Victor Abdullah

Epidemiology of obstructive sleep apnoea syndrome in Chinese children: a two-phase community study

Objective To determine the prevalence and risk factors of obstructive sleep apnoea syndrome (OSAS) in Chinese children using a two-phase community-based study design. Methods Children from 13 primary schools were randomly recruited. A validated OSAS screening questionnaire was completed by their parents. Children at high risk of OSAS and a randomly chosen low-risk group were invited to undergo overnight polysomnographic study and clinical examination. The the sex-specific prevalence rate was measured using different cutoffs (obstructive apnoea hypopnoea index ≥1, ≥1.5, ≥3 and ≥5 and obstructive apnoea index ≥5) and risk factors associated with OSAS were evaluated with logistic regression. Results 6447 completed questionnaires were returned (out of 9172 questionnaires; 70.3%). 586 children (9.1%; 405 boys and 181 girls) children belonged to the high-risk group. A total of 619 (410 and 209 from the high and low-risk group, respectively) subjects underwent overnight polysomnagraphy. Depending on the cutoffs, the prevalence rate of childhood OSAS varied from 4.8% to 40.3%. Using the International Criteria of Sleep Disorders version II, the OSAS prevalence for boys and girls was 5.8% and 3.8%, respectively. Male gender, body mass index z-score and increased adenoid and tonsil size were independently associated with OSAS. Conclusions The prevalence rate of OSAS in children was contingent on the cutoff used. The inclusion of symptoms as a part of the diagnostic criteria greatly reduced the prevalence. A further prospective and outcome study is needed to define a clinically significant diagnostic cutoff for childhood OSAS.

Natural history and predictors for progression of mild childhood obstructive sleep apnoea

Aims: The natural history of mild childhood obstructive sleep apnoea (OSA) was examined and factors associated with disease progression were identified. Methods: Subjects were recruited from an epidemiological study which examined the prevalence of OSA in Chinese children aged 6–13 years. The first 56 consecutive children identified with mild OSA (apnoea-hypopnoea index 1–5) were invited for a repeat assessment 2 years after the diagnosis. Results: 45 children participated in the follow-up study, in 13 of whom (29%) the OSA was found to have worsened. Compared with those in whom OSA had not worsened, the worsened OSA group had a greater increase in waist circumference, a higher prevalence of large tonsils (occupying ⩾50% of the airway) at both baseline and follow-up, and a higher prevalence of habitual snoring at both baseline and follow-up. The presence of large tonsils had a positive predictive value of 53% and a negative predictive value of 83% for worsening OSA over a 2-year period. Multivariate linear regression analysis showed that the change in obstructive apnoea-hypopnoea index was associated with age at baseline (β (SE) = −0.92 (0.34), p = 0.009), gender (male = 1; female = 0) (β (SE) = 4.69 (1.29), p<0.001), presence of large tonsils at baseline (β (SE) = 4.36 (1.24), p = 0.001), change in waist circumference (β (SE) = 0.30 (0.09), p = 0.002) and persistently large tonsils (β (SE) = 5.69 (1.36), p<0.001) over the 2-year period. Conclusions: Mild OSA in the majority of children does not resolve spontaneously. Subjects with tonsillar hypertrophy, especially boys, should be closely monitored to allow early detection of worsening OSA. Weight control should be stressed in the management of childhood OSA.

Cardiac remodelling and dysfunction in children with obstructive sleep apnoea: a community based study

Background: Childhood obstructive sleep apnoea (OSA) is suggested to be associated with cardiac structural abnormalities and dysfunction but existing evidence is limited and the treatment effect on echocardiographic outcome remains controversial. Objective: To examine the presence of subclinical cardiac abnormalities in childhood OSA and the effects of treatment on cardiac changes. Methods: Polysomnography (PSG) and echocardiographic examinations were performed in 101 children aged between 6 and 13 years who were invited from a community based questionnaire survey. They were classified into a reference group (apnoea–hypopnoea index (AHI) <1, n = 35), mild OSA group (AHI 1–5, n = 39) and moderate to severe group (AHI >5, n = 27) based on the PSG results. Treatments, including adenotonsillectomy or nasal steroids, were offered to the mild and moderate to severe OSA groups. Results: The moderate to severe OSA group had greater right ventricular (RV) systolic volume index (RVSVI), lower RV ejection fraction (RVEF) and higher RV myocardial performance index (RVMPI) than the reference group. They also had more significant left ventricular (LV) diastolic dysfunction and remodelling with larger interventricular septal thickness index (IVSI) and relative wall thickness than those with lower AHI values. The moderate to severe OSA group had an increased risk of abnormal LV geometry compared with the reference group (odds ratio 4.21 (95% CI 1.35 to 13.12)). Log transformed AHI was associated with RVSVI (p = 0.0002), RVEF (p = 0.0001) and RVMPI (p<0.0001), independent of the effect of obesity. Improvement in RVMPI, IVSI and E/e′ were observed in those with a significant reduction in AHI (>50%) comparing 6 month with baseline data. Conclusions: OSA is an independent risk factor for subclinical RV and LV dysfunction, and improvement in AHI is associated with reversibility of these abnormalities.

Sleep endoscopy with midazolam: sedation level evaluation with bispectral analysis.

Objective This study examines subjects’ level of consciousness with bispectral analysis in sedation endoscopy of the upper airway. Study Design A prospective study. Setting University hospital. Subjects and Methods Bispectral analysis levels recorded in natural sleep of 43 patients with obstructive sleep apnea during an overnight polysomnographic sleep study were directly compared with the levels recorded during midazolam sedation sleep endoscopy in the same subjects. The possible muscle relaxation effect of midazolam was examined via surface chin electrodes. Supine Müller maneuver findings in 50 patients with obstructive sleep apnea were also compared with soft tissue dynamics during midazolam sedation sleep endoscopy. Results In our study of the 43 patients with bispectral analysis during natural sleep and midazolam sedation sleep endoscopy, a predominance of bispectral analysis values indicating N1 and N2 sleep was observed during the sedation study. Midazolam failed to achieve deeper levels of sleep with minimal N3 and no convincing rapid eye movement. As N1 and N2 are the stages during which maximal dynamic activities occur, and they make up an average of 70.5% of total sleep time, from 210 sleep studies at our laboratory, the present technique would be ideal as a surgical assessment tool. No muscle relaxation effect could be detected at our protocol dose of midazolam. The supine Müller maneuver findings were significantly different from those observed during sedation sleep. Conclusion These findings support the value of sleep endoscopy as an efficient and informative technique for the examination of upper airway dynamics relevant to focused surgical planning.

Internal carotid artery hemorrhage after irradiation and osteoradionecrosis of the skull base.

OBJECTIVE: To evaluate the clinical presentation and management of internal carotid artery rupture after irradiation and osteoradionecrosis of the skull base. STUDY DESIGN AND SETTING: A retrospective review of the patients in an otorhinolaryngology-head and neck secondary and tertiary referral center. METHODOLOGY: From January 1993 to December 1996, patients with hemorrhage from internal carotid artery as a complication of irradiation and osteoradionecrosis of skull base were reviewed and analyzed. RESULTS: Four patients with internal carotid arterial rupture were included in this study. Angiography was performed in all cases. Embolization of the aneurysm was performed on 2 patients and the remaining 2 patients underwent occlusion of their internal carotid arteries. Three of the 4 patients did not survive. The fourth is currently alive and well 18 months after embolization of 1 internal carotid artery. CONCLUSION: Skull base osteoradionecrosis with bleeding from internal carotid artery is a potentially fatal complication of irradiation. Angiography was the mainstay of diagnosis with embolization of the aneurysm and embolization or ligation of the internal carotid artery being the management options. Internal carotid artery occlusion is the definitive treatment provided cross circulation is adequate. SIGNIFICANCE: The advantages and disadvantages of the treatment options are discussed and a management protocol is proposed.

The combined olfactory test in a Chinese population

OBJECTIVE To establish an olfactory test in the Hong Kong Chinese population. STUDY DESIGN Prospective analysis of the results of a combined olfactory test (COT) for patients with olfactory dysfunction and for normal subjects attending a secondary and tertiary ear, nose and throat centre. METHOD Our COT was based on and modified from the Connecticut Chemosensory Research Centre test. It consisted of an odour identification test involving nine substances and a threshold test using a series of threefold dilutions of 1-butanol. From September 1998 to June 2002, 188 Hong Kong Chinese patients with olfactory dysfunction and subjects with normal olfaction were prospectively recruited. The subjects were categorized into normal, hyposmic and anosmic groups. The olfactory function of the main group of subjects (n = 153) was assessed with the COT by a blinded observer and also quantified with a visual analogue scale; the results were analysed to validate the discriminative ability of the COT. Another subgroup of subjects (n = 35) was tested with the COT twice with a two-week interval to evaluate test-retest reliability. RESULTS There were 42 normal, 68 hyposmic and 43 anosmic subjects within the main group (total n = 153). The identification scores, threshold scores and combined olfactory scores were statistically significantly different between the anosmic, hyposmic and normal groups of subjects (p < 0.001). The combined olfactory score correlated with the visual analogue score and the correlation coefficient was 0.56 (p < 0.01). The mean time spent on each COT was 8.6 minutes (standard deviation = 3.4 minutes). The test-retest reliability of the COT was satisfactory, with a one-way model intraclass correlation coefficient of 0.87 (n = 35). CONCLUSION The satisfactory discriminative ability and test-retest reliability of the COT have been demonstrated in this study. The COT is a feasible method for assessing sense of smell in the Hong Kong Chinese population.

Leukotriene receptor antagonist in the treatment of childhood allergic rhinitis—a randomized placebo‐controlled study

This study was designed to assess the hypothesis that leukotriene receptor antagonists (LTRAs) would provide additional symptom relief in asthmatic children with persistent AR already taking regular antihistamine. The effects of 16‐week treatment of LTRA in addition to fexofenadine (FEX) on persistent AR in asthmatic children were examined.

Autograft Ossiculoplasty in Cholesteatoma Surgery: Is It Feasible?

Objective To investigate whether autologous ossicles can be safely used in ossicular reconstruction in cholesteatoma surgery after attempting cholesteatoma removal under the operating microscope.

Kimura's Disease of the Auricle

A 42-year-old man presented to our department with a 5year history of enlarging masses in both auricles (Fig 1). The physical examination revealed the auricular masses were nontender, firm, and lobulated with multiple small scabs on their surfaces. In addition, he had a 2-cm mobile and nontender upper deep cervical lymph node on each side of his neck. Laboratory results were significant for a white cell differential count that revealed an eosinophil count of 29.9% (normal range, less than 4.5%). A fine needle aspiration cytology of the cervical lymph node demonstrated granulomatous reaction. A trucut biopsy of the right ear lobe lesion showed chronic inflammatory infiltrates with a fibrotic stroma. The inflammatory infiltrates contained activated lymphoid cells and many eosinophils with small foci of necrosis. Ziehl-Neelsen staining for acid-fast bacilli was negative. No parasites were seen. The diagnosis of Kimura’s disease was made.