Help with math Heparin and units

[nssanders]

Can some please help me with these problems, I tried working them out for 2hours, I just can't figure what I doing wrong? I 've converted the lbs to kg but I'm having a hard time pick out what information is important to in this problem

1. Order for 250 ml D5W with 225 mg Nitropress to infuse at 3 mcg/kg/min. Patient weighs 110 lbs. How fast will you set your infusion controller ? ____________________mL/hr

1. Order is for Potassium phosphate 10 meq IV in 100 ml NS over 90 minutes. What rate would you set your infusion controller ? ______________________________

[CrunchyMama, ASN, RN]

For the 1st one....I did it like this (not sure if it's right)

Patient weighs 50kg, so 3x50=150mg=0.15mcg

225mg=0.15mg=37.5 =0.16mlx60(60mins in an hour)=10ml/hr

250ml ....xml ....225mg

For the 2nd...now sure what the question is? Does it want the amount given/hour?

[emtoh17]

I am confused by the title Heparin and units??

[cheezwhiz]

In the second one they just want you to determine how many mL will infuse over 60 mins. So what's relevant is the 100mL and the 90 mins. Ratio-proportion setup seems the most intuitive in this case.

100mL/90mins = XmL/60mins

...then you would state your answers in mL/h because that is the standard.

[nssanders]

That is the right answer by my answer sheet, but could you explain it how you got the answer I don't understand 3mcgxkgxmin= 50g=kg x 3 = 150mcg which is converted to mg 0.15, now I use formula D x v I plugged in 0.15 mg x250ml

H 225mg =0.16

Now how did you get the 10/ml/hr did

[chare]

weight based infusions over time can either be ordered hourly or per minute. regardless of which way, the formulae are very similar.

to solve for an infusion ordered per hour: (dose × weight) ÷ concentration = ml/hr.

to solve for an infusion ordered per minute: (dose × weight × 60) ÷ concentration = ml/hr.

when you set up this type problem it is important that you use the same units of measure throughout. for clarity, i always convert units to what are used in the order, and what i need to solve for.

1.order for 250 ml d5w with 225 mg nitropress to infuse at 3 mcg/kg/min. patient weighs 110 lbs. how fast will you set your infusion controller? 9 ml/hr

dose: 3 mcg

weight: 50 kg

conc: 900 mcg/ml

placing these values in the equation:

(3 × 50 × 60) ÷ 900 = x ml/hr

9000 ÷ 900 = 9 ml/hr

[chare]

intermittent iv infusions over time can either be ordered hourly or per minute. regardless of which way, the formulae are very similar.

to solve for an infusion ordered per hour: volume ÷ time ordered = ml/hr.

to solve for an infusion ordered per minute: (volume × 60) ÷ time ordered = ml/hr.

1. order is for potassium phosphate 10 meq iv in 100 ml ns over 90 minutes. what rate would you set your infusion controller? 66.6 (67) ml/hr

volume: 100

time: 90 minutes

placing these values in the equation:

(100 × 60) ÷ 90 = x ml/hr

6000 ÷ 90 = 66.6 (67) ml/hr

all infusion devices that i am familiar with allow you to set the infusion rate to one decimal place.