Monday, March 8, 2010

Responses to my Questions about Propofol

When I worked in heart surgery, every person in the room had a job to do. While I could tell you the basics of most of the drugs the anesthesia personnel were administering, I didn't always know the specifics about the dosing, just as they did not know the details about the job I was doing. In the short time I worked at SA, I never got around to fully exploring, much less questioning, the medications protocol. At the time, I had no reason to question the designers of the protocols, and I was spending more time than I should have had to spend, fighting for changes that were within my realm of expertise, and some that seemed like they should have been simple common sense.

After the Johnson book came out, people started to ask me about the use of certain drugs in cryonics, and after the Michael Jackson incident, the focus centered on propofol. People wanted to know why laymen had access to a drug most medical professionals working in hospitals aren't allowed access to. When I raised that issue on the Cold Filter cryonics forum, Mathew Sullivan responded that Suspended Animation (SA) was not carrying enough propofol to warrant anyone accusing them of hastening the deaths of patients. Not recalling what SA's dose was, and not having one of SA's handy-dandy laminated protocols available, (three years after my resignation from that company), I remembered the meds were listed in the CI-81 case report. When I read "20mg," and looked up the dosing for propofol, I thought, "Geeez...that's nothing more than a hand-waving gesture." (Note: Somewhere along the line, I inadvertently starting typing "25mg," rather than "20mg." Platt can go on about this all he wants, but it's really meaningless. What is important is that I was questioning an extremely small dose.)

When Harris explained the dose was 200mg, and Platt said the amount in the SA report was a typo, I wrote that even 200mg seemed like a meaningless dose. Platt responded to that, with some wisecrack about my expertise, (as if "expertise" has ever been important to someone who totally disregards an expert's advice on existing equipment and sends laymen to perform medical procedures). It doesn't take expertise to form the opinion that 200mg is not enough propofol to keep someone unconscious very long, with readily-available information, regarding propofol dosing. Propofol is super-fast acting, but the effects are very short-lived, and it moves rapidly from the central nervous system, into the peripheral tissues. I think anyone reading the following information would agree that 200mg of propofol doesn't seem like enough to do what Mathew, FD and Harris claimed it was doing, ("keeping people dead," while CPR was being administered).

"anesthesia induction (healthy adults less than 55 yo)
Dose: 2-2.5 mg/kg IV given as 40 mg q10sec until induction onset...
...anesthesia maintenance (healthy adults less than 55 yo)
Dose: 0.1-0.2 mg/kg/min IV; Alt: 25-50 mg IV prn"

Using the low end of this suggested dosing, for a 70kg (154lb) man, the dosing would be 140mg for induction, followed by 7mg per min (420mg per hour)."

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