1 DIAGNOSIS OF DYSPNEA IN CHILDREN

Polysomnographic diagnosis is usually necessary for adults, in whom clinical symptoms will be presented when there are more than five apneas per hour, or over 30 times in 7 hours of sleep. In the case of children, apnea-like symptoms may be observed even when there is continuous hypoventilation, but not a typical apnea. We measured the esophageal pressure (Peso) to evaluate the respiratory efforts in children with adenotonsillar hypertrophy and OSA, and discovered that the degree of Peso increased even without apnea when in deep sleep (Fig. 64.3). Therefore, because the measurement of polysomnography (PSG) in a child is difficult, and also because of the specific characteristic of children’s OSA, the diagnostic criterion of PSG is still unclear in children, especially in infants.

Fig 64.3

Monitoring oxygen saturation during sleep seems to be valid. The degree of stenosis in airways can be detected by profile roentgen film (Fig. 64.4), or by direct observation under a thin flexible fiberscope. A video camera is nowadays available in many families. A video record is also useful in observing respiratory situations, and even in cases without obvious desaturation, apnea could be found.

Fig. 64.4 Profile roentgen film of upper airway in children pre- and post-adenotonsillectomy.

In 37 children with adenotonsillar hypertrophy, we ­inv estigated the thickness of adenoid, size of the airway space, and the lowest saturation during sleep. The lowest saturation was correlated to neither adenoid thickness nor airway space (Fig. 64.5). The grade of upper airway stenosis by adenoid or tonsillar hypertrophy on profile roentgen films could not predict the severity of apnea during sleep. For precise diagnosis of respiratory severity caused by ­adenoid–tonsillar hypertrophy, video observation with simultaneous SpaO₂ monitoring is necessary. However, this result did not suggest that roentgenic measurement of stenosis is meaningless. When severe hypertrophy of the tonsil and adenoid is recognized, the possible existence of respiratory impairment should be investigated out of caution. Even in cases with moderate hypertrophy, severe apnea could be a possible accompaniment.

Fig. 64.5 Correlation between adenoid thickness, airway space and lowest saturation. No significant relationship was recognized.

On the other hand, the adenoid and tonsil keep growing after birth until around 8 years old. Although the airway space in the pharynx also becomes larger, the ratio of adenotonsillar thickness to airway space reaches its peak at 4–6 years old. A previous study pointed out that children with OSA showed severe hypertrophy at younger ages (less than 3 years), which differed significantly compared to physiological hypertrophy of normal children (Fig. 64.6). Earlier surgical treatments are necessary for these cases.

Fig. 64.6 Adenoid size was already large enough to induce sleep dyspnea in sleep apnea children less than 3 years old compared with a control group (Shintani et al. 1997).

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2 TREATMENTS

Antibiotics and other anti-inflammatory medicines are sometimes applied, only for acute nasal obstruction. Anti-allergic treatment is also necessary. We experienced a case of apnea cured by controlling a nasal allergy in a 4-year-oldboy with 3–10 second apnea, observed from 2 years old. Nasal allergic signs could be inspected, with the tonsil of 1°, and moderate adenoid. His bedroom was north-facing and relatively damp. After changing the bedroom to the south side with more sunshine, the allergic symptoms improved and the episodes of sleep apnea disappeared.

In cases of repeated upper airway inflammation, tonsil hypertrophy and adenoid face, positive surgery can be considered. Adenoidectomy and tonsillectomy are the first choices for children with OSA. These procedures are relatively simple with a low complication rate, and usually result in a cure. However, the decision to operate should be made not according to the roentgen degree of adenotonsillar hypertrophy, but based on good observation of sleep situations, as well as saturation monitoring. Mandibular distraction osteogenesis is applicable only for children with craniofacial deformities, for which it has better long-term effects. Tracheotomy is also appropriate for some children with severe obesity.

Nasal continuous positive airway pressure (CPAP) is usually the second-line treatment for children who do not respond to adenoidectomy and tonsillectomy, or when adenoidectomy and tonsillectomy are not indicated. In children with heavy obesity, weight reduction should be tried before surgical treatment. Lateral and prone positions are helpful in the relief of apnea. It is important to give instruction on sleep position in addition.

3 RECENT ADVANCEMENTS IN ADENOIDECTOMY AND TONSILLECTOMY

Traditional adenoidectomy is performed by the Le Force method or Beckmann method. These approaches were well applied for decades, and were recognized as useful. However, some complications were observed, such as the difficulty in total resection, injuries to the soft tissues of the Eustachian tube orifice, the posterior wall of the epipharynx and the soft palate, and bleeding during and after the operation. In order to improve these problems, new procedures have been developed.

3.1 MICRODEBRIDER ADENOIDECTOMY

The microdebrider system (Fig. 64.7) was applied in adenoidectomy. The probe of the microdebrider is curved about 30° ahead and is inserted through an oral approach, with access to the adenoid from behind the soft palate. The operation is carried out under direct vision using an endoscope from a nasal approach. Numerous advantages of microdebrider over traditional techniques have been cited, including reduced operation time (by nearly 5 minutes), decreased intraoperative and postoperative bleeding, improved ­visualization and precision for tissue removal, and an overall faster wound healing. The soft tissues around the torus tubalis and posterior nasal aperture could be ablated more easily and safely than in the traditional approach.

Fig. 64.7 Microdebrider system in adenoidectomy.

3.2 SUCTION COAGULATOR ADENOIDECTOMY

The suction coagulation system was another recommended method. In this approach, the soft palate should be elevated first by a catheter. The operation is under direct observation by 70° endoscope. The probe is appropriately angled in the tip (Fig. 64.8), and is inserted into the adenoid from an oral approach. After several seconds of electrification (with output being regulated between 30 and 45 W), the adenoid tissue is then coagulated and sucked out. The probe is pulled out after stopping the electrical charge, and then inserted again for coagulation. Coagulation should be performed from lateral to midline when around the torus tubalis, and from superior to inferior when near the posterior nasal aperture. Thus, a thorough removal of the adenoid can be ensured with little injury to the surrounding tissue. The operation may be completed when the epipharynx can be viewed from the posterior nasal aperture after careful hemostasis.

Fig. 64.8 Suction coagulation system.

3.3 COBLATION TONSILLECTOMY

The conventional management of tonsillectomy was performed. Nowadays, intracapsular tonsillectomy can be performed by a variety of technical means, such as cold dissection, electrocautery, microbipolar and radiofrequency. Coblation tonsillectomy has been recently introduced in clinical practice. Using this method, only the mucosa at the superior pole is to be incised by a surgical knife. Afterwards, dissection of the tonsil can be performed by alternatively applying dissection and coagulation models of the coblation system (Fig. 64.9).

Fig. 64.9 Coblation-assisted tonsillectomy.

4 EFFICACY OF SURGICAL TREATMENT

We use a sleep diary to evaluate the efficacy of the treatment. Figure 64.10 is a typical sleep diary of a boy with moderate OSA, pre- and postoperation. Before surgery, the boy consistently avoided going to bed at night, fighting desperately against sleep. As a consequence, his mother usually had to force him to go to bed at night. He sometimesawoke during the night. His time of awakening was very irregular in the morning. In the day time, he often took long naps. After surgery, many of these problems disappeared and his night sleep became undisturbed.

Fig. 64.10 A typical sleep diary of a boy with a moderate OSA pre- and postoperation.

Figure 64.11 shows the Peso pattern according to sleep stages in 15 cases of adenoid–tonsillar hypertrophy. Six of them underwent tonsillectomy adenoidectomy. Their postoperative Peso levels decreased significantly in comparison with preoperative levels. Figure 64.3 shows typical changes of respiratory dynamics in different sleep stages in a boy with severe OSA.

Fig. 64.11 Esophageal pressure levels before and after adenotonsillectomy.

Long-term surgical effects in the sleep situation were noted (Table 64.3). Before the operation, 90–100% of patients showed difficulty in spontaneous awakening, reporting snoring or impaired breathing. These symptoms decreased to 10–20% after surgery. Improvement of chest deformity could also be observed (see Fig. 64.2).

Fig. 64.2 Chest deformity pre- and post-adenoidectomy. A case of a 5-year-old boy (preoperation) with severe obstructive sleep apnea. The chest deformity improved obviously after 6 months and 12 months of adenotonsillectomy.