Help with PICU calculations please!!!

[NurseLay]

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. 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.

[NotReady4PrimeTime, RN]

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. 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.

[NurseLay]

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

[NotReady4PrimeTime, RN]

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!