Math Calculation

tawill5 · Jan 23, 2006

Hello! Calculate the heparin as follows:

25000 : 250 :: 800 : x

The problem is calculated by using the ratio and proportion technique.

25000x = 200000

x = 200000 divided by 25000

x = 8mls per hour

Daytonite, BSN, RN · Jan 23, 2006

Order: Heparin infusion at 800 units/hr
Available: premixed Heparin solution of 25,000 in 250 ml D5W
What is the rate in ml/hr?

If I had a penny for everytime I've had to readjust and re-calculate a Heparin drip, I'd probably have enough to buy dinner for my whole family. I understand that it is kind of new to you, but the old "dose desired over dose on hand time the amount" is always going to give you the answer to these Heparin problem in terms of rate in ml/hr--always. Set it up like this:

[800units (

dose desired

)

/

25,000units (

dose on hand

)]

x

250mL (

amount on hand

)

=

8mL

The dimensional analysis way to set this up, so your labels cancel out and you end up with your desired labels of ml/hr is as follows:

800units

/

1 hour

x

250mL/25,000units

=

8mL/hr.

(

Note that the "units" label cancels out

)

#2) Order: Start Nitroglycerin infusion at 5 mcg/min
Available: premixed Nitroglycerin bottle 50 mg in 250 ml of D5W
What is the rate in ml/hr?

This one is a little more of a challenge because you need to use a conversion ratio that you don't usually use. Here is how you set the equation up by dimensional analysis (setting up fractions with labels that are going to cancel out to give you the ending label (mL/hr) that you want)

5mcg/1 min (

dose desired

)

x

1 mg/1000mcg (

conversion factor to convert micrograms to milligrams

)

x

250 mL/50 mg (

dose on hand

) x 60 min/1 hr (

conversion factor to get from minutes to hour

)

Now, cancel out (divide out) labels which now leaves you with the following arithmatic problem:

(5 x 1 x 250 mL x 60)

/

(1 x 1000 x 50 x 1 hr) = 75,000 mL/50,000 hr.

=

1.5 mL/hr.

10ACGIRL · Jan 24, 2006

I need help pleeeeeasssssseeee! Just when I thought I was seeing the light with math calculations there was another problem thrown in. Is there a formula that can tell me the ml/hr if there is not time specified. please see the following question....
Order: Heparin infusion at 800 units/hr
Available: premixed Heparin solution of 25,000 in 250 ml D5W
What is the rate in ml/hr?
#2) Order: Start Nitroglycerin infusion at 5 mcg/min
Available: premixed Nitroglycerin bottle 50 mg in 250 ml of D5W
What is the rate in ml/hr?

i WISH i could help but, math was always my worst suject all threw school.