Inhaled beta2-agonists for asthma in mechanically ventilated patients

During an asthma attack, the airways narrow, causing breathing problems, wheezing and coughing. A small number of people with asthma need medications given by tubes during mechanically assisted breathing (ventilation). Inhaled bronchodilators help relieve asthma attacks in people who can breathe on their own. However, it is not known if inhaled beta2-agonists (commonly used as bronchodilators), work well for people on ventilation. This review of trials did not find enough evidence to show the effect of inhaled beta2-agonists on people who have mechanically assisted breathing or tubes. More research is needed.

Authors' conclusions: 

We did not find any relevant randomized controlled trials. Therefore, as yet no data are available to provide evidence for or against current practices regarding the use of inhaled beta2-agonists in asthmatic subjects who are intubated and ventilated.

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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 beta2-agonists on asthmatic patients who require intubation and mechanical ventilation.

Search strategy: 

Randomized controlled trials were sought from the Cochrane Airways Group Specialised Register. Primary authors and content experts were contacted to identify eligible studies, and bibliographies from known reviews and texts were searched. Searches are current as of September 2011.

Selection criteria: 

We included randomized, controlled clinical trials involving adult patients with acute asthma, who were intubated and supported with positive pressure ventilation. We included studies of patients treated with beta2-adrenergic agonist agents and a comparison group of either placebo, no medication, or 'standard' treatment.

Data collection and analysis: 

Two review authors independently examined all identified references. Two review authors independently reviewed the full text of any potentially relevant article.

Main results: 

The initial search in 1999 yielded 152 abstracts. Of these, four articles were identified as potential trials. None of the four trials met the inclusion criteria for the review. Further searches up to September 2011 have identified an additional 117 references, none of which were suitable for inclusion.