Nursing Students Pre-Nursing
Published Nov 17, 2010
guess?
6 Posts
I had an assignment with 25 questions did the rest these have me stumped so if you happen to be good at math I would greatly appreciate the help. Even if you just tell me how to figure them out and I do the rest.Anything...
A. Normodyme (labetalol HCL) 20 mg IVP slowly over 2 minutes
The label reads 5 mg/ml. How many milliliters of this antihypertensive (calcium channel blocker) will the patient receive per minute?
B. Your patient has meningitis.
Order: Pfizerpen (Penicillin G) 600,000 units IVPB q 4 hours
The directions are as follows:
Amount of diluent
concentration
20.0 ml
50,000 u/ml
10 ml
100,000 u/ml
4 ml
250,000 u/ml
1.8
500,000 u/ml
What is the best dilution to choose and how much of this antibiotic will you draw up?
whitebunny
120 Posts
1) well, if u r pushing 20mg, then u r pushing 4ml
u r pushing 10mg in a minute, in a minute u will push 2ml
then u will need 2 minutes to push 4 mls
then the answer is u need to push 2mls in one minute
2)600,000 units/4hr=150,000unites/hr, but that is not what the question is asking, the question is asking u to push 600,000 q4h
50,000 u/ml--->if 1ml has 50,000, u need to push 600,000, that is 12ml to draw and push, sounds good, push it in probabyl 10-15 minutes
4 ml----------->if 1ml has 100,000, 4ml then has 400,000, with another 2mls it would be 600,000 in total. So draw 6mls, maybe push it in 10-15 minutes,this sounds not too bad, but compare with choice 1, choice 1 is safer.
1.8------------> if 1ml has 250,000 units, that is too much, i wouldnt push that high concentration, too hard to push
500,000 u/ml-------------> 1 ml has 500,000, too dangerous to push, i wouldnt do that
i think math is not the problem, it is the problem how you analyze the question and filter the wrong information (for example, i beg everyone will do 600,000/4 first when they see the question)
klone, MSN, RN
14,825 Posts
A) If there are 5mg in 1 mL, how many mL would it take to equal 20mg? Once you figure that out, take that answer and then where it says you should push the entire thing over 2 minutes. If all of it would go in over 2 minutes, how many would go in over ONE minute?
B) Do a little research on side effects of Pen G. Is it caustic? Is it better to dilute it a lot? Or is it better to dilute it as little as possible?
sunkissed75, CNA
252 Posts
Egads!!! I'm not looking forward to math....
GeauxNursing
800 Posts
the first one is very basic./ Set it up to cancel out like terms.
20mg 1mL = 20
____ ___ __
2min 5mg 10 = Cancel the like terms (mg) You're left with mL/minute, which is what you're being asked to find. 20/10=2. 2mL/min.
Pepper The Cat, BSN, RN
1,783 Posts
For the first one look at how many ml you need to give. Dose is 20mg - you have 5 mg/ml. So what is your dose in mls? You are pushing it over 2 minutes. Once you know your dose, all you have to do is divide it by 2 to find ml/minutes.
For the 2nd one - well, we don't give antibiotics push in my hospital, but I imagine you would want to find the one that causes the least amount of harm? Is the least caustic to the veins?
turkishnurse
5 Posts
I can help you.
2ndyearstudent, CNA
382 Posts
B. Your patient has meningitis.Order: Pfizerpen (Penicillin G) 600,000 units IVPB q 4 hours What is the best dilution to choose and how much of this antibiotic will you draw up?
Is anyone else confused about the order? IV piggyback right? Not push? Which really doesn't make sense either if you were adding it to a 50mil bag and giving it over 1/2 hour like other antibiotics.
Piggy27
2 Posts
A.
20mg X 1ml/5mg = 4ml/2min. =2ml/min (answer}
note: cancel the mg to give you a unit of ml/min
B. I would probably choose the 20ml/50,000 u/ml as the best diluent, since it's not good to give an antibiotic that is too concentrated.
600,000u X 20ml/50,000u/ml = 240 ml q 4H
This is only my suggestion formula to the problem. Good luck
Reno1978, BSN, RN
1,133 Posts
Gosh, it's irritating when nursing school math is so far out there like this...
Since when is labetalol a calcium channel blocker? Everyone else has helped with the math on A: 2mL/min
B: This question is rather problematic just because nearly all IVPB medications are mixed in much larger volumes than presented.
But if you had 20mL of the drug that has 50000units/mL you'd need to administer 12mL (600000units / [50000units/mL])
If you had 10mL of the drug that has 100000units/mL, you'd need to administer 6mL (600000units / [100000units/mL])
If you had 4mL of the drug that has 250000units/mL, you'd need to administer 2.4mL (600000units / [250000units/mL])
If you had 1.8mL of the drug that has 500000units/mL, you'd need to administer 1.2mL (600000units / [500000units/mL])
My answer would be that it doesn't matter which one you pick since you should be tossing it into a IVPB bag anyhow (ideally, pharmacy should) giving you a much larger volume to give over an hour! LOL
u r right, lol
its IVPB
not IVP
so as long as the draw up mls are correct, toss it in a PB thats it
shaas, ASN, RN
87 Posts
Hi, there.
Here is my approach to these two problems. I hope it can be helpful.
Please, write them out on a piece of paper so that you can see how units cancel out.
A. Dimensional Analysis (DA):
(20 mg/2 min) x (1 mL/ 5mg) = 2 mL/min
*The patient will receive 2 mL per minute.
B. Appropriate Dilution:
i) The concentration of medication should be carefully considered, because if the solution is too concentrated, it can alter the pH and result in irritation and burning when administered. Penicillin G Potassium is one of these meds and it can potentially cause CNS toxicity if given too high of a concentration. However, if the concentration is too low, it will not be therapeutic. Because meningitis is a serious infection, and you're not treating for, say, arthritis, you would need to give the maximally safe dosage to treat it. I think this is why they are asking which dilution is the best option.
ii) Dosage Calculation (DA):
* At this point, the amount of diluent does not matter. You have the
concentration, so, choose one. I am going with 250,000 units/mL because
it is not the most concentrated among the choices given. This conc. is
the conversion factor in finding out how many mL you would need to
administer.
600,000 units x (1 mL/250,000 units) = 2.4 mL
*The best concentration is 250,000 units/mL and you would draw up 2.4 mL.