Sudden-onset asthma exacerbations: clinical features, response to therapy, and 2-week follow-up. Multicenter Airway Research Collaboration (MARC) investigators

Primary Care Asthma Attack Prediction Models for Adults: A Systematic Review of Reported Methodologies and Outcomes

Prognostic models hold great potential for predicting asthma exacerbations, providing opportunities for early intervention, and are a popular area of current research. However, it is unclear how models should be compared and contrasted, given their differences in both design and performance, particularly with a view to potential implementation in routine practice. This systematic review aimed to identify novel predictive models of asthma attacks in adults and compare differences in construction related to populations, outcome definitions, prediction time horizons, algorithms, validation, and performance estimation. Twenty-five studies were identified for comparison, with varying definitions of asthma attacks and prediction event time horizons ranging from 15 days to 30 months. The most commonly used algorithm was logistic regression (20/25 studies); however, none of the six which tested multiple algorithms identified it as highest performing algorithm. The effect of various study design characteristics on performance was evaluated in order to provide context to the limitations of highly performing models. Models used a variety of constructs, which affected both their performance and their viability for implementation in routine practice. Consultation with stakeholders is necessary to identify priorities for model refinement and to create a benchmark of acceptable performance for implementation in clinical practice.

Towards a personalised treatment approach for asthma attacks

Asthma attacks (exacerbations) are common, accounting for over 90 000 UK hospital admissions per annum. They kill nearly 1500 people per year in the UK, have significant associated direct and indirect costs and lead to accelerated and permanent loss of lung function. The recognition of asthma as a heterogeneous condition with multiple phenotypes has revolutionised the approach to the long-term management of the condition, with greater emphasis on personalised treatment and the introduction of the treatable traits concept. In contrast asthma attacks are poorly defined and understood and our treatment approach consists of bronchodilators and systemic corticosteroids. This review aims to explore the current limitations in the description, assessment and management of asthma attacks. We will outline the risk factors for attacks, strategies to modify this risk and describe the recognised characteristics of attacks as a first step towards the development of an approach for phenotyping and personalising the treatment of these critically important events. By doing this, we hope to gradually improve asthma attack treatment and reduce the adverse effects associated with recurrent courses of corticosteroids.

Exacerbation-Prone Asthma

Patients who are prone to exacerbations of asthma experience significant costs in terms of missed work and school, acute care visits, and hospitalizations. Exacerbations are largely driven by environmental exposures including pollutants, stress, and viral and bacterial pathogens. These exposures are most likely to induce acute severe "asthma attacks" in high-risk patients. These personal risk factors for exacerbations can vary with the phenotype of asthma and age of the patient. In children, allergic sensitization is a strong risk factor, especially for those children who develop sensitization early in life. Airway inflammation is an important risk factor, and biomarkers are under evaluation for utility in detecting eosinophilic and type 2 inflammation and neutrophilic inflammation as indicators of risk for recurrent exacerbations. Insights into inflammatory mechanisms have led to new approaches to prevent exacerbations using mAb-based biologics that target specific type 2 pathways. Challenges remain in developing an evidence base to support precision interventions with these effective yet expensive therapies, and in determining whether these treatments will be safe and effective in young children. Unfortunately, there has been less progress in developing treatments for acute exacerbations. Hopefully, greater understanding of mechanisms relating airway viruses, bacteria, mucin production, and neutrophilic inflammatory responses will lead to additional treatment options for patients experiencing acute exacerbations.

Acute Severe Asthma in Adolescent and Adult Patients: Current Perspectives on Assessment and Management

Asthma is a chronic airway inflammatory disease that is associated with variable expiratory flow, variable respiratory symptoms, and exacerbations which sometimes require hospitalization or may be fatal. It is not only patients with severe and poorly controlled asthma that are at risk for an acute severe exacerbation, but this has also been observed in patients with otherwise mild or moderate asthma. This review discusses current aspects on the pathogenesis and pathophysiology of acute severe asthma exacerbations and provides the current perspectives on the management of acute severe asthma attacks in the emergency department and the intensive care unit.

The Saudi Initiative for Asthma - 2019 Update: Guidelines for the diagnosis and management of asthma in adults and children

This is the fourth version of the updated guidelines for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of the SINA is to have guidelines that are up to date, simple to understand, and easy to use by healthcare workers dealing with asthma patients. To facilitate achieving the goals of asthma management, the SINA panel approach is mainly based on the assessment of symptom control and risk for both adults and children. The approach to asthma management is now more aligned for different age groups. The guidelines have focused more on personalized approaches reflecting better understanding of disease heterogeneity with integration of recommendations related to biologic agents, evidence-based updates on treatment, and role of immunotherapy in management. The medication appendix has also been updated with the addition of recent evidence, new indications for existing medication, and new medications. The guidelines are constructed based on the available evidence, local literature, and current situation at national and regional levels. There is also an emphasis on patient–doctor partnership in the management that also includes a self-management plan.

The Saudi Initiative for Asthma - 2016 update: Guidelines for the diagnosis and management of asthma in adults and children

This is an updated guideline for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have guidelines that are up to date, simple to understand and easy to use by nonasthma specialists, including primary care and general practice physicians. SINA approach is mainly based on symptom control and assessment of risk as it is the ultimate goal of treatment. The new SINA guidelines include updates of acute and chronic asthma management, with more emphasis on the use of asthma control in the management of asthma in adults and children, inclusion of a new medication appendix, and keeping consistency on the management at different age groups. The section on asthma in children is rewritten and expanded where the approach is stratified based on the age. The guidelines are constructed based on the available evidence, local literature, and the current situation in Saudi Arabia. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

Emergency department visits for acute asthma by adults who ran out of their inhaled medications

This study was designed to determine the percentage of asthma-related emergency department (ED) visits made by patients who recently ran out of their inhaled short-acting beta-agonists or inhaled corticosteroids and to characterize this understudied patient population. A secondary analysis was performed of data from four ED-based multicenter studies of acute asthma during 1996-1998 (n = 64 EDs). In each study, consecutive adult patients, aged 18-54 years, with acute asthma underwent a structured interview that assessed running out of inhaled medications. The analytic cohort comprised 1095 adults. Overall, 324 patients (30%; 95% confidence interval [CI], 27-32%) ran out of either of their inhaled beta-agonists or inhaled corticosteroids during the week before their index ED visit; 311 (28%; 95% CI, 26-31%) ran out of inhaled beta-agonists per se. Among a subset of 518 patients on inhaled corticosteroids, 55 patients (11%; 95% CI, 8-14%) ran out of inhaled corticosteroids. In the multivariable model, predictors of running out of an asthma medication were male sex, non-Hispanic black race, Hispanic ethnicity, no insurance, lower household income, and use of EDs as the preferred source of asthma prescriptions (all p < 0.05). Among patients who ran out of medications, 49% (95% CI, 43-55%) ran out of inhaled beta-agonists and 72% (95% CI, 58-84%) ran out of inhaled corticosteroids, before onset of their acute asthma symptoms. In 1095 adult ED patients with acute asthma, we found that 30% ran out of their inhaled asthma medications before the ED visit. Asthma patients who ran out of medications had sociodemographic characteristics that may help with identification of preventable ED visits. Multifaceted strategies needed to ensure optimal use of inhaled medications are warranted.

Magnesium sulphate in acute severe asthma in children (MAGNETIC): a randomised, placebo-controlled trial

BACKGROUND

Little evidence is available for the effect of nebulised magnesium sulphate (MgSO(4)) in acute asthma in children. We assessed the effect of MgSO(4) treatment in children with severe acute asthma.

METHODS

In this randomised placebo-controlled, multi-centre, parallel trial, we enrolled children (aged 2-16 years) with severe acute asthma who did not respond to standard inhaled treatment from 30 hospitals in the UK. Children were randomly allocated (1:1) to receive nebulised salbutamol and ipratropium bromide with either 2·5 mL of isotonic MgSO(4) (250 mmol/L; 151 mg per dose; MgSO(4) group) or 2·5 mL of isotonic saline (placebo group) on three occasions at 20-min intervals. Randomisation was done with a computer-generated randomisation sequence, with random block sizes of two to four. Both patients and researchers were masked to treatment allocation. The primary outcome measure was the Yung Asthma Severity Score (ASS) at 60 min post-randomisation. We used a statistical significance level of p<0·05 for a between-group difference, but regarded a between-group difference in ASS of 0·5 as the minimal clinically significant treatment effect. Analysis was done by intention to treat. This trial is registered with controlled-trials.com, number ISRCTN81456894.

FINDINGS

Between Jan 3, 2009, and March 20, 2011, we recruited and randomly assigned 508 children to treatment: 252 to MgSO(4) and 256 to placebo. Mean ASS at 60 min was lower in the MgSO(4) group (4·72 [SD 1·37]) than it was in the placebo group (4·95 [SD 1·40]; adjusted difference -0·25, 95% CI -0·48 to -0·02; p=0·03). This difference, however, was not clinically significant. The clinical effect was larger in children with more severe asthma exacerbation (p=0·03) and those with symptoms present for less than 6 h (p=0·049). We detected no difference in the occurrence of adverse events between groups.

INTERPRETATION

Overall, nebulised isotonic MgSO(4), given as an adjuvant to standard treatment, did not show a clinically significant improvement in mean ASS in children with acute severe asthma. However, the greatest clinical response was seen in children with more severe attacks (SaO(2)<92%) at presentation and those with preceding symptoms lasting less than 6 h.

FUNDING

National Institute for Health Research Health Technology Assessment Programme.

Exercise-induced wheeze, urgent medical visits, and neighborhood asthma prevalence

OBJECTIVE

Exercise-induced wheeze (EIW) may identify a distinct population among asthmatics and give insight into asthma morbidity etiology. The prevalence of pediatric asthma and associated urgent medical visits varies greatly by neighborhood in New York City and is highest in low-income neighborhoods. Although increased asthma severity might contribute to the disparities in urgent medical visits, when controlling for health insurance coverage, we previously observed no differences in clinical measures of severity between asthmatic children living in neighborhoods with lower (3%-9%) versus higher (11%-19%) asthma prevalence. Among these asthmatics, we hypothesized that EIW would be associated with urgent medical visits and a child's neighborhood asthma prevalence.

METHODS

Families of 7- to 8-year-old children were recruited into a case-control study of asthma through an employer-based health insurance provider. Among the asthmatics (n = 195), prevalence ratios (PRs) for EIW were estimated. Final models included children with valid measures of lung function, seroatopy, and waist circumference (n = 140).

RESULTS

EIW was associated with urgent medical visits for asthma (PR, 2.29; P = .021), independent of frequent wheeze symptoms. In contrast to frequent wheeze, EIW was not associated with seroatopy or exhaled NO, suggesting a distinct mechanism. EIW prevalence among asthmatics increased with increasing neighborhood asthma prevalence (PR, 1.09; P = .012), after adjustment for race, ethnicity, maternal asthma, environmental tobacco smoke, household income, and neighborhood income.

CONCLUSIONS

EIW may contribute to the disparities in urgent medical visits for asthma between high- and low-income neighborhoods. Physicians caring for asthmatics should consider EIW an indicator of risk for urgent medical visits.

[Incidence and characteristics of asthma exacerbations in Barcelona (ASMAB II)]

INTRODUCTION

A study has been made on the incidence and clinical characteristics of asthma exacerbations (AE) seen in hospital emergency departments (HED) and domiciliary services (DS) in Barcelona.

PATIENTS AND METHODS

AEs were identified over a 56 day period during the months of October and November 2003 and the patients seen in university hospitals were interviewed.

RESULTS

A total of 262 AE were identified, 188 in hospital emergency departments and 82 in domiciliary, which was a mean of 4.6 AE/day, giving an incidence of 0.37 AA/10(5) inhabitants. This incidence was no different from that obtained in the same months in 2002 (P>0.05). The mean age (+/-standard deviation) of the 143 cases of AE seen in university hospitals was 41+/-17 years; 87/143 (60%) were women and 57/138 (41%), smokers. In 36/61 (59%) the AE started in the home; in 88/132 (61%) it began 24 hours before arriving at the hospital centre. In 78/123 cases (63%) slow onset of nasal catarrh was noted before the AE and a viral infection was suspected. Inhaled corticoids were given to 45/112 patients (40%), and only one added oral corticoids 12 hours before admission. The AE were mild in 38/75 cases (51%), moderate in 28/75 (37%), severe in 8/75 (11%) and almost fatal in one patient (1.3%). Around 10% (13/137) of patients (10%) were re-admitted.

CONCLUSIONS

The daily incidence of AE is 0.37/10(5) inhabitants. More than half of the exacerbations started after nasal catarrh and 11% of the AE were severe.

Predicting response to therapy in acute asthma

PURPOSE OF REVIEW

To analyze the prediction of response of therapy into the context of acute adult asthma assessment in the emergency department (ED) setting.

RECENT FINDINGS

Close monitoring of the patient's condition at presentation (static assessment) and response to treatment (dynamic assessment), including serial measurements of lung function, is an essential part of the acute asthma care in the ED. The severity of airflow obstruction cannot be accurately judged by patient's symptoms and physical examination alone. Accordingly, it is very important to use an objective measure of airway obstruction (spirometry or peak flow meter). Although spirometry can be performed in acutely ill ED asthmatics, measurement of peak expiratory flow, with values expressed as predicted normal values, represents an alternative if spirometry is not available.

SUMMARY

Failure of initial therapy to improve expiratory flow predicts a more severe course and need for hospitalization. Although several score systems have been developed, different factors limit their applicability in the ED setting. Thus, peak expiratory flow rate measures at 15-60 min of treatment, joined with continuous monitoring of oxygen saturation may be the best ways to assess patients with acute asthma.

Asthma worsenings: approaches to prevention and management from the Asthma Worsenings Working Group

Most asthma patients prescribed maintenance asthma therapies still experience periods of asthma worsenings characterized by daytime or night-time symptoms, or an increased need for rescue medication. In fact, these episodes are highly prevalent even in patients with well-controlled disease. Published literature suggests that asthma worsenings likely represent a window of opportunity during which patients could intervene early to prevent exacerbations or further deterioration of asthma symptoms. However, current evidence suggests that most patients fail to respond or to self-manage appropriately during these periods.To address the issue of asthma worsenings, an interdisciplinary committee of respirologists, allergists, family physicians, pharmacists and certified asthma educators from across Canada developed a practical definition of asthma worsenings and provided approaches to the prevention and management of these episodes based on current literature. To date, combination inhaled corticosteroid/long-acting beta-agonist therapy, particularly single inhaler maintenance and reliever therapy, appears to be an effective strategy for preventing asthma worsenings and exacerbations. Addressing the potential barriers to appropriate patient self-management of asthma worsenings, such as failure to adequately identify and respond to worsenings, low expectations for controlling asthma, low health literacy and poor patient-health care professional communication, are also critical to the successful prevention and management of these episodes. Finally, an interdisciplinary team approach involving patients and their families, certified asthma educators, primary care physicians, pharmacists and specialists is likely to have the greatest impact on the identification, prevention and management of asthma worsenings.

Prospective study of inhaled corticosteroid use, cardiovascular mortality, and all-cause mortality in asthmatic women

BACKGROUND

Therapy with inhaled corticosteroids (ICSs) decreases the risk of asthma exacerbations. Recent studies have suggested that ICS therapy also may decrease the risk of cardiovascular disease, and perhaps of all-cause mortality. We examined this hypothesis in a large, well-characterized cohort of asthmatic women.

METHODS

In 1976, the Nurses' Health Study enrolled 121,700 registered nurses, who were 30 to 55 years of age. Participants were asked about "physician-diagnosed asthma" on biennial questionnaires. In 1998, asthmatic participants were sent a supplementary questionnaire on asthma diagnosis and management, including ICS use. Mortality was assessed through 2003, without knowledge of the 1998 (baseline) ICS status. The odds ratios (ORs) for death were adjusted for age, asthma severity, smoking, heart disease, cancer, stroke, aspirin, and statin use.

RESULTS

Among 2,671 eligible women (ie, those who responded to the 1998 supplement [85%], met criteria for persistent asthma, and had not received a prior diagnosis of COPD), 54% reported ICS use. Over the next 5 years, 87 women (3.3%) died (cardiovascular deaths, 22; cancer deaths, 31; other, 34 [including 4 from asthma]). Compared to asthmatic women who did not use ICSs, those receiving therapy with ICSs had lower all-cause mortality (OR, 0.58; 95% confidence interval [CI], 0.36 to 0.92). ICS users were at significantly lower risk of cardiovascular death (OR, 0.35; 95% CI, 0.13 to 0.93), but not of death from cancer (OR, 0.66; 95% CI, 0.32 to 1.38) or other causes (OR, 0.62; 95% CI, 0.30 to 1.27).

CONCLUSIONS

ICS use was associated with significantly lower cardiovascular and all-cause mortality in women with asthma. These observational data suggest that ICSs may indeed have antiinflammatory benefits beyond the airway, which is a possibility that merits further study.

Acute severe asthma

Acute severe asthma remains a major economic and health burden. The natural history of acute decompensations is one of resolution and only about 0.4% of patients succumb overall. Mortality in medical intensive care units is higher but is less than 3% of hospital admissions. "Near-fatal" episodes may be more frequent, but precise figures are lacking. However, about 30% of medical intensive care unit admissions require intubation and mechanical ventilation with mortality of 8%. Morbidity and mortality increase with socioeconomic deprivation and ethnicity. Seventy to 80% of patients in emergency departments clear within 2 hours with standardized care. The relapse rate varies between 7 and 15%, depending on how aggressively the patient is treated. The airway obstruction in the 20-30% of people resistant to adrenergic agonists in the emergency department slowly reverses over 36-48 hours but requires intense treatment to do so. Current therapeutic options for this group consist of ipratropium and corticosteroids in combination with beta2 selective drugs. Even so, such regimens are not optimal and better approaches are needed. The long-term prognosis after a near-fatal episode is poor and mortality may approach 10%.

Prospective study of sudden-onset asthma exacerbations in children

OBJECTIVES

Sudden-onset asthma exacerbations among adults have more rapid treatment responses than do slower-onset exacerbations. We hypothesized that a similar pattern would be evident in children presenting to the emergency department (ED) with an asthma exacerbation.

METHODS

Prospective cohort study at 44 North American EDs. Parents of children, aged 2 to 17 years, underwent a structured interview in the ED and follow-up interview by telephone 2 weeks later.

RESULTS

Of 1184 enrolled children, 11% had sudden-onset asthma (ED presentation < or = 3 hours after symptom onset). Sudden-onset patients were older than slower-onset patients (8.9 vs. 7.7 years, respectively; P = 0.004) and more likely to be white (26% vs. 17%, P = 0.01). They were less likely to report a history of steroid use or asthma hospitalization and reported fewer ED asthma visits during the past year (all P < 0.05). Although initial pulmonary index scores were similar (4.0 vs. 4.3, P = 0.24), patients with sudden-onset asthma were less likely to receive steroid treatment (73% vs. 84%, P = 0.002), had shorter ED length of stay (128 minutes vs. 150 minutes, P = 0.01), and in unadjusted analyses, were less likely to be admitted (16% vs. 24%, P = 0.04).

CONCLUSIONS

Patients with sudden-onset exacerbations had similar acute asthma severity as those with slower-onset exacerbations but had shorter ED length of stay and were less likely to be admitted to the hospital, suggesting a more rapid response to treatment.

Asthma exacerbations. 5: assessment and management of severe asthma in adults in hospital

It is difficult to understand why there is such a huge discrepancy between the management of severe asthma recommended by evidence-based guidelines and that observed in clinical practice. The recommendations are relatively straightforward and have been widely promoted both in guidelines and reviews. Specialist physicians need to be more proactive in their implementation of such guidelines through the use of locally derived protocols and assessment sheets, reinforced by audit. The common occurrence of severe asthma and its considerable burden to the community would support such an approach.

Medical audit on asthma in an emergency department

BACKGROUND

To determine the management of acute bronchial asthma in an adult emergency department.

METHODS

A retrospective medical audit of 46 consecutive adult patients with acute asthma exacerbations was performed. We collected information from 48 episodes of acute asthma over a 5-month period. Using classical audit methodology, four indicators were examined: severity evaluation, diagnostic tests, specific treatment, and discharge treatment plans.

RESULTS

The least recorded severity indicators were respiratory rate (27 %), heart rate (50 %) and peak expiratory flow (20 %). Heart and respiratory auscultation were recorded in all patients and oxygen saturation was recorded in 93 %. Laboratory blood test and chest radiograph were performed in all patients. Arterial blood gas was tested in 57 %, electrocardiography in 17 %, and coagulation in 39 %. No treatment was provided in 12 % of patients. Bronchodilator medications were administered in all treated patients and oxygen was prescribed in 60 %. Systemic corticosteroids (methylprednisolone or hydrocortisone) were administered in 80 % of treated patients. Seventeen percent of patients were discharged from hospital with no change to their usual treatment.

CONCLUSIONS

The following weak points were identified: 1) Severity assessment is inadequate, 2) use of diagnostic tests is excessive, 3) patients discharged to home with no treatment plan. Opportunities for improvement consisted of: 1) greater availability of peak expiratory flow meters, 2) individualized use of diagnostic tests, and 3) management protocols.

A comparison of levalbuterol with racemic albuterol in the treatment of acute severe asthma exacerbations in adults

This multicenter, randomized, double-blind trial compared nebulized levalbuterol (Lev) and racemic albuterol (Rac) in the treatment of acute asthma.

METHODS

Adults with acute asthma exacerbations (FEV(1) 20%-55% predicted) received prednisone and either Lev (1.25 mg, n = 315) or Rac (2.5 mg, n = 312). Nebulized treatments were administered every 20 minutes in the first hour, then every 40 minutes for 3 additional doses, then as necessary for up to 24 hours. The primary end point was time to meet discharge criteria. Secondary end points included changes in lung function and hospitalization rates. A subset of 160 patients had plasma (S)-albuterol concentrations determined at study entry.

RESULTS

Time to meet discharge criteria did not differ between the 2 treatments. FEV(1) improvement was greater following Lev compared with Rac, both after dose 1 and cumulatively over the entire treatment period (dose 1 in intent to treat [ITT] group: Lev 0.50 +/- 0.43 L, Rac 0.43 +/- 0.37 L; P = .02), particularly among the 60% of patients not on recent steroid therapy (dose 1: Lev 0.58 +/- 0.47 L, Rac 0.44 +/- 0.37 L; P < .01), and patients whose entry (S)-albuterol concentrations were in the highest quartile of those measured. A small and similar proportion of Lev-treated (7.0%) and Rac-treated (9.3%) patients required hospitalization (P = .28). Among patients not on steroids, fewer Lev- than Rac-treated patients required admission (3.8% vs 9.3%, P = .03), as was also the case for patients with high plasma (S)-albuterol concentrations. Asthma relapses (5% in 30 days) were lower than in previous reports and did not differ between groups.

CONCLUSIONS

This study suggests that early, regular nebulized beta(2)-agonist and systemic corticosteroid therapy may reduce hospitalization and relapse rates in patients with acute severe asthma. Lev was well tolerated and compared favorably with Rac in improving airway function, particularly in those who were not on inhaled or oral corticosteroids and in those who had high plasma (S)-albuterol concentrations at presentation.

Airway hyperreactivity in exacerbation of chronic asthma is independent of eosinophilic inflammation

We have developed an animal model to investigate the mechanisms underlying an acute exacerbation of chronic asthma. Sensitized BALB/c mice were exposed to aerosolized ovalbumin, either as chronic low-level challenge (mass concentration approximately 3 mg/m(3)) for 4 wk, a single moderate-level challenge (approximately 30 mg/m(3)), or chronic low-level followed by single moderate-level challenge (the acute exacerbation group). Compared with animals receiving chronic challenge alone, mice in the acute exacerbation group exhibited a more marked inflammatory response, with involvement of intrapulmonary airways and lung parenchyma, and increased numbers of lymphocytes and eosinophils in bronchoalveolar lavage fluid. They also developed airway hyperreactivity (AHR) to methacholine, demonstrable as increased transpulmonary resistance and decreased compliance. This pattern of AHR was absent in chronically challenged animals, but was also present in animals given single moderate-level challenge. However, compared with animals receiving a single moderate-level challenge, inflammation and AHR were induced more rapidly in the acute exacerbation group. Eosinophil-deficient GATA1 Deltadbl mice exhibited undiminished AHR in the acute exacerbation model. We conclude that in mice with pre-existing airway lesions resembling mild chronic asthma, exposure to a moderately high concentration of inhaled antigen induces features of an acute exacerbation. The inflammatory response involves distal airways and is associated with a distinct pattern of AHR, which develops independent of the enhanced eosinophilic inflammation.

Severity, control, and responsiveness in asthma

Guidelines for asthma management have proposed that initial treatment should be based on assessment of asthma severity. The treatments proposed for different degrees of asthma severity are essentially estimates of the intensity of treatment needed to achieve asthma control. Responsiveness to treatment is heterogeneous, however, even among asthmatic patients with asthma of similar severity. This heterogeneity calls attention to the importance of assessing asthma control and adjusting treatment accordingly. Application of a guidelines-based approach to asthma management thus requires general agreement on what is meant by severity, control, and responsiveness and requires further an awareness of asthma as causing symptoms and functional impairment in the present and also as causing risk of adverse events in the future.

Severe exacerbations of asthma

All asthmatics regardless of their perceived severity, are at risk of exacerbation, particularly if they are suboptimally treated in the outpatient arena. Fortunately most patients recover after administration of bronchodilators and anti-inflammatory medications, but preventable deaths continue to occur and refractory cases result in hospitalization and need for mechanical ventilation. We begin this article by reviewing the pathophysiology of acute exacerbations to build a foundation for the assessment of clinical status and to provide the rationale for a carefully contemplated and evidence-based therapeutic approach. We end this article with an in-depth examination of the particular problems that are encountered during mechanical ventilation and offer a strategy that helps minimize complications. In the final analysis, however, the greatest gains in the field of acute asthma will come not from its treatment but from its prevention by enhanced educational and environmental efforts and by the delivery of optimal medications at home.

Acute asthma in adults: a review

All patients with asthma are at risk of having exacerbations. Hospitalizations and emergency department (ED) visits account for a large proportion of the health-care cost burden of asthma, and avoidance or proper management of acute asthma (AA) episodes represent an area with the potential for large reductions in health-care costs. The severity of exacerbations may range from mild to life threatening, and mortality is most often associated with failure to appreciate the severity of the exacerbation, resulting in inadequate emergency treatment and delay in referring to hospital. This review describes the epidemiology, costs, pathophysiology, mortality, and management of adult AA in the ED and in the ICU.

Inhaled corticosteroids and leukotriene modifiers in the acute treatment of asthma exacerbations

Asthma exacerbation has a considerable impact on patients' quality of life and constitutes a challenging condition for primary health-care providers. Severe exacerbations are also an important cause of hospital admissions and require high costs. Despite this, a widely accepted definition is still lacking; etiologic and pathogenetic mechanisms are still incompletely defined. Although the efficacy of inhaled corticosteroids (ICS) and leukotriene modifiers in preventing mild to moderate asthma exacerbation is well recognized, their role within the context of an asthma action plan in general practice and in home-based early intervention for acute exacerbations is still controversial. Although systemic corticosteroids (CS) are standard care for severe exacerbation in the emergency department's (ED) management of asthma, published evidence suggests that high doses of ICS may be beneficial in the ED. The additive benefit of ICS when used with systemic CS is still debated. Data on leukotriene modifiers in the management of asthma exacerbation are limited. However, therapeutic strategies of this emergency including ICS and leukotriene modifiers seem logical and may be suitable, at least in certain patient groups. The availability of different drugs, active on different targets, can potentially contribute to a better management of asthma exacerbations.

Asthma severity and adequacy of management in accident and emergency departments in France: a prospective study

BACKGROUND

Recent guidelines have enabled doctors to establish accident and emergency department management strategies for acute asthma on the basis of severity of exacerbations at presentation. However, there is no available information on acute asthma patients classified according to severity of disease. Our aim was to describe the severity of such exacerbations at presentation, and the adequacy of treatment and management.

METHODS

We did a 12-month multicentre cross-sectional observational cohort study in adult patients with acute asthma who attended one of 37 accident and emergency departments in France. The doctors who examined the patients obtained information using a formatted chart. We classified exacerbations according to severity (life-threatening, severe, or mild to moderate), on the basis of clinical findings and peak expiratory flow value, as defined by currently used guidelines.

FINDINGS

Of 3772 patients with acute asthma, 975 (26%) had life-threatening attacks, 1834 (49%) had severe exacerbations without life-threatening features, and 963 (26%) had mild to moderate exacerbations. Initial treatment included nebulised b2 agonists, anticholinergics, and systemic corticosteroids in 3492 (93%), 1841 (49%), and 2252 (60%), respectively. According to severity classification, anticholinergics were used in 494 (51%), 913 (50%), and 434 (45%) of patients in life-threatening, severe, and mild to moderate exacerbations groups, respectively; corticosteroids were given in 666 (68%), 1117 (61%), and 468 (49%), respectively. The overall admission rate was 54.2%, and mean stay was 6.1 (SD 6.0) days. Patients were admitted in 747 (77%), 1018 (55%), and 278 (29%) of cases in life-threatening, severe, and mild to moderate groups, respectively. Three patients died in hospital.

INTERPRETATION

Acute asthma exacerbations are often life-threatening in patients who attend accident and emergency departments, and management of patients is not ideal, mainly because of underuse of corticosteroids and inappropriate admission rates according to severity.

The neurobiology of the stress cascade and its potential relevance for schizophrenia

This review explores the neurobiology of stress and its possible role in the etiology of schizophrenia. Major life events may play a role in onset and relapse in schizophrenia. Other data suggest that early stress exposure increases schizophrenia risk, especially in individuals with latent vulnerability. Animal research has led to an elucidation of the mechanisms by which stress and cortisol are toxic to the hippocampus and impair cognition. Associations among these factors have been found in a variety of human conditions, including psychiatric illness and normal aging. These mechanisms are plausible in schizophrenia, which is characterized by a degree of cortisol dysregulation, hippocampal abnormality, and cognitive impairment. Characterization of the role of the stress cascade in schizophrenia has implications for novel pharmacologic and other treatment, especially for cognitive symptoms, which are debilitating and largely refractory to treatment.

Rapid-onset asthma attack: a prospective cohort study about characteristics and response to emergency department treatment

STUDY OBJECTIVES

(1) To determine the frequency of rapid-onset asthma attacks (ROAAs) and slow-onset asthma attacks (SOAAs) in adult patients with acute, severe disease (18 to 50 years old), who presented to an emergency department (ED); and (2) to establish whether ROAA patients differ from SOAA patients in terms of clinical and spirometric characteristics; and (3) in terms of the response of treatment.

SUBJECTS AND METHODS

Four hundred three patients (with peak expiratory flow [PEF] or FEV(1) of < 50% of predicted value) with acute exacerbations of asthma were enrolled in the trial using a prospective cohort study. Asthma attacks were classified as an ROAA (< 6 h of symptoms) or an SOAA (> or = 6 h). All patients were treated with albuterol, four puffs at 10-min intervals (100 microg per actuation), delivered by metered-dose inhaler with a spacer device during 3 h.

RESULTS

On the basis of previously determined criteria, 11.3% of patients were classified as having a ROAA. Male patients comprised 53.6% of the ROAA group (p = 0.03). In ROAA patients, the exacerbation was less likely to be attributed to respiratory tract infection (p = 0.001) and more likely to have no identifiable cause (p = 0.0001). Also, ROAA patients had lower pulmonary function (FEV(1)) at presentation (mean difference, - 0. 13; 95% confidence interval [CI], - 0.22 to - 0.04 L; p = 0.04) than SOAA patients. At the end of treatment, ROAA patients had an overall 48.0 L/min (95% CI, 14.1 to 81.8 L/min) greater improvement in PEF and a 0.31 L (95% CI, 0.08 to 0.54 L) greater improvement in FEV(1) than SOAA patients. Also, ROAA patients presented with less accessory muscle use (p < 0.05) and higher oxygen saturation (p = 0. 005). Finally, SOAA patients showed an increased incidence of hospital admission (relative risk, 3.89; 95% CI, 1.01 to 15.0).

CONCLUSIONS

Data from this study support the notion that ROAAs constitute a distinct but uncommon acute asthma ED presentation, with a predominance of male patients. Upper respiratory tract infection was not believed to be a significant trigger factor in these patients, and ROAA patients had rapid deterioration of their conditions followed by a more rapid response to treatment and a lower hospital admission rate than SOAA patients. Thus, we have identified a subgroup of patients who appear to have common characteristics with patients with sudden-onset near-fatal/fatal asthma.