Friday, 7 November 2014

Can ethanol be neuroprotective?

Should we load head injured patients with a neuroprotective bolus of ethanol? Oh please let this be true!

Honestly, some papers are so good for journal club simply because they are so incredibly bad. The following is a great example. One might wonder if the peer reviewers were the head injured participants of this study.

These authors performed an un-blinded chart review with no methods to determine the physiologic values and outcomes of a cohort of 184 severely injured patients as defined by an ISS of >17. (Why 17 you might ask?)  Within this “matched” cohort, they compared those who had a blood alcohol level (BAL) greater than 0.05 g/dl (n=34) to those that were lower or had measurable alcohol (n=150).

Both groups had similar ISS. Those in the higher alcohol group had lower GCS scores (9.64 vs. 12) upon arrival. There was a trend towards higher values in the abbreviated injury score (AIS) for the head (3.29 vs. 2.81). But after two hours of admission the GCS scores “leveled out.”

Their conclusions are so great that I dare not paraphrase. “Severely injured patients with a raised BAL have higher incidence of severe traumatic brain injury...However the survival rate and in-hospital stay is not influenced. This supports the theory of a neuroprotective role of alcohol.”

Before you start hitting the bottle, please consider the following.

If someone is drunk, might they look to have a worse head injury? Yes you say? Then they would likely score higher on the head component of the AIS. Without getting too nerdy, this value is squared to become part of the ISS. Therefore almost half of the ISS in the drunk cohort came from their over appreciated “head injury.”

I think it is quite obvious that the drunk cohort was ultimately less injured but had the same outcomes. This would suggest a harmful effect of alcohol rather than a protective effect.

In the end, this is really a small and sloppy study that can’t tell us much of anything important. But its ultimate value may be for teaching critical appraisal of the literature. Cheers... and have one for me so long as I am not a trauma patient!

Covering: Scheyerer MJ, Dutschler J, Billeter A, et al. Effect of elevated serum alcohol level on the outcome of severely injured patients. Emerg Med J 2014;31:813-817

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