One would think that a lab technician would be familiar enough with doses that a decimal point error would be noticed. Yet, I see a couple of reasons for such an error.
1.) Partial familiarity with metric. This comes from using one system on the job and another system off of the job. One never gets a feel for either. It also means that there is a poor understanding of prefixes and their proper symbols, so that numbers less then one could result in other errors if scaled to the next prefix. Instead of writing 0.5 mg/mL, It would be better to write 500 μg/mL. But would a person only partially familiar with SI prefixes read the number correctly? 2.) You wrote that the dose should have been 0.5 mg/mL. Suppose it was written as .5 mg/mL and the decimal was not seen, due to the bad practice in the US of not preceding decimal numbers less then one with a zero. If the decimal point was not clear or faint, then it could have been read as a 5 instead of a 0.5. If a zero is always present and the decimal is faint (looking like 0 5), the technician would notice the number must be meant to be 0.5 as a zero is never placed before a number in an amount. We don't write 05 mg if we mean 5 mg. I get the feeling that the reason was most likely reason #2 and if it is, then how do you fix this from happening when so many Americans make the mistake of not preceding decimal points with a zero if there is no other digit? Jerry ________________________________ From: John M. Steele <[email protected]> To: U.S. Metric Association <[email protected]> Sent: Saturday, April 25, 2009 7:50:54 AM Subject: [USMA:44846] Re: Horse deaths in Florida I have seen a couple of sources quoting an Argentine paper, in turn quoting an anonymous source. If they are correct, it was a 10X error, perhaps due to a decimal point error. Not clear if the error was in the prescription or made by the pharmacy. http://www.heraldtribune.com/article/20090425/ARTICLE/904251062/2050/SPORTS?Title=Selenium-is-focus-in-horse-inquiry Citing anonymous sources, the Argentine newspaper La Nacion reported Friday that the horses' lab-made supplements included 5 milligrams per milliliter of sodium selenite instead of the prescribed 0.5 milligrams. It should be noted that the whole thing was an attempt to mimic a French supplement which has not been approved for use in the US, and may have been illegal. --- On Fri, 4/24/09, Jeremiah MacGregor <[email protected]> wrote: From: Jeremiah MacGregor <[email protected]> Subject: [USMA:44830] Re: Horse deaths in Florida To: "U.S. Metric Association" <[email protected]> Date: Friday, April 24, 2009, 10:42 PM It sure would be a real embarrassment for the USA if it turns out to be a metric error. Jerry ________________________________ From: Harry Wyeth <[email protected]> To: U.S. Metric Association <[email protected]> Sent: Friday, April 24, 2009 12:23:01 AM Subject: [USMA:44823] Horse deaths in Florida As a horse owner, I am shocked by the deaths of the polo horses in Florida. It seems there was a pharmacy error in compounding the stuff that was given the horses that died. I will try, and maybe others can also, to see if there was a metric/"traditional" mixup in preparing the compound. See http://abcnews.go.com/Health/story?id=7411620&page=1 HARRY WYETH
