IV fluids and rate calculations - PowerPoint Presentation

Slide1

IV fluids and rate calculations

Jennifer Kean MSN, RN, CCRN

IV fluids or medications administered by gravity

Sometimes, you will not have an IV pump available

When gravity is used, infusion sets are used that allow the nurse to count the drops per minute to regulate the flow

IV tubing comes in two sizes:

Macrodrip

- delivers 10, 15, or 20

gtts

/ml

Microdrip

- delivers 60

gtts

/ml

The

macrodrip

set is larger than the

microdrip

set

In order to calculate the

gtts

/min, the nurse must know the tubing drop factor

When to use which tubing

If large volumes of fluids must be administered, such as 125 ml/

hr

or more, a

macrodrip

set is required

When a volume of 50 ml/

hr

or less is needed, a

microdrip

set should be used

Usually, the drip chamber of the

macrodrip

tubing is

white

, and the drip chamber for the

microdrip

tubing is

blue

And, the

microdrip

tubing is generally used in the critical care unit for drips (norepinephrine, dopamine, or vasopressin) because they are infused at very slow rates, only about 20-50 ml/

hr

The MD or NP will write the order for the IV type and amount, and also the timeframe over which it must be infused

And, it is the nurse’s responsibility to regulate and maintain the infusion flow rate

Remember the formula!

Miss

DiLalo’s

formula (which I will NEVER forget!)

Ml x

gtts

Milliliters times drops over minutes

________

Minutes

A little bit more about the formula

Convert total

hours

to

minutes

1 hour = 60 minutes

Important!

Total volume to be infused (ml) x drop factor (drops) divided by total amount of time in minutes (minutes)

Example:

500 ml/180 min x 15

gtt

/ml x

X

500 x 12 x

X

X = 41.6, round to 42

gtts

/min

Another example

Cefuroxime 1 g in 50 ml of NS to infuse over 30 minutes

50 ml/ 30 min x 60

gtts

/ml x

X

50/30x 2/X

50x2 = 100

gtts

/min

Infusion via IV pump

Of course, there may be those fine occasions when you have access to an IV pump

Most of the pumps on the market today are “smart” pumps and can be programmed to whatever rate you need

The smart pump will have a library installed- you just enter the first 2 letters of the name of the med, and meds that start with those letters will show on the screen- all you have to do is select the right med and dose

Smart pumps were invented because of problems with too many errors being made

However, you may not get a smart pump, and therefore will have to calculate for ml/

hr

Another example

Lactated Ringer’s is ordered 1,000 ml to infuse over 12 hours

With this one, you do not have to worry about drops, just solve for ml/h

Formula:

x ml/ h = 1000 ml / 12 h

x = 1000/12

x = 83.3 or 83 ml/

hr

Try one!

Kefzol

1 g in 50 ml D5W to infuse over 30 minutes

So, x ml/ h; xml/h = 50/30 x 60/1

Remember to convert hours to minutes!

Answer

So.. It’s set at 100 ml/

hr

What if you don’t have a pump?

Then figure out drops/min; so it would be

100 ml x drop factor/ 30 minutes

100/30 = 33.3, or 33

gtts

/min

And…

You will need your watch with a second hand when you are setting the tubing drip factor

So, you cannot forget your watch!!!

So, it’s really not that hard

Just make sure you know the drop factor of the tubing you are using, the total milliliters to be infused, and over what period of time- or a combination of any of the 3

Don’t forget your watch!

Don’t forget the formula

! (Remember Miss

DiLalo

!!)

And, DON’T STRESS OUT!!! You’ll do great!!!