IV Flow Rates

  1. Hi! Help! I don't see anywhere on my formula list that talks about doing calculations with Units.

    Here's 2 problems i'm absoloutely stuck on.

    1.) The tricupsid valve repair patient has orders for D5W 1000 ml with 30,000 U heparin. Infuse at 500 u/hr. Drop factor is 60 gtt/ml.

    I need to find the ______ ml/h
    ______ ml/min
    _______ gtt/min


    2.) Your hypertensive patient has orders for Nipride 50 mg in 250 ml D5W. Infuse at 3 mcg/kg/min for a patient weighing 82 kg. Drop factor is 60 gtt/ml.

    I need to find __246 mcg/min__ amt. drug/min for 82 kg patient
    ______ amt drug/ml
    _______ ml/min
    ________ gtt/min

    Thanks for your help in advance!:smiletea2:
    •  
  2. 4 Comments

  3. by   RN BSN 2009
    help!
  4. by   morte
    Quote from iceyspots
    Hi! Help! I don't see anywhere on my formula list that talks about doing calculations with Units.

    Here's 2 problems i'm absoloutely stuck on.

    1.) The tricupsid valve repair patient has orders for D5W 1000 ml with 30,000 U heparin. Infuse at 500 u/hr. Drop factor is 60 gtt/ml.

    I need to find the ______ ml/h
    ______ ml/min
    _______ gtt/min
    2.) Your hypertensive patient has orders for Nipride 50 mg in 250 ml D5W. Infuse at 3 mcg/kg/min for a patient weighing 82 kg. Drop factor is 60 gtt/ml.
    I need to find __246 mcg/min__ amt. drug/min for 82 kg patient
    ______ amt drug/ml
    _______ ml/min
    ________ gtt/min
    1) you need to find units per ml first, divide that into dose=ml per dose(hourly), divide that by 60 (minutes)=ml/min; multiply that by 60=ggt/min
    2) amount of drug/ml is 50/250....(divide) ; ml/min= drug/ml x 0.246; gtt/min=ml/min x ggt factor, in this case 60
    i am no more/less prone to move decimal points than anyone else,lol. you need to have an idea of the range your answer needs to be in....when i first did the second prob., i had the first calc UPSIDE DOWN, what a mess that would have been! the first one, i doubt you would ever see, heparin is usually supplied premixed 25,000/500....a 1000 ml bag would be wasted.
    and dont let the "units" (pun intended) of measure confuse your arithmetic calc...
  5. by   RN BSN 2009
    thank you very much~~~~~~~~~~~
  6. by   Daytonite
    the tricupsid valve repair patient has orders for d5w 1000 ml with 30,000 u heparin. infuse at 500 u/hr. drop factor is 60 gtt/ml.

    i need to find the ______ ml/h
    ______ ml/min
    _______ gtt/min
    find ml per hour: you've been given the essential information, what's in the iv bag and how fast it's infusing. that's all you need to find this answer. you merely set these ratios up in a dimensional analysis equation in order to cancel out the labels on the numbers so you end up with a ratio, or fraction, that has "ml" in the numerator and "hour" in the denominator of the final answer. dimensional analysis is all about manipulating the terms of the equation.
    1000 ml/30,000 units (dose you have available) x 500 units/1 hour (what you are giving the patient) = 16.666 ml/hour
    find ml per minute: this merely requires a conversion factor to be applied

    to the problem
    1000 ml/30,000 units (dose you have available) x 500 units/1 hour (what you are giving the patient) x 1 hour/60 minutes (conversion factor) = 0.27777 ml/minute

    find drops per minute: you merely apply the drop factor of your tubing to the equation.
    1000 ml/30,000 units (dose you have available) x 500 units/1 hour (what you are giving the patient) x 1 hour/60 minutes (conversion factor) x 60 gtts/1 ml (drop factor of iv tubing) = 17 drops/minute (after rounding off)
    your hypertensive patient has orders for nipride 50 mg in 250 ml d5w. infuse at 3 mcg/kg/min for a patient weighing 82 kg. drop factor is 60 gtt/ml.

    i need to find __246 mcg/min__ amt. drug/min for 82 kg patient
    ______ amt drug/ml
    _______ ml/min
    ________ gtt/min
    i'm not sure i'm understanding exactly what you are supposed to calculate here, but i'll try. your 82 kg patient is supposed to get 246 mcg/min. that is 3 mcg (dose desired) x 82 kg (patient's weight).

    amount of drug per ml:
    500 mg/250 ml (dose on hand) x 1000 mcg/1 mg (conversion factor) = 2000 mcg/1 ml

    find ml per minute to be given: use the above answer to calculate this figure.
    3 mcg/1kg (dose to give) x 1/1 min (the time part of the dose to give) x 82 kg (weight of patient) x 1 ml/2000 mcg (amount of drug per ml) = 0.123 ml/min

    find gtts/min:
    0.123 ml/1 minute (infusion rate determined above) x 60 gtts/1 ml (drop factor of iv tubing) = 7.38 gtts/min = 7 gtts/min (rounded off)

close