Modified Asthma Predictive Index Research Articles

Factors Affecting Lung Function in Preschool Children with a History of Transient Tachypnea of the Newborn

Background: Transient tachypnea of the newborn (TTN) is a common cause of self-limiting respiratory distress in neonates. Increasing data suggest that TTN may be a risk factor for developing childhood wheezing attacks or asthma. Objectives: The aim was to evaluate lung functions in preschool children diagnosed with TTN in the neonatal period using an Impulse Oscillometry System (IOS) to assess the presence of respiratory morbidity and its contributing factors. Methods: In this prospective study, preschool children diagnosed with TTN in the neonatal period and healthy age-matched children were defined as the TTN group and control group, respectively. Impulse Oscillometry System values for resistance (R5-R20), reactance (X5-X20), resonant frequency (Z5), and reactance area (AX) were compared between both groups and within the TTN subgroups. Asthma diagnosis was determined following IOS testing using the Modified Asthma Predictive Index/ International Study of Asthma and Allergies in Childhood (ISAAC). Results: A total of 52 preschool children and 101 healthy controls participated in the study. R5 minus R20 was significantly higher, and X10 and X15 values were significantly lower in the TTN group compared to the controls. Additionally, higher R values and AX values were observed in TTN subgroups with a history of late preterm birth, noninvasive respiratory support, and maternal asthma. The rates of variable respiratory symptoms and ≥ 4 wheezing attacks in one year were 20.5% and 18%, respectively. By the end of the study, the rate of newly diagnosed asthma in the TTN group was 30.8%. Moreover, R values and Z5 were significantly higher, and X values were significantly lower in the TTN subgroup exposed to passive smoking (PS) compared to the TTN subgroup not exposed. Conclusions: Our study showed that preschool children diagnosed with TTN in the neonatal period may have peripheral airway obstruction, a known characteristic of asthma. In addition to TTN-related factors, exposure to cigarette smoke appears to negatively impact their lung function. These findings suggest that long-term medical care should be provided for these children.

Application of Asthma Prediction Tools in a Cohort of Infants with Severe Bronchiolitis.

Background: Severe bronchiolitis is a strong childhood asthma risk factor. Early and accurate asthma prediction is key. We applied the Asthma Predictive Index (API), the modified Asthma Predictive Index (mAPI), and the Pediatric Asthma Risk Score (PARS) in a cohort of high-risk infants to predict asthma at age 6 years. Methods: We conducted a 17-center cohort of infants (age <1 year) hospitalized with severe bronchiolitis during 2011-2014. We used only infancy data to predict asthma at age 6 years. Results: The prevalence of parent-reported asthma at age 6 years was 328/880 (37%). The prevalences of a positive index/score for stringent and loose API, mAPI, and PARS were 21%, 51%, 11%, and 34%, respectively. Area under the receiver operating characteristic curves [95% confidence interval (CI)] ranged from 0.57 (95% CI 0.55-0.60) for mAPI to 0.66 (95% CI 0.63-0.70) for PARS. Conclusions: An asthma prediction tool for high-risk infants is needed to identify those who would benefit most from asthma prevention interventions.

Bronchodilator response by interrupter technique to guide management of preschool wheeze

ObjectiveWe examined relationships between clinical features and pulmonary function before and after inhaled corticosteroid (ICS) treatment in wheezy preschool children, and specifically, whether measuring bronchodilator response (BDR) could predict benefit...

The Effect of Montelukast in Children with Asthma Predictive Index Negative Episodic Viral Wheezing

Background: The effectiveness of montelukast for wheezing in young children is not clear. We aimed to evaluate whether the use of montelukast in the treatment of wheezing affects the number of attacks in children aged 1 to 6 years. Methods: This is a single center study. It was conducted between August 2019-2020. Children with aged 0-6 years old with a wheezing complaint who applied to the pediatric allergy and immunology outpatient clinic were included in the study. Modified asthma predictive index of the patients were evaluated. It was classified as Episodic Viral Wheezing (EVW) or Multiple Trigger Wheezing (MTW) based on the type of wheezing. Montelukast treatment was started and the number of attacks was checked during five months. Results: The total of 141 children who applied with wheezing complaints were included in the study. The majority of the patients were boys (n = 99). The mean age of the children was 4.2 ± 1.5 years. The median number of attacks before treatment was 2 (2-3). In 2.8% of the patients, eczema, in 12.8% of them, rhinitis and in 26.7% of them, elevated eosinophils were detected. IgE levels were 148.25 ± 279.20 IU/mL. According to the number of attacks before treatment, there was a significant decrease in the number of attacks in followup (p &lt; 0.001). Conclusion: In this study, montelukast has been shown to reduce the number of EVW attacks and we believe montelukast may be a potential treatment option for EVW in preschool children.

Performance of Three Asthma Predictive Tools in a Cohort of Infants Hospitalized With Severe Bronchiolitis.

Childhood asthma develops in 30–40% of children with severe bronchiolitis but accurate prediction remains challenging. In a severe bronchiolitis cohort, we applied the Asthma Predictive Index (API), the modified Asthma Predictive Index (mAPI), and the Pediatric Asthma Risk Score (PARS) to predict asthma at age 5 years. We applied the API, mAPI, and PARS to the 17-center cohort of infants hospitalized with severe bronchiolitis during 2011–2014 (35th Multicenter Airway Research Collaboration, MARC-35). We used data from the first 3 years of life including parent interviews, chart review, and specific IgE testing to predict asthma at age 5 years, defined as parent report of clinician-diagnosed asthma. Among 875/921 (95%) children with outcome data, parent-reported asthma was 294/875 (34%). In MARC-35, a positive index/score for stringent and loose API, mAPI, and PARS were 24, 68, 6, and 55%, respectively. The prediction tools' AUCs (95%CI) ranged from 0.57 (95%CI 0.54–0.59) to 0.68 (95%CI 0.65–0.71). The positive likelihood ratios were lower in MARC-35 compared to the published results from the original cohorts. In this high-risk population of infants hospitalized with severe bronchiolitis, API, mAPI, and PARS had sub-optimal performance (AUC <0.8). Highly accurate (AUC >0.8) asthma prediction tools are desired in infants hospitalized with severe bronchiolitis.

Can bronchial challenge test with adenosine or methacholine at preschool age predict school‐age asthma?

Bronchial challenge test (BCT) measures current airways-hyperreactivity, however, its predictive role in pre-school children (<6 years) for the diagnosis of asthma at school age is still debatable. We aimed to find whether preschool children with a positive adenosine or methacholine BCT are more prone to asthma at school age. We included children aged 6-13 years with respiratory symptoms that were previously referred to our pulmonary function laboratory for BCT (methacholine or adenosine, depending on the question asked) at age 10 months to 6 years (baseline). BCT was considered positive based on spirometry results or wheezing, desaturation, and tachypnea reactions. The primaryoutcome measure was asthma diagnosis at school age using the well-validated International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. We used logistic regression analysis to explore whether positive BCT could predict school-age asthma while including age and collected modified asthma predictive indexin the model. One hundred and fifty-one of 189 children (53% males), completed the ISAAC questionnaire (response rate = 80%). Mean ages at BCT and at follow-up were 3.9 ± 1.28 and 9.4 ± 1.85 years, respectively. At baseline, 40 of 67 had a positive adenosine test and 73 of 84 had a positive methacholine BCT. Thirty-nine children were diagnosed with asthma at school age. Logistic regression analysis showed that a positive adenosine test at pre-school age was the best predictor, significantly increasing the odds of asthma at school age by 6.34 (95% CI: 1.23-32.81, p = .028), while methacholine did not show significance (p = .69). Choosing the relevant BCT for the question asked, positive adenosine, but not methacholine test, at pre-school, may predict asthma at school age.

Retrospective Cross-sectional Analysis of Factors Associated with Asthma in a Pediatric Cohort from Turkey.

It is difficult to identify young children at increased risk of developing asthma amongst those with recurrent wheezing. In this study, we aimed to determine factors associated with asthma in Turkish children. We performed a retrospective cross-sectional analysis on factors associated with asthma in 651 children (200 girls, 451 boys) admitted for recurrent wheezing. Amongst all included children, asthma frequency was 57.7%. Maturity, consanguinity, family income, passive smoking, father's, siblings' asthma were not found to be associated with asthma. Factors associated with asthma were: family's, parents', siblings' atopy, family's, mother's asthma, allergic rhinitis and atopic dermatitis, respiratory symptoms between wheezing attacks. The sensitivity (SN) of the modified asthma predictive index (mAPI) was 59.2% with a specificity (SP) of 91.3%, positive predictive index (PPI) of 65.1% and negative predictive index (NPI) of 82.3%. The SN of the modified Prevention and Incidence of Asthma and Mite Allergy (PIAMA) score was 22.9% with a SP of 89.2%, PPI of 84.6%, and NPI of 42.2%. Adjusted odds ratio for mAPI was 12.9, and for the modified PIAMA score 4. Our analysis confirmed previously described factors associated with asthma. Although the SN is limited, the mAPI and PIAMA risk scores can be used to predict asthma in Turkish children. Differential diagnoses and overlaps with other chronic pediatric diseases such as immunodeficiencies need to be carefully excluded when confirming the diagnosis asthma.

Identifying wheezing phenotypes in a pediatric Turkish cohort

Objective Characterization of wheezing phenotypes in children might help to identify the underlying mechanisms through which asthma occurs. In our study, we aimed to describe wheezing phenotypes in Turkish children and to identify risk factors according to phenotypes. Methods 651 wheezy children were evaluated and 5 wheezing phenotypes were described according to age of onset, atopy and persistence at 6 years of age and risk factors were identified. Results Distribution of wheezing phenotypes was transient early wheeze (TEW)(34.9%) non-atopic wheeze (NAW) (18%), atopic wheeze (AW) (22.3%), intermediate onset wheeze (IOW) (11.1%), late onset wheeze (LOW) (11.7%). LOW, AW, and IOW were associated with, father’s, sibling’s and family’s atopy (p:0.001) whereas LOW and AW were associated with mother’s asthma and atopy as well as family’s asthma (p < 0.05). Atopic dermatitis and allergic rhinitis were common of patients with LOW, AW, and IOW (p < 0.05). İnfection was the major trigger for TEW and NAW whereas multiple triggers were common of AW, LOW, and IOW. Allergens were mostly associated with AW, IOW and LOW. Aeroallergen-specific IgE positivity was mostly with AW, IOW, and LOW phenotype. Skin prick tests showed multiple allergen sensitivity in IOW, LOW groups and mostly single allergen in AW phenotype. Modified asthma predictive index (mAPI) positivity was high in all groups except TEW and NAW. Conclusions With this study we classified five wheeze phenotypes and found that atopy and family’s atopy history, maternal asthma were strongly associated with AW, LOW, and IOW phenotypes which were usually effected by allergens or multiple triggers.

Predictive prevalence of asthma in children with allergic rhinosinusitis

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Asthma is one of the most common chronic diseases of childhood. In India - prevalence is 10% to 15% in 5-11 year old children according to the World Health Organization (WHO) statistics. Many of these children go on to develop asthma but the ability to predict school-age asthma based on early life characteristics is currently limited. Early identification of these children at risk will help in reducing respiratory complications later in life. Asthma predictive index (API) - one of the first rule-based predictive models for early identification of children at high risk of subsequent asthma was described by Castro-Rodríguez et al based on the Tucson children’s respiratory study. Objectives of the study were to predict the prevalence of subsequent development of asthma in children with allergic rhinosinusitis using modified asthma predictive index (mAPI).&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This cross-sectional observational study was done in 100 children of age ≤3 years of either gender who visited department of ENT, Saveetha Medical College. Demographic details and the mAPI questionnaire filled by the parent were obtained. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Thirteen percent of the children had positive mAPI score, of which 14% (n=8) were male and 12% (n=5) were female children. Majority of them 77% had positive major criteria and 23% of them had positive minor criteria. Our study shows that 13% of these children who were included in the study will most likely develop asthma in their childhood and adult years.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; A positive mAPI substantially increases probability of future asthma. mAPI’s high predictive ability after a positive test can have clinical value for identifying children at risk of asthma. This study may help clinicians better to identify these at-risk children.&lt;/p&gt;

A Symptom-Based Algorithm for Screening Preschool Children at Risk of Persistent Asthma Symptoms: The CHILD Cohort Study

Background: Asthma is difficult to diagnose in preschool children causing delays in treatment and long-term morbidity. This study aims to develop a short, symptom-based algorithm screening tool for preschool children at 3 years to predict asthma diagnosis, persistent symptoms and morbidity in later childhood. Methods: Developed in the CHILD study cohort, the algorithm uses clinical predictors at 3 years of age to identify children with asthma or persistent symptoms at 5 years and was evaluated against standardized specialist clinician diagnosis and the modified Asthma Predictive Index (mAPI). External validation was performed in the general population Raine cohort (Australia) and the high-risk CAPPS (Canadian) cohort. Predictive accuracy was measured by sensitivity, specificity, AUROC, positive predictive value, and negative predicted value. Findings: The algorithm applied at age 3 years in the CHILD cohort study outperformed physician assessments and the mAPI at age 3 in identifying children whose wheeze persisted to age 5 years (AUROC=0.94), or with an asthma diagnosis at 5 years (AUROC=0.73). It had similar predictive performance for persistent wheeze when validated in the external Raine (AUROC=0.82) and CAPPS (AUROC=0.87) cohorts. Finally, the algorithm outperformed physician diagnoses in predicting subsequent health care burden (ED visits/hospitalization for wheeze/asthma) to age 5 years. Conclusions: Our symptom-based algorithm identifies children at age 3 years likely to suffer from persistent wheeze symptoms and health care burden to 5 years of age. The algorithm could be easily incorporated in electronic medical records to alert physicians of children at high risk for asthma and asthma related morbidity. Funding Statement: Canadian Institutes of Health Research (CIHR), Allergy, Genes and Environment Network of Centers of Excellence (AllerGen NCE, Inc.), Don & Debbie Morrison, Women’s and Children Health Research Institute (WCHRI), Canada Research Chairs (CRC) Declaration of Interests: None. Ethics Approval Statement: This study was approved centrally by the Hamilton Integrated Research Ethics Board (HiREB #07-2929) and all local ethics boards.

A Case-Based Review on the Diagnosis and Treatment Options for Recurrent Wheezing and Asthma in Preschool Children

To summarize the recent evidence on the various wheezing patterns in early life and provide a case-based review with insights into clinical application of individualized therapy in preschool children with recurrent wheezing. Preschool wheezing is often characterized predominantly by the risk domain with exacerbations and relatively limited impairment. In children with intermittent disease and a positive Modified Asthma Predictive Index, intermittent therapy with inhaled corticosteroids (ICSs) should be considered as an initial therapy to prevent exacerbations. Early administration of azithromycin at the onset of lower respiratory tract infections (LRTIs) reduces the risks of progression to severe illnesses in children who have a history of recurrent severe LRTIs, and more information is needed regarding the risks of developing drug-resistant organisms. In preschool children with mild persistent asthma, allergic sensitization to aeroallergens and absolute eosinophil count can help identify children most likely to have a good response to daily ICS. Recent clinical trials in preschool children with severe episodic wheezing and persistent asthma have made a significant impact on the approach for the care of these children, particularly with evidence directing individualized approaches based on specific clinical features and biomarkers.

Associations between patient clinical characteristics and the presence of cytomegalovirus DNA in the bronchoalveolar lavage fluid of children with recurrent wheezing

BackgroundThis study aimed to investigate the occurrence of Cytomegalovirus (CMV) DNA in the Bronchoalveolar lavage fluid (BALF) of children with recurrent wheezing and to identify associations with certain patient clinical characteristics.MethodsIn this cross-sectional study, pediatric patients (age < 36 months) admitted to Soochow University Hospital with recurrent wheezing (≥ 4 episodes of wheezing per year) were enrolled in the study. Cytomegalovirus DNA from their BALF was detected by real-time PCR. Subpopulations of blood immunoglobulins and T lymphocytes were quantified. The clinical characteristics of patients with and without BALF CMV DNA were compared. Comparisons of non-normally distributed continuous variables between groups were made using the Mann-Whitney U-test. Comparisons of frequency distributions were made using the Chi-squared test. Spearman’s rank correlation coefficient was used to evaluate correlations between the number of CMV DNA copies and continuous variables.ResultsA total of 111 patients aged 4 to 36 months (median 14.0 (IQR 8.0–22.0) months) were enrolled on to the study. Cytomegalovirus DNA was detected in 51.4% of patients (n = 111) with recurrent wheeze and was more prevalent among those aged 12 to 36 months with a positive modified asthma predictive index (mAPI) (n = 38, median 23.5 (IQR 19.7–31.2) months) than in those of the same age group with a negative mAPI (n = 25, median 15.0 (IQR 13.0–19.0) months) (57.9% vs. 20.0%, p = 0.003). Bronchoalveolar lavage fluid CMV DNA copy number [median 7560 (IQR 1200–71,150) copies/mL] was positively correlated with the duration of hospitalization (r = 0.33, p = 0.013), and negatively correlated with patient age (r = − 0.41, p = 0.002) and the percentage of BALF eosinophils (r = − 0.38, p = 0.004).ConclusionsCMV infection or reactivation in children with recurrent wheeze is associated with certain clinical characteristics, including younger age and lower levels of BALF eosinophils. Higher CMV DNA copy numbers were associated with a longer duration of hospitalization. Further studies are needed to address whether specific antiviral treatment could be beneficial for BALF CMV positive patients.

Palivizumab prophylaxis, respiratory syncytial virus and subsequent development of asthma.

Respiratory syncytial virus (RSV) infection is a disease commonly encountered during childhood and it may relapse. An experience in the early childhood would induce asthma development in the future. Palivizumab has a proven efficacy for the RSV prophylaxis so it may prevent asthma. Our aim was to evaluate the possible protective effect of palivizumab on the development of asthma by using the modified Asthma Predictive Index (mAPI). This study's data consist of 339 children between 2 to 5 years of age followed up in healthy children unit from 2008 to 2011. Cases were evaluated in terms of wheezing frequency and characteristic features. Evaluations were performed among three groups; palivizumab-treated children born preterm (group 1), palivizumab-untreated children born preterm (group 2) and term newborn children (group 3) with equal number of patients in each group (N.=113). Frequency of the answers about children's experienced wheezing times was significant between groups (P=0.003). A significant difference was found between the groups in terms of the clinician who diagnosed asthma (P=0.045). The groups were compared in terms of the mAPI positivity and a significant difference was found among the groups (P=0.001). Group 1 had lowest and group 3 had highest positivity. Group 1 and group 3 were different (P=0.000), group 2 was found higher than group 1, but was similar to group 3 (P=0.628). This study supports the benefit of administration of palivizumab to premature children to reduce the risk of asthma development.

Up-regulation of serum periostin and squamous cell carcinoma antigen levels in infants with acute bronchitis due to respiratory syncytial virus

BackgroundPeriostin and squamous cell carcinoma antigen (SCCA) are involved in the pathogenesis of asthma. Acute bronchitis due to respiratory syncytial virus (RSV) infection during infancy exhibits an asthma-like pathogenesis, suggesting that it may be associated with the subsequent development of asthma. However, the mechanism by which RSV infection leads to development of asthma has not yet been fully elucidated. MethodsInfants younger than 36 months were enrolled and classified into three groups. Group I included patients hospitalized with RSV-induced bronchitis. These patients were further stratified into two sub-groups according to whether the criteria for the modified Asthma Predictive Index (mAPI) had been met: Group I consisted of mAPI (+) and mAPI (−) patients; Group II included patients with food allergy as a positive control group; and Group III included children with no allergy as a negative control group. Serum periostin and SCCA levels were measured in the groups. This study was registered as a clinical trial (UMIN000012339). ResultsWe enrolled 14 subjects in Group I mAPI (+), 22 in Group I mAPI (−), 18 in Group II, and 18 in Group III. In Group I, the serum periostin and SCCA levels were significantly higher during the acute phase compared with the recovery phase. However, no significant differences were found between Group I mAPI (+) and mAPI (−). ConclusionsThe serum periostin and SCCA levels increased during acute RSV bronchitis. Both periostin and SCCA may play a role in the pathogenesis of acute bronchitis due to RSV.

Wheezing in Infancy: An Overview of Recent Literature.

Wheezing in infancy is a common presentation with many potential causes. In writing this review, we sought to summarize the newest recommendations and testing available for the more common etiologies of wheezing. Regarding the diagnosis of asthma, the modified asthma predictive index has recently been established as a useful predictive tool. Non-breath held multidetector CT with 3D volume rendering airway images is also a newer helpful diagnostic tool for tracheomalacia due to ease of use and its 100% positive predictive value. We found vaccines have greatly reduced the prevalence of epiglottitis, while advances in surgery are improving outcomes in infants with vascular rings. Wheezing in infants is a common problem with an extensive differential diagnosis from relatively benign to life threatening. To prevent over-looking a diagnosis that potentially requires surgical correction or emergent care, we recommend a structured approach to the history and physical exam with targeted testing directed towards the most likely diagnoses as outlined in this review.

Evaluation of pulmonary functions in preschool children born late-preterm.

The aim of this study was to evaluate the pulmonary functions of preschool children born late-preterm. Children aged between 3-7 years who were born at 340/7-366/7 weeks' gestation represented the target sample. Patients with a diagnosis of congenital cardiac, pulmonary and/or muscle diseases were excluded. Respiratory symptoms were evaluated using the modified asthma predictive index and International Study of Asthma and Allergies in Childhood criteria for children aged under and over 6 years, respectively. Skin prick tests were performed. Age-matched healthy controls were chosen according to the criteria proposed by the American Thoracic Society. Lung functions were evaluated using impulse oscillometry study in both groups. Data were recorded in the SPSS program. A total of 139 late-preterms and 75 healthy controls participated in the study. The mean gestational week of the late-preterms was 35.3±0.9 weeks. The main admission diagnosis to neonatal intensive care unit was respiratory distress. In the postdischarge period, 54.1% were hospitalized for pulmonary infections at least once, and 57.8% were passive smoking currently. Aeroallergen sensitivity was detected as 25.8% in the late-preterm group; 34.5% and 15.1% were diagnosed as having asthma and non-asthmatic atopy, respectively. Impulse oscillometry study parameters of R5, R10, and Z5 were higher and X10 and X15 were lower in late-preterms than in controls (p<0.05). Late-preterms with and without respiratory distress in the postnatal period revealed no statistical differences for any parameters. Our findings suggest that presence of increased peripheral airway resistance in late-preterms as compared to term-born controls.

Importance of high sensitivity C-reactive protein in the evaluation of wheezing in children.

AbstractBackgroundIt is important to determine the presence of asthma in children under the age of 3 with recurrent wheezing. Inflammatory markers have been investigated in the diagnosis and treatment of asthma. The aim of the present study was to investigate the relationship between recurrent wheezing with or without modified asthma predictive index (mAPI) positivity and high‐sensitivity‐C reactive protein (hs‐CRP) level in children aged 6–36 months.MethodsNinety‐nine children with recurrent wheezing and 47 healthy children aged 6–36 months were included in the present cross‐sectional, case–control study. Those children with wheezing were divided into two groups according to mAPI positivity.ResultsMean serum hs‐CRP was higher in the recurrent wheezers than in the control group (0.89 ± 1.7 mg/dL vs 0.12 ± 1.3 mg/dL, respectively; P = 0.002). There was a positive correlation between serum total IgE and hs‐CRP (P = 0,003; r = 0348). mAPI positivity was detected in 46 of the recurrent wheezers (46.5%). There was no significant difference in hs‐CRP between the mAPI‐positive and ‐negative groups. The best hs‐CRP cut‐off for differentiating between the patient and control groups was 0.11 mg/dL on receiver operating characteristic analysis (area under curve, 0.658; 95%CI: 0.571–0.744; P &lt; 0.05; sensitivity, 60%; specificity, 61.7%).ConclusionsHigh‐sensitivity CRP can be used to indicate respiratory and systemic inflammation independently of mAPI positivity in wheezy children.

Tidal flow variability measured by impedance pneumography relates to childhood asthma risk.

Lung function variability is a fundamental feature of asthma but has been difficult to quantify in children due to methodological limitations. We assessed the feasibility and clinical implications of overnight flow variability measurement at home using impedance pneumography in young children.44 children aged 3-7 years with recurrent or persistent lower airway symptoms were recruited. Patients were divided into high- or lower-risk groups (HR and LR groups) based on their risk of asthma (modified Asthma Predictive Index), and a third group was formed of children who had a history of wheeze and who were treated with inhaled corticosteroids (ICS group). Tidal volume and the derived flow were recorded through skin electrodes using impedance pneumography at home during sleep. Quantities describing overnight change in expiratory flow-volume minimum curve shape correlation (CSRmin) and respiratory chaoticity (minimum noise limit (NLmin)) were derived.Recordings were successful in 34 children. CSRmin differed between the HR and LR groups (p=0.002) and between the HR and ICS groups (p=0.003), indicating a stronger change in flow profile shape in the HR group. NLmin differed between the HR and LR groups (p=0.014), indicating momentarily lowered chaoticity in the HR group.Impedance pneumography was found feasible for quantifying nocturnal lung function variability and the measured variability was associated with risk of asthma in young children.

The infant and toddler with wheezing.

Recurrent wheezing is common in young infants and toddlers, with 50% of all children having at least one wheezing episode in the first 6 years of life. Initial wheezing episodes in young children often are linked to respiratory infections due to viral pathogens, such as respiratory syncytial virus, human rhinovirus, human metapneumovirus, and influenza virus. Bacterial colonization of the neonatal airway also may be significant in the late development of recurrent wheeze and asthma. Wheezing in young children can be classified into specific phenotypes based on the onset and persistence of wheezing. Although some children will only wheeze transiently in early childhood, persistent wheezing is often classified as immunoglobulin E (IgE) associated and/or atopic or nonatopic. By using a modified asthma predictive index, future development of asthma can be interpreted, especially in high-risk populations. It is recommended to follow National Asthma Education and Prevention Program (NAEPP) guidelines for initiation of treatment; however, asthma management of young children often requires tailored regimens. Inhaled corticosteroids used as a daily controller medication have been shown to aid symptoms and exacerbation control; however, these do not change the natural course of the disease or progression to asthma. Although randomized double-blind studies in preschoolers investigated a role of macrolide antibiotics in early infection as well as high-dose inhaled corticosteroids during severe lower respiratory tract infections, more research is needed in this field to understand mechanisms of asthma development and optimal treatment in this young age group.

Management of Preschool Children with Recurrent Wheezing: Lessons from the NHLBI's Asthma Research Networks

Recurrent wheezing in the preschool children is a common clinical problem, often associated with significant morbidity related to acute episodes. The management of these children has been complicated by a paucity of high-quality clinical trials in this age group. To fill this knowledge gap, National Heart, Lung,and Blood Institute's asthma research networks have performed a series of clinical trials in an effort to provide practitioners with guidance on appropriate management strategies. These studies establish daily inhaled corticosteroid (ICS) therapy in toddlers at high risk for subsequent asthma as an effective approach for the prevention of exacerbations and symptom reduction, but without evidence of disease-modifying properties. Additional studies have confirmed substantial heterogeneity in ICS response, in terms of both efficacy and effect on linear growth.Treatment with intermittent high-dose ICS was demonstrated to be an alternative approach to daily low-dose ICS for preventingsevere exacerbations in toddlers with intermittent butsignificant wheeze and a positive modified asthma predictive index. This review details the findings and clinical implications derived fromthese studies, discuss the utility of biomarkers andthe roleof oral corticosteroids during acute exacerbations, and summarizes ongoing clinical trials in this age group.