Key message: Inhaled corticosteroid therapy (ICS) reduces hospital admissions in patients with A health condition (or episodes of a health condition) that comes on quickly and is short-lived. asthma who are not treated with oral or intravenous corticosteroids. It is unclear whether ICS reduces admissions in those given systemic corticosteroids and whether it could be used in place of systemic corticosteroids.
There are a range of options for the Something done with the aim of improving health or relieving suffering. For example, medicines, surgery, psychological and physical therapies, diet and exercise changes. of acute asthma but it is usual for early treatment to include giving corticosteroids orally or intravenously. The use of inhaled corticosteroids in this setting is less common. The Cochrane Airways Group has now updated its review investigating this treatment option, adding 16 Randomization is the process of randomly dividing into groups the people taking part in a trial. One group (the intervention group) will be given the intervention being tested (for example a drug, surgery, or exercise) and compared with a group which does not receive the intervention (the control group). A trial in which a group (the ‘intervention group’) is given a intervention being tested (for example a drug, surgery, or exercise) is compared with a group which does not receive the intervention (the ‘control group’). (RCTs) with 1173 people, bringing the total to 32 Clinical trials are research studies involving people who use healthcare services. They often compare a new or different treatment with the best treatment currently available. This is to test whether the new or different treatment is safe, effective and any better than what is currently used. No matter how promising a new treatment may appear during tests in a laboratory, it must go through clinical trials before its benefits and risks can really be known. with 2374 people. The results of 20 RCTs with 1405 people were combined.
What did they find?
- Compared to An intervention that appears to be the same as that which is being assessed but does not have the active component. For example, a placebo could be a tablet made of sugar, compared with a tablet containing a medicine., ICS given in the Emergency Department had a significant benefit in reducing hospital admission. With an admission The speed or frequency of occurrence of an event, usually expressed with respect to time. For instance, a mortality rate might be the number of deaths per year, per 100,000 people. of around 32% in the placebo group, about eight patients would need ICS treatment to prevent one admission
- ICS therapy was also associated with reduced hospital admission when all patients were given systemic corticosteroid treatment as well, but the most recent evidence is conflicting
- ICS appear to reduce hospital admissions in both children and adults
- Reductions in hospital admissions were similar for adults and children, for high and low doses of ICS and for different methods of ICS delivery
- ICS showed small beneficial effects on tests of lung function and it is unclear if these were clinically meaningful
- There was limited evidence on side effects but ICS appeared to be well tolerated
How good is the evidence?
Overall the evidence was judged to be of moderate quality.
It remains unclear whether ICS could be used in place of systemic corticosteroids in the Emergency Department treatment of acute asthma and questions remain about the most appropriate dosage and delivery device.
New evidence on other treatment options for acute asthma
The Cochrane Airways Group has also recently updated a review on the The ability of an intervention (for example a drug, surgery, or exercise) to produce a desired effect, such as reduce symptoms. of inhaled magnesium sulfate for acute asthma. This includes 16 RCTs with nearly 900 people. It’s disappointing that the evidence was not high quality, with all studies at a high or unclear A way of expressing the chance of an event taking place, expressed as the number of events divided by the total number of observations or people. It can be stated as ‘the chance of falling were one in four’ (1/4 = 25%). This measure is good no matter the incidence of events i.e. common or infrequent. of Any factor, recognised or not, that distorts the findings of a study. For example, reporting bias is a type of bias that occurs when researchers, or others (e.g. drug companies) choose not report or publish the results of a study, or do not provide full information about a study.. It remains unclear whether magnesium sulfate improves lung function and reduces hospital admission, though indicators that it may be helpful for those with severe exacerbations of asthma warrant future An investigation of a healthcare problem. There are different types of studies used to answer research questions, for example randomised controlled trials or observational studies., the authors suggest.
A new Cochrane review on the addition of intravenous beta-agonists to inhaled beta-agonists for acute asthma was limited by the very small body of evidence on this topic, three trials with 104 people, so the value of this treatment option has yet to be established.
Another new Cochrane review compared intravenous beta-agonists with intravenous aminophylline for acute asthma and included eleven RCTs with 350 people. There was no consistent evidence favouring either approach, though side effects were fewer in people receiving beta-agonists, but the authors note that the results should be interpreted with caution given the small numbers of trials and patients.
An update to the Cochrane review on the use of non-invasive positive pressure ventilation for the treatment of respiratory failure caused by severe exacerbations of asthma highlighted the paucity of evidence available to guide clinicians about its use. Five RCTs with 206 patients were included, all judged to be low or very low quality and at high or unclear risk of bias.
These reviews add to a large collection of Cochrane Reviews are systematic reviews. In systematic reviews we search for and summarize studies that answer a specific research question (e.g. is paracetamol effective and safe for treating back pain?). The studies are identified, assessed, and summarized by using a systematic and predefined approach. They inform recommendations for healthcare and research. on asthma which have been gathered together on the Cochrane summaries website here
There’s also a special collection of Cochrane asthma reviews in the Cochrane Library highlighting a recent World Asthma Day here
You can also find a link to the latest version of the British Guideline on the Management of Asthma in the list below, which has cited evidence from 53 Cochrane reviews.
Edmonds ML, Milan SJ, Camargo Jr CA, Pollack CV, Rowe BH. Early use of inhaled corticosteroids in the emergency department treatment of acute asthma. Cochrane Database of In systematic reviews we search for and summarize studies that answer a specific research question (e.g. is paracetamol effective and safe for treating back pain?). The studies are identified, assessed, and summarized by using a systematic and predefined approach. They inform recommendations for healthcare and research. 2012, Issue 12. Art. No.: CD002308. DOI: 10.1002/14651858.CD002308.pub2. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD002308.pub2/abstract
Powell C, Dwan K, Milan SJ, Beasley R, Hughes R, Knopp-Sihota JA, Rowe BH. Inhaled magnesium sulfate in the treatment of acute asthma. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD003898. DOI: 10.1002/14651858.CD003898.pub5. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD003898.pub5/abstract
Travers AH, Milan SJ, Jones AP, Camargo Jr CA, Rowe BH. Addition of intravenous beta2-agonists to inhaled beta2-agonists for acute asthma. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD010179. DOI: 10.1002/14651858.CD010179 http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010179/abstract
Travers AH, Jones AP, Camargo Jr CA, Milan SJ, Rowe BH. Intravenous beta2-agonists versus intravenous aminophylline for acute asthma. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD010256. DOI: 10.1002/14651858.CD010256. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010256/abstract
Lim WJ, Mohammed Akram R, Carson KV, Mysore S, Labiszewski NA, Wedzicha JA, Rowe BH, Smith BJ. Non-invasive positive pressure ventilation for treatment of respiratory failure due to severe acute exacerbations of asthma. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD004360. DOI: 10.1002/14651858.CD004360.pub4.http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD004360.pub4/abstract
Scottish Intercollegiate Guidelines Network (SIGN) and British Thoracic Society. British Guideline on the Management of Asthma. Edinburgh: SIGN; 2008. (SIGN publication no. 101). [May 2008, revised January 2012]. Available from URL: http://www.sign.ac.uk/pdf/sign101.pdf