Continuous vs intermittent albuterol, at high and low doses, in the treatment of severe acute asthma in adults

The Saudi initiative for asthma - 2024 update: Guidelines for the diagnosis and management of asthma in adults and children

The Saudi Initiative for Asthma 2024 (SINA-2024) is the sixth version of asthma guidelines for the diagnosis and management of asthma for adults and children that was developed by the 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 aligned for age groups: adults, adolescents, children aged 5-12 years, and children aged <5 years. SINA guidelines have focused more on personalized approaches reflecting a better understanding of disease heterogeneity with the integration of recommendations related to biologic agents, evidence-based updates on treatment, and the 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 the 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.

Continuous Albuterol in Pediatric Acute Care: Study Demonstrates Safety Outside the Intensive Care Unit

There are little data to support the use of continuous aerosolized albuterol (CAA) in the non-intensive care unit (ICU) or non-emergency department (ED) setting for pediatric asthma patients. A 2014 study demonstrated low rates of adverse outcomes associated with administration of CAA on the acute care unit; however, the authors do not describe additional outcomes. We sought to determine whether administration of CAA within a respiratory cohort on an acute care floor was feasible and safe.

Management of severe asthma exacerbation: guidelines from the Société Française de Médecine d'Urgence, the Société de Réanimation de Langue Française and the French Group for Pediatric Intensive Care and Emergencies

BACKGROUND

The French Emergency Medicine Society, the French Intensive Care Society and the Pediatric Intensive Care and Emergency Medicine French-Speaking Group edited guidelines on severe asthma exacerbation (SAE) in adult and pediatric patients.

RESULTS

The guidelines were related to 5 areas: diagnosis, pharmacological treatment, oxygen therapy and ventilation, patients triage, specific considerations regarding pregnant women. The literature analysis and formulation of the guidelines were conducted according to the Grade of Recommendation Assessment, Development and Evaluation methodology. An extensive literature research was conducted based on publications indexed in PubMed™ and Cochrane™ databases. Of the 21 formalized guidelines, 4 had a high level of evidence (GRADE 1+/-) and 7 a low level of evidence (GRADE 2+/-). The GRADE method was inapplicable to 10 guidelines, which resulted in expert opinions. A strong agreement was reached for all guidelines.

CONCLUSION

The conjunct work of 36 experts from 3 scientific societies resulted in 21 formalized recommendations to help improving the emergency and intensive care management of adult and pediatric patients with SAE.

ERS/EAACI statement on severe exacerbations in asthma in adults: facts, priorities and key research questions

Despite the use of effective medications to control asthma, severe exacerbations in asthma are still a major health risk and require urgent action on the part of the patient and physician to prevent serious outcomes such as hospitalisation or death. Moreover, severe exacerbations are associated with substantial healthcare costs and psychological burden, including anxiety and fear for patients and their families. The European Academy of Allergy and Clinical Immunology (EAACI) and the European Respiratory Society (ERS) set up a task force to search for a clear definition of severe exacerbations, and to also define research questions and priorities. The statement includes comments from patients who were members of the task force.

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.

Comparison of a rapid albuterol pathway with a standard pathway for the treatment of children with a moderate to severe asthma exacerbation in the emergency department

OBJECTIVE

The objective of this study was to determine if a rapid albuterol delivery pathway with a breath-enhanced nebulizer can reduce emergency department (ED) length of stay (LOS), while maintaining admission rates and side effects, when compared to a traditional asthma pathway with a standard jet nebulizer.

METHODS

Children aged 3-18 presenting to a large urban pediatric ED for asthma were enrolled if they were determined by pediatric asthma score to have a moderate to severe exacerbation. Subjects were randomized to either a standard treatment arm where they received up to 2 continuous albuterol nebulizations, or a rapid albuterol arm where they received up to 4 rapid albuterol treatments with a breath-enhanced nebulizer, depending on severity scoring. The primary endpoint was ED LOS from enrollment until disposition decision. Asthma scores, albuterol dose, side effects, and return visits were also recorded.

RESULTS

A total of 50 subjects were enrolled (25 in each arm). The study LOS was shorter in the rapid albuterol group (118 vs. 163 minutes, p = 0.0002). When total ED LOS was analyzed, the difference was no longer statistically significant (192 vs. 203 minutes, p = 0.65). There were no statistically significant differences with respect to admission rates, asthma score changes, side effects, or return visits.

CONCLUSION

A rapid albuterol treatment pathway that utilizes a breath-enhanced nebulizer is an effective alternative to traditional pathways that utilize continuous nebulizations for children with moderate to severe asthma exacerbations in the ED.

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.

A clinical audit of the management of acute asthmatic attacks in adults and children presenting to an emergency department

OBJECTIVE

To compare the guidelines in the University Hospital of the West Indies (UHWI) acute asthma management protocol with actual practice in the Accident and Emergency Department.

METHODS

A prospective docket audit was done of all consecutive medical records of patients, presenting with a diagnosed acute asthmatic attack between June 1 and September 30, 2010, to the emergency department of the UHWI. A convenient sample was used. The audit tool used was created from the UHWI protocol for the emergency management of asthma in adults and children, as well as the British Adult Asthma Audit Tool. The audit tool assessed three main sections: initial assessment, initial management, and discharge considerations. Data were coded and entered in Microsoft Excel 2007 and statistical analyses conducted using Stata version 10. Management patterns were compared to the actual protocol and then discussed.

RESULTS

A total of 15 864 patients were seen during the study period. Of these, a total of 293 patients were seen for a presentation of acute asthma. More females (57.3%) than males were seen, with the mean age of 33.53 years. Only 31% of patients were given a severity assessment of mild, moderate, or severe. Peak expiratory flow rate (PEFR) was attempted and recorded in 62%, but only 18.1% of patients had both pre and post PEFR done. Only 4.4% of patients were administered nebulizations within the suggested time frame. Positively, 94.2% of patients were given a prescription for inhaled corticosteroids and bronchodilators to continue post-discharge.

CONCLUSIONS

Acute asthma management still remains an area of medical practice that continues to have long-standing difficulties. Failure to assess and document the severity of asthma attacks along with the under-utilization of PEFR was noted.

Evaluation of a high-dose continuous albuterol protocol for treatment of pediatric asthma in the emergency department

OBJECTIVES

This study aimed to assess the safety and efficacy of a high-dose continuous nebulized albuterol (CNA) protocol for treatment of asthma in the pediatric emergency department (ED). A secondary objective included a cost-benefit analysis of protocol use.

METHODS

In this retrospective chart review, we compared cohorts of patients treated in our ED for acute asthma exacerbation before and after implementation of a CNA protocol. Patients between the ages of 2 and 21 years seen between March 1 and May 31, 2008 (preprotocol, n = 393), and March 1 to May 31, 2009 (postprotocol, n = 373), were included. Safety data included medication-related adverse effects as well as serum potassium and glucose levels. Efficacy data included ED length of stay, disposition, return visits, time to first albuterol treatment, and corticosteroid administration. Cost analysis included the cost of medications and respiratory therapy time.

RESULTS

Postprotocol patients more often received CNA (57.9% vs 25.2%, P < 0.01). No significant adverse effects, including tachyarrhythmia and symptomatic hypokalemia, were found in either group. Serum potassium levels were higher in the postprotocol group (3.9 mEq/L [n = 34] vs 3.5 mEq/L [n = 28], P < 0.01). Emergency department stay was longer in the postprotocol group (217.8 minutes vs 187.2 minutes, P < 0.01). Emergency department disposition was similar in both groups. The mean cost per patient was higher in the postprotocol group ($327.21 vs $277.95, P < 0.01).

CONCLUSIONS

We found the CNA protocol to be safe. Superior efficacy to a traditional treatment approach was not demonstrated. The mean cost of treatment was higher in the postprotocol group. Further prospective studies should be conducted to confirm the findings of this retrospective, observational study.

The patient with asthma in the emergency department

Asthma is a highly prevalent disease that presents commonly to the emergency department (ED) in acute exacerbation. Recent asthma treatment guidelines have added content dedicated to the management of acute exacerbations. Effective management of an exacerbation requires rapid assessment of severity through physical examination, measurement of peak expiratory flow rate, and response to initial treatment. Most therapies are directed at alleviating bronchospasm and decreasing airway inflammation. While inhaled short-acting beta-agonists, systemic corticosteroids, and supplemental oxygen are the initial and often only therapies required for patients with mild moderate exacerbations, high-dose beta agonists and inhaled anti-cholinergics should also be given to patients with severe exacerbations. Adjunctive therapy with intravenous magnesium and Heliox-driven nebulization of bronchodilators should be considered for patients presenting with severe and very severe exacerbations. Early recognition and appropriate management of respiratory failure are required to mitigate the risk of complications including death. Disposition should be determined based on serial assessments of the response to therapy over the first 4 h in the ED. Patients stable for discharge should receive medications, asthma education including a written asthma action plan, and should have follow-up scheduled for them by ED staff. Rapid implementation of evidence-based, multi-disciplinary care is required to ensure the best possible outcomes for this potentially treatable disease.

The critically ill asthmatic--from ICU to discharge

Status asthmaticus (SA) is defined as an acute, severe asthma exacerbation that does not respond readily to initial intensive therapy, while near-fatal asthma (NFA) refers loosely to a status asthmaticus attack that progresses to respiratory failure. The in-hospital mortality rate for all asthmatics is between 1% to 5%, but for critically ill asthmatics that require intubation the mortality rate is between 10% to 25% primarily from anoxia and cardiopulmonary arrest. Timely evaluation and treatment in the clinic, emergency room, or ultimately the intensive care unit (ICU) can prevent the morbidity and mortality associated with respiratory failure. Fatal asthma occurs from cardiopulmonary arrest, cerebral anoxia, or a complication of treatments, e.g., barotraumas, and ventilator-associated pneumonia. Mortality is highest in African-Americans, Puerto Rican-Americans, Cuban-Americans, women, and persons aged ≥ 65 years. Critical care physicians or intensivists must be skilled in managing the critically ill asthmatics with respiratory failure and knowledgeable about the few but potentially serious complications associated with mechanical ventilation. Bronchodilator and anti-inflammatory medications remain the standard therapies for managing SA and NFA patients in the ICU. NFA patients on mechanical ventilation require modes that allow for prolonged expiratory time and reverse the dynamic hyperinflation associated with the attack. Several adjuncts to mechanical ventilation, including heliox, general anesthesia, and extra-corporeal carbon dioxide removal, can be used as life-saving measures in extreme cases. Coordination of discharge and follow-up care can safely reduce the length of hospital stay and prevent future attacks of status asthmaticus.

[Cerebral hemorrhage in a mechanically ventilated asthmatic child: multifactorial mechanisms]

We report the case of a 7-year-old boy with acute status asthmaticus requiring mechanic ventilation in the pediatric intensive care unit. He developed a brain hemorrhage during the course of his illness. We discuss the mechanisms that may have precipitated this neurological complication.

The Saudi initiative for asthma - 2012 update: Guidelines for the diagnosis and management of asthma in adults and children

This an 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 SINA is to have updated guidelines, which are simple to understand and easy to use by non-asthma specialists, including primary care and general practice physicians. This new version includes updates of acute and chronic asthma management, with more emphasis on the use of Asthma Control Test in the management of asthma, and a new section on "difficult-to-treat asthma." Further, the section on asthma in children was re-written to cover different aspects in this age group. The SINA panel is a group of Saudi experts with well-respected academic backgrounds and experience in the field of asthma. The guidelines are formatted based on the available evidence, local literature, and the current situation in Saudi Arabia. There was an emphasis on patient-doctor partnership in the management that also includes a self-management plan. The approach adopted by the SINA group is mainly based on disease control as it is the ultimate goal of treatment.

Aerosol therapy in patients receiving noninvasive positive pressure ventilation

In selected patients, noninvasive positive pressure ventilation (NIPPV) with a facemask is now commonly employed as the first choice for providing mechanical ventilation in the intensive care unit (ICU). Aerosol therapy for treatment of acute or acute-on-chronic respiratory failure in this setting may be delivered by pressurized metered-dose inhaler (pMDI) with a chamber spacer and facemask or nebulizer and facemask. This article reviews the host of factors influencing aerosol delivery with these devices during NIPPV. These factors include (1) the type of ventilator, (2) mode of ventilation, (3) circuit conditions, (4) type of interface, (5) type of aerosol generator, (6) drug-related factors, (7) breathing parameters, and (8) patient-related factors. Despite the impediments to efficient aerosol delivery because of continuous gas flow, high inspiratory flow rates, air leaks, circuit humidity, and patient-ventilator asynchrony, significant therapeutic effects are achieved after inhaled bronchodilator administration to patients with asthma and chronic obstructive pulmonary disease. Similarly to invasive mechanical ventilation, careful attention to the technique of drug administration is required to optimize therapeutic effects of inhaled therapies during NIPPV. Assessment of the patient's ability to tolerate a facemask, the level of respiratory distress, hemodynamic status, and synchronization of aerosol generation with inspiratory airflow are important factors contributing to the success of aerosol delivery during NIPPV. Further research into novel delivery methods, such as the use of NIPPV with nasal cannulae, could enhance the efficiency, ease of use, and reproducibility of inhalation therapy during noninvasive ventilation.

Managing outpatient asthma exacerbations

Asthma is a chronic inflammatory disease that renders individuals vulnerable to acute exacerbations. A wide variety of allergic and nonallergic triggers can incite an asthma exacerbation. The goals of managing an asthma exacerbation are prompt recognition, rapid reversal of airflow obstruction, avoidance of relapses, and prevention of future episodes. A written asthma home management plan is essential to minimize the severity of exacerbations. Short-acting beta-agonists, oxygen, and corticosteroids remain fundamental to early intervention in acute asthma exacerbations. Anticholinergics and magnesium sulfate can help nonresponders. Combination inhalers of the long-acting beta-agonist formoterol and inhaled steroid budesonide have been effective in flexible dosing in treating early acute exacerbations and as a daily controller medication outside the United States. Initiation or intensification of long-term controller therapy, treatment of comorbid conditions, trigger avoidance, and prompt follow-up can help prevent relapses. Listening to patient preferences and concerns enhances adherence, and regular follow-up care can help prevent future episodes.

Repeat dosing of albuterol via metered-dose inhaler in infants with acute obstructive airway disease: a randomized controlled safety trial

BACKGROUND

Airway obstruction and bronchial hyperactivity often times lead to emergency department visits in infants. Inhaled short-acting beta2-agonist bronchodilators have traditionally been dispensed to young children via nebulizers in the emergency department. Delivery of bronchodilators via metered-dose inhalers (MDIs) in conjunction with holding chambers (spacers) has been shown to be effective.

STUDY OBJECTIVE

: Safety and efficacy evaluations of albuterol sulfate hydrofluoroalkane (HFA) inhalation aerosol in children younger than 2 years with acute wheezing caused by obstructive airway disease.

METHODS

A randomized, double-blind, parallel group, multicenter study of albuterol HFA 180 microg (n = 43) or 360 microg (n = 44) via an MDI with a valved holding chamber and face mask in an urgent-care setting. Assessments included adverse events, signs of adrenergic stimulation, electrocardiograms, and blood glucose and potassium levels. Efficacy parameters included additional albuterol use and Modified Tal Asthma Symptoms Score ([MTASS] reduction in MTASS representing improvement).

RESULTS

Overall, adverse events occurred in 4 (9%) and 3 (7%) subjects in the 180-microg and 360-microg groups, respectively. Drug-related tachycardia (360 microg) and ventricular extrasystoles (180 microg) were reported in 1 patient each. Three additional instances of single ventricular ectopy were identified from Holter monitoring. No hypokalemia or drug-related QT or QTc prolongation was seen; glucose values and adrenergic stimulation did not significantly differ between treatment groups. In the 180-microg and 360-microg groups, mean change from baseline in MTASS during the treatment period was -2.8 (-49.8%) and -2.9 (-48.4%), and rescue albuterol use occurred in 4 (9%) and 3 (7%) subjects, respectively.

CONCLUSIONS

Cumulative dosing with albuterol HFA 180 microg or 360 microg via MDI-spacer and face mask in children younger than 2 years did not result in any significant safety issues and improved MTASS by at least 48%.

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.

A randomized, clinical trial comparing the efficacy of continuous nebulized albuterol (15 mg) versus continuous nebulized albuterol (15 mg) plus ipratropium bromide (2 mg) for the treatment of acute asthma

Multiple studies have examined adding nebulized ipratropium bromide to intermittent albuterol for the treatment of acute asthma. Although continuous nebulized treatments in themselves offer benefits; few data exist regarding the efficacy of adding ipratropium bromide to a continuous nebulized system. To compare continuous nebulized albuterol alone (A) vs. albuterol and ipratropium bromide (AI) in adult Emergency Department (ED) patients with acute asthma, a prospective, randomized, double-blind, controlled clinical trial was conducted on a convenience sample of patients (IRB approved). The setting was an urban ED. Consenting patients > 18 years of age with peak expiratory flow rates (PEFR) < 70% predicted, between October 15 and December 28, 1999, were randomized to albuterol (7.5 mg/h) + ipratropium bromide (1.0 mg/h), or albuterol alone via continuous nebulization using the Hope Nebulizer (B&B Technologies Inc., Orangevale, CA) for 2 h. Main outcome measures were changed in mean improvement at 60 and 120 min PEFR compared to baseline (time 0). Secondary measures were admission rates. Data were analyzed using appropriate parametric and non-parametric tests (p < 0.05 statistically significant). Sixty-two patients (30 women) completed enrollment: 32 in (AI) and (30) in (A). Four (A) and 2 (AI) patients are without 120 min data: 3 (A) and 1 (AI) were discharged after 60 min, whereas one each (A) and (AI) worsened and were admitted before 120 min. There were no statistically significant differences between treatment groups in age, sex, predicted or initial PEFR. Thirteen (19.4%) patients were admitted. There was no statistically significant difference in improvement of mean PEFR at 60 min or 120 min compared to baseline, between groups, using repeated measures analysis of variance. Mean improvement in PEFR at 60 min compared to baseline (time 0): (A) = 93.2 L/min (95% confidence interval [CI] 64.5-121.8), (AI) = 86.6 L/min (95% CI 58.9-114.3); mean improvement in PEFR at 120 min compared to baseline (time 0) (A) = 116.5 L/min (95% CI 84.5-148.5), (AI) = 126.4 L/min (95% CI 95.4-157.4). There was no statistically significant difference in admission rates between groups: 5/30 (A) and 8/32 (AI) (p = 0.62). There were no significant differences in mean improvement of PEFR at either 60 or 120 min between ED patients with acute asthma receiving continuous albuterol alone vs. those receiving albuterol in combination with ipratropium bromide.

[Management of severe acute asthma in adults]

Any life-threatening episode of asthma requires early pre-hospital specialized medical management by emergency medical crews. Gravity depends on both clinical criteria and a peak expiratory flow rate (PEFR) more than 30% below either the level predicted by the reference graph or the patient's reference value. Initial treatment combines continuous nebulizations containing a beta2-agonist and ipratropium bromide, with oxygen administration and intravenous corticosteroid bolus. Recommended as second-line treatment in the absence of adequate response are: intravenous magnesium sulphate and continuous-perfusion beta2-agonists (electric syringe), or, in the case of shock, epinephrine. If mechanical ventilation is required, its settings should aim for low tidal volumes, low frequency, and increased expiratory time.

Device Selection and Outcomes of Aerosol Therapy: Evidence-Based Guidelines

BACKGROUND

The proliferation of inhaler devices has resulted in a confusing number of choices for clinicians who are selecting a delivery device for aerosol therapy. There are advantages and disadvantages associated with each device category. Evidence-based guidelines for the selection of the appropriate aerosol delivery device in specific clinical settings are needed.

AIM

(1) To compare the efficacy and adverse effects of treatment using nebulizers vs pressurized metered-dose inhalers (MDIs) with or without a spacer/holding chamber vs dry powder inhalers (DPIs) as delivery systems for beta-agonists, anticholinergic agents, and corticosteroids for several commonly encountered clinical settings and patient populations, and (2) to provide recommendations to clinicians to aid them in selecting a particular aerosol delivery device for their patients.

METHODS

A systematic review of pertinent randomized, controlled clinical trials (RCTs) was undertaken using MEDLINE, EmBase, and the Cochrane Library databases. A broad search strategy was chosen, combining terms related to aerosol devices or drugs with the diseases of interest in various patient groups and clinical settings. Only RCTs in which the same drug was administered with different devices were included. RCTs (394 trials) assessing inhaled corticosteroid, beta2-agonist, and anticholinergic agents delivered by an MDI, an MDI with a spacer/holding chamber, a nebulizer, or a DPI were identified for the years 1982 to 2001. A total of 254 outcomes were tabulated. Of the 131 studies that met the eligibility criteria, only 59 (primarily those that tested beta2-agonists) proved to have useable data.

RESULTS

None of the pooled metaanalyses showed a significant difference between devices in any efficacy outcome in any patient group for each of the clinical settings that was investigated. The adverse effects that were reported were minimal and were related to the increased drug dose that was delivered. Each of the delivery devices provided similar outcomes in patients using the correct technique for inhalation.

CONCLUSIONS

Devices used for the delivery of bronchodilators and steroids can be equally efficacious. When selecting an aerosol delivery device for patients with asthma and COPD, the following should be considered: device/drug availability; clinical setting; patient age and the ability to use the selected device correctly; device use with multiple medications; cost and reimbursement; drug administration time; convenience in both outpatient and inpatient settings; and physician and patient preference.

A prospective evaluation of the 1-hour decision point for admission versus discharge in acute asthma

Study objectives were to evaluate the 1-hour decision point for discharge or admission for acute asthma; to compare this decision point to the admission recommendations of the Expert Panel Report 2 (EPR-2) guidelines; to develop a model for predicting need for admission in acute asthma. The design used was a prospective preinterventional and postinterventional comparison. The setting was a university hospital emergency department. Participants included 50 patients seeking care for acute asthma. Patients received standard therapy and were randomized to receive albuterol by nebulizer or metered-dose inhaler with spacer every 20 minutes up to 2 hours. Symptoms, physical examination, spirometry, pulsus paradoxus, medication use, and outcome were evaluated. Based on clinical judgment, the attending physician decided to admit or discharge after 1 hour of therapy. Outcome was compared to the EPR-2 guidelines. Post hoc statistical analyses examined predictors of the need for admission from which a prediction model was developed. Maximal accuracy of the admit versus discharge decision occurred at 1 hour of therapy. Using FEV(1) alone as an outcome predictor yielded suboptimal performance. FEV(1) at 1 hour plus ability to lie flat without dyspnea were the best indicators of response and outcome. A model predictive of the need for admission was developed. It performed better (P =.0054) than the admission algorithm of the EPR-2 guidelines. The decision to admit or discharge acute asthmatics from the ED can be made at 1 hour of therapy. No absolute value of peak flow or FEV(1) reliably predicts need for hospital admission. The EPR-2 guideline thresholds for admission are barely adequate as outcome predictors. A clinical model is proposed that may allow more accurate outcome prediction.

Levalbuterol compared with racemic albuterol in the treatment of acute asthma: results of a pilot study

This was a prospective, open-label, nonrandomized pilot study to evaluate efficacy and tolerability of levalbuterol (LEV) in acute asthma. Asthmatics (forced expiratory volume in 1 second [FEV1], 20-55% predicted) were sequentially enrolled into cohorts of 12 to 14 and received 0.63, 1.25, 2.5, 3.75, or 5.0 mg LEV or 2.5 or 5.0 mg racemic albuterol (RAC) every 20 minutes x 3. After the first dose, FEV1 changes were 56% (0.6 L) for 1.25 mg LEV and 6% (0.07 L) and 14% (0.21 L) for 2.5 and 5 mg RAC respectively. After three doses, FEV1 changes were 74% (0.9 L), 39% (0.5 L), and 37% (0.6 L) for 1.25 mg, LEV 2.5 mg, RAC and 0.63 mg LEV respectively. LEV doses greater than 1.25 mg did not further improve bronchodilation. Baseline plasma (S)-albuterol levels were negatively correlated with baseline FEV1 (R = - 0.3, P = .004) and percent change in FEV1 (R = -0.3, P = .006). LEV at a dose of 1.25 mg produced effective bronchodilation that was greater than both RAC doses. The negative correlation between (S)-albuterol levels and FEV1 could suggest a deleterious effect of (S)-albuterol. Larger comparative studies are warranted.

Management of respiratory failure in status asthmaticus

Status asthmaticus is a life-threatening episode of asthma that is refractory to usual therapy. Recent studies report an increase in the severity and mortality associated with asthma. In the airways, inflammatory cell infiltration and activation and cytokine generation produce airway injury and edema, bronchoconstriction and mucus plugging. The key pathophysiological consequence of severe airflow obstruction is dynamic hyperinflation. The resulting hypoxemia, tachypnea together with increased metabolic demands on the muscles of respiration may lead to respiratory muscle failure. The management of status asthmaticus involves intensive pharmacological therapy particularly with beta-adrenoceptor agonists (beta-agonists) and corticosteroids. Albuterol (salbutamol) is the most commonly used beta2-selective inhaled bronchodilator in the US. Epinephrine (adrenaline) or terbutaline, administered subcutaneously, have not been shown to provide greater bronchodilatation compared with inhaled beta-agonists. Corticosteroids such as methylprednisolone should be administered early. Aerosolized corticosteroids are not recommended for patients with status asthmaticus. Inhaled anticholinergic agents may be useful in patients refractory to inhaled beta-agonists and corticosteroids. In patients requiring mechanical ventilation, the strategy aims to avoid dynamic hyperinflation by enhancing expiratory time to allow complete exhalation. Complications of dynamic inflation are hypotension and barotrauma. Sedation with opioids, benzodiazepines or propofol is required to facilitate ventilator synchrony but neuromuscular blockade should be avoided as myopathy has been a reported complication. Overall, in the management of patients with status asthmaticus, the challenge to the pulmonary/critical care clinician is to provide optimal pharmacological and ventilatory support and avoid the adverse consequences of dynamic hyperinflation.

Management of the acute exacerbation of asthma

All patients with asthma are at risk of having asthma exacerbations characterized by worsening symptoms, airflow obstruction, and an increased requirement for rescue bronchodilators. The goals of managing an asthma exacerbation are prompt recognition and rapid reversal of airflow obstruction to avert relapses and future episodes. Short-acting beta-agonists, oxygen, and corticosteroids form the basis of management of acute asthma exacerbation, but a role is emerging for anticholinergics and newer agents such as levalbuterol and formoterol. Initiation or intensification of long-term controller therapy, treatment of comorbid conditions, avoidance of likely triggers, and timely follow-up care prevent setbacks. Acceptance of current treatment guidelines by physicians and adherence to the recommended clinical regimens by patients are essential for effective management of asthma. The physician should strive to establish a constructive relationship with the patient by addressing the patient's concerns, reaching agreement on the goals of therapy, and developing a written action plan for patient self-management.

Managing outpatient asthma exacerbations

Asthma is a chronic inflammatory disease that renders individuals prone to acute exacerbations. Several allergic and nonallergic triggers can incite an asthma exacerbation. The goals of managing an asthma exacerbation are prompt recognition, rapid reversal of airflow obstruction, prevention of relapses, and forestalling future episodes. A written asthma home-management plan is essential to minimize the severity of exacerbations. Short-acting b-agonists, oxygen, and corticosteroids are fundamental to early intervention in acute asthma exacerbation. Anticholinergics and magnesium sulfate can help nonresponders. Newer agents such as levalbuterol and long-acting b-agonists might be future additions to our armamentarium of drugs to treat acute exacerbations. Initiation or intensification of long-term controller therapy, treatment of co-morbid conditions, and avoidance of possible triggers along with prompt follow-up can help prevent relapses. Listening to patient preferences and concerns to enhance adherence and regular follow-up care can help prevent future episodes.

Continuous versus intermittent beta-agonists in the treatment of acute asthma

BACKGROUND

Patients with acute asthma treated in the emergency department are frequently treated with intermittent inhaled beta-agonists delivered by nebulisation. The use of continuous beta-agonist (CBA) via nebulisation in the emergency setting may offer additional benefits in acute asthma.

OBJECTIVES

To determine the efficacy (e.g., reductions in admission, improvement in pulmonary functions) and risks (e.g., adverse events, effects on vital signs) of continuous versus intermittent inhaled beta-agonists for the treatment of patients with acute asthma managed in the emergency department.

SEARCH STRATEGY

Randomised controlled trials were identified from the Cochrane Airways Review Group "Asthma and WHEEZ*" Register which is a compilation of systematic searches of CINAHL, EMBASE, MEDLINE and CENTRAL and hand searching of 20 respiratory journals. In addition, primary authors and content experts were contacted to identify eligible studies. Bibliographies from included studies, known reviews and texts were also searched. The search is considered updated to June 2003.

SELECTION CRITERIA

Only randomised controlled trials (RCTs) were eligible for inclusion. Studies were included if patients presented with acute asthma and were treated with either continuous or intermittent inhaled beta-agonists early in the ED treatment. "Continuous" nebulisation was defined as truly continuous aerosol delivery of beta-agonist medication (e.g., using a commercially available large-volume nebuliser, or a small-volume nebuliser with infusion pump) or sufficiently frequent nebulisations that medication delivery was effectively continuous (i.e., 1 nebulisation every 15 minutes or > 4 nebulisations per hour). Studies also needed to report either pulmonary function or admission results. Two reviewers independently selected potentially relevant articles and two additional reviewers independently selected articles for inclusion. Methodological quality was independently assessed by two reviewers.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers if the authors were unable to verify the validity of information. Missing data were obtained from authors or calculated from other data presented in the paper. The data were analysed using the Cochrane Review Manager (Version 4.1). Relative risks (RR), weighted mean differences (WMD) and standardized mean differences (SMD) are reported with corresponding 95% confidence intervals (CI); both peak expiratory flow rates (PEFR) and forced expiratory volume in one second (FEV-1) data are reported.

MAIN RESULTS

165 trials were reviewed and eight were included; a total of 461 patients have been studied (229 with CBA; 232 with intermittent beta-agonists). Overall, admission to hospital was reduced with CBA compared to intermittent beta-agonists (RR: 0.68; 95% CI: 0.5 to 0.9); patients with severe airway obstruction at presentation appeared to benefit most from this intervention (RR: 0.64; 95% CI: 0.5 to 0.9). Patients receiving CBA demonstrated small but statistically significant improvements in pulmonary function tests when all studies were pooled. Patients receiving CBA had greater improvements in % predicted FEV-1 (SMD: 0.3; 95% CI: 0.03 to 0.5) and PEFR (SMD: 0.33; 95% CI: 0.1 to 0.5); this effect was observed by 2-3 hours. Continuous treatment was generally well tolerated, with no clinically important differences observed in pulse rate (WMD: -2.87; 95% CI: -6.0 to 0.3) or blood pressure (WMD: -1.75; 95% CI: -5.6 to 2.1) between the treatment groups. Tremor was equally common in both groups (OR: 0.81; 95% CI: 0.5 to 1.3) and potassium concentration was unchanged (WMD: 0.02; 95% CI: -0.2 to 0.2).

REVIEWER'S CONCLUSIONS

Current evidence supports the use of CBA in patients with severe acute asthma who present to the emergency department to increase their pulmonary functions and reduce hospitalisation. Moreover, CBA treatment appears to be safe and well tolerated in patients who receive it.

Comparison of two methods of delivering continuously nebulized albuterol

OBJECTIVE

To compare the relative delivery of 2 methods for providing continuously nebulized albuterol (CNA): a small-volume nebulizer plus infusion pump versus a large-volume nebulizer.

DESIGN

An open, randomized comparison of 3 hours of CNA administration using an in vitro lung model with a follow-up particle size assessment of the large-volume nebulizer.

METHODS

Six different nebulizers of each type were connected to a lung model via a volume-limited mechanical ventilator and infant ventilator circuitry. Albuterol was nebulized at 10 mg/h for 3 hours in random order. The small-volume nebulizer used was the Airlife Misty Neb (Baxter, Valencia, CA); the large-volume nebulizer was the HEART Nebulizer (Vortran Medical, Orangevale, CA). One large-volume nebulizer was operated over 8 hours for the output and particle sizing study.

RESULTS

The small-volume nebulizer delivered a greater amount of albuterol (mean +/- SD percentage of total nebulized) to the model lung (5.75 +/- 1.38% vs. 4.12 +/- 0.67%; p < 0.025) than the large-volume nebulizer, but demonstrated greater variability. Although total output was not maintained after 8 hours of nebulization with the large-volume nebulizer, the percent of particles in the respirable range remained consistent.

CONCLUSIONS

The large-volume nebulizer evaluated in this study maintains consistent output up to 8 hours and provides an acceptable method for delivering CNA through an infant ventilator circuit.

Randomised pragmatic comparison of UK and US treatment of acute asthma presenting to hospital

BACKGROUND

Systemic corticosteroids and inhaled beta(2) agonists are accepted first line treatments for acute severe asthma, but there is no consensus on their optimum dosage and frequency of administration. American regimens include higher initial dosages of beta(2) agonists and corticosteroids than UK regimens.

METHODS

In a prospective, pragmatic, randomised, parallel group study, 170 patients of mean (SD) age 37 (12) years with acute asthma (peak expiratory flow (PEF) 212 (80) l/min) presenting to hospital received treatment with either high dose prednisolone and continuous nebulised salbutamol as recommended in the US or lower dose prednisolone and bolus nebulised salbutamol as recommended in the UK by the BTS.

RESULTS

Outcome measures were: deltaPEF at 1 hour (BTS 89 l/min, US 106 l/min, p=0.2, CI -8 to 41) and at 2 hours (BTS 49 l/min, US 101 l/min, p<0.0001, CI 28 to 77); time to discharge if admitted (BTS 4 days, US 4 days); rates of achieving discharge PEF (>60%) at 2 hours (BTS 64%, US 78%, p=0.04); time to regain control of asthma as measured by PEF >/=80% best with </=20% variability (BTS 3 days, US 4 days, p=0.6); PEF at 24 hours in patients admitted (BTS 293 l/min, US 288 l/min, p=0.8); and control of asthma in the subsequent month (no significant differences).

CONCLUSIONS

Treatment with higher doses of continuous nebulised salbutamol leads to a greater immediate improvement in PEF but the degree of recovery at 24 hours and speed of recovery thereafter is achieved as effectively with lower corticosteroid doses as recommended in the British guidelines.

Comparison of single 7.5-mg dose treatment vs sequential multidose 2.5-mg treatments with nebulized albuterol in the treatment of acute asthma

STUDY OBJECTIVE

s: The purpose of the current trial was to compare the relief of airway obstruction from treatment with a single dose of albuterol,7.5 mg (single-dose group), with that from three sequential doses of albuterol, 2.5 mg, spaced 20 min apart (multidose group).

DESIGN

Randomized clinical trial designed to test equivalence.

SETTING

Urban county hospital emergency department.

PATIENTS OR PARTICIPANTS

Adult patients between the ages of 18 and 60 years presenting to the emergency department with acute asthma, as defined by the American Thoracic Society criteria, with FEV (1) on presentation to the emergency department of < or = 75% of predicted were included in the study.

INTERVENTIONS

After the initial evaluation, patients were administered either albuterol, 2.5 mg via nebulizer every 20 min for a total of three doses, or albuterol 7.5 mg via nebulizer in a single dose.

MEASUREMENTS AND RESULTS

Ninety-four patients participated, 46 in the single-dose group and 48 in the multidose group. Patients in both groups had severe obstruction on presentation to the emergency department (single-dose group pretreatment FEV(1), 45% of predicted [SD, 16% of predicted]; multidose group pretreatment FEV(1), 47% of predicted [SD, 17% of predicted]; p = 0.62). The primary outcome measure was the change in FEV(1) percent predicted over time. The secondary outcome measures were disposition after treatment (ie, hospitalization or discharge to home) and the incidence of side effects. We noted a 44.5% improvement (SD, 56.2%) in pretreatment to posttreatment FEV(1) values in the single-dose group and a 38.1% improvement (SD, 37.3%) in the multidose group (p = 0.52). A similar proportion of patients in both groups required hospitalization (single-dose group, 48%; multidose group, 41%; p = 0.51). There was a trend for the patients in the single-dose group to experience more side effects than patients in the multidose group (patients in the single-dose group patients, 40% [SD, 19%]; multidose group patients, 22% [SD, 10%]; p = 0.06).

CONCLUSION

A single dose of 7.5 mg nebulized albuterol and sequential doses of 2.5 mg nebulized albuterol are clinically equivalent in the treatment of patients with moderate-to-severe acute asthma and result in similar dispositions from the emergency department.

Management of acute pediatric asthma

Pediatric asthma prevalence, morbidity, and severity are increasing. Direct costs associated with providing emergency department and inpatient care account for more than 40% of overall dollars spent for this disease in the United States. Physicians in many health care settings may be required to treat a child in severe respiratory distress caused by acute asthma. This article reviews the pathophysiology, evaluation, and treatment of severe asthma exacerbations, or status asthmaticus.

Continuous vs intermittent beta-agonists in the treatment of acute adult asthma: a systematic review with meta-analysis

BACKGROUND

Since the late 1980s, there has been considerable clinical and academic interest in the use of continuous aerosolized bronchodilators for the treatment of patients with acute asthma. These studies have suggested that this therapy is safe, is at least as effective as intermittent nebulization, and may be superior to intermittent nebulization in patients with the most severely impaired pulmonary function.

OBJECTIVES

To determine whether continuous nebulization offered an advantage over intermittent nebulization for the treatment of adults with acute asthma in the emergency department (ED).

DESIGN

Systematic review of randomized controlled trials of adults with acute asthma.

OUTCOMES

Change in pulmonary function tests as primary outcome, and admissions to the hospital and side effects as secondary outcomes.

RESULTS

Six studies including 393 adults with acute asthma were selected. No significant differences were demonstrated between the two delivery methods in terms of pulmonary function measures obtained after 1 h of treatment (standardized mean difference [SMD], -0.15; 95% confidence interval [CI], -0.35 to 0.05) and after 2 to 3 h of treatment (SMD, -0.19; 95% CI, -0.39 to 0.01). No significant heterogeneity was demonstrated (p > 0.5). At the end of treatment, there was a significantly greater decrease in pulse rate when the continuous nebulizer was used (weighted mean difference [WMD], -6.82; 95% CI, -8.67 to -3.90 beats/min; chi(2), 2.55; degrees of freedom [df], 4; p = 0.6). Additionally, the analysis showed a significant decrease of serum potassium concentration with the use of intermittent nebulization (WMD, 0.12; 95% CI, 0.24 to 0.01 mmol/L; chi(2), 0.5; df, 2; p = 0.8). However, this finding was obtained on the analysis of only two trials. Finally, at the end of the study period, no significant differences were identified between patients treated with continuous or intermittent nebulization with respect to hospital admission (relative risk, 0.68; 95% CI, 0.33 to 1.38; chi(2), 2.06; df, 1; p = 0.2).

CONCLUSIONS

Overall, this review supports the equivalence of continuous and intermittent albuterol nebulization in the treatment of acute adult asthma.

The Management of Acute Severe Asthma

Acute severe asthma exacerbations resulting in emergency department visits and hospitalization usually constitute a failure of long-term control therapy. However, even patients with relatively mild asthma can have severe life-threatening episodes. In both children and adults, viral respiratory infections are the major triggering event, although outbreaks of severe asthma have been associated with high concentrations of aeroallergens. Patients should be provided with written action plans on what to do for acute deterioration, and more severe patients may keep prednisone at home to begin after consultation with their physician. The primary therapy of acute asthma exacerbations remains frequent administration of aerosol β2-agonists and systemic corticosteroids for those patients not fully responding to the β2-agonists. Mild exacerbations may be treated with an increased dosage of inhaled corticosteroids. Patients at risk for acute exacerbations may benefit from peak flow measurement, particularly those who have difficulty perceiving airway obstruction. It is recommended that patients remain on full dose of prednisone until they achieve 70-80 percent of predicted normal or personal best peak flow. In the emergency department, the use of β2-agonists by metered-dose inhaler and holding chamber is as effective as nebulizer if given in a sufficient dose 6-10 puffs equivalent to 5 mg via nebulizer. In those patients not responding completely, the addition of ipratropium bromide has shown to produce additive bronchodilation and reduce hospitalizations. Other therapies such as magnesium sulfate, intravenous β2-agonists, heliox and ketamine have been used, but data demonstrating efficacy are insufficient to warrant recommending their general use.

Serum potassium levels, CPK-MB and ECG in children suffering asthma treated with beclomethasone or beclomethasone-salmeterol

Asthma morbidity and mortality has increased. One of the possible causes is the excessive use of beta agonists. The aim of this study is to compare the effects of six week treatment with beclomethasone alone (Ibec) or the combination of beclomethasone-salmeterol (Ibe + Isal) on serum potassium (K), CPK-MB and ECG in children suffering asthma. It was a prospective, randomised, open cross-over trial. Patients received either Ib2 (2 puff/12 hr, 100 micrograms per puff) or Ibe + Isal (B 2 puff/12 hr, 100 micrograms per puff and S 2 puff/12 hr, 25 micrograms per puff) with dose meter inhaler by 6 weeks, with a four-week wash-out period between the treatments. K, CPK-MB and ECG were assessed at baseline, and after each treatment period. There were 9 girls and 20 boys, aged 11 +/- 2.18 (mean +/- SD) years, baseline K was 4.57 +/- 0.43 mEq/l, after B K 4.38 +/- 0.39 IU and after BS K 4.38 +/- 0.40. The CPK-MB level were baseline 14.75 +/- 4.5, after B 20.10 +/- 6.9 and after BS 21 +/- 8.05 (p < 0.05). Baseline QTc was 0.416 +/- 0.02 msec, after B 0.425 +/- 0.027, and after BS 0.415 +/- 0.029. We conclude that the treatment of children with asthma with 400 micrograms per day of Ibec or concomitantly with 100 micrograms of Isal for 6 weeks does not alter the serum K+ or the QTc. However, the CPK-MB has a significant increment with both treatments but without clinical and/or ECG changes. We can't affirm that Ibec or Ibec plus Isal have a cardiotoxic side-effect by the only presence of high levels of CPK-MB. We agree that it is necessary a close follow up of these apparently asymptomatic patients not induce important cardiovascular changes although CPK-MB was increased.

Asma aguda em adultos na sala de emergência: o manejo clínico na primeira hora

Asma é doença com alta prevalência em nosso meio e ao redor do mundo. Embora novas opções terapêuticas tenham sido recentemente desenvolvidas, parece haver aumento mundial na sua morbidade e mortalidade. Em muitas instituições, as exacerbações asmáticas ainda constituem emergência médica muito comum. As evidências têm demonstrado que a primeira hora no manejo da asma aguda na sala de emergência concentra decisões cruciais que podem determinar o desfecho desta situação clínica. Nesta revisão não-sistemática, os autores enfocaram a primeira hora da avaliação e tratamento do paciente com asma aguda na sala de emergência, descrevendo uma estratégia apropriada para o seu manejo. São consideradas as seguintes etapas: diagnóstico, avaliação da gravidade, tratamento farmacológico, avaliação das complicações e decisão sobre onde se realizará o tratamento adicional. Espera-se que estas recomendações contribuam para que o médico clínico tome a decisão apropriada na primeira hora do manejo da asma aguda.

New medications for asthma

The therapy for chronic stable asthma and acute asthma exacerbations continues to evolve as the pathogenesis of asthma becomes better understood. Although the role of many standard therapies for asthma is well established, some carry significant side effects. The newer anti-inflammatory medications have demonstrated both therapeutic benefit as well as reassuring safety profiles. The challenge of the future is to incorporate the newer medications described, as well as those still being examined, into a treatment regimen that can deliver maximal therapeutic benefit with the lowest possible incidence of side effects.

Continuous versus intermittent nebulization of salbutamol in acute severe asthma: a randomized, controlled trial

STUDY OBJECTIVE

This study was conducted to compare the clinical and spirometric effects of continuous and intermittent nebulization of salbutamol in acute severe asthma.

METHODS

Forty-two consecutive patients presenting to the emergency department for acute severe asthma (peak expiratory flow [PEF] mean+/-SD, 24%+/-12% predicted) were prospectively randomly assigned to receive 27.5 mg of salbutamol by either continuous or intermittent nebulization over a 6-hour period. The continuous nebulization group received 15 mg of salbutamol during the first hour and 12.5 mg over the next 5 hours. The intermittent nebulization group received 5 mg of salbutamol every 20 minutes during the first hour and 2.5 mg hourly over the next 5 hours. All participants received oxygen and intravenous hydrocortisone. Clinical and spirometric assessment was performed at baseline, 40 minutes, 60 minutes, and at 3 and 6 hours after the start of the nebulization. Secondary endpoints were the respective rates of hospitalization and treatment failure.

RESULTS

A significant clinical and spirometric improvement was observed in both groups over baseline as soon as the 40th minute and was sustained thereafter (absolute PEF increase at the sixth hour 30%+/-18% and 32%+/-22% in the continuous and intermittent nebulization groups, respectively; P <.01 over baseline). PEF and the clinical score evolved similarly in both groups. There was no difference between the groups regarding the failure rate of the initial bronchodilator treatment to terminate the asthma attack (3 [14%] in the continuous nebulization group and 2 [9.5%] in the intermittent nebulization group, absolute difference 4.5% [95% confidence interval -14% to 23%]). Eight (38%) patients and 9 (43%) patients from the continuous and intermittent nebulization groups, respectively, required hospitalization according to predefined criteria (absolute difference 4.8% [95% confidence interval -24% to 34%]).

CONCLUSION

We did not observe an appreciable difference between continuous and intermittent nebulization of salbutamol in acute severe asthma. The decision to use one of these nebulization methods should be based on logistical considerations.

Dose-response evaluation of levalbuterol versus racemic albuterol in patients with asthma

Albuterol, in all marketed forms, is sold as a racemate, composed of a 50:50 mixture of (R)- and (S)-isomers. Racemic albuterol and the single isomer version (R)-albuterol (levalbuterol) were compared in a randomized, double-blind, dose-ranging five-way crossover study in patients (n = 20) with mild persistent to moderate persistent asthma. Placebo, racemic albuterol (2.50 mg), or levalbuterol (0.31, 0.63, or 1.25 mg) were delivered as single, nebulized doses to 5 male and 15 female nonsmoking patients with asthma aged 18-50 years. Serial pulmonary function was assessed at 15-min intervals and mean time to onset of activity and duration of improvement of forced expiratory volume in 1 sec (FEV1) were measured. In addition, blood chemistries, electrocardiogram (ECG) readings, and patient subjective assessment of adverse symptoms were recorded. Levalbuterol was found to provide significant bronchodilatory activity and was well tolerated. Levalbuterol 1.25 mg provided the greatest increase and duration in FEV1 improvement, whereas racemic albuterol (2.50 mg) and levalbuterol 0.63 mg provided comparable effects. The lower doses of levalbuterol were associated with a less marked effect on heart rate and potassium than racemic albuterol or high-dose levalbuterol. These data suggest that 0.63 mg levalbuterol provides bronchodilation equivalent to 2.50 mg racemic albuterol with less beta-mediated side effects.

Dose-response characteristics of nebulized albuterol in the treatment of acutely ill, hospitalized asthmatics

We investigated the bronchodilator dose-response to nebulized albuterol and the dose of albuterol which produces maximal bronchodilation in the acutely ill, hospitalized asthmatic. Consecutively admitted patients from the emergency room in status asthmaticus who fulfilled the inclusion criteria (age <41 years old and <12 pack-years of smoking) were studied. Albuterol was administered by nebulizer (Puritan-Bennett Raindrop) in repeated 2.5-mg treatments up to a total dose of 10 mg and the bronchodilator response was measured by a computerized spirometer. Twenty-two patients were studied. Baseline spirometry showed a (mean +/- SE) forced expiratory volume in 1 sec (FEV1) of 1.26 +/- 0.14 L (42 +/- 4.0% predicted), which increased significantly (p < 0.05) during albuterol titration to a maximum FEV1 of 1.70 +/- 0.19 L (57 +/- 5% of predicted). After cumulative doses of 2.5, 5.0, 7.5, and 10.0 mg of nebulized albuterol, 27%, 45%, 72%, and 77% of patients, respectively, attained maximum bronchodilation. The remaining 23% of patients did not respond to doses up to 10 mg of albuterol. The maximum FEV1 response to albuterol did not correlate with the initial severity of airflow obstruction (r = 0.36, p > 0.05). Pulse rate and arterial oxygen saturation were not significantly affected by nebulized albuterol up to a total dose of 10 mg. No arrhythmias were noted. In summary, most hospitalized asthmatics (72%) required a cumulative dose of 7.5 mg of nebulized albuterol to achieve maximum bronchodilation and a large fraction (50%) required higher albuterol doses than the standard 2.5 mg. The bronchodilatory response to nebulized albuterol varied widely among patients in status asthmaticus and could not be predicted from the initial severity of airflow obstruction. Because side effects were minimal, it would be reasonable to use 7.5 mg of nebulized albuterol as initial therapy. Alternatively, dose-response titration with albuterol would be advantageous.

Comparison of 2.5 vs 7.5 mg of inhaled albuterol in the treatment of acute asthma

PURPOSE

The optimal dose of albuterol to use in the treatment of acute asthma has yet to be established. The National Asthma Education and Prevention Program (NAEPP) recommends a starting dose of 2.5 to 5 mg of aerosolized albuterol every 20 min, although European authorities recommend higher doses. The purpose of this study was to compare 2.5 vs 7.5 mg of nebulized albuterol for the treatment of acute asthma.

SUBJECTS

We studied 160 patients presenting to the emergency department with acute asthma.

METHODS

On enrollment, patients underwent baseline testing, including initial spirometry. All patients received prednisone, 60 mg, orally. Patients then received in a randomized, double-blinded fashion, nebulized albuterol either 2.5 or 7.5 mg every 20 min for a total of three doses. Spirometry was repeated after each of the first two treatments and again 40 min after completion of the three treatments.

RESULTS

The pretreatment FEV1 was 36.9+/-16.6% of predicted normal in the low-dose group vs 41.5+/-15.4% of predicted normal in the high-dose group (not significant [NS]). The patients in the low-dose group had a 50.3+/-62.6% improvement in FEV1 pretreatment to post-treatment, whereas those in the high-dose group had a 44.6+/-48.2% improvement in FEV1 (NS). There was no difference in the admission rate in the low-dose group (43%) as compared with that of the high-dose group (39%; NS).

CONCLUSION

We conclude that there is no advantage to the routine administration of doses of albuterol higher than 2.5 mg every 20 min. It is possible that there may be an advantage in the most severely obstructed patients, although this study did not enroll enough patients with very severe asthma to evaluate this. As has been previously demonstrated, patients who subsequently require admission have a diminished response to albuterol. This decreased responsiveness is seen with the first aerosol administration and is unaffected by increasing the dose.

The effect of heliox on nebulizer function using a beta-agonist bronchodilator

OBJECTIVE

To evaluate nebulizer performance when heliox was used to power the nebulizer.

METHODS

Conventional and continuous nebulizer designs were evaluated. The conventional nebulizer was used with 5 mg albuterol and flows of 8 L/min air, 8 L/min heliox, and 11 L/min heliox; it was also used with 10 mg albuterol and a heliox flow of 8 L/min. The continuous nebulizer was set to deliver 10 mg of albuterol over 40 min at flows of 2 L/min air, 2 L/min heliox, and 3 L/min heliox; it was also used with 20 mg albuterol and a heliox flow of 2 L/min. A cotton plug at the nebulizer mouthpiece was used to trap aerosol during simulated spontaneous breathing. The amount of albuterol deposited on the cotton plug was determined spectrophotometrically. Particle size was determined using an 11-stage cascade impactor.

RESULTS

For both nebulizer designs, particle size and inhaled mass of albuterol decreased significantly (p < 0.001) when the nebulizer was powered with heliox rather than air. When powered with heliox, the reduction in inhaled mass of albuterol was less for the conventional nebulizer (16%) than the continuous nebulizer (67%). The nebulization time, however, was more than twofold greater with heliox (p < 0.001). Increasing the flow of heliox increased the particle size (p < 0.05), inhaled mass of albuterol (p < 0.05), and inhaled mass of particles 1 to 5 microm (p < 0.05) to levels similar to powering the nebulizer with air at the lower flow. Increasing the albuterol concentration in the nebulizer and using the lower heliox flow increased the inhaled mass of albuterol (p < 0.05) while maintaining the smaller particle size produced with that flow.

CONCLUSIONS

The use of heliox to power a nebulizer affects both the inhaled mass of medication and the size of the aerosol particles. The flow to power the nebulizer should be increased when heliox is used.

Four hours of continuous albuterol nebulization

BACKGROUND AND OBJECTIVES

Continuous albuterol nebulization (CAN) is a therapeutic modality available to treat status asthmaticus. Currently, CAN may be administered using a large-volume nebulizer (LVN) or a small-volume nebulizer attached to an infusion pump or refilled as needed. Few data are available regarding the reproducibility of aerosol characteristics during CAN. In this study, we determined the aerodynamic profile, drug output (DO), DO in respirable range (RD), solution output (SO), and changes in reservoir's albuterol concentration (AR) hourly during 4 hours of CAN.

DESIGN

A modified Puritan-Bennett 1600 jet nebulizer was tested with a large reservoir (LR; 250 mL), medium reservoir (MR; 45 mL), and small reservoir with infusion pump (SRP; 18 mL). We used 100-, 40-, and 4-mL initial fill volumes (with 10-mL/h infusion for SRP) of 1 mg/mL albuterol solution for the LR, MR, and SRP, respectively. Particle size distribution and DO consistency were determined by impaction and spectrophotometric analysis (275 nm). We also determined albuterol mass output. The SO was determined by gravimetric technique.

RESULTS

The PBsj produced a heterodisperse aerosol with a median mass aerodynamic diameter range of 1.8 to 2.2 microm. DO and RD paralleled SO. The LR had the highest SO, DO, and RD (8.03+/-2.36 vs 5.73+/-2.48 and 5.85+/-0.51 mg/h for MR and SRP, respectively). The AR showed no statistically significant changes.

CONCLUSIONS

The PBsj demonstrated consistent and adequate aerosol production during 4 hours of CAN. These bench data support the widespread use of a LVN for CAN.