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

Review of aerosol delivery in the emergency department

Aerosol delivery is a vital therapeutic strategy for both adult and pediatric patients presenting to the emergency department with respiratory distress. Aerosolized bronchodilators are frequently used as rescue medications for patients with diagnoses of asthma, chronic obstructive pulmonary disease (COPD), or pneumonia. Historically, emergency department providers utilized jet nebulizers (JNs) for medication delivery, but were challenged by a need for increasingly higher bronchodilator doses to elicit the desired response. Advancements in technology have led to the development of newer specialized aerosol delivery devices and treatment strategies which provide clinicians with improved options for aerosol delivery but may also cause some uncertainty regarding appropriate device selection. Initial investigations comparing these devices presented valuable evidence of in vitro benefit but were unable to demonstrate corresponding improvement in clinical results. More recently there has been an influx of clinical evidence that suggests improved clinical outcomes associated with more efficient aerosol delivery devices such as vibrating mesh nebulizers (VMN) compared to the standard JN device. VMN will likely become an increasingly important tool in emergency department treatment of patients with respiratory distress. Additional controlled studies are needed both to examine the effects of VMN on patient outcomes, as well as to analyze how performance differences between aerosol devices may affect dosing strategies. Future efforts should also focus on applying new evidence in the form of updated consensus guidelines and standardized treatment strategies.

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.

Management of acute asthma exacerbations

BACKGROUND

Acute asthma exacerbations are common events in the lives of asthmatics, and even the best-managed asthma patients will have acute asthma exacerbations. There are different levels of severity of exacerbations with corresponding management strategies the physician can use to treat acute events. These strategies, including some adjunctive therapies, are reviewed in this article.

METHODS

A review of the English-language scientific literature was performed regarding management of acute asthma exacerbations, focusing of published guidelines, meta-analyses, and database reviews.

RESULTS

Symptoms of exacerbations are reviewed with attention to determining the severity of the exacerbation and the place of management, either at home or in a more acute care setting. Medical therapies for the treatment of each severity level are reviewed as to their effectiveness. Post-exacerbation care is also discussed.

CONCLUSION

Asthma exacerbations will happen and both the provider and patient need to be educated on how to manage these occurrences. Whether the patient is managed at home or in a hospital setting will be determined by the level of severity. Regardless of the medical therapies employed, continued focus should be on further prevention of additional exacerbations.

Critical Asthma Syndrome in the ICU

Critical asthma syndrome represents the most severe subset of asthma exacerbations, and the critical asthma syndrome is an umbrella term for life-threatening asthma, status asthmaticus, and near-fatal asthma. According to the 2007 National Asthma Education and Prevention Program guidelines, a life-threatening asthma exacerbation is marked by an inability to speak, a reduced peak expiratory flow rate of <25 % of a patient's personal best, and a failed response to frequent bronchodilator administration and intravenous steroids. Almost all critical asthma syndrome cases require emergency care, and most cases require hospitalization, often in an intensive care unit. Among asthmatics, those with the critical asthma syndrome are difficult to manage and there is little room for error. Patients with the critical asthma syndrome are prone to complications, they utilize immense resources, and they incite anxiety in many care providers. Managing this syndrome is anything but routine, and it requires attention, alacrity, and accuracy. The specific management strategies of adults with the critical asthma syndrome in the hospital with a focus on intensive care are discussed. Topics include the initial assessment for critical illness, initial ventilation management, hemodynamic issues, novel diagnostic tools and interventions, and common pitfalls. We highlight the use of critical care ultrasound, and we provide practical guidelines on how to manage deteriorating patients such as those with pneumothoraces. When standard asthma management fails, we provide experience-driven recommendations coupled with available evidence to guide the care team through advanced treatment. Though we do not discuss medications in detail, we highlight recent advances.

Medical emergencies: pulmonary embolism and acute severe asthma

In this, the second of two articles covering specific medical emergencies, we discuss the definitions, epidemiology, pathophysiology, acute and chronic management of pulmonary embolus and acute severe asthma.

Inhaled and intravenous treatment in acute severe and life-threatening asthma

Management of life-threatening acute severe asthma in children and adults may require anaesthetic and intensive care. The inhaled route for drug delivery is not appropriate when only small respiratory gas volumes are shifted; the i.v. route may be associated with greater side-effects. Magnesium sulphate i.v. has a place in acute asthma management because it is a mild bronchodilator, and has a stabilizing effect on the atria which may attenuate tachycardia occurring after inhaled and i.v. salbutamol. If intubation and ventilation are required, a reduction in bronchoconstriction by any means before and during these procedures should reduce morbidity. This narrative review aims to show strengths and weakness of the evidence, present controversies, and forward opinions of the author. The review contains a practical guide to the setting up, use and efficiency of nebulizers, metered dose inhalers, and spacers (chambers). It also presents a commonsense approach to the management of severe asthmatics in whom delay in bronchodilatation would cause clinical deterioration. When self-inhaled agents have had no effect, i.v. drugs may help avoid intubation and ventilation. The review includes suggestions for the use of inhaled anaesthetics, anaesthetic induction, and brief notes on subsequent ventilation of the lungs.

Management of severe acute asthma in the emergency department

PURPOSE OF REVIEW

Asthma is one of the most common chronic diseases in most developed countries and control may be elusive. Deterioration in asthma control is common when patients are exposed to airway irritants, viruses, and/or when adherence to chronic anti-inflammatory medications is suboptimal. Acute asthma exacerbations are common, important reasons for presentations to emergency departments, and severe cases may result in hospitalization. Important knowledge gaps exist in what is known and what care is delivered at the bedside.

RECENT FINDINGS

The literature in asthma is rapidly expanding and recent advances in the care are important to summarize. Systematic reviews, especially high-quality syntheses performed using Cochrane methods, provide the best evidence for busy clinicians to remain current. Management of asthma is based on early recognition of severe disease with aggressive therapy using multimodal interventions that focus on both bronchoconstriction and inflammatory mechanisms.

SUMMARY

Treatment of severe acute asthma can effectively and safely reduce hospitalizations, airway interventions, and even death. Using the approach outlined herein will enable clinicians to assist patients to rapidly regain asthma control, return to normal activities, and improve their quality of life in the follow-up period.

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%.

Acute severe asthma

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

Intravenous magnesium sulphate provides no additive benefit to standard management in acute asthma

BACKGROUND

Treatment of acute asthma is based on rapid reversal of bronchospasm and airway inflammation. Magnesium sulphate (MgSO(4)) is known to have a bronchodilator effect on smooth muscle but studies have shown conflicting results on its efficacy in acute asthma, although its use is recommended in national and international guidelines.

AIMS

To determine if intravenous MgSO(4), when used as an adjunct to standard therapy, improves the outcome in acute asthma.

METHODS

A double blind, randomised placebo controlled trial comparing 1.2g MgSO(4) with standard therapy in adult patients with acute asthma. Patients had a PEF <or=75% predicted and all were treated with oxygen, nebulised salbutamol and ipratropium, and IV hydrocortisone. They then received 1.2g IV MgSO(4) or placebo. Outcome measures were % predicted PEF at 60 min and hospital admission rates.

RESULTS

One hundred and twenty nine patients were studied. Placebo and active treatment groups were well matched at baseline. MgSO(4) had no benefit with regards hospital admission rates or % predicted PEF at 60 min (p=0.48) for the whole group, or for subgroups of life-threatening (p=0.85), severe (p=0.63) and moderate (p=0.67) acute asthma.

CONCLUSION

This study did not show additional benefit from 1.2g IV MgSO(4) when given as an adjunct to standard therapy for acute asthma.

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.

The role of intrinsic efficacy in determining response to a beta2-agonist in acute severe asthma

BACKGROUND

Current guidelines recommend repeated doses of albuterol for the emergency treatment of acute asthma. However, approximately one-third of patients show little or no initial response to this partial beta(2)-agonist.

METHODS

We conducted a randomized, double-blind, proof-of-concept study to investigate whether a full beta(2)-agonist, isoproterenol, offers a therapeutic advantage in adults presenting with acute severe asthma (FEV(1)<50%) who fail to respond to an initial treatment of the partial beta(2)-agonist, albuterol. Study subjects were randomized to receive a 2-h continuous nebulization of either albuterol (7.5mg/h) (n=10, mean FEV(1)=37% predicted) or isoproterenol (7.5mg/h) (n=9, mean FEV(1)=33% predicted). Respiratory symptoms, vital signs and pulmonary function measures were collected.

RESULTS

Subjects from both treatment groups had similar baseline characteristics. The percent improvements from baseline FEV(1) at 60 and 120min were significantly higher in subjects receiving isoproterenol than those receiving albuterol (44 vs. 17% and 63 vs. 24%, respectively, P<0.05). The change in symptoms measured by the modified Borg score was also significantly greater in subjects receiving isoproterenol (P<0.01). Both treatments were well tolerated, though the mean increase in pulse rate at 60 and 120min (21 vs. 1 and 23 vs. 6beats/min, respectively, P<0.05) and the mean change in serum potassium at 120min (-0.52 vs. -0.07meq/L, P<0.05) from baseline were significantly greater in the isoproterenol group.

CONCLUSIONS

Our data suggest that in subjects presenting with acute severe asthma who fail to show an initial response to albuterol, the use of a beta(2)-agonist of higher intrinsic efficacy can be more effective in improving lung function and symptoms.

Heliox administration in the pediatric intensive care unit: an evidence-based review

OBJECTIVE

To provide a comprehensive, evidence-based review of helium-oxygen gas mixtures (heliox) in the management of pediatric respiratory diseases.

DATA SOURCE

A thorough, computerized bibliographic search of the preclinical and clinical literature regarding the properties of helium and its application in pediatric respiratory disease states.

DATA SYNTHESIS

After an overview of the potential benefits and technical aspects of helium-oxygen gas mixtures, the role of heliox is addressed for asthma, aerosolized medication delivery, upper airway obstruction, postextubation stridor, croup, bronchiolitis, and high-frequency ventilation. The available data are objectively classified based on the value of the therapy or intervention as determined by the study design from which the data are obtained.

CONCLUSIONS

Heliox administration is most effective during conditions involving density-dependent increases in airway resistance, especially when used early in an acute disease process. Any beneficial effect of heliox should become evident in a relatively short period of time. The medical literature supports the use of heliox to relieve respiratory distress, decrease the work of breathing, and improve gas exchange. No adverse effects of heliox have been reported. However, heliox must be administered with vigilance and continuous monitoring to avoid technical complications.

Severe exacerbations of asthma

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

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.

Use of isotonic nebulised magnesium sulphate as an adjuvant to salbutamol in treatment of severe asthma in adults: randomised placebo-controlled trial

BACKGROUND

Intravenous magnesium can cause bronchodilation in treatment of severe asthma, however its effect by the nebulised route is uncertain. We aimed to assess the effectiveness of isotonic magnesium sulphate as an adjuvant to nebulised salbutamol in severe attacks of asthma.

METHODS

We enrolled 52 patients with severe exacerbations of asthma presenting to the emergency departments at two hospitals in New Zealand. A severe exacerbation was defined as a forced expiratory volume at 1 s (FEV(1)) of less than 50% predicted 30 min after initial administration of 2.5 mg salbutamol via nebulisation. In this randomised double-blind placebo-controlled trial patients received 2.5 mg nebulised salbutamol mixed with either 2.5 mL isotonic magnesium sulphate or isotonic saline on three occasions at 30 min intervals. The primary outcome measure was FEV(1) at 90 min. Analysis was per protocol.

FINDINGS

At 90 min the mean FEV1 in the magnesium group was 1.96 L (95% CI 1.68-2.24) and in the saline group 1.55 L (1.24-1.87). The difference in the mean FEV(1) between the magnesium and saline groups was 0.37 L (0.13-0.61, p=0.003).

INTERPRETATION

Use of isotonic magnesium as an adjuvant to nebulised salbutamol results in an enhanced bronchodilator response in treatment of severe asthma.

A proposal for a practical treatment guideline designed for the initial two-hours of the management of patients with acute severe asthma and COPD using the principles of evidence-based medicine

We have proposed a clinical treatment guideline for the management of acute, severe asthma and chronic obstructive pulmonarydisease (COPD) using the principles of evidence-based medicine. The content is based upon practical clinical issues in need of consensus. A previous study has shown that this particular area is in serious need of quality control. Based on a strict 2 h time schedule with a unified treatment plan for both asthma and COPD, it is possible to secure for the patients a well-documented medical therapy promoting decision-making and clarification of the patient within this time limit. A summary of the statements is presented in a one-page, user-friendly format in order to cope with the clinician's need of having access to published evidence quickly and easily. A website (www.phanareth.dk or a website provided by Respiratory Medicine) has been established providing regular updates. A strategy for the implementation and the evaluation process has been planned after the publication of this paper. We believe this approach to be an important step towards an increase in the quality of guidelines and also a tool to make "guideline writers" aware of the responsibility of making their recommendations work.

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.

IV magnesium sulfate in the treatment of acute severe asthma: a multicenter randomized controlled trial

BACKGROUND

Studies of IV magnesium sulfate as a treatment for acute asthma have had mixed results, with some data suggesting a benefit for acute severe asthma, but not for mild-to-moderate asthma. In a multicenter cohort, this study tests the hypothesis that administration of magnesium sulfate improves pulmonary function in patients with acute severe asthma.

DESIGN

Placebo-controlled, double-blind, randomized clinical trial.

SETTING

Emergency departments (EDs) of eight hospitals.

PATIENTS

Patients aged 18 to 60 years presenting with acute asthma and FEV1 < or = 30% predicted on arrival to the ED.

INTERVENTION

All patients received nebulized albuterol at regular intervals and IV methylprednisolone. Two grams of IV magnesium sulfate or placebo were administered 30 min after ED arrival. The primary efficacy end point was FEV1 at 240 min, and the data analysis was intent to treat.

RESULTS

Two hundred forty-eight patients were included, and the mean FEV1 on ED arrival was 22.9% predicted. At 240 min, patients receiving magnesium had a mean FEV1 of 48.2% predicted, compared to 43.5% predicted in the placebo-treated group (mean difference, 4.7%; 95% confidence interval [CI], 0.29 to 9.3%; p = 0.045). A regression model confirmed the effect of magnesium compared to placebo was greater in patients with a lower initial FEV1 (p < 0.05). If the initial FEV1 was < 25% predicted, the final FEV1 was 45.3% predicted in the magnesium-treated group and 35.6% predicted in the placebo-treated group (mean difference, 9.7%; 95% CI, 4.0 to 15.3%; p = 0.001). If the initial FEV was > or = 25% predicted, magnesium administration was not beneficial; the final FEV1 was 51.1% predicted in the magnesium-treated group and 53.9% predicted in the placebo-treated group (mean difference, - 2.9%, 95% CI, - 9.4 to 3.7; p = not significant). Overall, the use of magnesium sulfate did not improve hospital admission rates.

CONCLUSION

Administration of 2 g of IV magnesium sulfate improves pulmonary function when used as an adjunct to standard therapy in patients with very severe, acute asthma.

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.

Relapse following treatment of acute asthma in the emergency department

Most patients presenting to the emergency department (ED) with acute asthma will have some, if not significant, relief of respiratory distress following treatment. The majority of patients are discharged to home; however, a significant portion of patients relapse and require urgent medical treatment. Many patients have continued respiratory symptoms and impairment in activities of daily living after ED treatment. In a large multicenter trial, we found that 17% of patients relapse within 2 weeks, requiring urgent medical treatment. The factors associated with asthma relapse were a history of numerous ED visits over the previous year, a history of urgent clinic visits over the previous year, use of a home nebulizer, multiple asthma triggers, and duration of symptoms between 1 and 7 days. In other studies, we found that many patients relapse before they can see their primary care physician, and that the lack of an identifiable primary care physician is associated with a higher incidence of relapse. Two interventions have been shown in studies to decrease the rate of relapse. The first, the administration of corticosteroids, has been adopted into general medical practice. Despite the routine use of corticosteroids following ED treatment, however, relapse remains a substantial problem. The second intervention involves focused long-term management by an asthma specialist. Several projects have demonstrated the efficacy of this approach in decreasing ED visits. Although it is time- and resource-intensive, this approach may be necessary for those patients who have frequent ED visits. Whether this approach is generalizable has yet to be demonstrated. In this article, we review the previous work on asthma relapse and suggest areas for further study.

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.

Treatment of acute asthma. A new look at the old and at the new

beta-Agonists remain the mainstay of therapy for acute asthma and, for most patients, standard doses are acceptable. Although the onset of action of systemic steroids is still not clear, steroids promote recovery and should be given to patients with acute illness. Intravenous magnesium sulfate appears to improve pulmonary function in the most severely ill patients but is not useful in patients with more moderate episodes. Ipratropium bromide is a weak bronchodilator that still needs to be tested as an adjunct to standard treatment regimens before its role in adults with asthma can be determined; given its ease of use and favorable safety profile it could be considered for patients with more severe acute illness. Aminophylline has not been found by most studies to improve outcomes and the narrow therapeutic range and unfavorable safety profile relegate it to a last-line agent or no use at all. Helium-oxygen mixtures currently have no role in moderately ill patients but have a theoretical advantage as a temporizing measure in severely ill patients. Drugs used in the management of chronic asthma, such as inhaled steroids and leukotriene-modifying agents, are making their way into the acute treatment arena, and other newly developed specific mediator inhibitors or blockers deserve attention. The use of isomers of beta-agonists is another area that is attracting attention and study. Systemic steroids are used to prevent relapse after emergency department discharge and the addition of other agents such as leukotriene-modifying agents or inhaled steroids may further prevent the need for urgent visits or hospitalization. The search for optimal treatment strategies for acutely ill patients is challenging and exciting and, with more attention and resources being devoted to this area, newer treatments will be found that will eventually have a greater impact on the high morbidity associated with acute asthma.

Management of respiratory failure in patients with asthma

The goal of management of patients with respiratory failure is to restore them to a state of quiet breathing, without complication. This goal is often achieved by pharmacotherapy alone. Inhaled albuterol sulfate, oxygen, and systemic corticosteroids are mainstays of acute care drug management, whereas other data support the use of inhaled steroids, ipratropium bromide, magnesium sulfate, theophylline, and heliox. Assisted ventilation by face mask or endotracheal tube may be required in refractory patients. In intubated patients, a ventilatory strategy that prolongs exhalation time and accepts hypercapnia minimizes lung hyperinflation and generally results in a good outcome. Acute asthma often represents failure of outpatient management; key aspects of the outpatient program should be addressed in the acute care setting to help prevent recurrent attacks.

Comparison of two regimens of beta-adrenergics in acute asthma

BACKGROUND AND METHODS

Inhaled adrenergics and steroids are the main agents used in acute asthma. Dosing recommendations for adrenergics, while generally becoming more aggressive, lack prospective validation. A double blind, randomized trial of two regimens of nebulized metaproterenol was conducted in patients presenting to an Emergency Department with an acute asthma exacerbation. Asthmatics age 16-55, with no other cardio-pulmonary disease, presenting with peak expiratory flow rate (PEFR) < 30% of predicted and greater than 80 L/m were enrolled. All patients received 125 mg of methylprednisolone and theophylline, if needed, to reach therapeutic levels. The experimental group received 0.3 cc metaproterenol in 2.5 cc of saline at times 0, 20", 40", 1', 2', 3', 4', 5', 6', and 7'. The control group received metaproterenol at times 0, 1 hr, and hours 3, 5, and 7. Placebo was given to control group patients at 20", 40", 2', 4', and 6'. PEFR and vital signs were measured 10 min after each treatment. Study end points included discharge upon reaching set criteria or admission if patients were not discharged following the hour 7 treatment.

RESULTS

Seventy one patients were enrolled, 40 in experimental group and 31 in the control group. The group characteristics did not differ at entry in any significant way, and the groups began with mean expected PEFR of 23.4% and 24.5%, respectively. There were no significant differences at any point in PEFR outcomes, time to discharge, or admission rate. The experimental group showed a greater increase in pulse rate and a reduced diastolic blood pressure at 20, 40 and 60 min. The experimental group had a 12- and 8-fold increase in the risk of a pulse rate > 140 at 40 and 60 min, respectively. This group also had two moderate complications, both near the 60-minute mark. These were an induction of atrial fibrillation in one patient and ischemic electrocardiographic changes in another.

CONCLUSION

Three treatments in the first hour, and hourly thereafter showed no benefit over treatments initially, at one hour, and every other hour in acute, moderate, or severe exacerbation of asthma. Side effects were markedly increased in the control group. Such dosing should not be recommended as routine therapy.