Shuk-yu Leung

Ambulatory blood pressure before and after adenotonsillectomy in children with obstructive sleep apnea.

INTRODUCTION Hypertension is found to be associated with obstructive sleep apnea (OSA) in both children and adults. But data on the effect of blood pressure after adenotonsillectomy (AT) for children with OSA are limited and controversial. OBJECTIVE To assess the impact of AT on different parameters of 24-h ambulatory blood pressure monitoring in children with OSA. METHODS We retrospectively reviewed records of OSA children who had undergone AT and a repeated sleep polysomnography after AT from 2001 to 2008. RESULTS Forty-four children were identified and included in the analysis. The mean apnea-hypopnea index (AHI) dropped from 14.14+/-15.9 to 3.3+/-7.1. (p<0.001). Twenty (45%) were cured of OSA. After AT, the diastolic BP load decreased significantly. Six out of eight (75%) hypertensive children became normotensive after surgery. For the pre-AT hypertensive group, both systolic and diastolic blood pressure decreased significantly during sleep after AT. However, eight children who were normotensive before AT became hypertensive after AT. These 10 post-AT hypertensive patients were more likely to have post-AT AHI>1 than the post-AT normotensive group, although the difference did not reach statistical significance. CONCLUSION In the current cohort of OSA children, 44% were cured of OSA and a significant decrease in overall diastolic blood pressure load in 24-h ambulatory blood pressure was achieved after adenotonsillectomy for children with OSA. But hypertension may persist or even occur in those previously normotensive children despite the improvement in AHI. Persistence of OSA may be a risk factor and further study is required. Cure of OSA should not be assumed after AT and follow-up PSG should be performed together with 24-h ambulatory blood pressure monitoring. In light of the current findings, long term study of the blood pressure is warranted for children with OSA.

A randomized placebo-controlled trial of traditional Chinese medicine as an add-on therapy to oral montelukast in the treatment of mild persistent asthma in children

OBJECTIVES Traditional Chinese medicine are commonly used for treatment of asthma. However, there are only very limited data about its efficacy in children. Therefore, we aimed to determine the efficacy of augmented Yu Ping Feng San (aYPFS) as an add-on to oral montelukast compared with montelukast alone for treatment of mild persistent asthma in children. DESIGN A single centre, placebo-controlled, double-blinded, randomized control trial was carried out. Participants with age 6-18 years who had mild persistent asthma were randomized according to random number list to receive either aYPFS plus montelukast for 24 weeks or placebo plus montelukast for 24 weeks. Primary outcome measure was lung function parameters. Secondary outcome measures were Asthma Control Test™ (ACT™) and Paediatric Allergic Disease Quality of Life Questionnaire (PADQLQ) scores, symptom-free days, short-acting β2-agonist use, use of rescue oral corticosteroids, days of hospitalization for asthma and number of emergency consultation with GPs or AED department. RESULTS Twenty-eight participants were randomized to aYPFS group and twenty-nine to placebo group. There was no significant difference in baseline characteristics. There was significant improvement in ACT™ score in aYPFS group (up to 6.9% change from baseline) (p=0.016) but not in the control group. There were no significant differences between groups in other primary and secondary outcome parameters. Dropout because of adverse effects is comparable in both groups. CONCLUSION Traditional Chinese medicine aYPFS as an add-on to montelukast improved symptoms of asthma control. Further studies with larger sample size are needed to evaluate its efficacy and safety in childhood asthma.

Management of Recurrent Preschool, Doctor-Diagnosed Wheeze

Preschool wheeze occurs in half of the children before they reach 6 y of age and recurrence is also common. Recurrent preschool wheeze is classified as either typical or atypical. For typical recurrent preschool wheeze, the diagnoses are either asthma or bronchiolitis/bronchitis. Responsiveness to a properly administered bronchodilator confirms asthma, atopic or otherwise. All atypical preschool wheeze should be referred to pediatric respirologist for assessment. Lung function test by impulse oscillometry (IOS) before and after bronchodilator is helpful to confirm airway hyperresponsiveness, an essential feature of asthma. Assessment of atopy is important by either skin prick test or serum IgE level. Treatment of acute wheeze includes standard supportive care, bronchodilator for those diagnosed with asthma and hypertonic saline for those diagnosed as having acute bronchiolitis. Other treatments included nebulized adrenaline for acute bronchiolitis and systemic steroids for asthma. For those with significant respiratory distress, continuous positive airway pressure (CPAP) or heated humidified high flow should be considered. Daily or intermittent inhaled corticosteroid or intermittent montelukast would reduce asthma exacerbation rate. A significant proportion of preschool wheeze persists till school age. An early diagnosis of asthma would be important to allow early optimal management.