HELP! Math question

  1. I can not figure out how to answer this:
    A doctors order reads "heparin IV at 1400 units/hr" for a patient undergoing percutaneous coronary intervention. The pharmacy sends heparin in a bag containing 25,000 units in 250ml of D5W. What infusion rate should you set on this IV pump?
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  2. 7 Comments

  3. by   TashaLPN2006RN2012
    well i loved doing my math stuff but i dont believe there is enough info?! unless it said 1400ml/hr?? instead of 1400 units. or what size tubing is used? i'm stumped on this one too...sorry i couldnt help
  4. by   TashaLPN2006RN2012
    D
    - X Q I'd do desired (dr order) over Have X quantity to figure it out
    H
  5. by   Jokerhill
    First break down what you have 25000u/250ml is the same as 100u/1ml. Then you need 1400u not 100u so 1ml X 14ml = 14ml.
    Another way is to take 25000 / 250 = 1400 / X , and do the math
    25000x = 35000 , x = 35000/25000 and you get X = 14
  6. by   Jokerhill
    The pharmacy wants it to be right so give them a call with your questions. Call a friend = final answer.
  7. by   ABerryGirl
    Here's how I would set up the problem:

    1400 units x 250 mls
    1 hour ........25000 units


    You then cross multiply (crossing out "units" to leave you with mls/hr). Your answer should be 14mls/hr.

    Here are a couple of good site that explain this problem using dimensional analysis.
    http://www-isu.indstate.edu/mary/tutorial.htm
    http://www.alysion.org/dimensional/analysis.htm

    It will get easier as you continue to do these type of problems....

    Good luck!
  8. by   AnnieOaklyRN
    First you need to figure out how many units are in each ML of the mixed solution: 25000 units divided by 250 mL = 100 units/mL

    Now you need to find out how many mL/hour you need to set the pump at to acheive the ordered units per hour. solution: 1400 units divided by 100 (because their are 100 units per mL)= 14 ml/Hour


    Swtooth
  9. by   Daytonite
    Quote from adamsmom
    a doctors order reads "heparin iv at 1400 units/hr" for a patient undergoing percutaneous coronary intervention. the pharmacy sends heparin in a bag containing 25,000 units in 250ml of d5w. what infusion rate should you set on this iv pump?
    iv pumps are almost always set at mls per hour, so those are the labels you are looking for in the final answer. do, this problem by dimensional analysis (factor label method)"
    1400 units/1 hour (dose desired) x 250 ml/25,000 units (dose on hand) = 350,000 ml/25,000 hour (after cancelling out the label "units" from the numerator and denominator of each term and completing the math), which is 14 ml/hour when rounded off. you will set the iv pump at 14.

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