Volume 2, Issue 3 , Pages 147-150, September 2007
Severe obstructive sleep apnoea syndrome in a 5-year-old girl
Article Outline
Summary
The obstructive sleep apnoea syndrome (OSAS) is a common cause of morbidity during childhood. Although pediatric OSAS usually stems from adenotonsillar hypertrophy, it is also related to craniofacial anomalies. We report a case of extremely severe OSAS in a 5-year-old girl who has undergone adenoidectomy and partial tonsillectomy 1.5 year previously. A second adenotonsillectomy was elected to resolve abnormal respiration during sleep. Polysomnography was repeated 8 weeks after surgery and revealed an outstanding improvement but not complete resolution. The residual number of apnoeas is attributed to the retrognathia of the patient.
Keywords: Severe obstructive sleep apnoea syndrome, Adenotonsillectomy, Retrognathia
1. Introduction
Obstructive sleep apnoea syndrome (OSAS) in children was first described nearly 30 years ago and it is characterized by persistent partial and/or intermittent complete upper airway obstruction that disrupt normal sleep ventilation and normal sleep patterns [1]. It occurs in children of all ages from neonates to adolescents with an estimated prevalence of 2% equally distributed among the sexes and a peak age range of 2–6 years, which historically was assumed to be related to the relative adenotonsillar hypertrophy at this age range. Although OSAS is related to pharyngeal lymphatic hypertrophy, it is not caused by large tonsils and adenoids only. Thus, it appears to be a dynamic process resulting from a combination of structural and dynamic neuromuscular abnormalities [2]. We present a case of extremely severe obstructive sleep apnoea syndrome in a 5-year-old girl with retrognathia who has undergone adenoidectomy and partial tonsillectomy 18 months previously.
2. Case report
A 5-year-old girl (height 1.17
m, weight 18kg, relative body mass index (BMI): 86.5%) presented to the pediatric clinic because of loud snoring, labored breathing during sleep, excessive daytime sleepiness and restless sleep (Fig. 1). The patient exhibited a knees-to-chest sleep position and mouth breathing accompanied respiration. Daytime symptoms included grogginess and great degree of somnolence even during sedentary activities. The patient's mother complained that her daughter presented learning and temperamental problems and attention deficit. Physical examination revealed normal growth figures, adenoidal face and dark rings round the eyes. The patient presented a crowded Class II division 2 malocclusion with a 7mm overjet and an apparent retrognathic profile in the lateral view (Fig. 1). On the auscultation breath sounds were normal but pulmonic component of the second heart sound was increased. Visual inspection of the pharynx showed kissing tonsils. The patient had undergone partial tonsillectomy and adenoidectomy 18 months ago and she was taking medication for allergic rhinitis. Endoscopic evaluation of nasopharynx by a pediatric otorhinolaryngologist showed adenoid and tonsillar hypertrophy. The girl underwent standard polysomnography which demonstrated severe OSAS (Fig. 2A). Based on the children's history, physical examination, and results of nocturnal polysomnography adenotonsillectomy was scheduled for improvement of sleep disordered breathing. Eight weeks after the operation polysomnography was repeated (Fig. 2B).
Fig. 1.
Photograph of the patient (profile).
Fig. 2.
Polysomnographic parameters preoperatively (A) and postoperatively (B).
No sedation or sleep deprivation was used to induce sleep during both full-night diagnostic polysomnographies (EMBLA S7000, Medcare Flaga, Iceland). The patient was accompanied by her mother throughout the nights she slept in the sleep laboratory. To determine the stages of sleep an electroencephalogram with four channels (C4-A1, C3-A2, O2-A1, O1-A2), an electro-oculogram and an electromyogram of the submentalis muscle were obtained. Arterial blood oxyhemoglobin was recorded with the use of a finger pulse oximeter. Thoracoabdominal excursions were measured qualitatively by respiratory effort sensors placed over the rib cage and abdomen. Snoring was detected with a vibration snore sensor and body posture with a body position sensor. Airflow was monitored using an oral thermistor placed in front of the mouth and a nasal cannula/pressure transducer inserted in the opening of the nostrils and linked to independent channels. All variables were recorded with a digital acquisition system (Somnologica 3.3, Medcare Flaga, Iceland). Sleep stage was scored manually in 30s epochs according to the guidelines outlined by Rechtschaffen and Kales by an experienced technician [3]. Obstructive apnoea was defined as cessation of airflow at the nose and mouth associated with out-of-phase movements of the rib cage and abdomen [1]. Hypopnoea was defined by a 50% or greater decrease in the amplitude of the nasal/oral airflow signal, often followed by hypoxemia or arousal [1]. The number of episodes of apnoeas and hypopnoeas per hour of sleep is referred to as the apnoea-hypopnoea index (AHI).
Prior to each sleep study nasal resistance to airflow was measured during wakefulness without decongestion, first in the upright seated position and then in supine position after lying down for 10min. Active anterior rhinomanometry (PDD-301/r, Piston, Budapest, Hungary) was performed and international recommendations were followed [4]. In brief, the patient wore a closely fitting face mask which didn’t distort the nostrils or the nasal valve and breathed through one only nostril (first the left and afterwards the right) with the mouth closed. The pressure probe was placed at the opening of the contralateral occluded nostril not being tested. Total resistance was then automatically calculated from the two unilateral measurements. Nasal resistance was given at a pressure difference of 150Pa across the nasal passage.
Arterial blood gases (PaO2, PaCO2) were measured by an automatic acid–base analyzer (ABL555, Radiometer, Copenhagen, Denmark) before each sleep study.
Table 1 illustrates the polysomnographic variables, the nasal resistance values and the arterial blood gases analysis of the patient before and after the operation.
Table 1. Polysomnographic variables, nasal resistance values and arterial blood gases before and after adenotonsillectomy
| Preoperative | Postoperative | |
|---|---|---|
| AHI (events/hour) | 117.0 | 3.7 |
| Oxygen desaturation events | 587 | 8 |
| Average oxygen saturation (%) | 87.7 | 97.7 |
| Lowest oxygen saturation (%) | 64 | 92 |
| Total sleep time (min) | 358 | 322 |
| S1+S2 (min) | 67 | 39 |
| S3+S4 (min) | 264 | 259 |
| REM (min) | 27 | 24 |
| Nasal resistance in seated position (cmH2OL−1s) | 4.2 | 2.1 |
| Nasal resistance in supine position (cmH2OL−1s) | 4.5 | 2.2 |
| pO2 (mmHg) | 64 | 97 |
| pCO2 (mmHg) | 42 | 44 |
In order to identify abnormal facial skeletal anatomy that may contribute to airway obstruction a lateral cephalometric roentgenogram was obtained after surgery (Fig. 3). The following angles and dimensions were measured: SNA, angle-measurement from the sella (S) to the nasion (N) to point A (subspinale), 78 degrees; SNB, angle-measurement from the sella (S) A to the nasion (N) to point B (supramentale), 71 degrees; MP-H, distance between the mandibular plane (MP) to the hyoid bone (H), 20mm. This cephalometric analysis confirmed the retrognathia of the patient.
Fig. 3.
Lateral cephalometric radiograph of the patient.
The patient was advised that she needed to be assessed by an orthodontic specialist.
3. Comment
The severity of OSAS (Fig. 2A) affecting a patient of such age is really impressive. Harvey et al. characterized OSAS in children as mild when AHI ranged between one and five events per hour and as moderate/severe when AHI exceeded five events per hour [5].
Adenotonsillar hypertrophy is clearly associated with the pathogenesis of childhood OSAS. However, the severity of OSAS is not proportional to the size of tonsils and adenoids, suggesting that other causes, such as obesity, craniofacial abnormalities and neuromuscular diseases must contribute [2]. Thus, adenotonsillectomy usually reverses pediatric OSAS. Nonetheless, there are children who have persistent apnoea postoperatively, as it was the case with our patient, and a number of others, despite being successfully treated by surgery, have recurrence of apnoea during adolescence [6]. Accordingly, it appears that childhood OSAS is a dynamic process resulting from a combination of structural upper airway narrowing and abnormal upper airway neuromotor tone, along with morbid obesity and craniofacial anomalies. Indeed, obese children are at risk of OSAS, and the degree of OSAS is proportional to the degree of obesity but that was not case with our patient [2]. In contrast, she presented prominent retrognathia which accounts for the residual number of apnoeas postoperatively.
The presented patient has undergone adenoidectomy and partial tonsillectomy 1.5 year previously. Buchinsky et al. [7] on the basis of a sample of 175 children who had undergone adenoidectomy considered significant adenoidal regrowth very rare. Conversely, Greenfeld et al. [8] in a series of 29 infants showed that one quarter of them presented postsurgical adenoid tissue regrowth along with recurrence of symptoms of OSAS and repeated adenoidectomy to resolve the syndrome.
Although in adults with OSAS sleep structure is frequently severely abnormal, children with OSAS have decreased frequency of cortical arousals in response to obstructive apnoeas and may, therefore, preserve their sleep architecture [9]. Our patient had, indeed, long periods of slow wave and rapid eye movement sleep even though obstructive apnoeas and hypopnoea's occurred at a rate of almost two events every minute. Our findings are consistent with previous studies showing no change in sleep architecture following surgical treatment of childhood OSAS [9].
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PII: S1871-4048(07)00029-9
doi:10.1016/j.pedex.2007.04.003
© 2007 Elsevier Ireland Ltd. All rights reserved.
Volume 2, Issue 3 , Pages 147-150, September 2007
