adenotonsillectomy is the first-line therapy for pediatric OSA, although intranasal steroids and montelukast can be considered for those with mild OSA and continuous positive airway pressure for those with moderate to severe OSA awaiting surgery, poor surgical candidates or persistent OSA. Bony or soft tissue upper airway surgery is reasonable for children failing medical management or those with persistent OSA following adenotonsillectomy. Weight loss and oral appliance therapy are also useful. A multi-modality approach to diagnosis and treatment is preferred.


Key points








  • History and physical examination are not sufficient to diagnose obstructive sleep apnea (OSA) in children. Overnight in-laboratory polysomnography remains the gold standard for OSA diagnosis.



  • Adenotonsillectomy is first-line therapy for pediatric OSA. Medical treatment may be considered for children with mild primary or persistent OSA.



  • Positive airway pressure is a treatment option for children who have persistent OSA after adenotonsillectomy or who are not surgical candidates. Poor tolerability and adherence limit its use.



  • Lateral neck radiographs, awake nasopharyngoscopy, drug-induced sleep endoscopy, cine MRI, and computed tomography are modalities commonly used to assess sites of obstruction in children with OSA.



  • Although evidence is limited, bony or soft tissue upper airway surgery for OSA is reasonable for children who fail medical management, especially for those with lingual tonsil hypertrophy or sleep-state–dependent laryngomalacia.






Introduction


Obstructive sleep apnea (OSA) is a sleep-related breathing disorder characterized by prolonged partial upper airway obstruction (hypopnea) and/or complete upper airway obstruction (apnea). The most recent diagnostic criteria for pediatric OSA require one of the following clinical findings: snoring, labored/obstructed breathing, or daytime consequences (sleepiness, hyperactivity), along with 1 or more polysomnography (PSG) findings. These PSG findings include (1) greater than or equal to 1 obstructive event (obstructive or mixed apnea, or obstructive hypopnea) per hour of sleep, or (2) obstructive hypoventilation manifested by peripheral arterial carbon dioxide (P a co 2 ) greater than 50 mm Hg for greater than 25% of sleep time, coupled with snoring, paradoxic thoracoabdominal movement, or flattening of the nasal airway pressure waveform ( Table 1 ).



Table 1

Rating scale: OSA severity classification in children



















OSA Severity PSG Criteria (AHI; events/h)
No OSA <1
Mild >1 to <5
Moderate >5 to <10
Severe >10

Abbreviation: AHI, apnea-hypopnea index.


Nature of the Problem (Epidemiology)


OSA is documented in 1% to 5% of children. Numerous studies report that OSA is associated with decreased neurocognitive, behavioral, and quality-of-life scores, as well as increased systemic blood pressure, increased pulmonary sequelae, and increased health care use. Moreover, children with OSA are more likely to have hypertension and metabolic syndrome as adults. Both neuropsychological behavior and quality of life tend to normalize after airway obstruction has resolved. Early identification can expedite treatment and prevent or reverse many of these negative health consequences.


Conditions associated with an increased prevalence of pediatric OSA include:




  • Male gender, especially in adolescents



  • Black race



  • Family history of OSA



  • Prematurity



  • Obesity



  • Allergic rhinitis



  • Down syndrome



  • Prader-Willi syndrome



  • Neuromuscular disorders



  • Chiari malformations/myelomeningocele



  • Craniofacial anomalies (eg, achondroplasia and Pierre Robin sequence)





Introduction


Obstructive sleep apnea (OSA) is a sleep-related breathing disorder characterized by prolonged partial upper airway obstruction (hypopnea) and/or complete upper airway obstruction (apnea). The most recent diagnostic criteria for pediatric OSA require one of the following clinical findings: snoring, labored/obstructed breathing, or daytime consequences (sleepiness, hyperactivity), along with 1 or more polysomnography (PSG) findings. These PSG findings include (1) greater than or equal to 1 obstructive event (obstructive or mixed apnea, or obstructive hypopnea) per hour of sleep, or (2) obstructive hypoventilation manifested by peripheral arterial carbon dioxide (P a co 2 ) greater than 50 mm Hg for greater than 25% of sleep time, coupled with snoring, paradoxic thoracoabdominal movement, or flattening of the nasal airway pressure waveform ( Table 1 ).



Table 1

Rating scale: OSA severity classification in children



















OSA Severity PSG Criteria (AHI; events/h)
No OSA <1
Mild >1 to <5
Moderate >5 to <10
Severe >10

Abbreviation: AHI, apnea-hypopnea index.


Nature of the Problem (Epidemiology)


OSA is documented in 1% to 5% of children. Numerous studies report that OSA is associated with decreased neurocognitive, behavioral, and quality-of-life scores, as well as increased systemic blood pressure, increased pulmonary sequelae, and increased health care use. Moreover, children with OSA are more likely to have hypertension and metabolic syndrome as adults. Both neuropsychological behavior and quality of life tend to normalize after airway obstruction has resolved. Early identification can expedite treatment and prevent or reverse many of these negative health consequences.


Conditions associated with an increased prevalence of pediatric OSA include:




  • Male gender, especially in adolescents



  • Black race



  • Family history of OSA



  • Prematurity



  • Obesity



  • Allergic rhinitis



  • Down syndrome



  • Prader-Willi syndrome



  • Neuromuscular disorders



  • Chiari malformations/myelomeningocele



  • Craniofacial anomalies (eg, achondroplasia and Pierre Robin sequence)





Anatomy/pathophysiology


The pathophysiology of OSA is complex and multifactorial with neurologic factors contributing to its development. Diminished electromyogram responsiveness of upper airway dilator muscles to negative pharyngeal pressure, decreased respiratory arousal thresholds, and high loop gain are all key physiologic factors that contribute to OSA. In addition, the upper airway typically becomes compromised secondary to soft tissue and/or bony abnormalities, thus prompting an evaluation of the 5 anatomic sites where obstruction most frequently occurs: the nose and nasopharynx, the posterior oropharynx, the lateral pharyngeal walls, the hypopharynx (base of the tongue), and the supraglottic larynx.


Persistent nasal airway obstruction may result from a deviated nasal septum, enlarged nasal turbinates, or polypoid changes. An assessment for these findings as well as that of a high-arched hard palate is also warranted. Anterior-posterior narrowing and lateral wall collapse of the posterior oropharynx have also been shown to contribute to OSA, as have base-of-tongue obstruction, lingual tonsil hypertrophy, and supraglottic collapse.


Diagnosis


Overnight in-laboratory polysomnography


Overnight, in-laboratory PSG is the gold standard for diagnosing OSA in children. A single overnight PSG has:




  • Good test-retest reliability and consistency



  • No significant first-night effect



  • Specific OSA severity criteria, which are shown in Table 1



  • A lack of consensus regarding the exact cutoff levels for OSA severity



  • A lack of consensus regarding when to use pediatric versus adult criteria for the diagnosis of OSA in adolescents



Overnight oximetry


In a cross-sectional study of 349 children (median age of 4.5 years), abnormal nocturnal pulse oximetry had a 97% positive predictive value (PPV) but a 47% negative predictive value (NPV) for detecting OSA compared with PSG. Therefore, a positive oximetry result is useful to establish a diagnosis of OSA, whereas a negative result cannot be used to rule out OSA.


Nap and ambulatory polysomnography


Nap PSGs are abbreviated studies that are typically performed during the daytime. For diagnosing pediatric OSA, they are reported to have a:




  • Sensitivity of 69% to 74%



  • Specificity of 60% to 100%



  • PPV of 77% to 100%



  • NPV of 17% to 70% to 17%



Nap PSG is not recommended for the definitive diagnosis of OSA by either the American Academy of Sleep Medicine or the American Academy of Pediatrics, because it can underestimate the presence or severity of OSA compared with in-laboratory nocturnal PSG.


Unattended full-montage home PSG has been reported to be adequate and feasible in school-aged children. These studies tend to underestimate the incidence of obstructive hypopnea events as well as overall OSA severity. Studies using a limited number of recording channels, and without electroencephalogram recording, have been found to have conflicting results.


Other noninvasive diagnostic methods


A study of the use of home video recording for screening OSA in children showed that a 30-minute video had a sensitivity of 94% and a specificity of 68%. Several sleep questionnaires are also available to screen for OSA; however, validation studies comparing these with PSG data are scarce. An in-depth review of available questionnaires was not able to identify any one tool with a sufficient combination of sensitivity and specificity. Therefore, these tests are not considered standard of care in the evaluation of pediatric OSA.




Evaluation


History and Physical Examination


Evaluation of children with OSA should include the common history and physical examination elements listed in Box 1 . This evaluation often also includes awake flexible nasopharyngoscopy and laryngoscopy in the office to assess for nasal disorder, adenoidal hypertrophy, lingual tonsil hypertrophy, laryngomalacia, or other obstructing airway lesions. Although this evaluation is important, history and physical examination alone are rarely sufficient to diagnose OSA. Prolonged wait times and poor availability of pediatric sleep laboratories for overnight PSG have prompted a search for alternative diagnostic screening tools. These tools typically include a combination of history and physical examination findings, but none have been found to be sufficient to predict OSA.



Box 1





  • History



  • Frequent snoring (≥3 nights/wk)



  • Labored breathing during sleep



  • Gasps/snorting noises/observed episodes of apnea



  • Sleep enuresis (especially secondary enuresis)



  • Sleeping in a seated position or with the neck hyperextended



  • Cyanosis



  • Headaches on awakening



  • Daytime sleepiness



  • Attention-deficit/hyperactivity disorder



  • Learning problems




  • Physical examination



  • Underweight or overweight



  • Tonsillar hypertrophy



  • Adenoidal facies



  • Micrognathia/retrognathia



  • High-arched palate



  • Failure to thrive



  • Hypertension



Symptom criteria and examination findings


Imaging


Modalities used to evaluate children with OSA include:




  • Lateral neck films to assess adenoidal size, nasal abnormalities, and lingual tonsil hypertrophy



  • Cephalometric imaging, which may correlate with endoscopic findings



  • Cine MRI (described later in this article)



  • Facial computed tomography (CT) for children with craniofacial disorders and bony abnormalities of the facial skeleton



  • Videofluoroscopy and dynamic cine CT scans are less commonly used because of concerns regarding radiation exposure



Drug-induced Sleep Endoscopy





  • Drug-induced Sleep Endoscopy (DISE)



  • Is used to identify sites of upper airway obstruction in adults and children with persistent OSA ( Table 2 )



    Table 2

    Summary of studies on DISE to identify site of obstruction for children with persistent OSA following adenotonsillectomy
























































































    Author N Mean Age (y) Persistent OSA (%) ID Site of Obstruction (%) Comments
    Myatt 8 NR NR 100 Also recommend rigid bronchoscopy
    Lin 26 11 100 NR 61% postoperative AHI <5
    Chan, 2012 22 7 NR NR For laryngomalacia Tx = supraglottoplasty
    Digoy 36 NR 100 100 For sleep state–dependent laryngomalacia
    Durr 13 8 69 100 Multilevel disease was common
    Fung 23 7 NR 100 DS with more lingual and pharyngeal collapse
    Truong 39 NR 100 NR Effective ID collapse in persistent and primary OSA
    Fishman 28 8 100 NR ID more obstruction than awake endoscopy
    Ulualp, & Szmuk, 2013 82 6 100 NR Most with multilevel obstruction
    Chan, 2014 23 2 NR NR Evaluating 4-point grading scale
    Wootten & Shott, 2010 11 8 100 NR 92% had subjective improvement

    Abbreviations: DS, Down syndrome; ID, identify; N, total number of patients; NR, not reported; Tx, treatment.

    Adapted from Manickam PV, Shott SR, Boss EF, et al. Systematic review of site of obstruction identification and non-CPAP treatment options for children with persistent pediatric obstructive sleep apnea. Laryngoscope 2015;126(2):495; with permission.



  • Was developed because sites of obstruction detected in awake patients do not always correlate with the sites of obstruction observed during sleep



  • Is useful to detect sleep state–dependent (late-onset) laryngomalacia



The choice of anesthetic agent used during the evaluation is important given that these agents can alter airway dynamics and potentially influence examination findings.




  • A recent systematic review on sites of obstruction reported that:



  • The most common location for single-site obstruction was the oropharyngeal lateral walls



  • The most common locations for multiple-site obstruction were the oropharyngeal lateral walls and the velum



An evaluation of children before adenotonsillectomy showed that these children had complete airway obstruction; even those with only grade I and grade II tonsils. Literature regarding how these modalities correlate with outcomes is scarce. Several scoring systems have been described, but a uniform grading system for DISE findings has yet to be agreed on.


Cine MRI





  • Cine MRI ( Table 3 )



  • Provides a high-resolution dynamic examination of the airway to identify sites of upper airway obstruction



  • Has no radiation exposure



  • Is particularly helpful when evaluating children with multiple sites of obstruction and to simultaneously identify primary and secondary sites of obstruction



  • Is performed with mild sedation using medications that most closely mimic natural sleep



  • Has been reported to identify the site of obstruction in 93% of cases



Table 3

Summary of studies on cine MRI to identify site of obstruction for children with persistent OSA following adenotonsillectomy
































Author N Mean Age (y) Persistent OSA (%) ID Site of Obstruction (%) Comments
Shott & Donnelly, 2004 15 10 100 93
Connelly et al 27 10 100 NR ID obstructive sites in children with DS
Fricke et al 89 10 58 33 LTH only

Abbreviation: LTH, lingual tonsillar hypertrophy.

Adapted from Manickam PV, Shott SR, Boss EF, et al. Systematic review of site of obstruction identification and non-CPAP treatment options for children with persistent pediatric obstructive sleep apnea. Laryngoscope 2015;126(2):493; with permission.


Management of pediatric obstructive sleep apnea


Weight loss


In adults, a recent systematic review reported that both surgical and nonsurgical weight loss significantly improved OSA by reducing both the body mass index (BMI) and the apnea-hypopnea index (AHI). Although the literature regarding weight loss for OSA in children is limited, research suggests that weight loss should be recommended in obese children with OSA. Bariatric surgery is reserved for children failing medical weight loss, particularly those with significant comorbid medical conditions. The American Society for Metabolic and Bariatric Surgery recommends that this approach be considered only for carefully selected, extremely obese adolescents meeting certain surgical criteria. A small study of 10 children reported significant improvement in OSA severity after bariatric surgery; BMI decreased from a mean of 60.8 kg/m 2 (standard deviation [SD] ± 11.07 kg/m 2 ) to 41.6 kg/m 2 (SD ± 9.5 kg/m 2 ), whereas AHI decreased from 9.1 to 0.65 events per hour.


Medication


Montelukast and intranasal corticosteroids are both used to treat mild to moderate OSA in children. In a prospective double-blind randomized trial of 46 children, a 12-week treatment with daily oral montelukast reduced OSA severity by a few events per hour and reduced adenoidal hypertrophy. In a large retrospective cohort study of more than 700 children with mild OSA who were treated with a combination of intranasal corticosteroids and oral montelukast for 12 weeks, the success rate of therapy was 81%. Follow-up PSG in 445 children revealed normalization of sleep parameters in 62% of children. The remaining 17% failed to show improvement or had worsening of their OSA. The investigators reported that nonresponders were more likely to be more than 7 years old and obese (BMI z-score >1.65). Long-term studies to guide the duration of therapy and predict response are lacking.


Positive airway pressure


Positive airway pressure (PAP) is positive pressure delivered via a nasal or full-face mask connected to a mechanical device that stents the airway by delivering intraluminal pressure that is higher than atmospheric pressure. PAP has been shown to effectively reduce the AHI and improve both subjective and objective sleep outcomes. Continuous PAP (CPAP) is typically titrated in a sleep laboratory in order to determine the optimum pressure requirement to eliminate obstructive events by each patient. A large series reported that the respiratory disturbance index (RDI) was reduced and oxygen saturation was increased in children aged 2 to 16 years using CPAP for OSA; however, at least 30% stopped the use of CPAP within 6 months. Many children discontinue the use of CPAP because of the discomfort of the mask or the noise created by the device. In addition, there are concerns that long-term use of the PAP mask can lead to skin defects or potentially facial flattening.


Adherence to PAP therapy can be objectively measured with compliance downloads that are available on all commercially available machines in the United States.


Oral appliances, orthodontics, and rapid maxillary expansion


Malocclusion and maxillofacial abnormalities have been associated with pediatric OSA. Oral appliances are typically recommended for the treatment of mild to moderate OSA in children who have permanent dentition in place. The use of oral appliances can also improve the tolerability of CPAP. As with masks used for CPAP, oral appliances can result in craniofacial abnormalities caused by the prolonged mechanical forces exerted on the maxilla and mandible.


Rapid maxillary expansion (RME) has also been advocated to improve nasal patency while improving OSA severity and sleep quality. These devices mechanically widen the palate and the nasal fossa. A study of a 60 children managed with RME reported a decrease in the mean AHI from 16.3 ± 2.5 to 8.3 ± 2.3 events/h at 4 weeks and 0.8 ± 1.3 events/h at 4 months posttreatment; the greatest benefit was achieved for children with mild to moderate OSA (AHI ≤15). Other studies have shown incomplete response to RME.


Evidence regarding orthodontic treatment of OSA in children is inconclusive. Therefore, conclusions regarding the treatment effect across multiple studies cannot be made.


Surgical management


Several surgical management options are available for children with OSA. Although adenotonsillectomy is primary therapy, several options exist for children who have persistent OSA after adenotonsillectomy ( Fig. 1 ).


Mar 28, 2017 | Posted by in OTOLARYNGOLOGY | Comments Off on Pediatric Obstructive Sleep Apnea
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