Wednesday, March 3, 2010

A Pound of Cure

When I was in my residency many years ago, when men were men, women were women, and sheep in Arkansas were (and still are) nervous , I remember that a falsified prescription was posted in the ED. It had apparently been submitted to a local pharmacy on a stolen prescription blank, and had been returned to us for unknown cause. However, it arrived, I still recall it as being taped up on the side wall of the department, a three-part carbon-copy prescription with a special red band on it indicating it was used for controlled medications. On it was written “MOFEEN 1 pound.”

For some reason unbeknownst to me, the dose of one pound of morphine has stuck in the back of my head for years on end. (It occupies the same Niche of Mystery as the full lyrics to “Muskrat Love.”) As a result, when nurse ask what dose of morphine they should give to a patient, I tend to say “about a pound.”

About two weeks ago one of the nurse I’ve known for years turned to me with an absolutely straight face and asked, “And how much is that, doctor?” (Insert sarcasm here.) I suddenly realized that, in fact, I had no idea how much a pound of morphine really was. So it was off to the calculator:

1 kg = 1000 gm
2.2 lbs = 1 kg
1000 gm/kg divided by 2.2 lbs/kg = 454 gm
(454 gm)(1000mg/gm) = 454,000 mg

By way of reference, most patients with cardiac chest pain get 2 to 4 mg. Those with severe trauma or orthopedic injuries often get 10 mg, and some of our high-level pain patients may take up to 200 mg per day. So when I ask for a pound of morphine, what I’m doing is asking the nurse to administer a dose equivalent to a town of 45,000 people who have all broken their hips at exactly the same moment.

Remind me to stop doing that.

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