Tuesday 16 August 2016

Isopropyl Alcohol Nasal Inhalation for Nausea in the ED?

Wouldn’t it be great to have something quick, safe, ubiquitous, non-invasive and cheap to give patients with nausea in the ED? How about getting them to sniff on an alcohol wipe?

Yes, you heard me correctly.

But unfortunately, it is probably no better than proper placebo and may cause downstream harm.

There have been some prior studies of alcohol nasal inhalation in the post-operative literature. In addition, aromatherapy has been used in other studies investigating treatments for nausea. So why not bring it to the ED?

This was a randomized double blind, placebo controlled trial performed in a single military ED in Texas. Inclusion criteria were patients aged 18 to 65 with a chief complaint of nausea >3/10 on a numerical rating scale (NRS).

Patients were randomized to hold either an alcohol prep pad or sterile saline wipe about 2.5cm from their nose. They were instructed to nasally inhale deeply for no more than 60 seconds and told to stop if the nausea was completely relieved. This was repeated at the 2 and 4 minute mark if they did not have success.

The primary outcome measure was nausea as reported on the NRS at 10 minutes.

Results? Only 80 patients were recruited but it didn’t matter because there was a huge treatment effect. At ten minutes, the NRS for the alcohol arm dropped from 6 to 3. The placebo had no effect at all. This is great stuff!

But not so fast…

For a placebo to have no effect for nausea is astounding. The vast majority of studies quote about a 30% reduction in nausea when using placebo. The results of this study would have been remarkably different had they used a proper placebo.

Another interesting piece of data was the use of subsequent antiemetics. They were given in only 72% of the placebo group but were required in 89% of the alcohol group. This 17% (95%CI -0.5 to 34.8) increase was not statistically significant but quite clearly worrisome. Could the alcohol sniffing cause paradoxical increased antiemetic requirements?

Probably the biggest argument for skepticism is simple methodology. Small studies demonstrating large treatment effects are usually proven wrong. In statistical speak, this is very likely a type I error.

Despite what you may have heard on the social media echo-chamber of the underqualified, we should not be getting our patients to sniff alcohol. This is unless it is a beautiful glass of Penfolds Grange Hermitage.  

Bon appetit!


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