im stuck :(

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Calculate the flow rate in gtt/min for the following order:

Ordered: Retrovir 2 mg/kg over 1 h

On hand: Retrovir 20-mL vial with 10 mg/mL - The patient weighs 212 lb. Use macrodrip tubing (15 gtt/mL). Dilute the desired dose in 100 mL D5W

step 1-convert patients weight from lb-kg =96.36 kg

step 2- multiply the dosage ordered by the patients weight= 2mg/kg * 96.36kg= 192.7mg/1hr -desired dose

step 3-calculate amount to administer- 20mL/10mg = (?)/192.72 mg/1hr

I end up with 385.44 mL/1hr

the 4th step i would take is to multiply the answer from step 3 by 15 gtt/mL =the answer doesnt seem right???

please help with some tips! :confused:

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Specializes in SNU/SNF/MedSurg, SPCU Ortho/Neuro/Spine.

step 1-convert patients weight from lb-kg =96.36 kg

step 2- multiply the dosage ordered by the patients weight= 2mg/kg * 96.36kg= 192.7mg/1hr

then you do:

192.7mg required per hour

so in 10mg/1ml 192.7mg/xml

gives you 19.27 round to 19.3ml then they ask you to dilute it into 100ml now you have 119.3ml

now your dose is

119.3/60 minutes (1hour) X15gtt = 29.825 then you round it to gtt and answer is 30gtt/min

does it help?

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Specializes in NICU, PICU, adult med/surg, peds BMT.

Ok I'm a math geek so I'll help you out. I'm not great with drip factors but I'll explain step by step my reasoning ams refer to your resources to see of it all makes sense. You were alright til step 3. So you have 192.7mg you must deliver in one hour. Your original question says 20mls of 10mg/ml solution. So to find the volume per hour you will take what you desire 192.7mg and divide it by what you have 10mg per ml. So it's desired over have or 192.7/10= 19.27 or 19.3mls of that solution = 193mg. Now the next step of your question says to dilute this volume in D5W to make 100ml to be delivered over 1 hour. So you will be mixing 80.7 (D5W) + 19.3 (med) = 100ml. So that 100ml has to be delivered over 1 hour wjth tubing that delivers 15gtts per ml. If thereis 15gtt per ml then you will find that your 100ml bag will contain (100 ml x 15 gtts) 1500 gtts to be delivered over one hour. Divide 1500 by 60 minutes to find out how many drips per minute. You will get 25 drips per minute. You will look at your drip chamber and count 6 drips per 15 seconds (25/4= amount per 15 seconds). Hope this helps. This gets easier.

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Specializes in NICU, PICU, adult med/surg, peds BMT.

Note the reason our answers are different is she added the 19.3 to 100 and I made my total volume = 100ml. In rereading the question it says dilute in 100mls so helpingothersinlife is accurate.

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Specializes in SNU/SNF/MedSurg, SPCU Ortho/Neuro/Spine.
Ok I'm a math geek so I'll help you out. I'm not great with drip factors but I'll explain step by step my reasoning ams refer to your resources to see of it all makes sense. You were alright til step 3. So you have 192.7mg you must deliver in one hour. Your original question says 20mls of 10mg/ml solution. So to find the volume per hour you will take what you desire 192.7mg and divide it by what you have 10mg per ml. So it's desired over have or 192.7/10= 19.27 or 19.3mls of that solution = 193mg. Now the next step of your question says to dilute this volume in D5W to make 100ml to be delivered over 1 hour. So you will be mixing 80.7 (D5W) + 19.3 (med) = 100ml. So that 100ml has to be delivered over 1 hour wjth tubing that delivers 15gtts per ml. If thereis 15gtt per ml then you will find that your 100ml bag will contain (100 ml x 15 gtts) 1500 gtts to be delivered over one hour. Divide 1500 by 60 minutes to find out how many drips per minute. You will get 25 drips per minute. You will look at your drip chamber and count 6 drips per 15 seconds (25/4= amount per 15 seconds). Hope this helps. This gets easier.

the only thing here is that I think it said to dilute into, not reconstitute to, and the med is given in ML so it is in liquid form not powder.

so we have to add the liquid amount we calculated which was 19.27 (or 19.3 depending in your instructions for rounding) to the 100ml of diluent

LOL vanlo, we posted at the same time!

and I am the old CSANTOS just changed my name to helpingothersinlife last year..!

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Specializes in NICU, PICU, adult med/surg, peds BMT.

I like helpingothersinlife!

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thank you :)

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