Urgent Help on Nursing Math, Please!!!

Senorasami · Apr 12, 2009

Wait. I'm confused with the first drug order. Is the drug order 267 mg/ meter squared? I've never seen a drug order like that.

Daytonite, BSN, RN · Apr 12, 2009

since your instructions are "using the nomogram, estimate the bsa and complete how many milliters you will administer?" there in a nomogram in your book.

i used the nomogram at this website: http://www.manuelsweb.com/bsa.htm

i came up with a bsa of 1.89 m2 for this problem. however, my answer is not the same as yours. . .probably because we used different bsa figures or we made different converversions.

drug order: vincristine 267 mg/m2

drug available: vincristine 50 mg/ml

patient weight:158.4 pounds (72 kg)

patient height: 70 inches (177.8 cm)

267 mg/m2

(dose desired)

x 1.89 m2/1

(patient's bsa)

x 1 ml/50 mg

(dose on hand)

= 10.0926 ml

, rounded off to

10.09 ml

(amount to give)

this problem is missing information. . .the drug available was not given. i came up with a bsa of 1.65 m2 for this problem.

drug order: methotrexate 25 mg/m2

patient weight: 154 pounds

patient height: 59 inches

morte, LPN, LVN · Apr 12, 2009

using Day's BSA (what ever that is) i get 41.25 which would be rounded to 41.....so it most be the differenct sources of BSA info.....

Daytonite, BSN, RN · Apr 12, 2009

using day's bsa (what ever that is) i get 41.25 which would be rounded to 41.....so it most be the differenct sources of bsa info.....

bsa is body surface area. it is "the surface area of the body expressed in square meters. body surface area is an important measure in calculating pediatric dosages, in managing burn patients, and in determining radiation doses. nomograms for accurately determining body surface area are available for both pediatric and adult patients." (page 245, taber's cyclopedic medical dictionary, 18th edition)

i don't know why i didn't think to look under the listing for body surface area (in the "b's") in my copy of taber's cyclopedic medical dictionary, but it has 2 nomograms there with both pounds/kg and inches/meters. i just thought the bsa calculator on manual's web would be more accurate.

Daytonite, BSN, RN · Apr 12, 2009

using Day's BSA (what ever that is) i get 41.25 which would be rounded to 41.....so it most be the differenct sources of BSA info.....

Did you convert all the numbers to kg and cm?

morte, LPN, LVN · Apr 12, 2009

thanks, i am used to thinking in mg/kg........

morte, LPN, LVN · Apr 12, 2009

Did you convert all the numbers to kg and cm?

just used your BSA of 1.65 and multiplied by 25.......since there is no divisor (dont think that is the right word, lol) this is the only step required......i am wondering if met. comes in multiple size tabs.....i cant remember what i have seen......trexall comes 5/7.5/10/15 mg tabs....dont have time to check other brands, am already late for dinner, lol......at this point this throws a monkey wrench into this prob....it would not be possible to do.....i am wondering if other brands come in a one mg dose.....will check back with you'all later....

christina_chavez · Apr 13, 2009

All of the information that I have typed in is correct as I went back and checked over. I just don't understand why all of this BSA thing is so confusing because I never get to come up with the correct answer. By the way I also used this formula listed below from my clinical calculations book and still have trouble! Thanks.

BSA: height(in) and weight (lb) SQUARE ROOT IT

3131

BSA: height(cm) and weight (kg) SQUARE ROOT IT

3600

morte, LPN, LVN · Apr 13, 2009

All of the information that I have typed in is correct as I went back and checked over. I just don't understand why all of this BSA thing is so confusing because I never get to come up with the correct answer. By the way I also used this formula listed below from my clinical calculations book and still have trouble! Thanks.
BSA: height(in) and weight (lb) SQUARE ROOT IT
3131
BSA: height(cm) and weight (kg) SQUARE ROOT IT
3600

yup, me neither.....lol....just spent ~2 hours, since i dont have a working calculator.....working the 1rst prob backwards ....you would need a BSA of ~2.05, and i get ~1.9.....not EVEN close....good luck....the only thing i can suggest is to SHOW all work.....