Referring Physicians >> Newsletters >> Advanced Evaluation and Management of Pediatric Obstructive Sleep Apnea
Advanced Evaluation and Management of Pediatric Obstructive Sleep Apnea — Beyond Tonsillectomy and Adenoidectomy
Obstructive sleep-disordered breathing is a spectrum of disorders ranging from the relatively minor primary snoring and upper airway resistance syndrome to the more severe obstructive hypoventilation and obstructive sleep apnea (OSA). These disorders are associated with varying degrees of snoring, increased respiratory effort, sleep disruption, and alterations of gas exchange. Nighttime signs and symptoms of OSA include snoring/noisy breathing with sleep, more effortful breathing, and witnessed apneas. Restless sleep, frequent awakening, night sweating, and nocturnal enuresis (bedwetting) are also associated with OSA. These issues are fairly common in children: The estimated prevalence of any degree of sleep-disordered breathing is 4-11% and the prevalence of OSA is 1-4%.
Behavioral and cognitive consequences of OSA
As a result of poor sleep quality, there can also be adverse daytime sequelae. Though excessive daytime sleepiness is a common symptom of OSA in adults, it is present in only approximately 15% of children with OSA. Interestingly, daytime sleepiness and fatigue may manifest in young children as irritability, nervousness, aggressiveness, hyperactivity, diminished attention, and poor school performance. Indeed, there is significant overlap of OSA symptoms with the major features of attention deficit hyperactivity disorder (ADHD), and there is growing evidence of an association between sleep-disordered breathing and ADHD. In addition, there is ongoing research that suggests sleep-disordered breathing can impact cognitive development, memory, and academic performance.
Cardiovascular and metabolic consequences of OSA
Obstructive sleep apnea can also cause adverse cardiovascular and metabolic sequelae in children. Specifically, children with sleep-disordered breathing are at risk of developing elevated blood pressure, elevated pulmonary arterial pressure, elements of cardiac remodeling, and endothelial dysfunction as compared to healthy children. The mechanisms for this interaction are still under investigation, but are likely related to chemoreflex and baroreflex activation of the sympathetic nervous system, oxidative stress, and potentially activation of the renin-angiotensin-aldosterone system. From a metabolic standpoint, there is evidence that OSA can contribute to dyslipidemia and insulin resistance (though much of this research has thus far been done in adults, many with obesity).
Etiology of OSA
The etiology of obstructive sleep apnea is multifactorial. Anatomic impingement of the airway is likely the most significant causal factor, though other contributing factors include decreased neuromuscular tone, genetic predisposition, metabolic factors, and obesity. Hypertrophy of the tonsils and adenoid tissue is extremely common in pediatric sleep-disordered breathing, particularly in children between 3 and 8 years of age. Other causes would include craniofacial abnormalities involving mandibular hypoplasia (such as Pierre Robin sequence and Treacher Collins syndrome) and mid-face hypoplasia (such as Crouzon syndrome, Apert syndrome, and achondroplasia). Diminished upper airway tone is a compounding factor, and is often seen in patients with Arnold-Chiari malformation, cerebral palsy and other neuromuscular disorders. Children with Down syndrome are at particular risk of OSA given the combination of maxillary hypoplasia, relative macroglossia, and overall hypotonia.
Evaluation of OSA
From an anatomic standpoint, tonsil and adenoid hypertrophy is the most common cause of sleep-disordered breathing in children. Thus, adenotonsillectomy is a reasonable first-line therapy in pediatric OSA. Historically, it was thought that adenotonsillectomy cured OSA in children in all cases. However, research done over the last 10-20 years indicates that the success rate — as indicated by sleep study parameters — is actually only 80-85% for all children. Further, when studying at-risk sub-groups — for example, children with Down syndrome, obesity, craniofacial abnormalities, etc — the success rate of adenotonsillectomy for the treatment of OSA is even lower. Thus, a multi-faceted, comprehensive approach to these more complex patients is often needed to provide adequate treatment.
Polysomnogram (sleep study) remains the gold standard to evaluate for residual sleep-disordered breathing after adenotonsillectomy. Sleep studies can provide objective data regarding the degree of sleep-disordered breathing, however, it does not identify at what level the airway obstruction is occurring. Obstruction may occur anywhere from the tip of the nose to the trachea. Identification of the site(s) of upper airway obstruction is crucial in determining appropriate medical and surgical options that can be offered. A basic examination of the upper airway in the ENT office is a good starting point; this involves evaluation of the child’s overall appearance, craniofacial features, nasal passages, oral cavity, and neck. A flexible endoscopic exam can also be performed in the clinic, and this provides visualization of the nasal passages, nasopharynx, oropharynx, hypopharynx, and larynx.
Physical exam in the clinic is useful, but there can be limitations in the amount of information obtained due to difficulties with cooperation in young children. In addition, there can be state-specific changes in airway dimensions that are difficult to appreciate in an awake patient. Specifically, during sleep, there is relaxation of upper airway tone that can allow for collapse of soft tissues into the air passage. While awake, however, the airway soft tissue tone is heightened. Thus, it is often helpful to obtain a state-specific examination. In our department, we’ve been utilizing drug-induced sleep endoscopy (DISE) for this exact purpose. This is a flexible fiberoptic nasopharyngoscopy exam performed with the patient under a very light anesthesia meant to simulate sleep. DISE is a dynamic evaluation that assesses the entire airway to determine the site(s) of airway obstruction. Though this is a relatively new technique, it shows promise as a tool to provide targeted airway surgery.
Treatment of pediatric obstructive sleep apnea after adenotonsillectomy is dependent upon the severity of physiologic disruption as well as the causative site (or sites). We work in close association with our pediatric sleep medicine colleagues to provide a comprehensive approach to patient management decisions. While use of CPAP remains a safe and often successful treatment option, patient compliance — especially in young children — can limit its usefulness. And even if CPAP is utilized successfully, it may be needed to be used for years. Often, patients and families are interested in potential surgical options that would make it so CPAP was not needed. In our series of approximately 30 patients undergoing drug-induced sleep endoscopy over the past 4 years, identified sites of obstruction have frequently included lingual tonsil hypertrophy, sleep-variant laryngomalacia, and nasal airway obstruction. In these cases, lingual tonsillectomy, supraglottoplasty, tongue base reduction, septoplasty, and inferior turbinate reduction surgery have been utilized with some success.
The potential for airway obstruction in the peri-operative period should be anticipated, particularly during induction and emergence from anesthesia. Thus, a detailed airway management plan is developed in conjunction with the anesthesia team, with multiple management options available that can be escalated quickly if needed. Most often, patients undergoing these more advanced sleep apnea surgeries can be extubated after surgery. However, they are monitored closely in the pediatric ICU setting. Patients usually undergo post-operative sleep studies 2-3 months after surgery. In our series, some have had complete resolution of severe apnea; others have shown persistent apnea but improved indices of obstruction.
For more information
The UW Health Pediatric ENT-Otolaryngology team specializes in the care of children with disorders of the head and neck. For questions about a patient or a referral, please contact one of our clinics.