Adenotonsillectomy

Most children with OSA will be treated with adenotonsillectomy (AT) as the first-line therapy.

Isolated adenoidectomy is commonly performed in children 5 years of age and younger.9,10 Tonsillectomy involves the complete removal of the palatine tonsils with dissection. The capsule of the tonsil is also removed with the tonsil and muscle disrupted. A frequently used method in pediatrics is electrocautery dissection, which involves the application of electric energy-generating temperatures of 400–600°C directly to the tonsillar tissue, separating the muscle and simultaneously coagulating the blood vessels. Coblation tonsillectomy is performed using a device that delivers a bipolar frequency current through a conductive saline medium, converting it to an ionized plasma layer with effective energy to break molecular bonds between the tissues. The heat produced is limited to 40–70°C. It is associated with less postoperative pain and shorter recovery time.¹¹ Other surgical techniques involve the use of harmonic scalpel (ultrasonic dissector), coagulator,^12,13 and bipolar scissors.¹³

Recently, tonsillotomy (TT) or partial removal of the hypertrophied tonsils, has gained favor over total tonsillectomy. In tonsillotomy, the capsule is not breached and the muscle is protected. Different surgical techniques used include use of a CO₂ laser,14,15 intracapsular microdebrider,¹⁶ coblation,¹⁷ electrocautery,¹⁸ or radiofrequency.^19,20 Tonsillotomy with or without adenoidectomy results in resolution of symptoms of OSA with less postoperative pain, faster recovery, and lower rate of secondary postoperative hemorrhage compared to total tonsillectomy.^14–18 One study of children with a mean age of 4 years showed improvement of apnea-hypopnea index (AHI) to normal and increased oxygen saturation 3–12 months following CO₂ laser tonsillotomy in combination with adenoidectomy.²¹ Following microdebrider technique there was complete resolution of OSA by polysomnography in 50% of patients.²² The major disadvantage of tonsillotomy is regrowth of tonsils with recurrence of snoring and obstructive symptoms. The rate of regrowth following tonsillotomy varies from 4% to 16%.^19,20,23 Celenk et al. reported that the majority of the children affected were younger than 4 years and had acute tonsillitis prior to tonsillar regrowth.¹⁹ However, in a 10-year post surgery follow-up study of children who underwent tonsillotomy by electrocautery versus conventional tonsillectomy, no difference in tonsillar regrowth was noted.¹⁸ Thus it is possible that factors affecting regrowth following tonsillotomy may include young age, inflammation, and surgical technique (radiofrequency).

AT results in improvements not only in symptoms, but also in sleep quality24,25 and homeostasis.²⁶ There are also improvements in daytime behavior,^27,28 academic performance.²⁹ neurocognitive functioning^27,30 and quality of life.^25,27,28 These improvements can persist up to 1 year after AT in preschool children with OSA.⁵ AT can also lead to weight gain with associated increase in growth markers (IGF-1 and IGFBP-3).^31–33 Children may have improved right ventricular function,³⁴ resolution of tachycardia and decreased pulse rate variability,³⁵ and significant decreases in diastolic blood pressure to near normal values.³⁶

Unfortunately, up to 27% of children will have persistence of OSAS following AT.³⁷ Factors that contribute to persistent OSA include obesity,^37–40 asthma,³⁷ Down syndrome,⁴¹ cerebral palsy,³⁹ gastroesophageal reflux disease,⁴² and high preoperative apnea–hypopnea index (AHI).^37,38,43 In this group of patients, postoperative polysomnography will help identify the response to AT and additional treatments needed for residual OSA.⁴⁴

Patients with mild OSAS may do well postoperatively from a respiratory standpoint, irrespective of the use of opiates for analgesia.⁴⁵ Complications following AT include postoperative bleeding, infection, upper airway obstruction secondary to airway edema, pulmonary edema, oxygen desaturation or respiratory failure requiring admission to the intensive care unit.^46,47 Pulmonary complication rates range between 5% and 38%.^48–51 Risk factors for pulmonary complications following AT are listed in Box 32-1.^48–52 These are the children who will benefit from overnight hospitalization for observation and monitoring following AT. One study reported an intensive care admission rate of 2.4% in a group of children with known risk factors for respiratory complications. Of these patients, about 1% required unanticipated transfer to the PICU.⁴⁷

Skeletal Advancement Procedures in Children with Craniofacial Abnormalities

Infants and children with craniofacial abnormalities and severe OSA can benefit from skeletal advancement procedures to prevent tracheostomy or to facilitate decannulation. Two procedures performed in children include mandibular distraction osteogenesis and rapid maxillary expansion.

Positive Pressure Therapy

See also Chapter 35 by Sivan and Gut.

Positive airway pressure therapy (PAP), i.e., continuous positive airway pressure (CPAP) or bi-level positive airway pressure (BPAP), can be a highly effective means of treatment for OSAS. PAP is the treatment of choice for patients who do not improve sufficiently following AT or when surgery is not possible or indicated. It is often used for patients with OSA related to obesity, Down syndrome, craniofacial disorders, and neuromuscular disorders such as cerebral palsy. Positive pressure therapy has been shown to be effective in children for the treatment of OSA. It is less invasive than surgery and offers temporary treatment for conditions such as postoperative airway obstruction.⁵³

AT remains the first line of treatment for OSA in most situations; however, residual symptoms may persist in up to 20% of children⁴³ with some studies reporting an even higher failure rate.^38,67 When a PSG reveals an AHI of more than 5 events per hour following AT, then PAP should be considered.⁶⁸ A titration study should be performed in the sleep laboratory with a technician in attendance. At this time, insufficient evidence and lack of FDA approval preclude the recommendation of auto-titrating devices in children. Practice guidelines for detailed, step-by-step titration strategies for positive pressure therapy in adults and children have been proposed in the Clinical Guidelines for the Manual Titration of Positive Airway Pressure in Patients with OSA sponsored by the American Academy of Sleep Medicine.⁶⁹ Four separate algorithms for CPAP and BPAP titrations for patients less than and greater than 12 years of age, respectively, are presented. These can be adapted for use in the sleep laboratory to guide technicians in decision making throughout the night. The goal for an optimal titration is to reduce the respiratory disturbance index to less than 5 events per hour with supine REM sleep recorded at the selected pressure. Evidence-based guidelines for the selection of continuous versus bi-level positive pressure therapy are lacking. Studies have not found an advantage in adherence or outcome in either adults or children.⁷⁰ The practice of the authors is to use bi-level therapy when high pressures (>14 CWP) are needed to relieve airway obstruction or the patient complains of intolerably high pressure during the study. Bi-level therapy is also utilized for OSA in the face of hypoventilation (P_ETCO₂ >50 mmHg), with coexisting muscle weakness, or with extreme obesity. A back-up rate can be provided with prolonged central apneas. Supplemental oxygen may be required with coexisting pulmonary disease when hypoxemia persists despite control of obstructive events and respiratory-related arousals.

The most important consideration in selecting the PAP interface is patient comfort. Generally, nasal masks are preferred over nasal–oral (full-face) masks in the pediatric population as there is less chance for gaseous distension of the stomach or aspiration if emesis occurs. However, some patients have marked nasal occlusion and a nasal–oral mask is the only route available. Some patients will prefer nasal prongs or ‘pillows,’ especially if they have a strong preference to sleep on their side. The headgear should be snug but not tight. Some redness of the skin in the morning that fades during the day is acceptable, but persistent tenderness or erythema over the nasal bridge is not, as it can lead to painful skin breakdown and thus must be addressed quickly. Covering the site with a hydrocolloid gel dressing is helpful as an interim solution. Masks should fit such that air leak, or the mask itself, does not irritate the eyes.

At each follow-up, potential problems with the interface and other complications associated with the therapy that might interfere with usage are discussed. Complications such as nasal dryness or congestion, epistaxis, eye irritation, skin compromise, gastric distension, emesis in those patients using full-face mask, and mouth breathing with excessive leak in those using nasal mask or prongs are addressed. Nasal steroids and/or warm humidification can help relieve nasal obstruction and improve adherence. Skin complications can be avoided by regular follow-up to assess mask fit and by changing the interface from time to time. Monitoring of facial growth for the development of mid-face hypoplasia related to nightly pressure from the mask interface has been suggested. At this time, in the United States, FDA-approved interfaces for PAP are only available for children age 7 years and older. Some countries have interfaces available for younger children and infants; however, in the USA these devices are used ‘off label’ at the discretion of the prescribing physician and this information should be shared with parents.

When the decision has been made to institute PAP, one of the most important considerations is preparing the child and family for the use of the therapy on a nightly basis. This approach varies with the age and developmental level of the child. The patient and family should be educated about the titration study, the PAP equipment, and the interface, with verbal and written material in advance.⁷⁰ The medical care team must convey a high level of confidence and trust in the parents’ abilities to master the techniques, and more importantly in their ability to work with their child to use the therapy each night. A parental approach that is consistent, committed, and calm should be emphasized. Patients ideally should be fitted with and given an appropriate interface to wear at home at bedtime for practice and desensitization prior to the study. The interface is worn without being attached to the tubing or positive pressure device so there is no flow or pressure. Parents are encouraged to build this into the child’s usual bedtime routine. If the child is to sleep with the practice mask in place, care must be taken to avoid re-breathing by modifying the mask. An age-appropriate reward system (behavior modification) for wearing the interface is often helpful. Child developmental psychologists with expertise in sleep medicine can guide desensitization in difficult cases. In this way, when the patient arrives for the titration study, the focus can be on identifying the correct settings to achieve adequate gas exchange, normal respiratory pattern, and optimal sleep quality. Similar to adults, split studies are possible with typically developing adolescents; the educational session need not be extensive and can be accomplished with pre-study explanation or video.⁷¹

Pressure titration is affected by the age of the child. Younger children generally do not tolerate pressures at the higher range (>15 CWP) and, in general, OSA can be managed with pressures lower than this. Children are also poorly tolerant of painful procedures, thus non-invasive monitoring of gas exchange is used rather than blood gases. The use of end-tidal CO₂ monitoring during the titration study can provide an accurate measure of ventilation and avoid the use of arterial or capillary blood gas collection. To this effect, a small end-tidal CO₂ catheter is placed at one of the nares under the mask interface. Readings are deemed accurate when a plateau is present in the waveform. If the plateau is lost the catheter can be repositioned at the first wakefulness opportunity. Because the catheter is small, the interface seal is not disrupted. However, subjects who use nasal prongs or pillows as their preferred interface cannot be monitored in this way and gas exchange must be inferred from SpO₂ measurements or transcutaneous CO₂ measurements. Blood gas sampling is not needed for sleep lab titration of PAP for OSA in children, but is useful for patients with severe, obesity-related OSA with hypoventilation who have been hospitalized for initiation of treatment.

Some children with OSA are very young or have developmental disabilities and thus cannot communicate with the polysomnographic technician or respiratory therapist to express discomfort with the interface or the pressures. Technicians and therapists who are skilled in working with children of all ages and abilities are required for a successful PAP titration in the pediatric sleep lab. Understanding that a patient’s discomfort can have different origins and working carefully with the child and parent to minimize fear and maximize comfort require patience and skills that develop over years of experience. Reducing pressures, selecting a different interface, and changing the patient’s position should all be tried. However, there are occasions, despite advance preparation, when the child’s inability to cooperate prevents completion of an adequate titration. If OSA is not severe, a further period of time acclimating in the home setting can be tried. The PAP interface and device can be used for a short time each night in the home on the best-tolerated pressure levels identified during the study with a gradual increase in the time used each night. When use has increased to more than 4–6 hours per night the laboratory titration can be repeated to identify optimal pressures. If the clinical situation dictates a more rapid initiation of therapy, then hospitalization would be indicated.

Expert opinion recommends periodic re-titration studies for children treated with PAP. This is logically based on the notion that children are growing and developing and that these changes may interact with upper airway anatomy and neuromuscular function such that positive pressure needs may increase or decrease. Thus, younger patients would need more frequent re-evaluations than older children. Repeat titration should be performed after surgeries of the upper airway, significant change in weight, and certainly if new symptoms indicating poor control of OSA or tolerance of PAP arise. Very limited data are available to guide the frequency of routine repeat titration studies in children.