Monday, 6 August 2007

The end of Nitrous?: ENIGMA study in Anesthesiology

The August issue of Anesthesiology has the full paper of the ENIGMA study. This is a large muticentre RCT of 2050 patients undergoing anesthesia longer than two hours (Westmead was one of the recruiting centres). One group received 70% nitrous in the gas mixture whereas the other group received no nitrous. The outcome favoured the no nitrous group in several measures.

The nitrous free group had better quality of recovery, a lower incidence of wound infection, fever, pneumonia, atelectasis, and severe nausea and vomiting. While the postop duration of hospitalisation was no different, there was a shorter duration of ICU stay in the non-nitrous group. Interestingly, there was a non-significant reduction in the incidence of death and myocardial infarction which favoured the nitrous free group (rate of MI will be studied in the ENIGMA II followup study).

6 comments:

  1. your original post on this matter a few months back caused me to give up nitrous after 28 years; your blog changed a practice 8 thousand miles away!(give or take a few) Thanks!

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  2. wow giving up nitrous in a practice is a profound effect from a blog article

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  3. No single article, speech, research report or opinion should change a decades-long practice of safe, readily-available, reliable and cost-effective medicine (in any specialty).

    An incredible amount of additional data will be needed to 'out' nitrous oxide. Count on the pharmaceautical industry to lead the search for excuses to suppplant N20 with a more expensive, proprietary "solution".

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  4. Hmmm as mentioned in the previous post, this is another example of throwing out the known for the more expensive unknown. Correct me if I'm wrong but its more of a comparison of oxygen versus nitrous!!!

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  5. This study was *not* sponsored by any money from the pharmaceutical industry. For the details it is best to read the full paper and accompanying editorial in Anesthesiology (August 2007 issue).

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  6. and, as an added benefit, since quitting nitrous, I think I've had one or two post-op nausea patients;I used to have the usual 8-10% rate. Various of my partners used to claim they never had nausea, and didn't use nitrous; I pooh-poohed it. Seems anecdotally to be true.

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