In the chaos of the Emergency Department, I love to keep
things simple. Nothing makes me happier than to be able to give a single dose
of a drug to cure a particular condition. No need for a prescription and no
need to worry about medication non-compliance. Acute exacerbations of asthma
are such a ubiquitous presentation that I have longed hoped that a single dose
of dexamethasone would be sufficient to effect a cure in suitable outpatients.
I have been looking for data to support my “hypothesis” for some time now.
Perhaps we have found it in the form of a recent systematic review and
meta-analysis published in the journal Pediatrics.
Six randomized trials were identified after an explicitly
defined search of Medline looking at dexamethasone vs. prednisone/prednisolone
for the outpatient treatment of asthma. The primary outcome was return visits
or hospital readmissions. As is the potential weakness of meta-analysis, there
was some heterogeneity in the studies identified. Dexamethasone was given as a
single IM dose in 3 studies, as a single oral dose in 1 study and as multiple
oral doses in 2 studies. Therefore combining them may be problematic.
Nevertheless, there were no differences in relative risk in
the primary outcome and the conclusion was “practitioners should consider
single or 2-dose regimens of dexamethasone as a viable alternative to 5 days of
prednisolone/prednisone.”
The whole point of a meta-analysis is to combine similar
smaller studies in order to have greater statistical power to detect differences
between groups. In addition, this greater number gives you better point
estimates, narrow confidence intervals and allows you to look at subgroups that
may have been impossible had the studies not been combined. Unfortunately this
meta-analysis only included ONE small
study with 117 patients that gave a
single dose of oral dexamethasone (0.6mg/kg up to 18mg). Perhaps the jury
is still out.
Whats the bottom line? I like the conclusion. I like the
fact that it is printed in pretty font in a high impact journal. This may
provide me with greater confidence (perhaps bravado) when prescribing a single
dose of dexamethasone for outpatient asthma. But the monkey on my back has me
worried that there still is a lack of high quality evidence to support this practice.
A single large good quality RCT will trump a meta-analysis any day. Can
someone please chuck a banana to the monkey and conduct a large RCT?
Covering:
Keeney, GE, Gray MP, Morrison AK, et al. Dexamethasone for Acute Asthma Exacerbations in Children: A
Meta-analyisis. Pediatrics 2014;133:493-499
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