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

High-flow nasal cannula and in-line aerosolised bronchodilator delivery during severe exacerbation of asthma in adults: a feasibility observational study

BACKGROUND

Asthma is a common chronic respiratory disease affecting 1-29% of the population in different countries. Exacerbations represent a change in symptoms and lung function from the patient's usual condition that requires emergency department (ED) admission. Recently, the use of a High-Flow Nasal Cannula (HFNC) plus an in-line vibrating mesh nebulizer (VMN) for aerosol drug delivery has been advocated in clinical practice. Thus, this pilot observational study aims to investigate the feasibility of HFNC treatment with VMN for in-line bronchodilator delivery in patients with severe asthma.

METHODS

This study was conducted from May 2022 to May 2023. Subjects ≥18 years old with a previous diagnosis of asthma who were admitted to the ED during severe exacerbation were included. The primary endpoint was the change in peak expiratory flow ratio (PEFR) after 2-h of treatment with bronchodilator delivered by HFNC with in-line VMN. Additional outcomes were changes in forced expiratory volume in 1 s (FEV1) and clinical variables before treatment.

RESULTS

30 patients, mean age of 43 (SD ± 16) years, mostly female (67%) were studied. A significant change in PEFR (147 ± 31 L/m vs. 220 ± 38 L/m; p < 0.001) was observed after treatment with HFNC and in-line VMN with significant improvement in clinical variables. And no subjects required invasive mechanical ventilation (IMV) during the study.

CONCLUSIONS

HFNC treatment with in-line VMN for bronchodilator delivery appears feasible and safe for patients with severe asthma exacerbation. These preliminary promising results should be confirmed with appropriately large-designed studies.

Strong and graded associations between level of asthma severity and all-cause hospital care use and costs in the UK

BACKGROUND

Hospital admissions account for a large share of the healthcare costs incurred by people with asthma. We assessed the hospital care use and costs associated with asthma severity using the UK Biobank cohort and linked healthcare data.

METHODS

Adult participants with asthma at recruitment were classified using their prescription data into mild and moderate-to-severe asthma and matched separately to asthma-free controls by age, sex, ethnicity and location. The associations of asthma, by severity, with the annual number of all-cause hospital admissions, days spent in hospital and hospital costs were estimated over a 10-year follow-up period using three specifications of negative binomial regression models that differed according to the sociodemographic and clinical characteristics adjusted for.

RESULTS

Of the 25 031 participants with active asthma, 80% had mild asthma and 20% had moderate-to-severe asthma. Compared with participants with mild asthma, those with moderate-to-severe asthma were on average 2.7 years older, more likely to be current (13.7% vs 10.4%) or previous (40.2% vs 35.2%) smokers, to have a higher body mass index (BMI), and to be suffering from a variety of comorbid diseases. Following adjustments for age, sex, ethnicity and location, people with mild asthma experienced on average 36% more admissions (95% CI 28% to 40%), 43% more days in hospital (95% CI 35% to 51%) and 36% higher hospital costs (95% CI 31% to 41%) annually than asthma-free individuals, while people with moderate-to-severe asthma experienced excesses of 93% (95% CI 81% to 107%), 142% (95% CI 124% to 162%) and 98% (95% CI 88% to 108%), respectively. Further adjustments for socioeconomic deprivation, smoking status, BMI and comorbidities resulted in smaller though still highly significant positive associations, graded by severity, between asthma and hospital use and costs.

CONCLUSIONS

Strong graded associations are reported between asthma severity and the extent of hospital use and costs in the UK. These findings could inform future assessments of the value of asthma management interventions.

Identification of ROBO2 as a Potential Locus Associated with Inhaled Corticosteroid Response in Childhood Asthma

Inhaled corticosteroids (ICS) are the most common asthma controller medication. An important contribution of genetic factors in ICS response has been evidenced. Here, we aimed to identify novel genetic markers involved in ICS response in asthma. A genome-wide association study (GWAS) of the change in lung function after 6 weeks of ICS treatment was performed in 166 asthma patients from the SLOVENIA study. Patients with an improvement in lung function ≥8% were considered as ICS responders. Suggestively associated variants (p-value ≤ 5 × 10⁻⁶) were evaluated in an independent study (n = 175). Validation of the association with asthma exacerbations despite ICS use was attempted in European (n = 2681) and admixed (n = 1347) populations. Variants previously associated with ICS response were also assessed for replication. As a result, the SNP rs1166980 from the ROBO2 gene was suggestively associated with the change in lung function (OR for G allele: 7.01, 95% CI: 3.29–14.93, p = 4.61 × 10⁻⁷), although this was not validated in CAMP. ROBO2 showed gene-level evidence of replication with asthma exacerbations despite ICS use in Europeans (minimum p-value = 1.44 × 10⁻⁵), but not in admixed individuals. The association of PDE10A-T with ICS response described by a previous study was validated. This study suggests that ROBO2 could be a potential novel locus for ICS response in Europeans.

Acute severe asthma: management and treatment

Patients with acute asthma attack usually access the emergency room with severe functional impairment, despite low perception of symptoms. In this scenario, early functional assessment is essential focusing on vital parameters and respiratory function, alongside perceived dyspnea. Impairment of ventilatory mechanics due to progressive dynamic pulmonary hyperinflation should be promptly treated with medical inhalation and/or intravenous therapy, reserving intensive treatment in case of non-response and/or worsening of the clinical conditions. Therapeutic planning at patient's discharge is no less important than treatment management during emergency room access as educating the patient about therapeutic adherence significantly impact long-term outcomes of asthma. With this review we aim at exploring current evidence on acute asthma attack management, focusing of pharmacological and ventilatory strategies of care and highlighting the importance of patient education once clinical stability allows discharge from the emergency department.

The nationwide retrospective cohort study by Health Insurance Review and Assessment Service proves that asthma management decreases the exacerbation risk of asthma

Medical costs have recently increased in South Korea due to the rising rate of asthma. Primary clinics serve an important role in asthma management, as they are the first stop for patients presenting with symptoms. The Health Insurance Review and Assessment Service (HIRA) in South Korea has assessed asthma-management quality since 2013, but studies are lacking on whether these assessments have been performed properly and contribute toward reducing asthma exacerbations. Therefore, we investigated whether the HIRA’s quality assessments have decreased asthma exacerbations using national health insurance claims data from 2013 to 2017 of 83,375 primary-clinic and 15,931 tertiary-hospital patients with asthma. These patients were classified into four groups based on disease severity according to the monthly prescribed amount of asthma medication using K-means clustering. The associations between HIRA assessments and asthma exacerbation were analyzed using a generalized estimating equation. Our results showed that exacerbation odds gradually decreased as the HIRA assessments progressed, especially in the mild-severity group, and that exacerbation risk among patients with asthma decreased in the order of assessment grades: “Unsatisfactory,” “Satisfactory,” and “Tertiary.” Therefore, we may conclude that asthma exacerbations may decrease with high quality asthma management; appropriate quality assessment could be helpful in reducing asthma exacerbations.

Long-term safety and pharmacodynamics of mepolizumab in children with severe asthma with an eosinophilic phenotype

BACKGROUND

Mepolizumab is approved for patients with severe asthma with an eosinophilic phenotype aged 12 or more (United States) or 6 or more (European Union) years, but its long-term use in children aged 6 to 11 years has not yet been assessed.

OBJECTIVE

We sought to assess the long-term safety, efficacy, and pharmacodynamics of mepolizumab in children aged 6 to 11 years with severe asthma with an eosinophilic phenotype.

METHODS

In this open-label, uncontrolled, repeat-dose extension study (NCT02377427), children aged 6 to 11 years with severe asthma with an eosinophilic phenotype (blood eosinophil counts ≥150 cells/μL at screening or ≥300 cells/μL in the previous year) received a body weight-dependent dose of subcutaneous mepolizumab of 40 mg (<40 kg) or 100 mg (≥40 kg) over 52 weeks. End points included the incidence of adverse events (AEs) and immunogenicity (primary), absolute blood eosinophil counts (cells per microliter; secondary), and annualized exacerbation rates and asthma control questionnaire/childhood asthma control test scores (exploratory).

RESULTS

Over 52 weeks, 30 children received mepolizumab; 27 (90%) and 7 (23%) experienced on-treatment AEs and serious AEs, respectively. No serious AEs were treatment related. There were no fatal AEs. No specific patterns of AEs were evident, and no anti-drug antibody or neutralizing antibody responses were reported. Compared with baseline values, mepolizumab treatment reduced blood eosinophil counts and asthma exacerbations and improved asthma control across all treatment groups.

CONCLUSION

Long-term safety, pharmacodynamic, and efficacy data from this study support a positive benefit-risk profile for mepolizumab in children with severe asthma with an eosinophilic phenotype and were similar to data in studies in adults and adolescents.

Asthma knowledge, care, and outcome during pregnancy: The QAKCOP study

Asthma is the most common chronic medical condition affecting pregnancy. Optimizing asthma management in pregnancy is paramount for the well-being of both the mother and the baby. The primary objectives of this study were to assess patient’s knowledge about asthma, the level of asthma care, and fetal and maternal outcomes among pregnant asthmatic women in this wealthy country with tremendous improvement in maternal and fetal health care. The secondary objective was to identify barriers to asthma control. This was a cross-sectional, face-to-face, prospective study of 80 pregnant women with physician-diagnosed asthma. About 56% of patients reported worsening of their asthma control during pregnancy, of which 52.3% felt this worsening in the third trimester. About 65% of patients had uncontrolled asthma during their pregnancy, and inhaler technique was incorrect in 64.4%. Only 38% of patients knew the difference between controller and reliever asthma medications, 12.7% of patients had received written asthma action plan, 17% had a spirometry done in the previous 5 years, and 3.8% had peak expiratory flow meter at home. The main reasons for uncontrolled asthma were lack of knowledge about right asthma medications in 30% and fear of side effects of inhaled corticosteroids in 19% of patients. No financial reason was reported. Significant associations between total number of pregnancies, poor perception of asthma medications, asthma exacerbation during delivery and poor asthma control were observed. Preeclampsia and congenital anomalies occurred at higher rates than previously reported among general population in this country. The tremendous improvements in maternal health care and socioeconomic status do not seem to be a barrier to the globally recognized poor asthma care in pregnancy. Important strategies are much needed.

An early innate response underlies severe influenza-induced exacerbations of asthma in a novel steroid-insensitive and anti-IL-5-responsive mouse model

BACKGROUND

Acute worsening of asthma symptoms (exacerbation) is predominantly triggered by respiratory viruses, with influenza causing the most severe exacerbations. The lack of an adequate animal model hampers mechanistic insight and the development of new therapeutics.

AIM

We developed and characterized a robust, consistent, and reproducible mouse model of severe exacerbation of chronic allergic asthma.

METHODS

Chronic allergic airway inflammation was induced following a house dust mite (HDM) sensitization protocol. HDM-sensitized mice and controls were infected with influenza virus A/X31 H3N2 and either or not treated with inhaled fluticasone propionate (FP), systemic corticosteroids (Pred), or anti-IL-5. Mice were killed at different time points after infection: Cellular accumulation and cytokines levels in the airways, PenH as a measure of airway hyper-responsiveness (AHR), and lung histology and viral replication were assessed.

RESULTS

Infection with low-dose A/X31 H3N2 led to prolonged deterioration of lung function, aggravated mucus production, peri-vascular, peri-bronchial, and allergic inflammation that was unresponsive to inhaled corticosteroids, but responsive to systemic corticosteroids. The exacerbation was preceded at 14 h after virus exposure by a marked innate, but no Th2 and Th1 response subsequently followed by enhanced numbers of eosinophils, neutrophils, dendritic, and T cells into the lung lumen, parenchyma, and draining lymph nodes in HDM-sensitized mice. Anti-IL-5 treatment attenuated eosinophils and prevented the X31-induced exacerbation.

CONCLUSIONS

Together, these findings indicate that an early innate response that involves eosinophils underlies the exacerbation. This model recapitulates all major features of severe asthma exacerbations and can serve to discern driving mechanisms and promote the development of novel therapeutics.

Assessment of acute asthma severity in the ED: are heart and respiratory rates relevant?

BACKGROUND

Assessment of acute asthma severity in the emergency department (ED) determines the appropriate initial therapy. The aim of this study was to evaluate the usefulness of heart and respiratory rates as determinants of severity of asthma exacerbations.

METHODS

It was a pooled analysis of individual patient data from different controlled clinical trials performed over a 9-year period. The sample was characterized by patients with a diagnosis of asthma, age 18 to 50 years, and a forced expiratory volume in the first second (FEV1) or a peak expiratory flow less than or equal to 50% of predicted at ED presentation.

RESULTS

One thousand one hundred ninety-two severe acute asthmatics (age 33.9 ± 10.3 years and FEV1 = 27.4% ± 9.7%) were enrolled. Two-thirds of patients were categorized as having severe acute asthma (FEV1, 31%-50% of predicted) and the remaining third as life-threatening asthma (FEV1, ≤30% of predicted). There were no relationships between the intensity of airway obstruction as measured by the FEV1 and the degree of tachycardia (r = 0.05, P > .1) or tachypnea (r = 0.06, P > .1). Only 22% and 19% of the patients, respectively, met the heart rate and respiratory rate requirements for acute severe asthma (≥120/min and ≥25/min, respectively). In contrast to FEV1 and arterial oxygen saturation, baseline heart and respiratory rates did not predict admissions of patients at the end of treatment.

CONCLUSIONS

This pooled analysis suggests a poor performance of heart and respiratory rates as determinants of acute asthma severity in the ED.

A local perspective to asthma management in the accident and emergency department in Malta

AIM

This study was performed to assess the management of adult patients presenting to the Mater Dei Hospital Accident and Emergency (A&E) department with acute asthma.

SUBJECTS AND METHODS

Asthmatic patients age 14 or older who presented to A&E department between January and October 2010 with asthma exacerbations were included. Data were collected from the clinical notes and analyzed.

RESULTS

A total of 244 patients (67.2% females) were included, 126 (51.6%) were admitted, 97 (39.8%) discharged and 21 (8.6%) discharged themselves against medical advice. There was a decline in the presentations between January and July, followed by an upward trend until October (P = 0.42). Pulse oximetry was performed in 207 patients (84.8%), arterial blood gases in 133 (54.5%), peak expiratory flow rate in 106 (43.4%) and chest radiography in 206 (84.4%) patients. The respiratory rate was documented in 151 (61.8%), heart rate in 204 (83.6%) and ability to complete sentences in 123 (50.4%) patients. One hundred and ninety six patients (80.3%) were given nebulized bronchodilators, 103 (42.2%) intravenous corticosteroids, 7 (2.87%) oral corticosteroids, 109 (44.7%) oxygen, 28 (11.5%) antibiotics and 9 (3.69%) magnesium. Systemic corticosteroids and antibiotics were more commonly prescribed to patients admitted (P < 0.001).

CONCLUSION

Management of acute asthma in Malta requires optimization in order to compare with international guidelines.

β2-Adrenoceptor agonists are required for development of the asthma phenotype in a murine model

β(2)-Adrenoceptor (β2AR) agonists are the most effective class of bronchodilators and a mainstay of asthma management. The first potent β2AR agonist discovered and widely used in reversing the airway constriction associated with asthma exacerbation was the endogenous activator of the β2AR, epinephrine. In this study, we demonstrate that activation of the β2AR by epinephrine is paradoxically required for development of the asthma phenotype. In an antigen-driven model, mice sensitized and challenged with ovalbumin showed marked elevations in three cardinal features of the asthma phenotype: inflammatory cells in their bronchoalveolar lavage fluid, mucin over production, and airway hyperresponsiveness. However, genetic depletion of epinephrine using mice lacking the enzyme to synthesize epinephrine, phenylethanolamine N-methyltransferase, or mice that had undergone pharmacological sympathectomy with reserpine to deplete epinephrine, had complete attenuation of these three cardinal features of the asthma phenotype. Furthermore, administration of the long-acting β2AR agonist, formoterol, a drug currently used in asthma treatment, to phenylethanolamine N-methyltransferase-null mice restored the asthma phenotype. We conclude that β2AR agonist-induced activation is needed for pathogenesis of the asthma phenotype. These findings also rule out constitutive signaling by the β2AR as sufficient to drive the asthma phenotype, and may help explain why chronic administration of β2AR agonists, such as formoterol, have been associated with adverse outcomes in asthma. These data further support the hypothesis that chronic asthma management may be better served by treatment with certain "β-blockers."

Analytic review: management of life-threatening asthma in adults

Asthma remains a troubling health problem despite the availability of effective treatment. A small but significant number of asthmatics experience life-threatening attacks culminating in intensive care unit admission. Standard treatment includes high dose systemic corticosteroids and inhaled bronchodilators. Patients with especially severe attacks may develop respiratory failure and need endotracheal intubation and mechanical ventilation. Severe airway obstruction may lead to dynamic hyperinflation and the possibility of hemodynamic collapse and barotrauma. Fortunately, most intubated asthmatics survive if physicians adhere to key management principles intended to avoid or minimize hyperinflation. The purpose of this review is to discuss the pathogenesis of life-threatening asthma and to provide practical guidance to promote rationale, safe, and effective management.

[Adult asthma exacerbations in questions]

In this article a French working party critically review the international literature to revise the definition, pathophysiology, treatment and cost of exacerbations of adult asthma. The various guidelines do not always provide a consistent definition of exacerbations of asthma. An exacerbation can be defined as deterioration of clinical and/or functional parameters lasting more than 24 hours, without return to baseline, requiring a change of treatment. No single clinical or functional criterion can be used as an early marker of an exacerbation. Innate and acquired immune mechanisms, modified by contact with infectious, irritant or allergenic agents, participate in the pathogenesis of exacerbations, which are accompanied by bronchial inflammation. In 2010, mortality is related to progression of exacerbations, often occurring before the patient seeks medical attention. The objective of treatment is to control asthma and prevent exacerbations. However, many factors can trigger exacerbations and often cannot be controlled. The efficacy of inhaled corticosteroids has been demonstrated on reduction of the number of exacerbations and the number of asthma-related deaths. This treatment is cost-effective, especially in terms of reduction of exacerbations.

Assessing PaCO2 in acute respiratory disease: accuracy of a transcutaneous carbon dioxide device

BACKGROUND

Pulse oximetry non-invasively assesses the arterial oxygen saturation of patients with acute respiratory disease; however, measurement of the arterial partial pressure of carbon dioxide (PaCO(2)) requires an arterial blood gas. The transcutaneous partial pressure of carbon dioxide (PtCO(2) ) has been used in other settings with variable accuracy. We investigated the accuracy of a PtCO(2) device in the assessment of PaCO(2) in patients with asthma and suspected pneumonia attending the emergency department.

METHODS

Patients with severe asthma (FEV(1) < 50% predicted) or suspected pneumonia (fever, cough and respiratory rate >18/min) were enrolled. Subjects were excluded if they had a history of chronic obstructive pulmonary disease or other conditions associated with respiratory failure. Arterial blood gases were taken at the discretion of the investigator according to clinical need, and paired with a simultaneous reading from the PtCO(2) probe.

RESULTS

Twenty-five patients were studied with one set of data excluded because of poor PtCO(2) signal quality. The remaining 24 paired samples comprised 12 asthma and 12 pneumonia patients. The range of PaCO(2) was 19-64 mmHg with a median of 36.5 mmHg. Bland-Altman analysis showed a mean (SD) PaCO(2) - PtCO(2) difference of -0.13 (1.9) mmHg with limits of agreement of plus or minus 3.8 mmHg (-3.9 to +3.7).

CONCLUSION

A PtCO(2) device was accurate in the assessment of PaCO(2) in patients with acute severe asthma and suspected pneumonia when compared with an arterial blood gas. These bedside monitors have the potential to improve patient care by non-invasively monitoring patients with acute respiratory disease at risk of hypercapnia.

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.

A national audit of the secondary care of "acute" asthma in Wales--February 2006

BACKGROUND

No national audit of acute asthma in secondary care has been undertaken since 1991 in spite of further revisions of national guidelines. There has been no audit of the patient course through the ambulance, accident and emergency units (A&E), medical admission units (MEAU) and in-patient care in an integrated manner.

AIM

To audit the care of acute asthma in the various areas of secondary care in all hospitals in Wales in February 2006.

METHODS

Standardised audit forms were produced to assess ambulance performance during transfer, A&E and MEAU care and in-patient care where admission occurred. The results were compared to national guidelines.

RESULTS

Acute asthma in Wales is a common reason for hospital attendance, 30% of such patients appear to be mild but 19% are severe/acute severe. British Thoracic Society (BTS)/Sign assessment of severity is rarely performed and both monitoring of progress and the discharge process are disappointing. There are major incompatibilities between BTS/Sign guidelines and the current Welsh Ambulance Service protocol. A similar problem exists with the British Society of Accident and Emergency Medicine (BAEM) protocol for moderate asthma.

CONCLUSIONS

This audit demonstrates disappointing adherence to BTS/Sign guidelines for the care of acute asthma. A new approach to acute asthma care in Wales is required.

Asthma exacerbations . 4: Prevention

Asthma exacerbations are common. They account for a significant morbidity and contribute a disproportionate amount to the cost of asthma management. The optimal strategies for the prevention of asthma exacerbations include the early introduction of anti-inflammatory treatment-most commonly, low dose inhaled corticosteroids. This should be coupled with a structured education programme which has a written action plan as an integral component. Where patients continue to be poorly controlled, the addition of a long acting beta agonist should be considered. The latter should not be used as monotherapy and should always be used with inhaled corticosteroids. Atopic patients with a history of repeated exacerbations, especially if they are steroid dependent and with a raised IgE, may be considered as potential candidates for omalizumab. In the early stages of an asthma exacerbation, doubling the dose of inhaled corticosteroids has been shown to be ineffective. The ideal strategy for the management of worsening asthma in patients on combination treatment, especially salmeterol and fluticasone, is uncertain. There is an emerging body of evidence for strategies on how to prevent progression to an exacerbation in patients taking a combination of budesonide and formoterol.