Aroonwan Preutthipan

QT dispersion in childhood obstructive sleep apnoea syndrome.

The difference between maximal and minimal QT interval and corrected QT interval defined as QT dispersion and corrected QT dispersion may represent arrhythmogenic risks. This study sought to evaluate QT dispersion and corrected QT dispersion in childhood obstructive sleep apnoea syndrome. Forty-four children (34 male) with obstructive sleep apnoea syndrome, aged 6.2 plus or minus 3.5 years along with 38 healthy children (25 male), 6.6 plus or minus 2.1 years underwent electrocardiography to measure QT and RR intervals. Means QT dispersion and corrected QT dispersion were significantly higher in obstructive sleep apnoea syndrome than controls, 52 plus or minus 27 compared to 40 plus or minus 14 milliseconds (p equal to 0.014), and 71 plus or minus 29 compared to 57 plus or minus 19 milliseconds (p equal to 0.010), respectively. Interestingly, QT dispersion and corrected QT dispersion in obstructive sleep apnoea syndrome with obesity, 57 plus or minus 30 and 73 plus or minus 31 milliseconds, were significantly higher than in control, 40 plus or minus 14 and 57 plus or minus 19 milliseconds (p equal to 0.009 and 0.043, respectively). However, QT dispersion and corrected QT dispersion in obstructive sleep apnoea syndrome without obesity, 43 plus or minus 20 and 68 plus or minus 26 milliseconds, were not significantly different. In conclusion, QT dispersion and corrected QT dispersion were significantly increased only in childhood obstructive sleep apnoea syndrome with obesity. Obesity may be the factor affecting the increased QT dispersion and corrected QT dispersion.

Home Mechanical Ventilation in Children

The number of children dependent on home mechanical ventilation has been reported to be increasing in many countries around the world. Home mechanical ventilation has been well accepted as a standard treatment of children with chronic respiratory failure. Some children may need mechanical ventilation as a lifelong therapy. To send mechanically ventilated children back home may be more difficult than adults. However, relatively better outcomes have been demonstrated in children. Children could be safely ventilated at home if they are selected and managed properly. Conditions requiring home ventilation include increased respiratory load from airway or lung pathologies, ventilatory muscle weakness and failure of neurologic control of ventilation. Home mechanical ventilation should be considered when the patient develops progressive respiratory failure or intractable failure to wean mechanical ventilation. Polysomnography or overnight pulse oximetry plus capnometry are used to detect nocturnal hypoventilation in early stage of respiratory failure. Ventilator strategy including non-invasive and invasive approach should be individualized for each patient. The author strongly believes that parents and family members are able to take care of their child at home if they are trained and educated effectively. A good team work with dedicated members is the key factor of success.

Obstructive sleep apnoea syndrome: the Asian perspective

Obstructive sleep apnoea syndrome (OSAS) refers to the occurrence of repetitive episodes of partial or complete upper airway obstruction during sleep, resulting in disruption of normal ventilation and sleep patterns.1 The previous epidemiological studies used various definitions of OSAS and were conducted in Western countries in different age groups of children. Redline et al.2 found a prevalence of OSAS of approximately 2% in children and adolescents 2 to 18 years of age in the USA, and African Americans are 3.5 times more likely to have OSAS than white individuals. In Asia, 1,142 school-age Thai children were recently screened by questionnaire surveys and OSAS was confirmed by polysomnography (PSG). The prevalence of OSAS was systematically estimated to be 0.69%.3 Two studies in Singapore reported the OSAS prevalence of 2.4% in children aged 7−8 years4 and 0.7% specifically in obese school-age children.5 These studies indicate that childhood OSAS in Asia is not uncommon. Its prevalence is probably lower than that observed in Western populations. Information regarding childhood OSAS in Asia is limited. We first reported OSAS in Thai children diagnosed by standard PSG in 1997.6 Of all

Clinical and Pathological Correlation in Pediatric Invasive Pulmonary Aspergillosis

Introduction Invasive’ pulmonary aspergillosis (IPA) has been one of the major causes of mortality in immunocompromised patients. The gold standard method for a diagnosis of IPA is histopathological examination of the lung tissue; however, post-procedural bleeding limits the feasibility of lung biopsy. The European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and The National Institute of Allergy and Infectious Disease Mycoses Study Group (EORTC/MSG) defined IPA. The objective of this study was to validate the EORTC/MSG 2008 definition of IPA, compared with histopathology in the pediatric population. Methods Histopathological examinations of lung tissues of children aged 1 month–18 years with respiratory tract infection at the time of obtaining biopsy were retrieved. Retrospective chart reviews for clinical characteristics were performed. IPA diagnosis was classified according to the EORTC/MSG 2008 definition. Results During the 10-year period, there were 256 lung tissues, of which 58 specimens were suspected to have pulmonary infection. Fourteen patients (24%) were noted to have IPA. Seven patients (50%) with proven IPA were classified as probable, while the remaining 50% were classified as possible, and none were classified as no IPA, by using EORTC/MSG 2008 definition. Other 44 specimens demonstrated 14 (32%), 14 (32%), and 16 (36%) were classified as probable, possible, and no IPA, respectively. When comparing probable or possible IPA with no IPA, we found that the EORTC/MSG 2008 definition had 100% sensitivity, 36% specificity, 33% positive predictive value, and 100% negative predictive value in diagnosis of IPA. Conclusion Our study illustrated that the EORTC/MSG 2008 definition provided an excellent sensitivity but low specificity for diagnosing IPA.

Using non-invasive bi-level positive airway pressure ventilator via tracheostomy in children with congenital central hypoventilation syndrome: two case reports

IntroductionDue to the economic downturn in Thailand, two baby girls with congenital central hypoventilation syndrome had to wait for several months to obtain definite diagnosis and long-term mechanical ventilation. Genetic investigation later revealed 20/25 polyalanine expansion of PHOX2B gene in both girls. In this report we highlight the use of non-invasive bi-level positive airway pressure ventilators via tracheostomy, overnight end-tidal carbon dioxide trend graphs and outcomes of the patients whose diagnosis and treatment were delayed.Case presentationCase 1: A Thai baby girl showed symptoms of apnea and cyanosis from birth and required invasive mechanical ventilation via tracheostomy during sleep. At 5 months, she unfortunately was discharged from the hospital without any ventilatory support due to financial problems. She subsequently developed cor pulmonale, respiratory failure and generalized edema and was referred to us when she was 9-months old. An overnight polysomnogram was consistent with a central hypoventilation disorder, in which the severity of oxygen desaturation and hypercapnia was worsening during non-rapid eye movement compared to rapid eye movement sleep. At 12 months she was allowed to go home with a conventional home ventilator. The ventilator was changed to bi-level positive airway pressure when she was 4-years old. After she received adequate home ventilation, she thrived with normal growth and development.Case 2: A Thai baby girl developed apnea and cyanosis from the age of 5 weeks, requiring ventilatory support (on and off) for 5 months. After being extubated, she had been put on supplemental oxygen via nasal cannula for 2 months. She was then referred to us when she was 7-months old. An overnight end-tidal carbon dioxide trend graph revealed marked hypercapnia without increase in respiratory rate. An overnight polysomnogram was consistent with a central hypoventilation disorder. Since 9 months of age she has been on home bi-level positive airway pressure via tracheostomy without any complications.Genetic testing confirmed 20/25 polyalanine expansions of PHOX2B gene in both girls.ConclusionsBi-level positive airway pressure, originally designed as a non-invasive ventilator, was found to work effectively and safely, and may be used as an invasive ventilator via tracheostomy in young children with congenital central hypoventilation syndrome.

Spirometric airflow obstruction in asymptomatic Bangkok school children: prevalence and risk factors

A14-226 Spirometric airflow obstruction in asymptomatic Bangkok school children: prevalence and risk factors A. Preutthipan, S. Suwanpromma, C. Boonlarbtaweechoke, U. Udomsapayakul. Division of Pediatric Pulmonology, Faculty of Medicine Ramathibodi Hospital, Bangkok, Thailand; Department of Pediatrics, Lerdsin General Hospital, Bangkok, Thailand; Section for Clinical Epidemiology & Biostatistics, Faculty of Medicine, Ramathibodi Hospital, Bangkok, Thailand