Management of the acute exacerbation of asthma

Thai pediatricians' current practice toward childhood asthma

BACKGROUND

Childhood asthma is a substantial health burden in Thailand. Due to a lack of pediatric respiratory specialists (pediatric pulmonologists and allergists; RS), most Thai children are cared for by general pediatricians (pediatric primary care providers (PCP)).

OBJECTIVES

We investigated whether current practices of Thai pediatricians complied with asthma guidelines and compared practices (diagnosis and treatments) provided by PCP and RS.

METHODS

A cross-sectional study was conducted using electronic surveys including four case scenarios of different asthma phenotypes distributed to Thai pediatricians. Asthma diagnosis and management were evaluated for compliance with standard guidelines. The practices of PCP and RS were compared.

RESULTS

From 800 surveys distributed, there were 405 respondents (51%). Most respondents (81%) were PCP, who preferred to use clinical diagnosis rather than laboratory investigations to diagnose asthma. For acute asthmatic attacks, 58% of the pediatricians prescribed a systemic corticosteroid. For uncontrolled asthma, 89% of the pediatricians prescribed at least one controller. For exercise-induced bronchospasm, 55% of the pediatricians chose an inhaled bronchodilator, while 38% chose a leukotriene receptor antagonist (LTRA). For virus-induced wheeze, 40% of the respondents chose an LTRA, while 15% chose inhaled corticosteroids (ICS). PCP prescribed more oral bronchodilators (31% vs. 18%, p = 0.02), antibiotics (20% vs. 6%, p < 0.001), and antihistamines (13% vs. 0%, p = 0.02) than RS for the management of an acute asthmatic attack.

CONCLUSIONS

Most of the Thai pediatricians' practices toward diagnosis and treatment of acute asthmatic attack and uncontrolled asthma conform to the guidelines. PCP prescribed more oral bronchodilators, antibiotics, and antihistamines than RS.

The association between farming activities and respiratory health in rural school age children

This study assessed the prevalence of asthma in Canadian children living on and off farms and the risk of asthma and respiratory symptoms of children exposed to certain farming activities. A cross-sectional survey was sent to parents of school children ages 6 to 13 living in an agricultural community in rural Saskatchewan. History of asthma and respiratory symptoms (cough, phlegm, or wheeze), location of home, and exposure to farming activities including haying, harvesting, moving, or playing with hay bales, feeding livestock, cleaning or playing in barns, cleaning pens, and emptying or filling grain bins were assessed. The response rate was 90.6% (n = 553). The prevalence of asthma and respiratory symptoms were 18.8% and 39.8%, respectively, and did not differ by home location (farm/nonfarm). In the adjusted multivariable models conducted with each farming activity separately, children who were exposed to emptying and filling of grain bins had a higher odds of asthma (odds [OR] = 2.18, 95% confidence interval [CI]: 1.03-4.62]. Reports of playing on or near hay bales (OR = 1.89, 95% CI:1.19-3.01), (OR = 2.08, 95% CI:1.07-4.06), and cleaning pens (OR = 2.70, 95% CI:1.05-6.97) were associated with increased respiratory symptoms. Certain farming activities associated with dust and animals appear to be risk factors for asthma and respiratory symptoms in this study population and should be avoided.

Reversal of bronchial obstruction with bi-level positive airway pressure and nebulization in patients with acute asthma

Jet nebulization (JN) and non-invasive mechanical ventilation (NIMV) through bi-level pressure is commonly used in emergency and intensive care of patients experiencing an acute exacerbation of asthma. However, a scientific basis for effect of JN coupled with NIMV is unclear. Objective. To evaluate the effect of jet nebulization administered during spontaneous breathing with that of nebulization with NIV at two levels of inspiratory and expiratory pressures resistance in patients experiencing an acute asthmatic episode. Methods. A prospective, randomized controlled study of 36 patients with severe asthma (forced expiratory volume in 1 second [FEV(1)] less than 60% of predicted) selected with a sample of patients who presented to the emergency department. Subjects were randomized into three groups: control group (nebulization with the use of an unpressured mask), experimental group 1 (nebulization and non-invasive positive pressure with inspiratory positive airway pressure [IPAP] = 15 cm H(2)O, and expiratory positive airway pressure [EPAP] = 5 cm H(2)O), and experimental group 2 (nebulization and non-invasive positive pressure with IPAP = 15 cm H(2)O and EPAP = 10 cm H(2)O). Bronchodilators were administered with JN for all groups. Dependent measures were recorded before and after 30 minutes of each intervention and included respiratory rate (RR), heart rate (HR), oxygen saturation (SpO(2)), peak expiratory flow (PEF), forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and forced expiratory flow between 25 and 75% (FEF(25-75)). Results. The group E2 showed an increase of the peak expiratory flow (PEF), forced vital capacity (FVC), FEV(1) (p < 0.03) and F(25-75%) (p < 0.000) when compared before and 30 minutes after JN+NIMV. In group E1 the PFE (p < 0.000) reached a significant increase after JN+ NIMV. RR decreased before and after treatment in group E1 only (p = 0.04). Conclusion. Nebulization coupled with NIV in patients with acute asthma has the potential to reduce bronchial obstruction and symptoms secondary to augmented PEF compared with nebulization during spontaneous breathing. In reversing bronchial obstruction, this combination appears to be more efficacious when a low pressure delta is used in combination with a high positive pressure at the end of expiration.

An overview of asthma

Asthma is a disease characterized by reversible airflow obstruction and airway hyperresponsiveness. This disease accounts for thousands of hospitalizations each year. Critical care nurses play an important role in the management of acute asthma and in the prevention of acute exacerbations. This article presents an overview of asthma, its pathophysiology, signs and symptoms, and management.

Systemic corticosteroid therapy for acute asthma exacerbations

Acute exacerbations of asthma may represent reactions to airway irritants or failures of chronic treatment. The costs to both the patient and society are high. Exacerbations often are frightening episodes that can cause significant morbidity and sometimes death. The emergency department (ED) visits and hospitalizations often required lead to significant health care expenses. Thus, preventing and optimizing management of acute exacerbations is critical. Corticosteroids are a cornerstone of asthma therapy. They have been shown to lower admission rates and reduce risk of relapse. This article provides an overview of the role of corticosteroids (including betamethasone, dexamethasone, methylprednisolone, and prednisolone) in the management of acute asthma exacerbations, with an aim toward effective decision making about the choice of therapy.

Advances in asthma and COPD management: delivering CFC-free inhaled therapy using Modulite technology

Inhaled corticosteroids (ICS) and long-acting beta-agonists (LABA) are currently used in the management of asthma and chronic obstructive pulmonary disease (COPD). Localized targeted delivery of these drugs into the lungs is achieved by means of two types of inhalation devices; pressurized metered-dose inhalers (pMDIs) and dry powder-inhalers (DPIs). For environmental reasons, the chlorofluorocarbon (CFC) propellants used in pMDIs are now being replaced by ozone friendly hydrofluoroalkanes (HFAs). These new generation HFA-based pMDIs, developed to provide effective lung deposition of the active moiety, have a favorable safety and tolerability profile. However, HFA-based re-formulation of LABAs and ICS for pMDIs presents particular technical difficulties, especially in terms of ensuring dose content uniformity. This review focuses on the technology and clinical efficacy of the HFA solution pMDIs using Modulite platform technology (Chiesi Farmaceutici S.p.A). Modulite technology allows the development of HFA solution formulations that can mimic the established CFC-based drug formulations on a microgram to microgram basis and provides formulations with novel particle size distributions that improve on existing delivery systems; by manipulation of aerosol clouds and particle size, the delivery of HFA-formulated drugs can be optimized to either achieve fine particle fractions and deposition patterns similar to established CFC-based drug formulations, thus facilitating the transition to new environment-friendly pMDIs in the clinical setting, or achieve finer drug particles able to penetrate deeper into the bronchi for targeted drug delivery as medical need may dictate. Long-term, multiple-dose clinical studies of Modulite formulations of beclomethasone dipropionate (BDP), budesonide and formoterol have been demonstrated to be therapeutically equivalent to their respective previously established CFC or DPI formulations. As a result, a number of Modulite pMDIs have either recently gained regulatory approval in several European countries, or have completed clinical trials and are in the regulatory submission phase. Availability, in pMDI form, of drugs like formoterol, ICSs, and ICS/LABA combinations, all central to the effective management of asthma and COPD, is therefore expected to impact positively in assuring the continued availability of vital treatment options to patients and physicians.

Anticholinergic agents in asthma: chronic bronchodilator therapy, relief of acute severe asthma, reduction of chronic viral inflammation and prevention of airway remodeling

PURPOSE OF REVIEW

It is difficult to identify specific groups of asthmatic patients who may benefit from acute or chronic use of anticholinergic agents. Therefore, an important consideration is how anticholinergic agents can be used to achieve clinically effective treatment of asthma.

RECENT FINDINGS

A genotype-stratified study revealed that greater bronchoprotective effect of anticholinergic agents was observed in asthmatic patients with the Arg/Arg genotype of the beta2-adrenergic receptor. Anticholinergic agents could add to the bronchodilation obtained with beta2-agonists on acute severe asthma. CD8+ T lymphocytes induced by chronic hepatitis C viral infection causes chronic obstructive pulmonary disease-like inflammation in asthma. Virus-specific CD8+ T lymphocytes may induce cholinergic activation in asthma through M2 receptor dysfunction. Therefore, anticholinergic agents are highly effective for asthma associated with chronic viral infection. In contrast, asthma with chronic obstructive pulmonary disease-like inflammation appears to be poorly responsive to beta2-agonists and can lead to partially irreversible airflow limitation. Moreover, a recent report suggested that treatment with inhaled tiotropium bromide markedly inhibited the increase in airway smooth muscle mass, myosin expression, and contractility in asthma.

SUMMARY

Anticholinergic agents may benefit stable asthmatics, particularly those who have the Arg/Arg genotype. These agents have a demonstrated role in combination with beta2-agonists in the treatment of acute severe asthma, and may benefit asthmatics with chronic obstructive pulmonary disease-like inflammation. Moreover, these agents could be also beneficial in preventing airway remodeling in asthmatic airways.

Office-based management of asthma in adults

Asthma is a systemic inflammatory disease manifested most often as episodic dyspnea with wheeze or cough. It is the pulmonary manifestation of an immunoregulatory imbalance that involves the release of pro-inflammatory cytokines into the airway by either IgE-mediated or other poorly understood immunologic mechanisms. Efforts are currently underway to identify asthma susceptibility genes that will allow office-based internists of the future to determine a genetic risk profile to identify asthma susceptibility and risk factors before it occurs. Present therapies allow management of the great majority of adults with asthma such that these patients can have normal lifestyles.

Children with asthma: a concern for the family

According to the Centers for Disease Control and Prevention (CDC), asthma is a growing health problem in the United States; there are now 9 million children under the age of 18 diagnosed with this illness. As a chronic illness, asthma has a major impact on the life of the individual as well as the family. This article illustrates the process of incorporation of standardized guidelines for the management of pediatric asthma through the collaborative efforts of the nurse, family, and child. Inclusion of a written asthma management plan that is client specific can help to ensure successful management of this common and deadly childhood illness. It is essential that nurses focus on educating the families of children with asthma in an effort to assist them in managing this chronic illness. A case study approach is used to illustrate the complexity of the problem and facilitate the nurse's understanding of the process of assessment of need.

Childhood asthma: breakthroughs and challenges

As we move forward, our goal is to control and eliminate asthma and other allergic disorders. This may come through broadly applied manipulation of environmental, dietary, and infectious risk factors, possibly during the perinatal period. Or we may learn to identify genetically susceptible children and to intervene with individualized genotype-specific treatment before the onset of disease. Maybe we'll learn how to block the mechanisms that give rise to chronic inflammation, or how to subdue Th2 activation. However, as the Swedish proverb says--Don't throw away the old bucket until you know whether the new one holds water. To continue using the old bucket, we have to fix the leaks. One approach to reducing asthma disparities is through traditional disease prevention stages. Primary prevention targets asthma incidence; secondary prevention mitigates established disease and involves disease detection, management, and control; and tertiary prevention is the reduction of complications caused by severe disease. Once causative factors at each level of disease prevention are understood, this knowledge can be translated into clinical practice and public health policy. We need reliable diagnostic criteria to provide correct treatment for infants and toddlers. This will require longitudinal cohort studies supported by assessment of pulmonary function and inflammatory markers. We must find ways to convince more physicians to embrace controller therapy for more severe disease, and to identify the patients with less severe disease who also require ongoing controller therapy. We need to close the gap between what we know and what we do in practice. We need to link basic research to healthcare delivery, and to gain acceptance and support from the intended recipients of new interventions. We need better strategies for improving adherence. We need accountability, foresight, and imagination.