Expert Q & A Series : Childhood Asthma, OSA and sleep habits in children
DailyRounds 7 Q&A with Dr Daniel YT Goh
Cluster Chair, Khoo Teck Puat — National University Children’s Medical Institute, National University Health System
Head of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore
Head of Paediatrics, National University Hospital, Singapore
Senior Consultant, Division of Paediatric Pulmonology & Sleep, National University Hospital, Singapore
1. DailyRounds: PETITE Research group’s study concluded that 400 micrograms Budesonide once daily is as effective as 200 micrograms twice daily in controlling childhood asthma. Can you comment on this?
Dr Goh: There have been several studies demonstrating the efficacy of once daily inhaled corticosteroids in mild asthma. Most of these studies are in the management of stable and well-controlled asthma rather than the starting dose. The PETITE study (’98) does suggest that 400mcg once a day may be as good as 200mcg twice a day of Budesonide as an initial therapy. It is however important to note that the daily dose of Budesonide is 400mcg which is higher than the usual starting dose (of 200 mcg per day) in mild childhood asthma and the duration of follow-up in the study was limited. There may be some benefit in terms of ease of use and improved compliance with once a day dosing.
It is well known that patients do have reduced compliance over time and if prescribed twice a day medications, often take once a day; but if prescribed once a day medications, may actually stop taking altogether, resulting in intermittent or irregular treatment and certainly poorer outcomes. Hence, strict reinforcement of compliance and close monitoring has to be emphasized if this is to be considered.
2. DailyRounds: Studies have shown a significant association between early pneumonia and an increased risk for asthma and wheeze in later life. In your professional opinion, would preventing such RTIs in early childhood reduce the burden of asthma in a society? How should one ensure that this happens?
Dr Goh: These findings from longitudinal studies do suggest that pneumonia in the first three years of life is associated with an increased risk of lower lung function (FEV1) and increased risk of asthma and subsequently chronic obstructive pulmonary disease.
It is however unclear whether having respiratory ailments early in life begins a cascade that results in lingering lung injury or whether pneumonia occurs in young developing lungs that are already vulnerable. There is (to date) not enough evidence to recommend active measures to avoid respiratory tract infections in childhood for the prevention of subsequent asthma and wheeze.
Besides, there are few proven effective measures to avoid respiratory tract infections in early childhood, apart from maintaining a healthy and balanced diet, rest, exercise as well as vaccination.
3. DailyRounds: In your experience, what is the best assessment to check/ monitor control of asthma, and how often should it be done?
Dr Goh: Symptoms are the key parameters to monitor asthma control. These can be in the form of asthma symptom scores eg. the asthma control tests.
In addition, the use of tests such as spirometry and exhaled nitric oxide may be useful to monitor control over longer periods of time and the latter can detect deteriorating control (or eosinophilic inflammation) and an impending asthma exacerbation. The frequency of these tests depends on the overall lability or instability of the disease control and can range from weeks to several months.
4. DailyRounds: In an acute case of asthma, if all standard/ conventional therapy fails, what is your treatment recommendation?
Dr Goh: What is considered standard and conventional therapy for asthma exacerbations varies from center to center. Generally it would include bronchodilators, systemic steroids and other drugs such as magnesium sulphate. Other options include intravenous salbutamol, intravenous Aminophyliine, ventilatory support using CPAP as well as BiPAP and invasive mechanical ventilation. The choices vary depending on the response and status of the patient, as well as the facilities available and the expertise of the managing team.
5. DailyRounds: Studies have showed that children from predominantly-Asian countries have significantly later bedtimes, shorter total sleep times, increased parental perception of sleep problems, and were more likely to room-share than children from predominantly-Caucasian countries/regions. What is your professional opinion on which sleeping practices are better for a healthier, wholesome life?
Dr Goh: These studies demonstrate the observed differences in sleep habits and practices between populations but do not explain why, nor the impact (if any) of these differences. There are significant cross-cultural variations in sleep in childhood and one cannot conclude if Asian children are suffering any effect of the reduced sleep. Perhaps each population has its sleep threshold and there is no evidence suggesting any ill effects (or benefits) of these observed sleep differences. It is interesting to note that Asian children do on a whole perform better in maths and science than their Caucasian counterparts, hence it is difficult to conclude if any specific sleeping pattern or practice is better or healthier. More studies are needed to evaluate the impact of the observed differences in sleep across cultures.
6. DailyRounds: What is your take on the use of anti inflammatory agents (such as topical intranasal steroid sprays and leukotriene receptor antagonists) in children with OSA? Is that the best, and most effective form of treatment to begin with, or should one directly opt for more aggressive measures?
Dr Goh: Studies have demonstrated improvement in apnea-hypopnea indices (AHI) with anti-inflammatory medications such as topical nasal steroids and leukotriene receptor antagonists. These improvements are however mild and generally reduces the AHI by a few points (per hour) and do not eliminate or cure the OSA. By themselves they are probably not the treatment of choice except for the mildest of severity of OSA or in anticipation of definitive treatment (eg Tonsillectomy and Adenoidectomy) or in patients with mild residual OSA post T&A.
7. DailyRounds: What are the biggest, most practice- relevant lessons we have taken from the ISAAC study?
Dr Goh: The most valuable information we have gained from the ISAAC studies over the years is the time-trend data in asthma and allergy prevalence in all participating countries and the comparative data across regions and around the world. It has given us insights into the changing disease burden as well as distribution of this burden across different countries and regions. Several latter phases of the study have also attempted to look at factors associated with asthma and allergies but the data still largely describes associations and not cause-effect relationships.