Expiratory Airflow Limitation Research Articles

Biologic treatment options for severe asthma.

Asthma is a common condition that causes episodic expiratory airflow limitation due to bronchial smooth muscle constriction and airways inflammation resulting in increased respiratory symptoms and acute asthma exacerbations. Patients with severe asthma have relied on either recurrent courses or daily use of oral corticosteroids (OCS) to control their disease. However a high level of OCS exposure is associated with significant morbidity and mortality. In recent years the elucidation of the role of T2 inflammation underpinning asthma pathogenesis has led to the development of monoclonal antibody (mAb) therapies targeting this pathway. Established therapies now include omalizumab targeting IgE, mepolizumab and reslizumab targeting IL-5, benralizumab targeting the IL-5R and dupilumab targeting IL-4R. For many patients these therapies have been transformative and their use has additionally advanced our understanding of the immunology that underpins the disease. This article reviews the biologic therapies currently available for the treatment of severe asthma.

Pulmonary Disease Is Associated With Human T-Cell Leukemia Virus Type 1c Infection: A Cross-sectional Survey in Remote Aboriginal Communities.

The human T-cell leukemia virus type 1 (HTLV-1) subtype c is endemic to central Australia. We report the first large-scale, community-based, health survey of HTLV-1 and its disease associations in this setting. Aboriginal community residents aged >2 years in 7 remote communities were invited to do a health survey that included a questionnaire, spirometry, and clinical examination by a physician blinded to HTLV-1 status, clinical records, and spirometry results. Blood was drawn for HTLV-1 serology and proviral load (PVL). Pulmonary disease was assessed clinically and spirometrically and, where records were available, radiologically after the clinical assessment. Associations between specific diseases and HTLV-1 status were determined using logistic regression, adjusting for available confounders. Overall, 579 residents (164 children aged 3-17 years; 415 adults) were examined (37.7% of the estimated resident population). HTLV-1 prevalences for children and adults were 6.1% and 39.3%, respectively. No associations were found between HTLV-1 and any assessed clinical condition among children. Chronic pulmonary disease and gait abnormalities were more common among adults with HTLV-1 infection. Adjusted odds ratios among participants with PVL ≥1000 per 105 peripheral blood leukocytes were 7.08 (95% confidence interval [CI], 2.67-18.74; P < .001), 9.81 (95% CI, 3.52-27.35; P < .001), and 14.4 (95% CI, 4.99-41.69; P < .001) for clinically defined chronic pulmonary disease, moderate-severe expiratory airflow limitation, and radiologically determined bronchiectasis/bronchiolitis, respectively, and 5.21 (95% CI, 1.50-18.07; P = .009) for gait abnormalities. In the first study of HTLV-1 disease associations based on community recruitment and blinded assessment, HTLV-1 infection was strongly associated with pulmonary disease and gait abnormalities.

Long Noncoding RNAs in the Regulation of Asthma: Current Research and Clinical Implications.

Asthma is a chronic airway inflammatory disorder related to variable expiratory airflow limitation, leading to wheeze, shortness of breath, chest tightness, and cough. Its characteristic features include airway inflammation, airway remodeling and airway hyperresponsiveness. The pathogenesis of asthma remains extremely complicated and the detailed mechanisms are not clarified. Long noncoding RNAs (lncRNAs) have been reported to play a prominent role in asthma and function as modulators of various aspects in pathological progress of asthma. Here, we summarize recent advances of lncRNAs in asthma pathogenesis to guide future researches, clinical treatment and drug development, including their regulatory functions in the T helper (Th) 1/Th2 imbalance, Th17/T regulatory (Treg) imbalance, eosinophils dysfunction, macrophage polarization, airway smooth muscle cells proliferation, and glucocorticoid insensitivity.

A model-based approach for assessing bronchodilator responsiveness in children: The conventional cutoff revisited

A model-based approach is developed to establish clinically relevant cut-offs for bronchodilator response in children. A dynamic nomogram is proposed for predicting the probability of asthma in childhood clinical practice.

Role of hsCRP as a marker in assessing severity of asthma

Asthma is usually characterized by chronic airway inflammation along with respiratory manifestations like, shortness of breath, wheezing, chest tightness and variable expiratory airflow limitation. Studies have indicated increased levels of systemic markers high sensitivity C-reactive protein in patients with bronchial asthma. Assessment of the levels of high sensitivity C-reactive protein in asthmatic patients.It is a comparative-descriptive and observational study, done during the study period April 2014 – June 2015, and the number of asthmatic patients was 80 and 24 healthy controls. High sensitivity C-reactive protein (hsCRP) levels increased in asthmatic patients irrespective of the use of Inhaled corticosteroids. The mean high sensitivity C-reactive protein level of group A (steroid naïve) is 3.9085 which is higher than that of group B (steroid using patients) 2.7575 and healthy controls 0.5138. Although using Inhaled corticosteroids lead to decrease in hsCRP levels, the difference between the means of hsCRP among the two groups A and B was not statistically significant (p=0.093). But when hsCRP levels of group A and group B are compared with the controls, there was high statistical significance (p=0.001). In Pulmonary function test results, the relationship between hsCRP and FEV1 (forced expiratory volume) showed a negative correlation of hs CRP with FEV1%, and it had even more significant negative correlation in patients who are steroid naïve than patients using steroids. Diminished pulmonary function is related with raise serum hsCRP level more in steroid naive patients. Serum hsCRP can be used as one of the indirect parameters for the assessment of degree of severity in the airways manifestation.

Association Between Mouth Breathing and Asthma: a Systematic Review and Meta-analysis.

This systematic review and meta-analysis evaluated the association between asthma and mouth breathing. We performed a systematic search in the PubMed, SCOPUS, Lilacs, Web of Science, Google Scholar and OpenThesis databases. Asthma is defined as a heterogeneous disease characterized by variable symptoms of wheezing, shortness of breath, chest oppression and/or cough, and limitation of expiratory airflow. Although several studies have examined the association between asthma and mouth breathing, there are no systematic reviews or meta-analyses that synthesize the available bodies of evidence. We used the odds ratio as a measure of the association between asthma and mouth breathing. Summary estimates were calculated using random-effects models, and the risk of bias was estimated using the Newcastle-Ottawa Scale for case-control studies and the National Institutes of Health tool for cross-sectional studies. Nine studies were included in the present systematic review. Data from 12,147 subjects were analyzed, of which 2083 were children and adolescents and 10,064 were adults. We found an association between mouth breathing and asthma in children and adolescents (OR 2.46, 95% CI 1.78-3.39) and in adults (OR 4.60, 95% CI 1.49-14.20). However, limitations were found in the methodological description of the included studies, as well as high heterogeneity among studies evaluating adult populations. This meta-analysis showed an association between mouth breathing and asthma in children, adolescents and adults, but the results should be interpreted with caution. Further studies with standardized criteria for the investigation of mouth breathing are needed.

Measuring Airway Resistance and Characterizing the Flow‐Volume Envelope with External Expiratory Loading in Healthy Adults

Expiratory flow limitation is a key characteristic in chronic obstructive pulmonary disease (COPD). Increased airway resistance occurs due to bronchoconstriction, destruction of elastic tissue in the airways, and mucus hypersecretion from goblet cells caused by irritation of the epithelium. Obstruction can lead to dynamic hyperinflation, dyspnea, and exercise intolerance. However, increased airway resistance is just one of many abnormalities in COPD and asthma ‐ COPD in particular is an exceedingly heterogeneous disease. Therefore, isolating the effects of expiratory airflow limitation is challenging.PURPOSEIn order to study abnormal lung mechanics in isolation, we measured pulmonary function with and without expiratory loading in healthy adults.METHODSForty‐eight volunteers (26±5 yr, 171.8±10.2 cm, 72.2±13.3 kg) completed spirometry and body plethysmography according to the ATS/ERS standards under three randomized conditions: control, expiratory loading of 7 and 11 cmH2O. The expiratory load was added by installing a threshold inspiratory muscle trainer in reverse. We analyzed the shape of the flow‐volume (F‐V) loops with rectangular area ratio (RAR) using custom MATLab software.RESULTSAirway resistance was increased (F[1.5, 27.5]= 446.0, p&lt;0.05) with 7 and 11 cmH2O vs control (9.20±1.02 and 11.76±1.68 cmH2O vs. 2.53± 0.80 cmH2O). RAR (F[1.9, 77.9]= 3.71, p&gt;0.05) was reduced with 7 and 11 cmH2O vs control (0.45±0.07 and 0.47±0.09L vs. 0.48±0.08L). FEV1 was reduced (F[1.6, 60.38.6]= 67.54, p&lt;0.05) with 7 and 11 cmH2O vs control (3.26±0.82 and 3.23±0.79L vs. 4.03±1.04L). FVC was also reduced (F[1.5, 55.31] = 77.71, p&lt;0.05) with 7 and 11 cmH2O vs control (4.15±1.01 and 4.17±1.02L L vs. 5.05±1.33L L). PEF was reduced (F[1.5, 55.99] = 72.69, p&lt;0.05) with 7 and 11 cmH2O vs control (6.02±1.65 and 5.95±1.85L vs. 8.39±2.85L L). FEV1/FVC (F[1.9, 69.17] = 5.5, p&gt; 0.05) and FRC (F[1.863, 33.53]= 0.93, p&lt;0.05) were not different between resistance conditions or compared to the control.CONCLUSIONSExpiratory loading reduced FEV1, FVC, PEF and provided a doseresponse in airway resistance and RAR. There were no differences in FEV1/FVC. While RAR was reduced with expiratory loading, the magnitude was of little clinical importance. Therefore, a concave expiratory F‐V relationship was consistently absent – a key limitation for model comparison with pulmonary function in COPD. This is most likely due to the imposed resistance being applied outside of the airways, leading to higher airway pressures. The higher airway pressures are likely to resist dynamic airway compression and either maintain the equal pressure point position or possibly move it proximally.

Imposed Expiratory Resistance and Pulmonary Function in Young Healthy Volunteers

Expiratory flow limitation is a primary characteristic in chronic obstructive pulmonary disease (COPD) and asthma. High airway resistance results from bronchoconstriction, destruction of elastic tissue, and mucus hypersecretion caused by irritation of the epithelium. As a result, the airways become narrowed. Obstruction can lead to dynamic hyperinflation, dyspnea, and exercise intolerance. However, increased airway resistance is just one of many abnormalities in COPD and asthma – COPD in particular is an exceedingly heterogeneous disease. Isolating the effects of expiratory airflow limitation, alone, is therefore challenging. In order to study abnormal lung mechanics in isolation, we aimed to test whether adjustable imposed external expiratory resistance in young healthy volunteers produced deficits in the flow‐volume relationship similar to that of patients with COPD or asthma.PURPOSEMeasure pulmonary function in young healthy volunteers with and without imposed external expiratory resistance.METHODSThirty‐nine healthy adults (25.6 ± 4.7 years, 171.6 ± 10.5 cm, 72 ± 13.7 kg, 23 men, 16 women) completed standard pulmonary function testing according to the ATS/ERS standards. The testing included four conditions in random order: control, imposed expiratory loading of 7 cmH2O, 11 cmH2O, and 20 cmH2O. Resistance was imposed with a threshold inspiratory muscle trainer (Vacumed, Ventura, CA) installed in reverse in the spirometer (Parvo Medics, Sandy, UT). Volunteers with FEV1/FVC&lt;0.70 were excluded from analysis (n=6).RESULTSParticipants had reduced FEV1 (F[1.6, 51.8] = 68.2, p &lt; 0.05) at 7 and 11 cmH2O vs. control (3.28 ± 0.84 and 3.26 ± 0.83 L, respectively, vs. 4.10 ± 1.08 L). FVC was reduced (F[1.4, 45.6] = 71.6, p &lt; 0.05) at 7 and 11 cmH2O vs control (4.15 ± 1.05 and 4.16 ± 1.05 L, respectively, vs. 5.10 ± 1.36 L). FEV1/FVC was reduced (F[1.5, 46.5] = 5.4, p &lt; 0.05) at 7 and 11 cmH2O vs control (77.6 ± 8.48 and 78.7 ± 6.18 %, respectively, vs. 80.7 ± 5.30 %). PEF was reduced (F[1.6, 51.5] = 74.7, p &lt; 0.05) with 7 and 11 cmH2O vs control (6.12 ± 1.73 and 6.07 ± 1.91 L/s, respectively, vs. 8.70 ± 2.87 L/s).Volunteers with additional imposed expiratory loading of 20 cmH2O (n=7) had reduced FEV1 (F[3, 18] = 10.6, p &lt; 0.05) at 11 and 20 cmH2O vs. control (3.07 ± 0.52, and 3.15 ± 0.63 L, respectively, vs. 4.09 ± 0.91 L). FVC was reduced (F[1.2, 6.9] = 16.7, p &lt; 0.05) at 7, 11, and 20 cmH2O vs control (4.01 ± 0.76, 3.93 ± 0.74, and 4.04 ± 0.85 L, respectively, vs. 5.02 ± 1.14 L). FEV1/FVC was reduced (F[3, 18] = 2.7, p = 0.08) at 20 cmH2O vs control (78.5 ± 5.99 % vs. 81.9 ± 5.48 %, p &lt; 0.05). PEF was reduced (F[1.3, 7.6] = 12.9, p &lt; 0.05) with 7 and 20 cmH2O vs control (5.76 ± 1.22 and 5.50 ± 1.78 L/s, respectively, vs. 8.05 ± 2.47 L/s).CONCLUSIONSImposed expiratory resistance reduced key spirometric variables. A concave expiratory flow‐volume relationship was consistently absent – a key limitation for model comparison with pulmonary function in COPD. This is most likely due to the external imposed loading leading to higher airway pressures. This likely resists dynamic airway compression and either maintains the equal pressure point position or possibly moves it proximally.

Pulmonary rehabilitation: promising nonpharmacological approach for treating asthma?

Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation with a history of respiratory symptoms that vary over time and in intensity, together with variable expiratory airflow limitation. The goal of asthma treatment is to reach symptoms control, reduction in future risk and improvement in quality of life (QoL). Guideline-based pharmacologic therapies and the effect of inhaled steroids and bronchodilators have been widely studied over the past decades. We provide an overview of the available evidence on pulmonary rehabilitation as a nonpharmacologic therapy in asthmatic patients. Recently, some studies have highlighted the promising role of nonpharmacologic therapies in asthma, such as pulmonary rehabilitation demonstrating that a pulmonary rehabilitation programme consisting of exercise training, breathing retraining, educational and psychological support, improve exercise capacity, asthma control and QoL and reduce dyspnea, anxiety, depression and bronchial inflammation at any step of the disease. Pulmonary rehabilitation shows positive results on exercise tolerance, respiratory symptoms and QoL in asthmatic patients at any steps of the diseases. However, additional information is required to better characterize rehabilitation programmes in order to improve clinical care in asthma.

Role of peak expiratory flow rate and chest radiography in children above 5 years of age with acute asthma

Background: Asthma is a heterogeneous disease characterized by cough, wheeze and shortness of breath that vary in intensity and time with variable expiratory airflow limitation, associated with chronic airway inflammation. Aim of the study was to assess the usefulness of Peak Expiratory Flow Rate [PEFR] and oxygen saturation in determining severity of acute asthma, to measure objective change in PEFR and oxygen saturation following bronchodilator therapy and the role of chest X-rays in acute asthma.Methods: A prospective study of 50 children above 5 years with acute asthma who presented to the emergency department in a tertiary care hospital were included. PEFR and oxygen saturation before and after bronchodilator therapy was measured. Indication for chest X-rays, its clinical correlation and change in standard treatment of acute asthma based on X-ray reports was noted.Results: The mean PEFR and PEFR % of expected was lower in severe asthma when compared to moderate asthma and was statistically significant (p&lt;0.001). The % of expected PEFR before salbutamol therapy was 48.78±14.36, which improved significantly to 67.13±14.22 after treatment (p&lt;0.001). Oxygen saturation before and after salbutamol therapy was 94.96 ± 4.11 and 96.96±2.87 respectively with the change being significant (p value &lt;0.001). Chest X-rays were performed in 12 (24%) children as per standard guidelines, of which 1(9%) was abnormal showing right basal consolidation. Chest X-ray correlated with clinical findings in 1 child and the findings on chest X-ray altered the ongoing treatment by addition of antibiotic.Conclusions: PEFR and oxygen saturation is useful in the emergency department to objectively assess the severity of acute asthma and the response to initial bronchodilator therapy. Chest X-rays are not routinely indicated in the standard treatment of acute asthma.

Quantitative Relationship Between Expiratory Airflow Limitation and Dynamic Hyperinflation: A Thermo-statistical Model

Clinical assessment of expiratory flow limitation (EFL) is important for diagnosing chronic pulmonary disease (COPD). Either EFL or dynamic hyperinflation (DH) in COPD has been understood based on wave speed theory, which is widely accepted as the standard concept. However, a theoretical perspective on the relationship between EFL and DH may require another approach. This article proposed another explanation for EFL with the introduction of pulmonary entropy with thermo-statistical considerations on choke state of the pulmonary system. According to Gibbs' thermodynamic equilibrium theory, the choke state of the pulmonary system was characterized by a critical pressure (Pc) emergence in the pulmonary parenchyma, which was proportional to the elastic recoil pressure (Pel) and the slope of maximal flow-volume curve (σ). Thermodynamic balance between energies (supplied from the body as heat, stored as the entropy of lungs, and dissipated in the respiratory system) explained the work of breathing (WOB), by which it was explained that an intrinsic PEEP (PEEPi) was emerging as a difference between sufficient and insufficient WOB for energy demands of the body. It was concluded that EFL would limit the WOB into less than demanded during exercise, and that the difference between demand and performance would induce a product of PEEPi and DH in volume.

Reasons for recurrent visits of emergency department by pediatric asthmatic patients in Al-Qassim Region.

Introduction:Bronchial asthma has been the subject of controversy for several decades. The Global Initiative for Asthma (GINA) describes asthma as “a heterogeneous disease, usually characterized by chronic airway inflammation. It is defined by the history of respiratory symptoms such as wheeze, shortness of breath, chest tightness, and cough that vary over time and in intensity, together with variable expiratory airflow limitation.“ Although not strictly a definition, this description captures the essential features for clinical purposes. Bronchial asthma is defined as a chronic lung disease characterized by airway obstruction, inflammation and hyper-responsiveness that leads to symptoms like wheezing, coughing, chest tightening and shortness of breath especially at night or in the morning. It is one of the most common medical emergency conditions in the pediatrics all over the world. The primary care provider is the cornerstone of this study; his/her awareness about reasons of recurrent visits of emergency department by pediatric asthmatic patients would help to reduce the frequency of ED visits, which lead to minimizing the load on hospitals by addressing patient's concerns, correcting some misconceptions, and improving the patients' and their parents' knowledge and awareness.Aim:This study aims to identify the predictors associated with frequent visits to the ED among asthmatic children at main governmental hospitals in Al-Qassim Region.Materials and Methods:This is a cross-sectional study conducted at three different emergency departments in Qassim region such as Maternity and Children Hospital in Buraidah, King Saud Hospital in Unayzah, and Alrass General Hospital. A validated interview questionnaire was used which includes general demographic characteristics, whether the caregiver has been educated about asthma as a disease, about the use of medicines and inhalers, about the management of symptoms, reasons for using the ED for asthma care, prescription received during the ED visit, and referral from ED.Results:Children with less than 3 visits to ED for the last 6 months were 70.3% while those with 3 or more visits were 29.7%. Nearly all patients (88.3%) had already been diagnosed with asthma with their attending physician. The most commonly known medication was beta-agonist (62%) while the most common reason for ED visit was “to obtain oxygen“ and “to obtain a bronchodilator.“ The prevalence of ED referral to PHC was low (9.7%). Based on the adjusted regression model, we observed that medication used (AOR = 1.760, P = 0.046) and referral from ED (AOR = 3.711, P < 0.001) were the significant factors being associated with 3 or more visits to ED.Conclusion:Recurrent ED visitation of children with asthma was moderately low. Furthermore, medication used and referral from ED were identified as the predictors being associated with recurrent visits to ED. Further research is needed in order to validate the predictors being associated with recurrent ED visitation of asthmatic children in our region.

COMPARATIVE OUTCOMES BETWEEN INHALED BUDESONIDE AND ORAL MONTELUKAST IN MILD PERSISTENT CHILDHOOD ASTHMA

Background: Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation. It is defined by the history of recurrent respiratory symptoms such as wheeze, shortness of breath, chest tightness and cough that vary over time and in intensity, together with variable expiratory airflow limitation.&#x0D; Aim: To compare the clinical efficacy of oral montelukast with inhaled budesonide as controller medication in mild persistent childhood asthma.&#x0D; Methods: 54 Children of both genders aged 3 to 12 years, diagnosed as mild persistent childhood asthma in OPD and in pediatric indoor admissions at the tertiary care Hospital in Mumbai were enrolled in this randomized prospective parallel-group comparative study. 28 (51.9%) patients of group A were started on Oral montelukast &amp; 26 (48.1%) of group B were started on inhaled budesonide.&#x0D; Results: Amongst patients of Group A, 9 were asymptomatic &amp; 19 were symptomatic at 4 weeks of treatment.10 were asymptomatic &amp; 18 were symptomatic at 3 months of treatment. P-Value was 0.09 suggesting no significant change/improvement in control of asthma symptoms at 3months than at 4 weeks in children treated with oral montelukast. Out of 26 patients of Group B, 6 were asymptomatic &amp; 20 were symptomatic at 4 weeks of treatment. 17 were asymptomatic &amp; 9 were symptomatic at 3 months of treatment. P-Value was 0.046 suggesting a statistically significant improvement in control of asthma symptoms at 3 months than at 4 weeks in children treated with inhaled budesonide.&#x0D; Conclusion: More children on inhaled budesonide were controlled on their asthma symptoms, required significantly less reliever medications, had lesser episodes of night awakening due to asthma symptoms and had improvement in their day-time symptoms and activity than those on oral montelukast.

The Global Impact of Asthma in Adult Populations.

Asthma is a disease characterized by chronic airway inflammation, leading to intermittent symptoms of wheeze, dyspnea, cough and chest tightness in combination with variable expiratory airway obstruction. Clinical diagnosis is usually established based on the presence of symptoms and documented variability in expiratory airflow limitation as measured by pulmonary function testing. Presently, asthma is a major chronic disease affecting approximately 334 million people worldwide. The epidemic spares no age group, race or ethnicity; however ethnicity and socioeconomic status do influence the prevalence, morbidity and mortality of asthma in the United States and various countries throughout the world. Moreover, asthma places a huge burden at the societal, financial and health-care levels of multiple nations.

Should vitamin D be routinely checked for all chronic obstructive pulmonary disease patients?

Aims and Objectives:This study aimed to compare the vitamin D levels between chronic obstructive pulmonary disease (COPD) patients and healthy controls and to describe the correlation between vitamin D levels and lung functions.Methods:Fifty COPD patients (cases) and 30 healthy volunteers (controls) were recruited and their serum vitamin D level was measured together with lung function (forced vital capacity and forced expiratory volume in 1 s [FEV1]) by spirometry. vitamin D was categorized as ≤20 nmol/l: deficient, 21–50 nmol/l: inadequate, and ≥51 nmol/l as sufficient.Results:In this case–control cross-sectional study, lower vitamin D levels were associated with lower lung function in both cases as well as controls, the effect being more pronounced in cases. Mean FEV1 at vitamin D ≤20 nmol/l (0.98 ± 0.40 vs. controls 1.93 ± 0.24 with P = 0.006), mean FEV1 at vitamin D 21–50 nmol/l (1.55 ± 0.54 vs. 2.20 ± 0.31 with P = 0.000), and mean FEV1 at vitamin D ≥51 nmol/l (2.06 ± 0.54 vs. 2.20 ± 0.31 with P = 0.002). Moreover, the severity of predicted postbronchodilator FEV1% was also much lower among COPD cohort versus healthy volunteers (mean FEV1%: cases 47.88 ± 14.22 vs. controls 58.76 ± 15.05 with P = 0.002).Conclusions:Importantly, lung function in both the groups was affected by decreased vitamin D level; decrease in FEV1 was more pronounced among COPD patients compared to controls showing more expiratory airflow limitation. Vitamin D levels are associated with changes in lung function in cases of COPD as well as healthy controls. Larger studies to confirm the association in Indian context are required and routine assessment of vitamin D may be undertaken to obviate the effects of low vitmain D level on lung function.

Magnesium Concentration in Asthma Patients in Gaza Strip - Case Control Study

Asthma is a common heterogeneous inflammatory chronic disorder of the airways. It is “defined by the history of respiratory symptoms such as wheeze, shortness of breath, chest tightness, and cough that vary over time and in intensity often with variable expiratory airflow limitation can be demonstrated”. According to the World Health Organization, asthma is the most common chronic respiratory disorder among children. Magnesium deficiency is associated with increased contractility of smooth muscle cells. Since contractility of bronchial smooth muscle is important in patients with asthma, magnesium deficiency could negatively influence the clinical condition. On the basis of the critical role of Mg in the regulation of bronchial smooth muscle, studies have shown that intravenous application or inhalation of Mg could alleviate symptoms in asthmatic patient. In the present study which was a case-control study plasma concentration of magnesium in 50 asthma patients (27 male, 23 female) in Gaza strip were measured and compare with 50 healthy non-asthmatic controls (37 male, 13 female). Questionnaire interview was applied. The concentrations of Mg were measured by using spectrophotometer. The mean±SD magnesium level in plasma was 1.52±0.4 mg/dl, 2.02±0.27 mg/dl in cases and control respectively, there was statically significant difference between cases and control (P=0.000). Thirty-nine (78%) of cases had Mg deficiency while seven (14%) of control had Mg deficiency. Seven (14%) of patient had sensitivity to dairy product (P=0.031). Forty-five (90%) of patient had health problems especially frequent inflammation of eyes, nose and throat (P=0.000). There were significant differences between cases and control in family history of disease (P=0.000). The finding of this study demonstrate that asthmatics patient had lower plasma magnesium level compared to healthy controls in Gaza strip.

Prevalence of bronchial asthma in primary school students in Assiut

Objective Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation. It is defined by the history of respiratory symptoms such as wheezing, shortness of breath, chest tightness, and cough that vary over time and in intensity, together with variable expiratory airflow limitation. Patients and methods This study was conducted on primary school students of Assiut Governorate and some villages connected with Assiut Pediatric Hospital from April 1, 2017, to October 1, 2017; students aged 9–12 years were eligible for the study. On the basis of the International Study of Allergy and Asthma in Childhood, a modified questionnaire was formulated to fulfill the aims of the study. We distributed the questionnaire (in Arabic) to be answered by students and their caregivers after explaining the questions. Results This was a study carried out on the prevalence of bronchial asthma in Assiut district among primary school children, and it shows that Assiut children have a prevalence of asthma of 7.6%.

A role of impulse oscillometry for diagnosis of mild bronchial obstruction

The aim of this study was to investigate a role of impulse oscillometry (IO) for detection of mild bronchial obstruction. Methods . The study involved 87 patients with different respiratory diseases. Bronchial obstruction according to spirometry results was found in 50 patients (the study group). The control group patients did not demonstrate any abnormalities in spirometry, body plethysmography and lung diffusing test. Results . An abnormal increase in frequency-dependent resistive component of respiratory impedance (Rrs) at the oscillation frequency of 5Hrz and 10 Hrz [both the relative oscillation frequency (Rrs5–Rrs20)/Rrs20 and the absolute oscillation frequency (Rrs5–Rrs20)] was found in patients with mild bronchial obstruction. The resonance frequency (fres) shifted towards higher frequency; reactance area (AX) increase and expiratory airflow (DXrs5) limitation were also found in those patients. Rrs5, Rrs20, and the reactive resistance (Xrs5) were within the normal range. Conclusion . Rrs5 и Xrs5 could detect mild bronchial obstruction only in 32 % of the cases. AX is more useful parameter as it increased in 64% of the patients. The severity of bronchial obstruction diagnosed with IO or spirometry was not identical in some cases.

Underdiagnosis and Overdiagnosis of Asthma.

Asthma is diagnosed on the basis of respiratory symptoms of wheeze, cough, chest tightness, and/or dyspnea together with physiologic evidence of variable expiratory airflow limitation. The prevalence of asthma varies widely around the world, ranging from 0.2% to 21.0% in adults and from 2.8% to 37.6% in 6- to 7-year-old children. Population-based studies in children, adults, and the elderly suggest that from 20% to 70% of people with asthma in the community remain undiagnosed and hence untreated. Underdiagnosis of asthma has been found to be associated with underreporting of respiratory symptoms by patients to physicians as well as poor socioeconomic status. On the opposite side of the spectrum, studies of patients with physician-diagnosed asthma suggest that 30-35% of adults and children diagnosed with asthma do not have current asthma, suggesting that asthma is also overdiagnosed in the community. Overdiagnosis of current asthma can occur because of physicians' failure to confirm variable airflow limitation at the time of diagnosis or when sustained clinical remission of disease goes unrecognized. In this review, we define under- and overdiagnosis and explore the prevalence and burden of under- and overdiagnosis of asthma both in patients and within healthcare systems. We further describe potential solutions to prevent under- and overdiagnosis of asthma.

Asthma treatment in children: A pragmatic approach

Background. Asthma is a heterogeneous condition characterised by chronic inflammation and variable expiratory airflow limitation, with airway reversibility. Management of chronic inflammation with anti-asthma medication improves asthma control and quality of life. Objectives. To provide an evidence-based approach for chronic asthma management in young children and adolescents and provide guidance on the use of new asthma drugs in children. Methods. The South African Childhood Asthma Working Group (SACAWG) convened in January 2017. The asthma treatment task group reviewed the available scientific literature and international asthma treatment guidelines. The evidence was then graded according to the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system and recommendations were made based on scientific evidence and local context. Asthma management recommendations were made for children ˂6 years of age and older children and adolescents, as well as for stepping up and stepping down of therapy. This review does not include biologics or novel asthma drugs, which are covered in another CME article in this edition of SAMJ . Conclusions. To ensure good response, treatment and adherence, type of medication, device and checking of technique are all critical. Stepping up of therapy should be done only after ensuring good adherence and technique. Once therapeutic response is achieved, medication administration has to be stepped down to improve ease of use and avoid unnecessary side-effects.