OK, I've had a brain infarct. I can not remember the formula for determining the doseage e.g. mcg/kg/min when you just have the ml/hr infusing. I had a handout for IV drip calculations but I misplaced it. I would be mucho appreciative to anyone who could help me.
To know the mcg/kg/min on a running pump you multiply the cc/hr by the constant.
Here is the formula to determine the constant:
Mg
---- X 1000 divided by pt's wt in kg divided by 60 = the C.
Volume
I hope that helps. So many hospitals now have pumps that do it all so it is easy to forget!
I use this to get my cal factor:
X mg in the bag, divided by the X ml in the bag, times 1000 converts to mcg), divided by 60 (minutes), divided by kg (per KG) in wt = cal factor.
(Xmg / Xml) X (1000)/ (60)/ (Xkg) = cal factor
example: Pt weighs 90kg, you have 400mg dopamine in 250cc= 400/250=1.6 X 1000=1600/60=26.6 divided by 90kg= 0.296 rounded to 0.3
So you come on and accept a pt getting 20ml/hr dopamine as above, and as a good nurse you want to do your own calculation as to how many mcg/kg/min they are on, (take RATE ml/hr TIMES cal factor= DOSE mcg/kg/min) 20 X 0.30 = 6 mcg/kg/min
If you know the ordered dose and you want to calculate the cc/hr ; example order same pt: give 7 mcg/kg/min, (DOSE mcg/kg/min DIVIDED by cal factor= RATE ml/hr) : 7 divided by 0.3= 23.3 ml/hr
Take levophed or any med ordered mcg/min do the same equation without the kg
levophed 4mg/250ml bag: 4 /250 X1000 /60 = 0.266 round up to 0.27
10ml of above bag= RATE TIMES CAL FACTOR = DOSE: 10 X 0.27= 2.7 mcg/min DOSE
10 mcg ordered DOSE DIVIDED BY CAL FACTOR = RATE: 10 / 0.27 = 37 ml/hr RATE
Just remember the simple equation by rote and you don't need any charts, papers, etc., just a calculator.:)
