Asthma: exacerbation: no clear role for routine use of iv aminophylline

Clinical bottom line (level 1a-)

  1. Patients with acute asthma treated in an emergency setting who receive iv aminophylline and standard care compared with placebo and standard care have no improvement in pulmonary function.
  2. Patients who receive aminophylline are not clearly less likely to be admitted to hospital, but are more likely to develop vomiting (NNT = 5 at hours) and arrhythmias (NNH = 7 at hours) .
Belda et al: Cochrane Library 2000; 3 : -
Expires October 2003

The study

Systematic review of all randomised controlled trials of
  • Patients: adults with acute asthma treated in an emergency setting with beta2-agonists. Steroids or other bronchodilators were optional.
  • Intervention: intravenous aminophylline and standard care compared with placebo and standard care
  • Outcome: pulmonary function - change in PEFR or FEV 1 , admission to hospital, adverse effects

    Articles found in ?all languages using Cochrane Airways Group register (derived from Medline, Embase, CINAHL), 1966 to 1999 (search terms: detailed in text ) and hand-searching respiratory journals and meeting abstracts. Bibliographies of relevant articles were searched, and trialists working in the field were contacted to identify relevant studies.

    Selection criteria: see above: by 2 independent reviewers
    Appraisal criteria: by 2 independent reviewers: using Jadad criteria
    Articles excluded if:
    • patients aged < 18
    • studies involving only patients with COPD, or studies where asthma and COPD patients could not be separated
    • patients requiring mechanical ventilation at presentation
    • in-patients for more than 24 hours


    15 studies found involving 739 patients
    • Subgroup analysis based on severity at presentation was performed.
    Studies were found to be significantly heterogeneous for admission to hospital.

    The evidence

    Outcome Time to outcome CER OR
    (95% CI)    		 NN T
    (95% CI)
    admitted to hospital hours 44/160
    (27.5%)    		 0.57
    (0.32 to 1.02)     		10
    (NNT = 6 to infinity;
    NNH =  250 to infinity)
    tremor hours 45/129
    (34.9%)    		 1.53
    (0.89 to 2.62)     		-10
    (NNT = 38 to infinity;
    NNH =  4 to infinity)
    vomiting hours 15/167
    (9.0%)    		 4.18
    (2.38 to 7.36)     		-5
    (-10 to -3)
    arrhythmia/palpitations hours 13/128
    (10.2%)    		 2.92
    (1.49 to 5.70)     		-7
    (-23 to -3)

    • PEFR (% predicted) : aminophylline v. placebo: mean difference -1.5% (95% CI: -2.8% to -0.15%)
    • FEV1 (% predicted): aminophylline v. placebo: 0.25% (95% CI: -2.5% to 3.0%)
    • Subgroup analysis for severity failed to show any difference between the two groups in mild-moderate or severe cases of asthma.

    Comments

    1. Studies were too small to report on the occurrence of hypokalaemia or convulsions.
    2. Most studies did not provide data beyond the first hour of follow-up.
    3. The subgroup analysis involved small numbers of patients and compared patients receiving different regimens, so should be treated with caution.
    4. Studies failed to report outcomes such as length of stay if admitted, subsequent relapse or death.

    Citation

    1. Belda J, Parameswaran K, Rowe BH: addition of intravenous aminophylline to beta2-agonists in adults with acute asthma. Cochrane Library 2000; 3 : -
    Search Terms: asthma* in Cochrane Library
    Contributor: Chris Ball, October 2001
    Reviewer:

    Clinical Question.
    Patient asthma exacerbation
    Intervention or Exposure iv aminophylline and standard care
    Comparison placebo standard care
    Outcome pulmonary function, admission to hospital