Math Again

  1. 2 I'm doing some practice problems, and this is from nursesaregreat.com:

    A procainamide drip is ordered (2 gm in 250 cc of D5W) to infuse at 4mg/kg/min. The patient weighs 165 lbs. Calculate the drip rate in cc/hr for which the infusion pump will be set at.

    165 lbs = 75 kg
    2gm = 200,000 mcg
    4mg = .004 mcg

    I'm trying to do the formula like this:

    solution cc
    __________ X 60min/hr X kg X mcg/kg/min = cc/hr
    drug mcg



    Am I doing this right? The answer should be 30, but that's not what I'm getting. I'm sort of hoping this problem has a mistake in it because it has fried my brain! I did, however, catch the preposition at the end of the sentence, so maybe I should have majored in English.
  2. Enjoy this?

    Join thousands and get our weekly Nursing Insights newsletter with the hottest discussions, articles, and toons.


  3. Visit  RNrerun profile page

    About RNrerun

    Joined Jan '12; Posts: 9; Likes: 2.


    11 Comments so far...

  4. Visit  Asmorris profile page
    0
    I have tried it a few different ways and keep getting 2250/hr.

    250cc/2g x 4mg/kg/min x kg/2.2lbs x g/1000mg x 60min/hr= 2250cc/hr
    Last edit by Asmorris on Jan 22, '12 : Reason: error
  5. Visit  jmdRN profile page
    1
    4mg = .004 mcg
    is wrong.

    4 MILIgrams (mg) = 4000 MICROgrams (mcg)

    And.. why are you working it down to mcg when the question is asking for mg/kg/min?

    Is it really suggesting you run it at 4mg/kg/min (which is a very HIGH dose) or did you have a typo there?

    When you break down numbers/values to smaller-than-required values, you introduce a greater risk of decimal place errors.
    Last edit by jmdRN on Jan 22, '12
    GrnTea likes this.
  6. Visit  Asmorris profile page
    0
    2.25cc/hr if it was supposed to be 4 mcg instead of 4 mg
    Last edit by Asmorris on Jan 22, '12 : Reason: error
  7. Visit  JROregon profile page
    0
    I keep getting 2250 cc/hr.

    300 mg/min (amt needed)
    ______________________ X 250 cc = 3.75 cc/min X 60 = 2250 cc/hr

    2000 mg (amt you have)

    By the way, 2 grams = 2,000,000 mcg.
  8. Visit  Esme12 profile page
    0
    Procainamide is administered intravenously or orally. When administered intravenously, a loading dose should first be given, though care should be taken not to cause hypotension. Procainamide's major active metabolite is N-acetyl procainamide (NAPA), which is approximately equipotent with the parent drug as an antiarrhythmic agent. NAPA has an elimination half-life about twice that of procainamide, and it can reach somewhat higher plasma levels during chronic procainamide administration. Loading dose is 100 mg IV bolus given slowly over 5 minutes. Max dose is 17 mg/kg. Use is discontinued when dysrhythmia is suppressed, or if hypotension ensues, QRS complex widens by 50% or more, or maximum dose is achieved.

    Now the math.....you will find these very valuable
    DosageHelp.com - Helping Nursing Students Learn Dosage Calculations
    http://www.davesems.com/files/drug_d...lculations.pdf
  9. Visit  JROregon profile page
    0
    I like dosagehelp.com. Simplifies the questions. Like jmdRN says don't "over" convert your grams and milligrams. If you have a problem with both mg and gm, just convert one to the other. When you are taking a test, make sure that you remember which is a larger mass. If you have 1 gram of something, it's going to be 1,000,000 mcg. I think you found a problem with a typo.
  10. Visit  KelRN215 profile page
    0
    Well, in your problem, you say the dose is in mg/kg/min and then you're trying to work out the answer in mcg/kg/min. So there's problem #1. 4 mg/kg/min seems like an extremely high dose of procainamide... 300 mg/min? Seems unlikely.
  11. Visit  RNrerun profile page
    0
    Wow. Thanks for all the help. I'm going to assume there's something wrong with this problem. I'm trying to re-learn all these calculations that I haven't done in years and years, and it doesn't take much to confuse me. I have been using dosagehelp.com to practice, and I'll check out the other one that Esmel reccommended. I'll have to take a medications test at the hospital, and I'm trying to get all this straight in my head before I go in there!

    Thanks!
  12. Visit  Asmorris profile page
    0
    Good luck on the test!
  13. Visit  lethomson91 profile page
    1
    Quote from RNrerun
    Wow. Thanks for all the help. I'm going to assume there's something wrong with this problem. I'm trying to re-learn all these calculations that I haven't done in years and years, and it doesn't take much to confuse me. I have been using dosagehelp.com to practice, and I'll check out the other one that Esmel reccommended. I'll have to take a medications test at the hospital, and I'm trying to get all this straight in my head before I go in there!

    Thanks!
    There's nothing wrong with the problem.

    In this case, the patient's weight is irrelevant - it doesn't impact the dose, so it's simply left out.

    dose ordered = 2 g in 250 cc (cc = mL)
    infusion rate = 4mg/min

    4mg/min x 250mL/2g x 1g/1000mg x 60min/hr = 30 mL/hr
    GrnTea likes this.
  14. Visit  Esme12 profile page
    1
    Quote from lethomson91
    There's nothing wrong with the problem.

    In this case, the patient's weight is irrelevant - it doesn't impact the dose, so it's simply left out.

    dose ordered = 2 g in 250 cc (cc = mL)
    infusion rate = 4mg/min

    4mg/min x 250mL/2g x 1g/1000mg x 60min/hr = 30 mL/hr
    The thread is over a year old....and I beg to differ.......the weight IS relevant.....

    A procainamide drip is ordered (2 gm in 250 cc of D5W) to infuse at 4mg/kg/min. The patient weighs 165 lbs. Calculate the drip rate in cc/hr for which the infusion pump will be set at.

    This math question is all about the weight.
    KelRN215 likes this.


Nursing Jobs in every specialty and state. Visit today and find your dream job.

Top