International consensus on (ICON) pediatric asthma.

Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Several guidelines and/or consensus documents are available to support medical decisions on pediatric asthma. Although there is no doubt that the use of common systematic approaches for management can considerably improve outcomes, dissemination and implementation of these are still major challenges. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), recently formed by the EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus on (ICON) Pediatric Asthma. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences, thus providing a concise reference. The principles of pediatric asthma management are generally accepted. Overall, the treatment goal is disease control. To achieve this, patients and their parents should be educated to optimally manage the disease, in collaboration with healthcare professionals. Identification and avoidance of triggers is also of significant importance. Assessment and monitoring should be performed regularly to re-evaluate and fine-tune treatment. Pharmacotherapy is the cornerstone of treatment. The optimal use of medication can, in most cases, help patients control symptoms and reduce the risk for future morbidity. The management of exacerbations is a major consideration, independent of chronic treatment. There is a trend toward considering phenotype-specific treatment choices; however, this goal has not yet been achieved.

Safety and efficacy of warfarin in patients with moderate thrombocytopenia.

INTRODUCTION: Patients with moderate thrombocytopenia and comorbidities requiring anticoagulation are currently sub-optimally treated because of bleeding concerns. Guidance on anticoagulating such patients is currently lacking because of limited data on safety and efficacy of anticoagulation in such patients. METHODS: This retrospective study compared the incidence of bleeding and thrombosis in a cohort of warfarinized patients with sustained platelet counts below 100×109/L against a cohort with normal platelet counts (>140×109/L). Primary outcomes of safety and efficacy were determined by incidence rate ratios (IRR) of bleeding and thrombotic events. International normalized ratio (INR) and platelet counts during adverse events in thrombocytopenic arm were secondary outcomes. RESULTS: 137 thrombocytopenic patients (104,985 patient-exposure days) were compared against 939 normal patients (715,193 patient-exposure days). IRR of minor, major bleeding and thrombosis among thrombocytopenic patients were 3.03 (95% CI: 1.57-5.60), 1.48 (95% CI: 0.44-3.98), and 0.807 (95% CI: 0.09-3.43) respectively. Median INR and platelet count readings during minor and major bleeds were 3.60 (IQR: 2.70-4.12) and 3.12 (IQR: 2.82-4.22), and 99×109/L (IQR: 77.0-147.0×109/L) and 115×109/L (IQR: 107.5-169.5×109/L) respectively. CONCLUSION: Warfarinized thrombocytopenic patients are at higher risk of minor bleeding complications with a higher tendency for major bleeding but derive similar benefits against thrombotic events compared to normal patients. Bleeding events are associated with higher INRs. A narrow INR target with an upper limit below 2.5 together with closer anticoagulation monitoring may improve safety of patients.

Pulmonary function and scoliosis in children with spinal muscular atrophy types II and III.

AIMS: The objectives were to evaluate the clinical course of spinal muscular atrophy (SMA) types II and III patients necessitating scoliosis surgery at the National University Hospital, Singapore. METHODS: A retrospective review of SMA types II and III patients, born over a 10-year period between 1983 and 1992, was conducted. RESULTS: There were eight patients: four with SMA type II and four with SMA type III. The mean age at scoliosis surgery was 9 years 7 months (range 7 years 6 months-12 years 4 months). The mean preoperative Cobb angle was 65.4 degrees (range 43-90 degrees ) and the mean postoperative Cobb angle was 22.6 degrees (range 12-45 degrees ), with a mean correction of 64.8% (range 47.7-77.8%). The decline in percentage predicted forced vital capacity (FVC) was 7.7% (95% CI: 12.4% to 3.0%) per year preoperatively and this was reduced to 3.8% (95% CI: 5.8% to 1.9%) per year postoperatively. The mean length of preoperative and postoperative lung function follow-up was 6.3 months (range 0.03-31 months) and 44 months (range 0-110 months), respectively. CONCLUSIONS: This study suggests that pulmonary function in SMA types II and III continues to decline after scoliosis surgery, though the rate of decline is less marked. Overall, the combined results from this study and all other previously published studies are conflicting in regard to the effect of scoliosis surgery on pulmonary function in SMA types II and III, though half of the studies (3 of 6) did demonstrate a continued decline in lung function postoperatively. This decline in pulmonary function despite spinal stabilization is likely secondary to the progressive neuromuscular weakness of the disease.

Unfused hypoplastic tongue in a newborn.

Malformations of the tongue are rare. There are < 50 cases of tongue hypoplasia reported in the literature since the first case described by de Jussieu in 1718. These are usually associated with the hypoglossia-hypodactaly syndrome. We describe a newborn with a hypoplastic anterior tongue unfused to the posterior tongue and airway obstruction. Its embryology, theories of pathogenesis, treatment and clinical course are discussed.

Risk factors for predicting mortality in a paediatric intensive care unit.

Rapid advances in critical care technology and rising cost of medical care have spurred the development of outcome analysis including mortality risk prediction. The main objective of this study was to assess the risk factors contributing to mortality in our paediatric intensive care unit (PICU). This is a cohort study, consisting of consecutive admissions to the PICU from 1 January to 31 December 1997. The factors studied included multi-organ dysfunction syndrome (MODS), Pediatric Risk of Mortality III (PRISM III) scores in the first 24 hours (PRISM III-24), mechanical ventilation, renal replacement therapy, age, and diagnosis-related groups. Univariate and multivariate statistical methods were used. Univariate analysis showed that need for mechanical ventilation, renal replacement therapy, presence of MODS involving 3 or more organs and PRISM III-24 scores were significantly associated with outcome (P < 0.0005). Relative risk of mortality in the presence of MODS and PRISM III-24 scores > or = 8 were 11.3 (95% CI: 3.3 to 38.3) and 15.8 (95% CI: 2.0 to 127.8), respectively. Using Cox Proportional Hazards model, the relative risk of mortality for any new admission could be calculated by the equation RR = e0.1032 x P, where P = PRISM III-24 scores.

House dust mite allergen levels in a Singapore hospital.

House dust mite allergens constitute one of the most important allergens in house dust. In this study, the levels of two common dust mite allergens, Der p I and Der f I, in a general hospital in Singapore were evaluated. Our results showed that these allergens were detected in 42/74 (or 57%) of the dust samples. Der p I was found to be the predominant allergen detected (p < 0.001). The allergen levels were, however, low with only 1/74 having a Der p I concentration above 2 micrograms g-1 dust. None of the samples had Der f I concentrations above this level. Of the various niches studied (mattresses, pillows, sofas, carpets, blinds and floors), the blinds and floors had the lowest concentration of allergen (p < 0.05). These low levels in the hospital compared to homes were attributed to the vigorous cleaning schedule in the hospital, the use of plastic to encased mattresses and pillows, vinyl covered sofas and vinyl lined floors. These practices may be adopted in the home as a means to reduce mite allergen exposure.

Allergens of Bipolaris species.

Skin prick tests done previously revealed a significantly higher percentage of sensitization to an extract of Bipolaris sp. among atopic individuals (34/147, 23.1%) compared to non-atopic individuals. Bipolaris-specific IgE levels were quantified in sera from a representative group of 38 individuals using the Fluorescence Allergosorbent Test (FAST). Result obtained by FAST were found to be comparable to the skin prick test results (r2 = 0.60, p < 0.001 for IgE levels vs wheal sizes; r2 = 0.44, p < 0.001 for IgE levels vs erythema sizes). Characterisation of the extract's allergenic component by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed 28 protein bands with molecular weights (MW) ranging from 11 kDa to above 100 kDa. Immunoblotting with sera of 10 Bipolaris-sensitive (skin prick test, 3 +) individuals showed that Bipolaris spore extract contained at least 4 IgE binding proteins (MW 11-13 kDa, 16-17 kDa, 20-22 kDa and 36 kDa). All 10 sera reacted to the protein at MW 20-22 kDa, 2 sera with MW 11-13 kDa, 3 sera with 16-17 kDa and 6 sera with 36 kDa. This study has thus demonstrated that spores of Bipolaris sp. contain allergenic components which may elicit IgE-mediated reactions.

A filter bank-based source extraction algorithm for heart sound removal in respiratory sounds.

In this paper, we consider the problem of heart sounds (HS) removal from respiratory sounds (RS), and a novel semi-blind single-channel source extraction algorithm is proposed. The proposed method is able to extract the underlying pure RS from the HS corrupted noisy input signals by incorporating the filter banks and template-based matching using FIR filters. For performance evaluation of the presented method, the average power spectral densities (PSD) of the input RS segments without HS have been compared with the PSD of the reconstructed signals over six selected frequency bands from 20 to 800Hz. The proposed method is tested for various types of RS recordings and found effective by yielding an overall maximum spectral difference of 2.8707+/-0.9875dB for a frequency range below 800Hz.

An acoustical respiratory phase segmentation algorithm using genetic approach.

This paper proposes a robust and fully automated respiratory phase segmentation method using single channel tracheal breath sounds (TBS) recordings of different types. The estimated number of respiratory segments in a TBS signal is firstly obtained based on noise estimation and nonlinear mapping. Respiratory phase boundaries are then located through the generations of multi-population genetic algorithm by introducing a new evaluation function based on sample entropy (SampEn) and a heterogeneity measure. The performance of the proposed method is analyzed for single channel TBS recordings of various types. An overall respiratory phase segmentation accuracy is found to be 12 +/- 5 ms for normal TBS and 21 +/- 9 ms for adventitious sounds. The results show the robustness and effectiveness of the proposed segmentation method. The proposed method has been a successful attempt to solve the clinical application challenge faced by the existing phase segmentation methods in terms of respiratory dysfunctions.

Monitoring and treatment practices of childhood asthma in Singapore: a questionnaire study.

INTRODUCTION: Asthma is the most common chronic disease in children in Singapore. More than 20 percent of children will have been diagnosed with asthma by the age of 15 years. Most children are seen in the primary care setting, thus it is of value to study the management practices, especially of general practitioners, with comparison to gold standards. The aims of the study were to investigate: (a) Methods of monitoring asthma control; (b) Practices in managing acute exacerbations; and (c) Choice of therapy in maintenance treatment. METHODS: 2,100 questionnaires consisting of 35 questions were sent by post to general practitioners and various paediatric doctors throughout Singapore. 173 valid responses were received and results were compared to the 2006 Global Initiative for Asthma guidelines. RESULTS: 76.3 percent of respondents were general practitioners. 89.1 percent did not use symptom score cards / diaries. 37.6 percent did not use peak-flow meters / spirometers. 83.8 percent used a short-acting beta-agonist in acute exacerbations, but only 41.0 percent used oral corticosteroids in outpatients. A significant number used long-acting beta-agonists (LABA) in combination with inhaled steroids (29.5-41.6 percent) or as monotherapy (5.8-8.7 percent) for maintenance treatment. 91.3 percent never used immunotherapy in practice. CONCLUSION: Greater usage of diaries / score cards can be encouraged along with objective peak flow / spirometry measurements. Management of acute exacerbations is appropriate but corticosteroids are under-prescribed by most doctors. LABA continues to be prescribed for maintenance despite a lack of established safety profile for infants, along with recommendations that they only be used selectively in patients poorly-controlled by medium-dosage inhaled corticosteroids.

Sleep architecture and respiratory disturbances in children with obstructive sleep apnea.

Little is known regarding sleep architecture in children with the obstructive sleep apnea syndrome (OSAS). We hypothesized that sleep architecture was normal, and that apnea increased over the course of the night, in children with OSAS. We analyzed polysomnographic studies from 20 children with OSAS and 10 control subjects. Sleep architecture was similar between the groups. Of obstructive apneas 55% occurred during rapid eye movement (REM) sleep. The apnea index, apnea duration, and degree of desaturation were greater during REM than non-REM sleep. OSAS data from the first and third periods of the night (periods A and C) were compared. Both the overall and the REM apnea index increased between periods A and C (11 to 25/h, p < 0.02; and 24 to 51/h, p < 0.01, respectively). There was no difference in Sa(O(2)) over time. Spontaneous arousals, but not respiratory-related arousals, were more frequent during non-REM than REM sleep; these did not change from periods A to C. We conclude that children with OSAS have normal sleep stage distribution. OSAS is predominantly a REM phenomenon in children. Obstructive apnea worsens over the course of the night, independent of the changing amounts of REM sleep. We speculate that this increase in apnea severity may be secondary to upper airway muscle fatigue, changes in upper airway neuromotor control, or changes in REM density.

Effects of an acaricide on mite allergen levels in the homes of asthmatic children.

Previous study by the current authors has shown that treating homes with D'Allergen, an acaricidal agent, can reduce bronchial hyper-reactivity in asthmatic children with house dust mite allergy. In the present study, the effects of a single D'Allergen treatment on the levels of major dust mite allergens, Der p I and Der f I was evaluated, and the duration of its effectiveness in the environment determined. Twenty randomly selected homes were treated with the acaricide and ten remained untreated. Dust samples were collected from mattresses, upholstered sofas and carpets of these homes before and 1, 2 and 4 months after treatment. The samples were then assayed for Der p I and Der f I allergens using a sandwich enzyme immunoassay. The results showed that D'Allergen was effective in reducing dust mite allergen levels in all three niches by 1.5-22.3 times below baseline values. This effect, however, was only present for 2 months, and the dust mite allergen levels increased to those of the baseline by the fourth month after treatment. These results indicated that repeated applications of the acaricide were required at 2-3 monthly intervals to obtain optimal effectiveness.

The economic cost of asthma in Singapore.

BACKGROUND: Asthma is a common chronic disorder. In Singapore, it is estimated that 140,000 individuals have current asthma and more than 100 individuals die of this disease annually. OBJECTIVE: This study estimates the economic cost of asthma, both direct and indirect, to the patient and community. METHOD: Direct cost estimates were based on all levels of medical care, which included inpatient care, emergency room visits, specialist outpatient and primary healthcare, and medication costs. Indirect costs were estimated from cost of time lost by patients and their families attending to medical needs and the loss of productivity due to absenteeism. These estimates were calculated to the 1992/93 US dollar. RESULTS: The total cost of asthma in Singapore was estimated to be US $33.93 million per annum. This was made up of US $17.22 million in direct costs and US $16.71 million in indirect costs. Inpatient hospitalisation accounted for the largest proportion of direct medical expenditure, approximately US $8.55 million. The loss of productivity from acute asthma accounted for the largest proportion of the indirect costs at US $12.70 million. The cost estimates did not include premature death due to disease. These estimates represent approximately US $238 per asthmatic person per year or US $11.90 per person per year. CONCLUSION: This study shows that the economic cost of asthma is also considerable in populations outside the Western hemisphere, and justifies the need for a concerted effort to reduce asthma morbidity worldwide.

Under-recognition of childhood asthma in Singapore: evidence from a questionnaire survey.

In a recent study on the prevalence of childhood asthma and allergies using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires, 6238 Singapore school children in two age-groups, 6-7 years (n = 2030) and 12-15 years (n = 4208), were evaluated. Of the 1856 children who reported asthma-like symptoms (wheezing, exercise-wheezing, persistent nocturnal cough), 919 (49%) had not been diagnosed asthmatic. Of these undiagnosed children, 731 (39%) reported current symptoms of asthma. Under-recognition of asthma was more prevalent among those with persistent nocturnal cough and mild symptoms. In addition, the discordance between wheezing in the last 12 months and a diagnosis of asthma was significantly higher among the younger age-group (6-7 years), but exercise-induced wheezing was less recognized as a symptom of asthma among the older age-group (12-15 years). This study has shown that there is a substantial degree of under-recognition of asthma among school children in Singapore.

Geographical comparison of the prevalence of childhood asthma and allergies in Singapore.

A previous study suggested that differences in the prevalence of respiratory illnesses such as asthma in school children in different regions of Singapore were not due to the influence of air pollution or environmental factors but possibly to cultural and socio-economic factors. The effects of socio-economic or demographic variables were, however, not shown in that study. In this study, we set out to discover whether regional differences in the prevalence of atopic diseases such as asthma, rhinitis and eczema in Singapore school children could be explained by different demographic profiles. The prevalence of asthma and allergies were evaluated in 6238 Singapore school children in two age groups (6-7 years [n = 2030] and 12-15 years [n = 4208]). They were from four regions, based on residential post codes. Demographic and socio-economic data were also obtained. The questionnaire of the International Study on Asthma and Allergies in Childhood (ISAAC) was used. The data showed that children residing in the northern regions of Singapore had a significantly lower prevalence of asthma and rhinitis than those in other regions. When controlled for demographic influences (age, sex and race) and socio-economic factors (type of housing), however, the differences between these regions were reduced. No geographical difference in the prevalence of eczema was observed. Thus, geographical differences in the prevalence of asthma and rhinitis in Singapore could in part be explained by demographic and socio-economic differences in the population.

Parents' perceptions towards their child's use of inhaled medications for asthma therapy.

OBJECTIVE: Understanding patients' and their parents' perceptions towards asthma medication is important in developing strategies to ensure patient compliance. In this study, parents' perceptions towards their children's use of inhaled medication for asthma treatment were evaluated. METHODOLOGY: A questionnaire was administered by interviewing parents of 210 asthmatic children attending the Department of Paediatrics, National University Hospital. RESULTS: Our results showed that 76/210 (36%) of parents either felt opposed to inhaler therapy and/or preferred oral medications. The main reasons for their reluctance to use inhalers were related to fear of dependence, side effects and overdosage, and the child's dislike for inhalers. A third of these parents felt that inhalers were only indicated for very severe asthma. CONCLUSIONS: We conclude that a significant proportion of parents have reservations regarding the use of inhalers for the treatment of asthma. These factors should be taken into consideration when planning an effective asthma education programme.

Immunoglobulin (Ig) and IgG subclasses in Asian children with bronchial asthma.

Selective immunoglobulin deficiencies have been shown to be associated with atopic disease. In this study, serum immunoglobulin (Ig) G, A, M, E and IgG subclasses of 92 Asian asthmatic children were studied and compared with those of age-matched controls. The children, aged between 0.7 and 17.4 years (mean age 7.5 years), were recruited from the National University Hospital, Singapore. The serum Ig levels were measured by enzyme-linked immunosorbent assay, except for IgE which was measured by the fluorescent allergosorbent test. As expected, serum total IgE levels were markedly higher in the asthmatic children than in the controls (geometric mean = 513 units/ml and 164 units/ml, respectively; p < 0.0001). Serum IgM levels were also slightly higher in the asthmatic patients than in the controls (geometric mean = 1.74 and 1.51 milligrams, respectively; p < 0.04). Mean serum IgG and A and IgG subclasses (1-4) levels in the asthmatics did not differ significantly from those in the controls. However, four asthmatic children were found to have selective IgA deficiency (serum IgA < 0.08 milligrams). None of the patients was found to be IgG subclass-deficient.

Prevalence and severity of asthma, rhinitis, and eczema in Singapore schoolchildren.

This study was part of an international effort to evaluate the epidemiology of asthma and allergic diseases around the world. The aim was to assess the prevalence and severity of these disorders in Singapore schoolchildren. The international study of asthma and allergies in childhood (ISAAC) written questionnaire was administered to 6238 schoolchildren. The respondents were parents of a 6-7 year cohort (n = 2030), and schoolchildren aged 12-15 years (n = 4208). The overall cumulative and 12 month prevalence of wheezing were 22% and 12%, respectively. The prevalence of doctor diagnosed asthma was 20%. Rhinitis was reported by 44% and chronic rashes by 12%. Multiple logistic regression analysis showed that a higher prevalence of wheezing and rhinitis was associated with males, and subjects of higher socioeconomic status (based on type of housing and total family income). More severe asthma related symptoms were present in Malays and Indians than in the Chinese. Allergic disorders are common in Singapore and prevalence is comparable to some populations in the West. Demographic and socioeconomic factors appear to influence the prevalence and severity of these disorders.

Month of birth and childhood atopic diseases in the tropics.

The relationship between the month of birth and prevalence of diagnosed asthma, asthma-like symptoms (wheezing, nocturnal cough, and exercise wheezing), rhinitis, and eczema was investigated in four cohorts each of primary schoolchildren and secondary school (high school) adolescents in Singapore by questionnaire survey. Significantly increased prevalence rates of diagnosed asthma and asthma-like symptoms were observed in certain birth months of the year for two adolescent cohorts, while significant association between birth month and presence of symptoms of rhinitis was found in a cohort of 6-7-year-olds. However, when demographic factors were taken into consideration by multivariate analysis, only the association between asthma, asthma-like symptoms, and birth month remained significant in one of the adolescent cohorts. There was, therefore, only a weak association between the month of birth and atopic disease in our schoolchildren. The overall seasonal trends, however, did show two main seasons (March-May and September-November) associated with higher prevalence of these diseases.