Hi I am going into my second year of nursing which will be pediatrics and maternity. This is the first time I have posted something here although I always read everyone's responses and always find it very helpful so I thought I would give it a try myself. can someone please help me with a couple of dosage calculation problems my professor gave us to prepare for the first day exam? I have asked my professor for the same help but then just told me to read the questions so I am very confused now. below are the problems I could use some explanation on if anyone can help me.
I am still confused on when to round to the tenth place. This two dosage calc questions are similar, yet the answer are rounded differently. Can you please help me understand what I am doing wrong?
3. A physician's order states chloramphenicol 50 mg/kg/day I.V. in divided doses q 6 hours. The child weighs 17 kg.
Each dose would be mg.
3. 50 mg q 6h = 4 doses
x 17 kg
850 = 850 mg/day
850 = 212.5 mg/dose = 213 mg/dose (I left it as 212.5)
4
1. _302.2 mg_ The physician orders Augmentin (amoxicillin and clavulanate potassium)
oral suspension 35 mg/kg/day PO divided in three equal doses.
Patient's weight: 57 lbs
How many milligrams should be administered for one dose?
57 lbs = 25.9 kg 35 mg x 25.9 kg = 906.5 mg/day
906.5 = 302.2 mg/dose
3
On the following question I don't understand why the answer is 0.85mg/kg/day.
5. Yes The physician orders Paveral (codeine sulfate) elixir 3.3 mg po q 6 hrs for pain.
The drug guide recommended dosage is 0.5-1 mg/kg/day
Patient's weight: 34.1 lbs.
Is the physicians order safe?
34.1 lbs = 15.5 kg 3.3 mg x 4 doses = 13.2 mg/day
13.2 mg/day = 0.85 mg/kg/day
15.5 kg
Safe since 0.85 falls within range of 0.5 -1 mg/kg/day
The way I set-up that question is like this:
0.5mg/kg/day X 15.5kg = 7.75mg/day minimum/day
1mg/kg/day X 15.5kg = 15.5mg/day maximum/day
Then I multiply 3.3mg X 4 = 13.2mg/day. Since what the Doctor prescribed is within range I say that this is a safe dose. However my final answer is 13.2mg/day not 0.85mg/kg/day.
Then I proceeded to do the next test and I see the solution is set-up different. Can you please tell me what I am missing?
5. ____yes___ The physician orders Paveral (codeine sulfate) elixir 2.8 mg po q 6 hrs for pain.
The drug guide recommended dosage is 0.5-1 mg/kg/day
Patients weight: 34 lbs.
Is the physicians order safe?
34/2.2= 15.45454545454= 15.5 kg
0.5 x 15.5 = 7.75= 7.8 mg/day is the lower range
1 x 15.5= 15.5 mg/day is the higher range
Safe range is 7.8-15.5 mg/day
MD ordered 2.8 mg q 6 hrs = 2.8 x 4= 11.2 mg/day
11.2 falls in the safe range of 7.8-15.5= dose is safe
Does your school have formal rounding rules? Ours is as follows:
"]When rounding final answers...If the answer is less than 1 such as 0.456 calculate to the thousandth place and use that last number to round to the hundredth place....so 0.456 would round to 0.46. ]If your final answer is greater than 1 such as 1.78....calculate to the hundredth place and use that last number to round to the tenth place....so 1.78 would round to 1.8." with the main exception to date being drips (gtts) which are always whole numbers.
Yes I believe that is how we do it, just a few problems had us a little confused that I think just made us second guess ourselves with everything. Thank you so much for your help!
I'm sorry I totally get all of what you have explained to me, just had one more question I ran into this problem and the final answer was 212.5 which we had discussed early on already and my professor rounded to 213 why is that
I know if its .5-.9 you round but the rule of more than one and calculating to the hundreths place and rounding to the tenths doesn't apply in this question so how do I know to when to round and not to in this situation because technically .5 is 1/2 pill or 1/2 tsp etc..
That sheet you link to is literally a more complicated way to say the same exact thing I just did. Calculating to the thousandth to round to the hundredth is the same thing as just rounding to the hundredth place. Its just a "longer" way to do it. It also follows the same exact rules as my school with pedi and adult rounding.
As for rule one, whole number rounding is for when instructed to do so which is no different then my school. I can think of quite a few ways that rounding to a whole number with meds can be terrible and change a dose completely. I get that half of a mg is usually not going to be a big deal (from OPs #3). But there are meds that a half mL and such would be a major difference. So in what situation exactly would it be appropriate to round to a whole number? This is truly a question of curiosity since some students seem to be taught to whole number round for some problems. I just have an issue because if my program ( and many others from what I have seen on this forum) do not whole number round outside of IV flow rate, yet some students are taught that it is appropriate and seem to always get confused when its ok to do so.
cwebb
15 Posts
is'nt dimensional analysis and ratio proportions different? we are taught ratio proportion way