How do you come up with Body Surface area? What would be considered average?
Mike Payne On 02/01/2011, at 21:09 , Paul Trusten wrote: > Dosing some medications in amount of drug per square meter of body surface > area *(BSA) instead of body mass takes into account the metabolic and drug > elimination differences among patients. BSA dosing is often used for > anti-cancer (chemotherapy) drugs. > ----- Original Message ----- > From: Bill Potts > To: [email protected] ; 'U.S. Metric Association' > Cc: [email protected] ; 'Gentry, Elizabeth' > Sent: 02 January, 2011 11:34 > Subject: RE: [USMA:49395] powers of ten--becoming an exponent proponent > > I agree with you, Paul. And, for the grade level at which exponents should be > taught, that seems about right. > > The one thing that puzzles me is the milligrams per square meter dosage. I > can only think of this being used for some kind of skin cream, which leads to > the question of how one easily determines a patient's skin area. I have to > assume, though, that an approximation is probably close enough and that > order-of-magnitude errors are unlikely. :o) > > Bill > > From: [email protected] [mailto:[email protected]] On Behalf Of > Paul Trusten > Sent: Sunday, January 02, 2011 08:40 > To: U.S. Metric Association > Cc: [email protected]; [email protected]; Gentry, Elizabeth > Subject: [USMA:49395] powers of ten--becoming an exponent proponent > > The previous discussion of Zimbabwe currency in the article in question > (http://news.yahoo.com/s/ap/20110102/ap_on_re_af/af_zimbabwe_numbers_game ) > reminded me that part of our problem in accepting metrication in the U.S. is > that we Americans are not yet proponents of exponents. We tend to limit the > teaching of exponents to a small part of our mathematics education and don't > apply that education to the practical subject of measurement. When I stop > to consider the metric system, I sense that I am returning to eighth-grade > algebra, when I should have learned something about exponents much earlier > than that. At least to me, facility in exponential notation makes the > meanings of the SI prefixes easier to understand and manipulate. > > I don't know what it's like in metric countries, but, here in the land of the > foot and the mile, even the simplest application of exponents in connection > with SI falls on innumerate ears. For example, in pharmacy I have yet to > hear one of my colleagues look at the symbol m2 and pronounce it "square > meter." They will pronounce it "meters squared," which may be good as an > exponential statement but, I think, bad as a measurement unit. Some (usually > outside of pharmacy) can't even get that far, and will state a dose of 50 > mg/m2 as "50 milligrams emm two," reading it out to me with difficulty, not > knowing what it means. Pharmacists use common sense and can interpret, based > on the drug being ordered, that 50 milligrams per square meter is what was > meant, but if two people are communicating purely on the basis of the > expression being used, with nothing else to refer to, who knows? From the > resulting confusion, we may get a medical Gimli Glider. > > I remember, in the fourth grade (which, for me, was 50 years ago), learning > "decimal places," and learning the "millions place" and the "thousands > place," but at that time, those places were never connected to the concept of > bases and exponential notation. Had that been done for us,I think we could > have adapted to the metric system the very next day and become metric > citizens. > > As I mentioned, I haven't been in the fourth grade for 50 years, and the > timing of the study of exponents may have changed since then (big grin). I'd > be interested in what the teachers on this list think of the above. > > So, my question is:: to what extent do you think a thorough grounding in > exponential notation in the early years of mathematics education (2nd, 3rd > grade?) would improve the ability of the U.S. to go metric? > > Paul T.
