Help with PICU calculations please!!!

Specialties PICU

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Specializes in Pediatric critical care.

Okay so I was given this math test, and it says that I can use any online or paper resource, so I'm using you guys! I have completed it, but there are two that I just don't seem to understand. Here goes:

1. A 4 year old child weighs 15 kg. A morphine drip (112.5mg in 50ml of NS) is infusing at 1 ml/hr. How many mg/kg/hr are being delivered?

---Okay, so I figured that the concentration is 2.25mg/1ml and then 2.25mg/15kg/1hr=33.75mg/kg/hr-----This is a different answer than what I had written on my paper the first time. Initially I had 7.5mg/kg/hr and now I don't understand how I got that. :banghead: Please explain!!!!!

For question two---Rule of sixes--For drugs infused in doses of 0.1mcg/kg/min (epinephrine, isoproterenol, levarterenol, Neo-synephrine): Multiply weight in kg by 0.6, place this number in milligrams of drug in solution totaling 100mg---then 1ml/hr delivers 0.1mcg/kg/min

2. A 10 year old boy weighing 88 lbs needs an epinephrine drip (based on rules of sixes) made so 1ml/hr=0.1mcgs/kg/min. How many milligrams of epinephrine would be added to bag a NS to equal 100ml?

---Okay, so I got 40kg, then using the rule 40kg x 0.6=24mg My answer 24mg of epinephrine would be added???

I am totally confused:no: Any help would be appreciated.

Thanks in advance guys!!!

Sorry Janfrn, I didn't know I double posted, please delete one. I don't know how.

Specializes in NICU, PICU, PCVICU and peds oncology.
Okay so I was given this math test, and it says that I can use any online or paper resource, so I'm using you guys! I have completed it, but there are two that I just don't seem to understand. Here goes:

1. A 4 year old child weighs 15 kg. A morphine drip (112.5mg in 50ml of NS) is infusing at 1 ml/hr. How many mg/kg/hr are being delivered?

---Okay, so I figured that the concentration is 2.25mg/1ml and then 2.25mg/15kg/1hr=33.75mg/kg/hr-----This is a different answer than what I had written on my paper the first time. Initially I had 7.5mg/kg/hr and now I don't understand how I got that. :banghead: Please explain!!!!!

Okay, I'm not getting either of your responses!! Let's start with what we have... an infusion of morphine 112.5 mg in 50 mL NS... 112.5 mg / 50 mL = 2.25 mg/mL. The infusion is running at 1 mL/hr... or 2.25 mg/hr. Right? 2.25mg/hr / 15 kg = 0.15 mg/kg/hr. Or if you prefer, 150 mcg/kg/hr. (It's a lot, but it's not even close to the highest I've ever run.)

For question two---Rule of sixes--For drugs infused in doses of 0.1mcg/kg/min (epinephrine, isoproterenol, levarterenol, Neo-synephrine): Multiply weight in kg by 0.6, place this number in milligrams of drug in solution totaling 100mg---then 1ml/hr delivers 0.1mcg/kg/min

2. A 10 year old boy weighing 88 lbs needs an epinephrine drip (based on rules of sixes) made so 1ml/hr=0.1mcgs/kg/min. How many milligrams of epinephrine would be added to bag a NS to equal 100ml?

---Okay, so I got 40kg, then using the rule 40kg x 0.6=24mg My answer 24mg of epinephrine would be added???

Bingo! That one is easy. If you want to try a different method, you could do this: 40 kg X 0.1 mcg X 60 minutes /1000 mcgs (in 1 mg) and you'll get the smae answer.

Sorry Janfrn, I didn't know I double posted, please delete one. I don't know how.

Don't worry, I took care of it.

Specializes in Pediatric critical care.

Thank you Jan, I really appreciate it! It seemed so confusing! Maybe I was thinking too much into it. I really don't know.

Specializes in NICU, PICU, PCVICU and peds oncology.

Yeah, you were. Always start with what you have, then figure out what you need to give you what you want. Most of our math is simple algebra. I sucked at math all the way through school, and If I can do a lot of the calcs in my head now, you can do it anytime with a calculator!

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