Intravenous beta2-agonists for acute asthma in the emergency department

Interventions for escalation of therapy for acute exacerbations of asthma in children: an overview of Cochrane Reviews

BACKGROUND

Asthma is an illness that commonly affects adults and children, and it serves as a common reason for children to attend emergency departments. An asthma exacerbation is characterised by acute or subacute worsening of shortness of breath, cough, wheezing, and chest tightness and may be triggered by viral respiratory infection, poor compliance with usual medication, a change in the weather, or exposure to allergens or irritants. Most children with asthma have mild or moderate exacerbations and respond well to first-line therapy (inhaled short-acting beta-agonists and systemic corticosteroids). However, the best treatment for the small proportion of seriously ill children who do not respond to first-line therapy is not well understood. Currently, a large number of treatment options are available and there is wide variation in management.

OBJECTIVES

Main objective - To summarise Cochrane Reviews with or without meta-analyses of randomised controlled trials on the efficacy and safety of second-line treatment for children with acute exacerbations of asthma (i.e. after first-line treatments, titrated oxygen delivery, and administration of intermittent inhaled short-acting beta₂-agonists and oral corticosteroids have been tried and have failed) Secondary objectives - To identify gaps in the current evidence base that will inform recommendations for future research and subsequent Cochrane Reviews - To categorise information on reported outcome measures used in trials of escalation of treatment for acute exacerbations of asthma in children, and to make recommendations for development and reporting of standard outcomes in future trials and reviews - To identify relevant randomised controlled trials that have been published since the date of publication of each included review METHODS: We included Cochrane Reviews assessing interventions for children with acute exacerbations of asthma. We searched the Cochrane Database of Systematic Reviews. The search is current to 28 December 2019. We also identified trials that were potentially eligible for, but were not currently included in, published reviews. We assessed the quality of included reviews using the ROBIS criteria (tool used to assess risk of bias in systematic reviews). We presented an evidence synthesis of data from reviews alongside an evidence map of clinical trials. Primary outcomes were length of stay, hospital admission, intensive care unit admission, and adverse effects. We summarised all findings in the text and reported data for each outcome in 'Additional tables'.

MAIN RESULTS

We identified 17 potentially eligible Cochrane Reviews but extracted data from, and rated the quality of, 13 reviews that reported results for children alone. We excluded four reviews as one did not include any randomised controlled trials (RCTs), one did not provide subgroup data for children, and the last two had been updated and replaced by subsequent reviews. The 13 reviews included 67 trials; the number of trials in each review ranged from a single trial up to 27 trials. The vast majority of comparisons included between one and three trials, involving fewer than 100 participants. The total number of participants included in reviews ranged from 40 to 2630. All studies included children; 16 (24%) included children younger than two years of age. Most of the reviews reported search dates older than four years. We have summarised the published evidence as outlined in Cochrane Reviews. Key findings, in terms of our primary outcomes, are that (1) intravenous magnesium sulfate was the only intervention shown to reduce hospital length of stay (high-certainty evidence); (2) no evidence suggested that any intervention reduced the risk of intensive care admission (low- to very low-certainty evidence); (3) the risk of hospital admission was reduced by the addition of inhaled anticholinergic agents to inhaled beta₂-agonists (moderate-certainty evidence), the use of intravenous magnesium sulfate (high-certainty evidence), and the use of inhaled heliox (low-certainty evidence); (4) the addition of inhaled magnesium sulfate to usual bronchodilator therapy appears to reduce serious adverse events during hospital admission (moderate-certainty evidence); (5) aminophylline increased vomiting compared to placebo (moderate-certainty evidence) and increased nausea and nausea/vomiting compared to intravenous beta₂-agonists (low-certainty evidence); and (6) the addition of anticholinergic therapy to short-acting beta₂-agonists appeared to reduce the risk of nausea (high-certainty evidence) and tremor (moderate-certainty evidence) but not vomiting (low-certainty evidence). We considered 4 of the 13 reviews to be at high risk of bias based on the ROBIS framework. In all cases, this was due to concerns regarding identification and selection of studies. The certainty of evidence varied widely (by review and also by outcome) and ranged from very low to high.

AUTHORS' CONCLUSIONS

This overview provides the most up-to-date evidence on interventions for escalation of therapy for acute exacerbations of asthma in children from Cochrane Reviews of randomised controlled trials. A vast majority of comparisons involved between one and three trials and fewer than 100 participants, making it difficult to assess the balance between benefits and potential harms. Due to the lack of comparative studies between various treatment options, we are unable to make firm practice recommendations. Intravenous magnesium sulfate appears to reduce both hospital length of stay and the risk of hospital admission. Hospital admission is also reduced with the addition of inhaled anticholinergic agents to inhaled beta₂-agonists. However, further research is required to determine which patients are most likely to benefit from these therapies. Due to the relatively rare incidence of acute severe paediatric asthma, multi-centre research will be required to generate high-quality evidence. A number of existing Cochrane Reviews should be updated, and we recommend that a new review be conducted on the use of high-flow nasal oxygen therapy. Important priorities include development of an internationally agreed core outcome set for future trials in acute severe asthma exacerbations and determination of clinically important differences in these outcomes, which can then inform adequately powered future trials.

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.

The Differences in Acute Management of Asthma in Adults and Children

Acute asthma or wheeze is a common presentation to emergency services for both adults and children. Although there are phenotypic differences between asthma syndromes, the management of acute symptoms follow similar lines. This article looks at the similarities and differences in approaches for children and adults. Some of these may be age dependent, such as the physiological parameters used to define the severity of the attack or the use of age appropriate inhaler devices. Other differences may reflect the availability of evidence. In other areas there is conflicting evidence between adult and pediatric studies such as a temporary increase in dose of inhaled corticosteroids during an acute attack. Overall there are more similarities than differences.

Childhood asthma: a guide for pediatric emergency medicine providers

Pediatric asthma is a disease that is managed across outpatient physicians, hospitalists, critical care physicians, and emergency department (ED) physicians. Scoring systems may facilitate a rapid assessment of the child with asthma in the ED. Short-acting beta agonists are still the mainstay of therapy for acute exacerbations along with corticosteroids and ipratropium bromide. ED providers must also know the indications for noninvasive ventilation and intubation. Most patients can be treated and discharged from the ED after acute exacerbation, and should be given a plan for going home that provides educational material and emergency scenarios to help prevent future acute incidents.

Asthma medication delivery: mists and myths

Asthma is usually treated with inhaled corticosteroids (ICS) and bronchodilators generated from pressurized metered dose inhalers (pMDI), dry powder inhalers (DPI), or nebulizers. The target areas for ICS and beta 2-agonists in the treatment of asthma are explained. Drug deposition not only depends on particle size, but also on inhalation manoeuvre. Myths regarding inhalation treatments lead to less than optimal use of these delivery systems. We discuss the origin of many of these myths and provide the background and evidence for rejecting them.

Addition of intravenous aminophylline to inhaled beta(2)-agonists in adults with acute asthma

BACKGROUND

Asthma is a chronic condition in which sufferers may have occasional or frequent exacerbations resulting in visits to the emergency department (ED). Aminophylline has been used extensively to treat exacerbations in acute asthma settings; however, it's role is unclear especially with respect to any additional benefit when added to inhaled beta(2)-agonists.

OBJECTIVES

To determine the magnitude of effect of the addition of intravenous aminophylline to inhaled beta(2)-agonists in adult patients with acute asthma treated in the ED setting.

SEARCH METHODS

We identified trials from the Cochrane Airways Group register (derived from MEDLINE, EMBASE, CINAHL standardised searches) and handsearched respiratory journals and meeting abstracts. Two independent review authors screened and obtained potentially relevant articles and handsearched their bibliographic lists for additional articles. In the original version of this review published in 2000 we included searches of the database up to 1999. The 2012 review was updated with a revised search from inception to September 2012.

SELECTION CRITERIA

Randomised controlled trials comparing intravenous aminophylline versus placebo in adults with acute asthma and treated with inhaled beta(2)-agonists. We included patients who were treated with or without corticosteroids or other bronchodilators provided this was not part of the randomised treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and one review author entered data into RevMan, which was checked by a second review author. Results are reported as mean differences (MD) or odds ratios (OR) with 95% confidential intervals (CI).

MAIN RESULTS

Fifteen studies were included in the previous version of the review, and we included two new studies in this update, although we were unable to pool new data. Overall, the quality of the studies was moderate; concealment of allocation was assessed as clearly adequate in only seven (45%) of the trials. There was significant clinical heterogeneity between studies as the doses of aminophylline and other medications and the severity of the acute asthma varied between studies.There was no statistically significant advantage when adding intravenous aminophylline with respect to hospital admissions (OR 0.58; 95% CI 0.30 to 1.12; 6 studies; n = 315). In 2000 it was found that there was no statistically significant effect of aminophylline on airflow outcomes at any time period; the addition of two trials in 2012 has not challenged this conclusion. People treated with aminophylline and beta(2)-agonists had similar peak expiratory flow (PEF) values compared to those treated with beta(2)-agonists alone at 12 h (MD 8.30 L/min; 95% CI -20.69 to 37.29 L/min) or (MD -1.21% predicted; 95% CI -14.21% to 11.78% predicted) and 24 h (MD 22.20 L/min; 95% CI -56.65 to 101.05 L/min). Two subgroup analyses were performed by grouping studies according to mean baseline airflow limitation (11 studies) and the use of any corticosteroids (nine studies). There was no relationship between baseline airflow limitation or the use of corticosteroids on the effect of aminophylline. Aminophylline-treated patients reported more palpitations/arrhythmias (OR 3.02; 95% CI 1.15 to 7.90; 6 studies; n = 249) and vomiting (OR 4.21; 95% CI 2.20 to 8.07; 7 studies; n = 321); however, no significant difference was found in tremor (OR 2.60; 95% CI 0.62 to 11.02; 5 studies; n = 249).

AUTHORS' CONCLUSIONS

The use of intravenous aminophylline did not result in significant additional bronchodilation compared to standard care with inhaled beta(2)-agonists in patients experiencing an asthma exacerbation in the ED setting, or in a significant reduction in the risk of hospital admission. For every 100 people treated with aminophylline an additional 20 people had vomiting and 15 people arrhythmias or palpitations. No subgroups in which aminophylline might be more effective were identified. Our update in 2012 is consistent with the original conclusions that the risk-benefit balance of intravenous aminophylline is unfavourable.

Inhaled magnesium sulfate in the treatment of acute asthma

BACKGROUND

Asthma exacerbations can be frequent and range in severity from relatively mild to status asthmaticus. The use of magnesium sulfate (MgSO(4)) is one of numerous treatment options available during acute exacerbations. While the efficacy of intravenous MgSO(4) has been demonstrated, little is known of the role of inhaled MgSO(4).

OBJECTIVES

To determine the efficacy of inhaled MgSO(4) administered in acute asthma on pulmonary functions and admission rates.

SPECIFIC AIMS

To quantify the effects of inhaled MgSO(4) i) in addition to inhaled β(2)-agonist, ii) in comparison to inhaled β(2)-agonist alone or iii) in addition to combination treatment with inhaled β(2) -agonist and ipratropium bromide.

SEARCH METHODS

Randomised controlled trials were identified from the Cochrane Airways Group register of trials in September 2012. These trials were supplemented with trials found in the reference list of published studies, studies found using extensive electronic search techniques, as well as a review of the grey literature and conference proceedings.

SELECTION CRITERIA

Randomised (or pseudo-randomised) controlled trials including adults or children with acute asthma were eligible for inclusion in the review. Studies were included if patients were treated with nebulised MgSO(4) alone or in combination with β(2)-agonist and/or ipratropium bromide and were compared with β(2)-agonist alone or inactive control.

DATA COLLECTION AND ANALYSIS

Trial selection, data extraction and risk of bias were assessed independently by two review authors. Efforts were made to collect missing data from authors. Results are presented as standardised mean differences (SMD) for pulmonary function and risk ratios (RR) for hospital admission; both are displayed with their 95% confidence intervals (CI).

MAIN RESULTS

Sixteen trials (21 references) of unclear and high risk of bias were eligible and included 896 patients who were randomised (838 patients completed). Seven of the 16 included studies involved adults exclusively, three included adults and paediatric patients, four studies enrolled paediatric patients and in the remaining two studies the age of participants was not stated.The design, definitions, intervention and outcomes were different in all 16 studies; this heterogeneity made direct comparisons difficult (see additional tables 1-3).The overall risk of bias among the included studies was variable and this is reflected in the 'Summary of findings' table with most outcomes being judged as only moderate or less.Inhaled magnesium sulfate in addition to inhaled β(2)-agonistThere was no statistically significant improvement in pulmonary function when inhaled MgSO(4) and β(2)-agonist was compared with β(2)-agonist alone (SMD 0.23; 95% CI -0.27 to 0.74; three studies, n = 188); however, there was considerable between study heterogeneity. There was no clear advantage in terms of hospital admissions (RR 0.76 95% CI 0.49, 1.16; four studies, n = 249), and there were no serious adverse events reported.Inhaled magnesium sulfate versus inhaled β(2)-agonistThe results of pulmonary function in three studies that compared inhaled MgSO(4) versus β(2)-agonist were too heterogeneous to combine; however, two of the studies found poorer lung function on MgSO(4). There was no significant difference in terms of hospital admissions in a single small study when MgSO(4) was compared to β(2)-agonist (RR 0.53 95% CI 0.05, 5.31; one study, n = 33), and there were no serious adverse events reported.Inhaled magnesium sulfate in addition to inhaled β(2)-agonist and ipratropiumA further comparison has been included in the 2012 update of this review of MgSO(4) given in addition to inhaled ipratropium and β(2)-agonist therapy (as recommended by the GINA guidelines). However, there is not yet enough data for this outcome to come to any definite conclusions, but both small studies in adults with severe asthma exacerbation found improvements in pulmonary function with additional inhaled MgSO(4).

AUTHORS' CONCLUSIONS

There is currently no good evidence that inhaled MgSO(4) can be used as a substitute for inhaled β(2)-agonists. When used in addition to inhaled β(2)-agonists (with or without inhaled ipratropium), there is currently no overall clear evidence of improved pulmonary function or reduced hospital admissions. However, individual study results from three trials suggest possible improved pulmonary function in those with severe asthma exacerbations (FEV1 less than 50% predicted). Heterogeneity among trials included in this review precludes a more definitive conclusion. Further studies should focus on inhaled MgSO(4) in addition to the current guideline treatment for acute asthma (inhaled β(2) -agonist and ipratropium bromide). As the evidence suggests that the most effective role of nebulised MgSO(4) may be in those with severe acute features and this is where future research should be focused. A set of core outcomes needs to be agreed upon both in adult and paediatric studies to allow improved study comparison in future. 

Addition of intravenous beta(2)-agonists to inhaled beta(2)-agonists for acute asthma

BACKGROUND

Inhaled beta-agonist therapy is central to the management of acute asthma. This review evaluates the benefit of an additional use of intravenous beta(2)-agonist agents.

OBJECTIVES

To determine the benefit of adding intravenous (IV) beta(2)-agonists to inhaled beta(2)-agonist therapy for acute asthma treated in the emergency department.

SEARCH METHODS

Randomised controlled trials (RCTs) were identified using the Cochrane Airways Group Register which is a compilation of systematic searches of MEDLINE, EMBASE, CINAHL, and CENTRAL as well as handsearching of 20 respiratory journals. Bibliographies from included studies and known reviews were also searched. Primary authors and content experts were contacted to identify eligible studies. The search was performed in September 2012.

SELECTION CRITERIA

Only RCTs were considered for inclusion. Studies were included if patients presented to the emergency department with acute asthma and were treated with IV beta(2)-agonists with inhaled beta(2)-agonist therapy and existing standard treatments versus inhaled beta(2)-agonists and existing standard treatments.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and confirmed their findings with corresponding authors of trials. We obtained missing data from authors or calculated from data present in the papers. We used fixed-effect model for odds ratios (OR) and for mean differences (MD) we used both fixed-effect and random-effects models and reported 95% confidence intervals (CI).

MAIN RESULTS

From 109 potentially relevant studies only three (104 patients) met our inclusion criteria: Bogie 2007 (46 children), Browne 1997 (29 children) and Nowak 2010 (29 adults). Bogie 2007 investigated the addition of intravenous terbutaline to high dose nebulised albuterol in children with acute severe asthma, requiring intensive care unit (ICU) admission. Browne 1997 investigated the benefit of adding intravenous salbutamol to inhaled salbutamol in children with acute severe asthma in the emergency department. Nowak 2010 investigated addition of IV bedoradrine to standard care (nebulised albuterol, ipratropium and oral corticosteroids) among adults, and was reported as a conference abstract only.There was no significant advantage (OR 0.29; 95%CI 0.06 to 1.38, one trial, 29 adults) for adding IV bedoradrine to standard care (nebulised albuterol, ipratropium and oral corticosteroids) with regard to hospitalisation rates.Various outcome indicators for the length of stay were reported among the trials. Browne 1997 reported a significantly shorter recovery time (in terms of cessation of 30 minute salbutamol) for children in the IV salbutamol with inhaled salbutamol group (four hours) versus the 11.1 hours for the inhaled salbutamol group (P = 0.03). Time to cessation of hourly nebuliser was also significantly shorter (P = 0.02) for the IV plus inhaled salbutamol group (11.5 hours versus 21.2 hours), and they were ready for emergency patient discharge on average 9.7 hours earlier than the inhaled salbutamol group (P < 0.05). In a paediatric ICU study Bogie 2007 reported no significant advantage in length of paediatric ICU admission (hours) for adding IV terbutaline to nebulised albuterol (MD -12.95, 95% CI: -38.74, 12.84).Browne 1997 reported there were only six out of 14 children with a pulmonary index score above six in the IV plus inhaled salbutamol group at two hours compared with 14 of the 15 in the inhaled salbutamol group (P = 0.02)In Browne 1997 there was a higher proportion of tremor in the IV plus inhaled salbutamol group than in the inhaled salbutamol group (P < 0.02). Nowak 2010 did not report any statistically significant adverse effects associated with adding IV bedoradrine to standard care (nebulised albuterol, ipratropium and oral corticosteroids). Troponin levels were elevated in three children in the IV terbutaline + nebulised albuterol group at 12 and 24 hours in Bogie 2007

AUTHORS' CONCLUSIONS

There is very limited evidence from one study (Browne 1997) to support the use of IV beta(2)-agonists in children with severe acute asthma with respect to shorter recovery time, and similarly there is limited evidence (again from one study Browne 1997) suggesting benefit with regard to pulmonary index scores; however this advantage needs to be considered carefully in relation to the increased side effects associated with IV beta(2)-agonists. We identified no significant benefits for adults with severe acute asthma. Until more, adequately powered, high quality clinical trials in this area are conducted it is not possible to form a robust evaluation of the addition of IV beta(2)-agonists in children or adults with severe acute asthma.

Intravenous beta(2)-agonists versus intravenous aminophylline for acute asthma

BACKGROUND

Inhaled beta(2)-agonist therapy is central to the management of acute asthma. For rapid bronchodilation in severe cases, penetration of inhaled drug to the affected small conducting airway may be impeded, and the intravenous (IV) rather than inhaled administration of bronchodilators may provide an earlier response. IV beta(2)-agonist agents and IV aminophylline may also be considered as additional interventions in this setting and this review compares IV beta-agonist agents and IV aminophylline in the treatment of people with acute asthma.

OBJECTIVES

To compare the benefit of IV beta(2)-agonists versus IV aminophylline for acute asthma treated in the emergency department and in patients admitted to hospital with acute severe asthma.

SEARCH METHODS

Randomised controlled trials (RCTs) were identified using the Cochrane Airways Group Register, which is compiled from systematic searches of bibliographic databases as well as handsearching of respiratory journals and conference abstracts. The latest search was run in September 2012. We searched bibliographies from included studies and known reviews were also searched. Primary authors and content experts were contacted to identify eligible studies.

SELECTION CRITERIA

We included RCTs of patients who presented to the emergency department with acute asthma, and patients admitted to hospital with acute severe asthma, and were treated with IV beta(2)-agonists versus IV aminophylline. Two review authors independently selected potentially relevant articles and selected articles for inclusion. Methodological quality was independently assessed using two scoring systems and two review authors.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two review authors. Missing data were obtained from authors or calculated from data present in the papers. Trials were combined using a random-effects model for odds ratios (OR) or mean differences (MD) and reported with 95% confidence intervals (95% CI).

MAIN RESULTS

Eleven studies met our inclusion criteria and in total they included 350 patients. However, opportunities to combine these studies in meta-analyses were limited by the variations in the range of outcomes reported in the trials.Length of stayTwo studies reported length of stay. They were both paediatric trials (with one in paediatric intensive care unit), and there was no significant difference between the two groups (MD 23.19 hours; 95% CI -2.40 to 48.77 hours; 2 studies; N = 73). Individual separate MD analyses for the two studies also indicated no significant difference between the aminophylline and beta(2)-agonist on this outcome. However, this finding should be interpreted with caution owing to the small number of trials and participants the analysis.Pulmonary functionThere were no significant differences in the sequential or summative pulmonary function demonstrated across the studies.Heart rateData for serial heart rates were reported in three studies at various points from 15 to 60 minutes and in each case there were no significant differences between people in the IV aminophylline or beta(2)-agonist groups. The difference between the two groups with respect to final heart rate was statistically significant (MD 10.00; 95% CI 0.99 to 19.01), although these data are from a single, small study and should be interpreted with caution.Adverse effectsThe analyses for giddiness (OR 59.22; 95% CI 2.80 to 1253.05; 1 study; N = 30), nausea/vomiting (where reported as a combined outcome) (OR 14.18; 95% CI 1.62 to 124.52; 2 studies; N = 96) and nausea (OR 6.53; 95% CI 1.60 to 26.72; 2 studies; N = 49) all significantly favoured beta(2)-agonists. In view of the very small number of studies and number of patients contributing to these analyses these results should be interpreted with caution. A closely related review considering the possible benefits of adding IV aminophylline to beta-agonists in adults with acute asthma also indicates a higher incidence of adverse effects associated with IV aminophylline.

AUTHORS' CONCLUSIONS

In the included RCTs there was no consistent evidence favouring either IV beta(2)-agonists or IV aminophylline for patients with acute asthma. The opportunity to draw clear conclusions is limited by the heterogeneity of outcomes evaluated and the small sample sizes in the included studies. It is recommended that these data should be viewed carefully alongside the conclusions from separate Cochrane reviews comparing IV beta(2)-agonists plus inhaled beta(2)-agonists versus inhaled beta(2)-agonists alone and IV aminophylline plus inhaled beta(2)-agonists versus inhaled beta(2)-agonists alone.

Fatal and near-fatal asthma in children: the critical care perspective

OBJECTIVE

To characterize the clinical course, therapies, and outcomes of children with fatal and near-fatal asthma admitted to pediatric intensive care units (PICUs).

STUDY DESIGN

This was a retrospective chart abstraction across the 8 tertiary care PICUs of the Collaborative Pediatric Critical Care Research Network (CPCCRN). Inclusion criteria were children (aged 1-18 years) admitted between 2005 and 2009 (inclusive) for asthma who received ventilation (near-fatal) or died (fatal). Data collected included medications, ventilator strategies, concomitant therapies, demographic information, and risk variables.

RESULTS

Of the 261 eligible children, 33 (13%) had no previous history of asthma, 218 (84%) survived with no known complications, and 32 (12%) had complications. Eleven (4%) died, 10 of whom had experienced cardiac arrest before admission. Patients intubated outside the PICU had a shorter duration of ventilation (median, 25 hours vs 84 hours; P < .001). African-Americans were disproportionately represented among the intubated children and had a shorter duration of intubation. Barotrauma occurred in 15 children (6%) before admission. Pharmacologic therapy was highly variable, with similar outcomes.

CONCLUSION

Of the children ventilated in the CPCCRN PICUs, 96% survived to hospital discharge. Most of the children who died experienced cardiac arrest before admission. Intubation outside the PICU was correlated with shorter duration of ventilation. Complications of barotrauma and neuromyopathy were uncommon. Practice patterns varied widely among the CPCCRN sites.

Critical care for pediatric asthma: wide care variability and challenges for study

OBJECTIVES

To describe pediatric severe asthma care, complications, and outcomes to plan for future prospective studies by the Collaborative Pediatric Critical Care Research Network.

DESIGN

Retrospective cohort study.

SETTING

: Pediatric intensive care units in the United States that submit administrative data to the Pediatric Health Information System.

PATIENTS

Children 1-18 yrs old treated in a Pediatric Health Information System pediatric intensive care unit for asthma during 2004-2008.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirteen-thousand five-hundred fifty-two children were studied; 2,812 (21%) were treated in a Collaborative Pediatric Critical Care Research Network and 10,740 (79%) were treated in a non-Collaborative Pediatric Critical Care Research Network pediatric intensive care unit. Medication use in individual Collaborative Pediatric Critical Care Research Network centers differed widely: ipratropium bromide (41%-84%), terbutaline (11%-74%), magnesium sulfate (23%-64%), and methylxanthines (0%-46%). Complications including pneumothorax (0%-0.6%), cardiac arrest (0.2%-2%), and aspiration (0.2%-2%) were rare. Overall use of medical therapies and complications at Collaborative Pediatric Critical Care Research Network centers were representative of pediatric asthma care at non-Collaborative Pediatric Critical Care Research Network pediatric intensive care units. Median length of pediatric intensive care unit stay at Collaborative Pediatric Critical Care Research Network centers was 1 to 2 days and death was rare (0.1%-3%). Ten percent of children treated at Collaborative Pediatric Critical Care Research Network centers received invasive mechanical ventilation compared to 12% at non-Collaborative Pediatric Critical Care Research Network centers. Overall 44% of patients who received invasive mechanical ventilation were intubated in the pediatric intensive care unit. Children intubated outside the pediatric intensive care unit had significantly shorter median ventilation days (1 vs. 3), pediatric intensive care unit days (2 vs. 4), and hospital days (4 vs. 7) compared to those intubated in the pediatric intensive care unit. Among children who received mechanical respiratory support, significantly more (41% vs. 25%) were treated with noninvasive ventilation and significantly fewer (41% vs. 58%) were intubated before pediatric intensive care unit care when treated in a Pediatric Health Information System hospital emergency department.

CONCLUSIONS

Marked variations in medication therapies and mechanical support exist. Death and other complications were rare. More than half of patients treated with mechanical ventilation were intubated before pediatric intensive care unit care. Site of respiratory mechanical support initiation was associated with length of stay.

Leukotriene receptor antagonists in addition to usual care for acute asthma in adults and children

BACKGROUND

Acute asthma presentation in the emergency setting frequently leads to hospital admission. Currently available treatment options include corticosteroid therapy, beta(2)-agonists and oxygen. Antileukotriene agents are beneficial in chronic asthma as additional therapy to inhaled steroids. Their value when used orally or intravenously in the acute setting requires evaluation.

OBJECTIVES

To determine if the addition of a leukotriene receptor antagonist (LTRA) produces a beneficial effect in children and adults with acute asthma who are currently receiving inhaled bronchodilators and systemic corticosteroids.

SEARCH METHODS

We searched the Cochrane Airways Group's Specialised Register of trials with predefined terms. Searches are current to February 2012.

SELECTION CRITERIA

We included randomised trials comparing antileukotrienes and standard acute asthma care versus placebo and standard care in people with acute asthma of any age. We considered any dose and method of delivery of the leukotriene agent.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion in the review and extracted data. We then checked data and resolved disagreements by discussion. We contacted study authors where necessary to provide additional information and data.

MAIN RESULTS

Eight trials, generating 10 treatment-control comparisons, that recruited 1470 adults and 470 children met the entry criteria. These studies were of mixed quality, and there was heterogeneity in the severity of asthma exacerbation.For oral treatment, there was no significant difference in hospital admission between LTRAs and control in three trials on 194 children (risk ratio (RR) 0.86; 95% confidence interval (CI) 0.21 to 3.52). Using a broader composite outcome which measured requirement for additional care there was no significant difference between treatments (RR 0.87; 95% CI 0.60 to 1.28). Results demonstrated some indication of improvement in lung function with a significant difference in forced expiratory volume in one second (FEV(1)) favouring LTRAs in two trials on 641 adults (mean difference (MD) 0.08; 95% CI 0.01 to 0.14). There were insufficient data to assess this outcome in children. The most common adverse event described was headache; however, there was no significant difference between LTRAs and control (RR 0.81; 95% CI 0.22 to 2.99). Due to insufficient numbers, we were unable to conduct a subgroup analysis based on age.The combined results of two trials of intravenous treatment in 772 adults and one trial in 276 children demonstrated a reduction in the risk of hospital admission which was not quite statistically significant (RR 0.78; 95% CI 0.61 to 1.01). There was a statistically significant small difference in FEV(1) in the adult studies (MD 0.12; 95% CI 0.06 to 0.17), but not in the single trial in children (MD 0.01; 95% CI -0.06 to 0.08).

AUTHORS' CONCLUSIONS

Presently, the available evidence does not support routine use of oral LTRAs in acute asthma. Further studies are required to assess whether intravenous treatment can reduce the risk of hospital admission, and what the most appropriate dose regimen is. Additional research is also needed into safety and efficacy of additional doses for those on maintenance therapy, and larger paediatric trials are required to allow subgroup analysis. Prolonged studies would be required to establish other health economic outcomes in admitted patients.

Common pediatric respiratory emergencies

Pediatric respiratory illnesses are a huge burden to emergency departments worldwide. This article reviews the latest evidence in the epidemiology, assessment, management, and disposition of children presenting to the emergency department with asthma, croup, bronchiolitis, and pneumonia.

Acute lung failure

Lung failure is the most common organ failure seen in the intensive care unit. The pathogenesis of acute respiratory failure (ARF) can be classified as (1) neuromuscular in origin, (2) secondary to acute and chronic obstructive airway diseases, (3) alveolar processes such as cardiogenic and noncardiogenic pulmonary edema and pneumonia, and (4) vascular diseases such as acute or chronic pulmonary embolism. This article reviews the more common causes of ARF from each group, including the pathological mechanisms and the principles of critical care management, focusing on the supportive, specific, and adjunctive therapies for each condition.

An integrative review of systematic reviews related to the management of breathlessness in respiratory illnesses

BACKGROUND

Breathlessness is a debilitating and distressing symptom in a wide variety of diseases and still a difficult symptom to manage. An integrative review of systematic reviews of non-pharmacological and pharmacological interventions for breathlessness in non-malignant disease was undertaken to identify the current state of clinical understanding of the management of breathlessness and highlight promising interventions that merit further investigation.

METHODS

Systematic reviews were identified via electronic databases between July 2007 and September 2009. Reviews were included within the study if they reported research on adult participants using either a measure of breathlessness or some other measure of respiratory symptoms.

RESULTS

In total 219 systematic reviews were identified and 153 included within the final review, of these 59 addressed non-pharmacological interventions and 94 addressed pharmacological interventions. The reviews covered in excess of 2000 trials. The majority of systematic reviews were conducted on interventions for asthma and COPD, and mainly focussed upon a small number of pharmacological interventions such as corticosteroids and bronchodilators, including beta-agonists. In contrast, other conditions involving breathlessness have received little or no attention and studies continue to focus upon pharmacological approaches. Moreover, although there are a number of non-pharmacological studies that have shown some promise, particularly for COPD, their conclusions are limited by a lack of good quality evidence from RCTs, small sample sizes and limited replication.

CONCLUSIONS

More research should focus in the future on the management of breathlessness in respiratory diseases other than asthma and COPD. In addition, pharmacological treatments do not completely manage breathlessness and have an added burden of side effects. It is therefore important to focus more research on promising non-pharmacological interventions.

[Stocked medications in emergency physician-based medical services in Germany. Reality and requirements according to guidelines]

BACKGROUND

The emergency medical service (EMS) should work according to criteria of evidence-based medicine. In Germany the EMS of each state is under the control of at least one medical supervisor known as emergency medical directors (EMD) and most states have several different EMDs responsible for one or more provinces of the state. The German Medical Association advises these supervisors to specify the pharmacological resources in store for use in physician powered EMSs. This study examines the pharmacological resources in EMSs which is provided by the EMDs in Germany. Furthermore, a comparison of the inventory analysis of stored drugs was carried out with the requirements according to guidelines for selected tracer diagnoses.

METHOD

In the period of May 2008 to January 2009 a total of 148 EMDs were contacted and asked to supply drug storage lists for emergency physician-staffed rescue vehicles in their respective jurisdiction. The addresses of all EMDs who could be identified by the federal office of the National Association of Emergency Medical Director, Germany were used over the period. The evaluation was conducted anonymously. The tracer diagnoses "cardiopulmonary resuscitation", "acute coronary syndrome", "status generalized tonic-clonic seizure," "severe asthma attack", "acute exacerbation of chronic obstructive pulmonary disease", "supraventricular tachycardia", "severe brain trauma" and "acute heart failure with signs of hypoperfusion" were selected. Current and established guidelines have been identified with the homepage of the Scientific Medical Societies in Germany and supported by the leading European and International guidelines.

RESULTS

The corresponding lists were returned by 95 different emergency service areas (response rate 64.2%). With a total of 39 groups of substances 142 different drugs could be identified, an average of 54±9.6 and median 55 (range 31-77). Listed are agents giving the provision in percent, for which the comparison with guidelines for tracer diagnoses could show deficits: sodium bicarbonate 75.8%, calcium 50.5%, magnesium 45.3%, noradrenaline 65.3%, adenosine 58.9%, dobutamine 57.9%, lorazepam iv 13.7%, salbutamol 41.1%, ipratropium bromide 13.7% (the last two as liquid preparations for inhalation). With a frequency of about 30-80%, depending on the respective tracer diagnosis, no medical emergency treatment according to the highest level of evidence is possible.

CONCLUSION

Due to recent treatment recommendations provision with sodium bicarbonate, calcium, magnesium, noradrenaline, adenosine, lorazepam iv, dobutamine and as well with ipratropium bromide and salbutamol (both as liquid preparations for inhalation) should be improved. For the future, a federal uniform minimum standard due to evidence-based principles is desirable.

Management of status asthmaticus in children

Asthma is a common chronic inflammatory disorder of the airways characterized by recurrent wheezing, breathlessness, and coughing. Acute exacerbations of asthma can be life-threatening; annual worldwide estimated mortality is 250,000 and most of these deaths are preventable. While most of the acute exacerbations can be managed successfully in the emergency room, few children have severe exacerbations requiring intensive care. Mainstay of treatment for status asthmaticus are inhaled β2 agonist and anticholinergic agents, oxygen along with corticosteroids. Children who do not respond well to initial treatment require parenteral β2 agonist and magnesium. Rarely, sick children need parenteral aminophylline infusion and mechanical ventilation. Guidelines for diagnosis, treatment, ventilator management and supportive care for status asthmaticus in children are discussed in the protocol.

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.

Comparative effectiveness of medical interventions in adults versus children

OBJECTIVE

To estimate the comparative effectiveness of medical interventions in adults versus children.

STUDY DESIGN

We identified from the Cochrane Database of Systematic Reviews (Issue 1, 2007) meta-analyses with data on at least 1 adult and 1 pediatric randomized trial with binary primary efficacy outcome. For each meta-analysis, we calculated the summary odds ratio of the adult trials and the pediatric trials, respectively; the relative odds ratio (ROR) of the adult versus pediatric odds ratios per meta-analysis; and the summary ROR across all meta-analyses. ROR <1 means that the experimental intervention is more unfavorable in children than adults.

RESULTS

Across 128 eligible meta-analyses (1051 adult and 343 pediatric trials), the summary ROR did not show a statistically significant difference between adults and children (0.96; 95% confidence intervals, 0.86 to 1.08). However, in all meta-analyses except for 1, the individual ROR's 95% confidence intervals could not exclude a relative difference in efficacy over 20%. In two-thirds, the relative difference in observed point estimates exceeded 50%. Nine statistically significant discrepancies were identified; 4 of them were also clinically important.

CONCLUSIONS

Treatment effects are on average similar in adults and children, but available evidence leaves large uncertainty about their relative efficacy. Clinically important discrepancies may occur.

[Status asthmaticus. Role of extracorporeal lung assist procedures]

The successful application of a pumpless extracorporeal lung assist procedure ("interventional lung assist, iLA) in three cases of severe refractory status asthmaticus, which could not be solved with conventional pharmacological and respiratory therapy is reported. After an individual risk-benefit analysis such a therapy can be used to reduce lung injury due to invasive mechanical ventilation. Because of the complexity of this therapy it should only be applied in special medical centers with sufficient experience in dealing with extracorporeal lung assist procedures.

Acute severe asthma: new approaches to assessment and treatment

The precise definition of a severe asthmatic exacerbation is an issue that presents difficulties. The term 'status asthmaticus' relates severity to outcome and has been used to define a severe asthmatic exacerbation that does not respond to and/or perilously delays the repetitive or continuous administration of short-acting inhaled beta(2)-adrenergic receptor agonists (SABA) in the emergency setting. However, a number of limitations exist concerning the quantification of unresponsiveness. Therefore, the term 'acute severe asthma' is widely used, relating severity mostly to a combination of the presenting signs and symptoms and the severity of the cardiorespiratory abnormalities observed, although it is well known that presentation does not foretell outcome. In an acute severe asthma episode, close observation plus aggressive administration of bronchodilators (SABAs plus ipratropium bromide via a nebulizer driven by oxygen) and oral or intravenous corticosteroids are necessary to arrest the progression to severe hypercapnic respiratory failure leading to a decrease in consciousness that requires intensive care unit (ICU) admission and, eventually, ventilatory support. Adjunctive therapies (intravenous magnesium sulfate and/or others) should be considered in order to avoid intubation. Management after admission to the hospital ward because of an incomplete response is similar. The decision to intubate is essentially based on clinical judgement. Although cardiac or respiratory arrest represents an absolute indication for intubation, the usual picture is that of a conscious patient struggling to breathe. Factors associated with the increased likelihood of intubation include exhaustion and fatigue despite maximal therapy, deteriorating mental status, refractory hypoxaemia, increasing hypercapnia, haemodynamic instability and impending coma or apnoea. To intubate, sedation is indicated in order to improve comfort, safety and patient-ventilator synchrony, while at the same time decrease oxygen consumption and carbon dioxide production. Benzodiazepines can be safely used for sedation of the asthmatic patient, but time to awakening after discontinuation is prolonged and difficult to predict. The most common alternative is propofol, which is attractive in patients with sudden-onset (near-fatal) asthma who may be eligible for extubation within a few hours, because it can be titrated rapidly to a deep sedation level and has rapid reversal after discontinuation; in addition, it possesses bronchodilatory properties. The addition of an opioid (fentanyl or remifentanil) administered by continuous infusion to benzodiazepines or propofol is often desirable in order to provide amnesia, sedation, analgesia and respiratory drive suppression. Acute severe asthma is characterized by severe pulmonary hyperinflation due to marked limitation of the expiratory flow. Therefore, the main objective of the initial ventilator management is 2-fold: to ensure adequate gas exchange and to prevent further hyperinflation and ventilator-associated lung injury. This may require hypoventilation of the patient and higher arterial carbon dioxide (PaCO(2)) levels and a more acidic pH. This does not apply to asthmatic patients intubated for cardiac or respiratory arrest. In this setting the post-anoxic brain oedema might demand more careful management of PaCO(2) levels to prevent further elevation of intracranial pressure and subsequent complications. Monitoring lung mechanics is of paramount importance for the safe ventilation of patients with status asthmaticus. The first line of specific pharmacological therapy in ventilated asthmatic patients remains bronchodilation with a SABA, typically salbutamol (albuterol). Administration techniques include nebulizers or metered-dose inhalers with spacers. Systemic corticosteroids are critical components of therapy and should be administered to all ventilated patients, although the dose of systemic corticosteroids in mechanically ventilated asthmatic patients remains controversial. Anticholinergics, inhaled corticosteroids, leukotriene receptor antagonists and methylxanthines offer little benefit, and clinical data favouring their use are lacking. In conclusion, expertise, perseverance, judicious decisions and practice of evidence-based medicine are of paramount importance for successful outcomes for patients with acute severe asthma.

Review article: management of acute severe and near-fatal asthma

Despite a decline in the Australian overall asthma mortality, near-fatal/critical asthma continues to be a significant management issue for emergency physicians and intensivists. Near-fatal asthma is a unique subtype of asthma, with a variety of clinical presentations, requiring rapid and aggressive intervention. The pharmacological and non-pharmacological management of near-fatal asthma remains very complex. The present review discusses recent advances and evidence for current available strategies targeting this time critical emergency.

[Bronchial asthma and chronic obstructive pulmonary disease with acute exacerbation: preclinical differential diagnostic and emergency treatment]

Chronic obstructive pulmonary disease (COPD) and bronchial asthma are the most common causes of obstructive pulmonary diseases and acute dyspnoea. In the preclinical emergency situation a distinction between bronchial asthma and exacerbated COPD is difficult because symptoms are similar. Although the preclinical measures differ only marginally, a differential diagnosis from other causes of respiratory obstruction and acute dyspnoea, such as cardiac decompensation, anaphylaxis, aspiration of foreign bodies, tension pneumothorax and inhalation trauma is necessary because alternative treatment options are required. In the treatment of COPD and bronchial asthma inhalative bronchodilatory beta(2)-mimetics are the first choice especially for serious obstructive emergencies because there is an unfavorable relationship between effect and side-effects for the intravenous route. Dosable aerosols, nebulization and if necessary, continuous nebulization, are appropriate application forms even for serious obstructive crises with the need of a respirator. In these cases a minimal inspiratory flow in patients is not required. Theophylline only plays a minor role to beta(2)-mimetics and anticholinergics as a bronchodilator in asthma and COPD guidelines, even in serious obstructive diseases. For severe asthma attacks the administration of magnesium is a possible additional option. Systemic intravenous administration of steroids has an anti-inflammatory effect and for this reason is the second column of treatment for both diseases. Invasive ventilation remains a last resort to ensure respiratory function and indications for this are given in patients with clinical signs of impending exhaustion of breathing.

Asthma in childhood

Management decisions for pediatric asthma (in patients younger than 12 years of age) based on extrapolation from available evidence in adolescents and adults (age 12 years and older) is common but rarely appropriate. This article addresses the disparity in response between the two age groups, presents the available pediatric evidence, and highlights the important areas in which further research is required. Evidence-based recommendations for acute and interval management of pediatric asthma are provided.

State of the evidence on acute asthma management in children: a critical appraisal of systematic reviews

OBJECTIVE

Our goal was to evaluate clinical, methodologic, and reporting aspects of systematic reviews on the management of acute asthma in children.

METHODS

We undertook a systematic review of systematic reviews on acute asthma management in children. We identified eligible reviews by searching the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, Medline, and Embase 1990 to March 2006. Data were extracted on clinical issues, methodologic characteristics, and results of the reviews. Methodologic quality was assessed with the Overview Quality Assessment Questionnaire and with additional questions on heterogeneity. Separate reporting on children in mixed adult-pediatric population reviews was assessed. Methodologic quality of systematic reviews published in peer-reviewed journals was compared with Cochrane reviews.

RESULTS

A total of 23 systematic reviews were included: 14 were published in the Cochrane Library, and 9 were published in peer-reviewed journals. Eight reviews included children only, and 15 were mixed-population reviews. The majority of reviews defined the study population as having "acute asthma" without a more precise definition, and 16 different health outcomes were reported. The overall quality according to the Overview Quality Assessment Questionnaire was good, with Cochrane reviews showing minimal flaws and journal reviews showing minor flaws (median scores: 7 vs 5). Results on children were reported separately in 8 of 15 mixed-population reviews. Clinical heterogeneity was explored in only 2 of 23 reviews, and the methods used to identify and address heterogeneity were diverse.

CONCLUSIONS

The methodologic quality of both the Cochrane and journal reviews on the management of acute asthma in children seems good, with Cochrane reviews being more rigorous. However, their usefulness for clinical practice is hampered by a lack of clear definitions of included populations, clinically important health outcomes, and separate reporting on children in mixed reviews. A major threat to these reviews' validity is the insufficient identification and handling of heterogeneity.

Principles of managing children with asthma in the emergency department

INTRODUCTION: Paediatric asthma exacerbations comprise a significant portion of emergency department (ED) visits and hospitalizations. Recognition of diagnostic symptoms and signs, and timely use of appropriate medications may reduce the need of hospitalizations and the impact of this disease on the lives of children and their families. OBJECTIVE: To review the pathophysiology of asthma, the current recommendations for conventional medical treatment in the ED, the controversies surrounding adjunct therapies, and the importance of discharge planning and follow-up. CONCLUSIONS: Paediatric asthma exacerbations may be successfully treated in the ED with the use of appropriate inhaled and systemic medications.

Treatment in the pediatric emergency department is evidence based: a retrospective analysis

BACKGROUND

Our goal was to quantify the evidence that is available to the physicians of a pediatric emergency department (PED) in making treatment decisions. Further, we wished to ascertain what percentage of evidence for treatment provided in the PED comes from pediatric studies.

METHODS

We conducted a retrospective chart review of randomly selected patients seen in the PED between January 1 and December 31, 2002. The principal investigator identified a primary diagnosis and primary intervention for each chart. A thorough literature search was then undertaken with respect to the primary intervention. If a randomized control trial (RCT) or a systematic review was found, the intervention was classified as level I evidence. If no RCT was found, the intervention was assessed by an expert committee who determined its appropriateness based on face validity (RCTs were unanimously judged to be both unnecessary and, if a placebo would have been involved, unethical). These interventions were classified as level II evidence. Interventions that did not fall into either above category were classified as level III evidence.

RESULTS

Two hundred and sixty-two patient charts were reviewed. Of these, 35.9% did not receive a primary intervention. Of the 168 interventions assessed, 80.4% were evidence-based (level I), 7.1% had face validity (level II) and 12.5% had no supporting evidence (level III). Of the evidence-based interventions, 83.7% were supported by studies with mostly pediatric patients.

CONCLUSION

Our study demonstrates that a substantial proportion of PED treatment decisions are evidence-based, with most based on studies in pediatric patients. Also, a large number of patients seen in the PED receive no intervention.

The yellow zone in asthma treatment: is it a gray zone?

OBJECTIVE

To review the available literature on methods of preventing and minimizing exacerbations and to target problems for improvement.

DATA SOURCES

PubMed and Cochrane Review searches of the English-language literature using the following key yellow zone terms: asthma exacerbation, self-management plans, inhaled corticosteroids, and acute management of asthma exacerbations.

STUDY SELECTION

Articles relevant to our yellow zone intervention inquiry.

RESULTS

The National Institutes of Health (NIH) guidelines advocate that physicians give patients written action plans with instructions on managing home (yellow zone) exacerbations. However, the criteria used to identify the yellow zone are ambiguous and often confusing to patients and physicians. In addition, apart from a passing mention that doubling doses of inhaled corticosteroids may be an option in asthma step-up care, the guidelines contain no recommendations for yellow zone treatment strategies. This deficiency is directly related to the paucity of organized evidence on the efficacy of the various pharmacological interventions that can be used during an exacerbation.

CONCLUSIONS

Translating the NIH guidelines into realistic clinical practice requires a clearer and more patient-friendly definition of the yellow zone, and this improved definition will facilitate the prescription of effective interventions in the management of yellow zone exacerbations.

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.

Inhaled beta-agonists for asthma in mechanically ventilated patients

BACKGROUND

A small number of patients with acute severe asthma require intubation and positive pressure ventilation. The beneficial effects of inhaled bronchodilators on acute asthma in spontaneously breathing subjects are well established, but there remain important questions regarding inhaled beta2-agonists, for patients who are intubated and receiving ventilation.

OBJECTIVES

To determine the effects of inhaled beta-agonists on asthmatic patients who require intubation and mechanical ventilation.

SEARCH STRATEGY

Randomised controlled trials were sought from the Cochrane Airways Group Asthma Register. Primary authors and content experts were contacted to identify eligible studies and bibliographies from known reviews and texts were searched.

SELECTION CRITERIA

Randomised, controlled clinical trials involving adult patients with acute asthma, who were intubated and supported with positive pressure ventilation. Studies were to be included if patients were treated with beta2-adrenergic agonist agents and there was a comparator group treated with either placebo, no medication, or 'standard' treatment.

DATA COLLECTION AND ANALYSIS

Two reviewers independently examined all identified articles. The full text of any potentially relevant article was reviewed independently by two reviewers.

MAIN RESULTS

The search yielded 152 abstracts. Of these, four articles were identified as potential trials. None of the four trials met the inclusion criteria for the review.

REVIEWER'S CONCLUSIONS

There are no data from randomised controlled trials to provide evidence for or against current practices regarding the use of inhaled beta2-agonists in asthmatic subjects who are intubated and ventilated.