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Calculating IV Flow Rates

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The system has a calculator to help determine IV flow rates and/or drug infusion rates.  The system will calculate the infusion rate in micrograms/kilograms/minute and the IV flow rate in microdrops per minute, if the following information is entered:
The patient's weight (displays automatically if it has been entered elsewhere in the system).
The total amount of medication added (in mg).
The total volume (in cc) of IV fluid (dilutent) to which the drug is added.
The number of microdrops per cc the IV set delivers (the IV set size).
The hang time in minutes (time over which it is to be infused).

 

To calculate the infusion rate in micrograms/kilograms/minute and the hang time, you would need to enter the following information:
The patient's weight (displays automatically if entered on the admission form or the Vital Signs menu).
The total amount of medication added (in mg)
The total volume (in cc) of IV fluid (the "dilutent") to which the drug is added.
The number of microdrops per cc the IV set delivers (the IV set size)
The flow rate in microdrops per minute.

 

Follow the steps below for using the calculation program or select Help on the IV Calculation menu for on line assistance.

 

Select IV Flow Rates and Drip Doses on the Pharmacy Options menu to display the IV calculation menu. For the calculation program to work, the following criteria must be met: Values must be entered for at least two of the first three fields. Values must be entered for at least two of the second three fields. If a value is missing from the first three fields and the second three fields, then the hang time in minutes must be entered.

 

If the patient's weight has been entered, it will automatically display in pounds.  If not, enter the weight in pounds using the numerical keypad.

 

Select OK.

 

Use the numerical keypad for the following steps.  Use the decimal point (.) to enter tenths.

 

Enter the total amount of medication ordered in milligrams and then select OK.

 

Enter the rate of the infusion or "dose" in micrograms per kilograms per minute if known.  Select OK even if the rate of infusion is left blank.

 

Enter the total fluid volume to be used in ccs.  Select OK.

 

Enter the IV set size (microdrops per cc the IV set delivers).  Select OK.

 

Enter the flow rate in microdrops per minute.  Select OK even if the flow rate is left blank.

 

Enter the hang time in minutes.  If unknown, leave blank.  Select OK.

 

Select Calculate to have the system calculate missing values.

 

Select the box labeled Zero to remove a calculated value.

 

When working only with IV fluids (no medication added), only the last four categories will be utilized.  The system will calculate any of the four values left blank if the remaining three values are supplied.

 

Select POC Whiteboard > Patient  > Pharmacy > IV Flow Rates and Drip Doses

 

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Figure 2.93 IV Calculation Menu

 

 

IV Calculation Example #1
The doctor has ordered one liter of Lactated Ringers solution to be run in over three hours.  What rate must be entered into the IV pump to achieve this?
The patients weight is not needed for this calculation, so you can select OK regardless of the entry in the weight field.
No medication is being used, so you may leave this field blank and select OK.
Similarly, since no medication is being used, the rate of infusion of drug may be left blank.  Select OK.
Enter the total volume of IV fluid to be used (1000 cc in this case) and select OK.
Enter the IV set size (microdrops per cc).  Usually this will be ten drops/cc (check the package) or 10,000 microdrops/cc. Enter 10,000.  Select OK.
Since the flow rate (in microdrops/minute) is what you wish to have the system calculate, leave this field blank and select OK.
Enter the "hang time" ordered in minutes.  (In this case, three hours or 180 minutes).  Select OK.
Select Calculate.
In a moment, note the system fills in the flow rate of 55,600 microdrops per minute (55.6 drops per minute).

 

IV Calculation Example #2
The doctor has ordered Dopamine five micrograms per kilogram per minute.  What drip rate must you enter to deliver Dopamine at this rate for this patient?
Note the patients weight in pounds.  The calculator converts this to kilograms internally, but only pounds will be displayed.  Fill in the weight if this field is blank.  For the purposes of this example, enter 165 pounds.  Select OK.
Since Dopamine is usually supplied as 400mg per vial, double-check the vial and enter 400 in the field labeled Tot medication.  Select OK.
Enter the specified rate of infusion as ordered.  For this example, enter five.  Select OK.
Enter the total volume of IV fluid (in cc) into which the Dopamine will be diluted.  For this example, enter 250.  Select OK.
Enter the IV set size.  In this case, enter 60 (microdrops per cc).  Select OK.
Since flow rate is what we will be asking the system to calculate, leave this field blank.  Select OK.
Since hang time is still unknown, leave this field blank also.  Select OK.
Now select Calculate.
In a moment, notice the system has filled in 14 microdrops per minute in the field labeled Flow Rt. In addition, the Hang time field has been filled in with 1071 minutes (almost eighteen hours). This is the time it will take for the 250 cc of fluid to be infused.