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Clinical Calculations: Module 7: Intravenous Medications

Infusions of Intravenous Fluids

Module 7 - Infusions of Intravenous Fluids

What’s in this module?

This module will focus on the delivery of intravenous (IV) fluids.  You will need to know about IV fluids delivered either by gravity or by using a pump.

Summary of problem types in this module

  1. IV fluids delivered using a pump: how many milliliters per hour (ml/hr) should the nurse set on the pump?
  2. IV fluids delivered by gravity: how many drops per minute (gtt/min) should the nurse give?
  3. IV fluids delivered by gravity:  how long will it take for the fluid to infuse?
  4. IV fluids delivered by gravity:  if the flow rate needs to be changed after reassessment, how many drops per minute (gtt/min) should the nurse give?

Equivalents to know

You should now know all your commonly used equivalents.

Rounding rules to know

You will continue to use the rounding rules for numbers >1 and <1 for time calculations.

You will also need to refer to three of your rounding rules for IV fluids:

  1. For IV fluids being administered by an infusion pump (ml/hr), the number of ml to be infused each hour is to be expressed as a whole number. Therefore, you would round to the nearest whole ml.

  1. For IV fluids being administered by gravity (drops per min), the number of drops must be expressed as a whole number. Therefore, you would round to the nearest whole drop. (Ex: 34.5 = 35 gtts/min, 38.4=38 gtts/min)

  1. When calculating how long it will take IV fluids to infuse, you are to express your answer in hours and minutes. Be sure to take the math out three (3) places past the decimal point before converting the partial hour to minutes. (Ex: 4.462 hours where 0.462 x 60 = 27.72 = 28 mins for a final answer of 4 hrs 28 mins).

Starting factors and answer units

Several new starting factors and answer units will be used in this module. 

New starting factors and answer units will be shown with the sample problems in each section below.

An Introduction to Fluid Given Intravenously

Let’s look at the fluids and equipment involved so you’ll have a mental picture of the activities involved in administering IV fluids.  You’ll learn much more in your labs, clinical rotations, and more advanced courses.  This is a brief overview.

 

Image of a 1000 mL bag of intravenous fluid. The label says 0.9% Sodium Chloride Injection USP.

https://www.dentaled.com/uploads/1/1/7/5/117512429/s752231677794524308_p44_i4_w800.jpeg  Retrieved 6/10/19

 

The standard bag of IV fluid contains 1000 ml of fluid.  You’ll note that the amount is shown on the fluid bag.  There are several types of fluid.  The type to be used is indicated in the healthcare provider’s prescription and is based on the client’s medical needs.

The fluid in the bag illustrated above is 0.9% Sodium Chloride, also called Normal Saline or NS.   NS is often the fluid used.  Other common fluids are Lactated Ringer’s (LR),  5% Dextrose in Water (D5W), and combination fluids such as 5% Dextrose with Normal Saline (D5NS) or Lactated Ringers (D5LR).   You will encounter many other types of fluid during your nursing career, but let’s start with a short list.

Image of a 250 mL bag of intravenous fluid. The label indicates that it is 5% Dextrose in Water (D5W).

https://i2.wp.com/www.stepwards.com/wp-content/uploads/2017/01/D5W250mL.jpg    Retrieved 6/10/19

 

Other smaller bags of fluid are infused as well.  The illustration above shows D5W 250 ml.  The smaller bags often contain medication to be infused intravenously over a longer time than could be achieved by directly injecting the medication into the client’s IV line.  Typical sizes are 500 ml and 250 ml.

 

Image illustrates how a primary bag of IV fluid and a secondary bag of IV fluid are hung on an IV pole for gravity infusion. The primary bag has been lowered so that the secondary bag can flow. There is IV tubing connected to both bags. The tubing for the secondary bag is connected to the tubing for the primary bag.

https://opentextbc.ca/clinicalskills/wp-content/uploads/sites/82/2015/09/intravenous_equipment_labels-2.png      Retrieved 6/12/19

 

This diagram above shows a setup for an IV infusion by gravity.  Note that this IV set can use a smaller secondary IV bag (called a piggyback bag) as well as a primary bag.   Secondary bags are often used to infuse medication.  Regulation of the flow rate is done using the roller clamp and watching the drip chamber.  Whether the fluid is infused by gravity or by pump, an IV pole will be used. 

In both types of infusion, the IV bag hangs from one of the hooks at the top of the pole.

 

Image of IV tubing with a roller clamp. Used for gravity infusions.

https://slideplayer.com/slide/12373323/73/images/24/Primary+IV+set+for+intravenous+therapy..jpg    Retrieved 6/12/19

 

The illustration above shows an IV set for gravity infusion.  The bag spike is inserted into the bag hanging on the IV pole.  The connector end is attached to the client’s IV access site.  The roller clamp is used to adjust the drip rate of the IV fluid by observing drops fall into the drip chamber.

 

Image of an IV piggyback hanging from a pole with a hand adjusting the roller clamp.

https://opentextbc.ca/clinicalskills/wp-content/uploads/sites/82/2015/09/Sept-22-2015-093.jpg    Retrieved 6/12/19

 

The illustration above shows a nurse adjusting an IV fluid infusion by gravity.  The nurse watches the drip chamber and uses the roller clamp to adjust the flow rate.  Note the label on the IV line.  It records the date, time, and nurse who opened the IV set and put it into use.  Always check your client’s IV insertion site (see illustration below) when you’re working with IV fluids.  The site should be clean and not reddened or swollen.

 

Image of an IV catheter in a patient's hand.

https://media.npr.org/assets/img/2012/10/09/istock_000010478250xsmall-e6365ddf295d1e7f1e6a2d664c9669ba931795ac-s6-c30.jpg    Retrieved 6/12/19

 

You’ll need to know the drop factor for the IV set in order to calculate the drops per minute to give for a gravity infusion.  The package of the infusion set will show the drop factor.  In this module, we will use common macrodrip factors: 10 gtt/ml, 15 gtt/ml, and 20 gtt/ml.  The set illustrated below has a drop factor of 20 gtt/ml.

 

Image of a disposable infusion set (IV tubing). On the right side it indicates that the drop factor for the tubing is 20 drops per milliliter.

sc01.alicdn.com/kf/UT8qz9bXuRXXXagOFbXb/226098527/UT8qz9bXuRXXXagOFbXb.jpg    Retrieved 6/12/1

 

Image of an infusion pump. The lighted screen indicates that a rate of 20 milliliters per hour has been set on the pump. The volume to infuse is set at 9999 milliliters. That amount of fluid that has been infused is 0 milliliters.

www.elbadrmedical.com/images/Products/Shenke/6001.jpg   Retrieved 6/10/19

 

In a hospital setting, an IV pump is generally used.  An example is shown above.  You’ll notice that the nurse will need to enter the rate of infusion in ml/hr and the total amount to be infused.  The pump will also show the amount already infused at the bottom of the display.  There is also a battery indicator in case the client is well enough to unplug the pump and get out of bed or chair.

 

Image of IV tubing for an infusion pump. The difference is that the tubing has a fluid chamber instead of a roller clamp.

https://www.wolfmed.com/media/catalog/product/cache/1/image/560x/040ec09b1e35df139433887a97daa66f/C/A/CADD217357_2.jpg

Retrieved 6/10/19

 

The illustration above shows an IV set for a pump.  The blue and white cartridge on the left is inserted in the pump and allows the pump to control the flow of the IV fluid.  The area in which the cartridge is installed is often behind a door that closes to keep it secure.  Each pump manufacturer will have slightly different sets that work with their own pumps. 

 

Image of an infusion pump. The fluid cartridge has been inserted into a chamber on the left side of the pump. On the right side of the pump are the controls to control the rate and the screen where the rate of infusion and volume to be infused will be displayed.

https://i.ytimg.com/vi/J9I1dg7OIZ0/maxresdefault.jpg   Retrieved 6/10/19

 

In the illustration above, the installation of the cartridge in the pump is visible.  The nurse is starting to program the pump.

 

Image of a patient in a bed with an infusion pump on a pole next to the bed. A nurse is programming the pump.

https://www.bd.com/assets/images/our-products/infusion/alaris-pump-module_1_IF_0214_0225.png   Retrieved 6/10/19

 

The nurse can use the pump to change the flow rate or amount to be infused as needed.  This is important when changing bags when they are empty or when prescriptions have changed.

 

Image of a patient's hand with an IV catheter inserted and tubing connected. A nurse has connected a syringe to the tubing and is injecting medication into the tubing.

www.cwladis.com/math104/bolus.jpg   Retrieved 6/10/19

 

The nurse can also use the injection port in the IV tubing to give IV medication that does not need to be given mixed into a fluid bag.  This method of drug administration is called an IV bolus.  The amount of medication to administer is calculated using the same methodology you used to calculate the ml to give in any other injection.  The medication may contain restrictions on administration time such as “give over 5 minutes” to make certain that it is not given too quickly.

 

Problem Type 1:  IV Infusions Delivered by a Pump

 

Your answer for this type of problem will be the ml/hr to which the nurse will adjust the flow of IV fluid. The nurse will use the IV pump to adjust the flow by entering the total quantity to be infused and the correct flow rate into the pump.

To solve these problems, you will need the amount of fluid and the time for infusion of the fluid.

The SF for these problems is 1 hour.  The AU is mL (per hour).  The answer will be rounded to a whole number.

 

Example 1:

A nurse is caring for a client who has a new prescription for IV fluids.  The prescription is 1000 mL D5NS IV over 10 hours.

Here’s the problem set up in the dimensional analysis format:

SF = 1 hour

AU = mL

Equivalents:

1000 mL = 10 hr

Equation for the flow rate:

The equation is 1 hour over 1 times 1000 milliliters over 10 hours. When solved, the flow rate is 100 milliliters per hour.

Example 2:

A nurse is caring for a client who has a new prescription for IV fluids containing medication.  The prescription is 250 mL LR IV over 2 hours. 

The medication added does not affect the setup of the problem.

Here’s the problem set up in the dimensional analysis format:

SF = 1 hour

AU = mL

Equivalents:

250 mL = 2 hr

Equation for the flow rate:

       The equation is 1 hour over 1 times 250 milliliters over 2 hours. When solved, the flow rate is 125 milliliters per hour.         

 

Problem Type 2: IV Infusions Delivered by Gravity

 

Your answer for this type of problem will be the gtst/min to which the nurse will adjust the flow of IV fluid. The nurse will use the roller clamp to adjust the flow while watching the drops fall into the drip chamber of the IV set.

To solve these problems, you will need the amount of fluid, the time for infusion of the fluid, and the drop factor of the IV set the nurse is using.

The SF for these problems is 1 minute.  The AU is drops (per minute).  The answer will be rounded to a whole number.

 

Example 1:

Your client has a prescription for NS 1000 mL IV over 9 hours.  The drop factor of the IV tubing is 20 gtts/mL.  How many gtts/min will be given in this gravity infusion?

Here’s the problem set up in the dimensional analysis format:

SF = 1 min

AU = gtts

Equivalents:

60 min = 1 hr 

1000 mL = 9 hrs

20 gtts = 1 mL

Equation for the rate in gtts:

      The equation is 1 minute over 1 times 1 hour over 60 minutes times 1000 milliliters over 9 hours times 20 drops over 1 milliliter. After crossing out the like units, the equation ends with drops. The solution of the problem is 37.03 which rounds to 37 drops for a flow rate of 37 drops per minute.

The flow rate is 37 gtts/min.

 

Example 2:

Your client has a new prescription for LR 1000 mL IV.  The fluid is to be infused at 125 mL per hour.  The drop factor of the IV tubing is 15 gtts/mL.  How many gtts/min will be given in this gravity infusion?

Here’s the problem set up in the dimensional analysis format:

SF = 1 min

AU = gtts

Equivalents:

60 min = 1 hr 

125 mL = 1 hr

15 gtt = 1 mL

Equation for the rate in gtt:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 125 milliliters over 1 hour times 15 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. The solution to the equation is 31.2 which rounds to 31 drops for a flow rate of 31 drops per minute.

The flow rate is 31 gtts/min.

 

Problem Type 3:  Time to Complete IV Infusion by Gravity

 

Your answer for this type of problem will be the hours and minutes required to infuse a given amount of IV fluid by gravity.

To solve these problems, you will need the amount of fluid, the drop factor for the IV tubing (gtts/ml), and the flow rate for infusion of the fluid (gtts/min).

The SF for these problems is the amount of fluid to be infused.  The AU is the hours required for the infusion.  One additional step is required to convert partial hours into minutes. Do not round the number of hours you calculate the number of minutes. In your final answer, the number of minutes will be rounded to a whole number.

 

Example 1:

A nurse is caring for a client who has a new prescription for IV fluids.  The prescription is 1000 mL D5NS IV.  The flow rate is 30 gtts/min and the drop factor is 20 gtts/ml.

Here’s the problem set up in the dimensional analysis format:

SF = 1000 mL

AU = hrs

Equivalents:

20 gtts = 1 mL

30 gtts = 1 min

60 min = 1 hour

Equation for the dose in ml:

The equation is 1000 milliliters over 1 times 20 drops over 1 milliliter times 1 minute over 30 drops times 1 hour over 60 minutes. After the like units are cancelled, the remaining unit is hour. When the equation is solved, the answer is 11.111 hours. Do not round at this point.

Convert 0.111 hours to minutes:

    60 min  X  0.111 portion of an hour  =  6.66 min  =  7 mins

Final answer:  11 hours 7 mins  (time to infuse)

 

Example 2:            

A nurse is caring for a client who has a new prescription for IV fluids.  The prescription is 500 mL NS IV.  The flow rate is 40 gtts/min and the drop factor is 15 gtts/mL.

Here’s the problem set up in the dimensional analysis format:

SF = 500 mL

AU = hrs

Equivalents:

15 gtts = 1 mL

40 gtts = 1 min

60 min = 1 hour

Equation for the dose in ml:

The equation is 500 milliliters over 1 times 15 drops over 1 milliliter times 1 minute over 40 drops times 1 hour over 60 minutes. After like units are cancelled, the remaining unit is hour. The solution of the equation is 3.125 hours. Do not round at this point.

Convert 0.125 hours to minutes:

    60 min  X  0.125 portion of an hour  =  7.5  =  8 mins

Final answer:  3 hours 8 mins (time to infuse)

 

Problem Type 4:  Adjusted Flow Rate for IV Infusion by Gravity

 

Your answer for this type of problem will be the gtts/min to which the nurse will adjust the flow of IV fluid. The nurse will use the roller clamp to adjust the flow while watching the drops fall into the drip chamber of the IV set.

To solve these problems, you will need the amount of fluid, the time for infusion of the fluid, and the drop factor of the IV set the nurse is using.

The SF for these problems is 1 minute.  The AU is drops (per minute).  The answer will be rounded to a whole number.

 

Example 1:

A client is receiving 1000 mL NS IV over 10 hours, infused by gravity.  The drop factor of the IV set is 20 gtt/mL.  What is the initial flow rate in gtts/min?

Here’s the problem set up in the dimensional analysis format:

SF = 1 min

AU = gtts

Equivalents:

1000 mL = 10 hrs

20 gtts = 1 mL

60 mins = 1 hr

Equation for the rate in gtts:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 1000 milliliters over 10 hours times 20 drops over 1 milliliter. After like units are cancelled, the unit remaining is hour. When the equation is solved, the answer is 33.3 which rounds to 33 drops per minute.

The initial flow rate is 33 gtts/min.

The nurse reassesses the flow rate of the IV fluid after 4 hours.  The amount of NS remaining in the bag is 700 mL.  The fluid should be flowing at 100 mL/hr.  After 4 hours, 600 mL should remain in the bag.  The nurse will need to adjust the flow rate.  What is the new flow rate in gtts/min?

Equation for the new rate in gtts:

10 hrs total time – 4 hrs time elapsed = 6 hours remaining

700 mL fluid remaining

The equation is 1 minute over 1 times 1 hour over 60 minutes times 700 milliliters over 6 hours times 20 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. When the equation is solved, the answer is 33.8 which rounds to 39 drops for a flow rate of 39 drops per minute.

The adjusted flow rate is 39 gtts/min.

 

Example 2:

A client is receiving 500 mL LR IV over 3 hours, infused by gravity.  The drop factor of the IV set is 15 gtts/mL.  What is the initial flow rate in gtts/min?

Here’s the problem set up in the dimensional analysis format:

SF = 1 min

AU = gtts

Equivalents:

60 min = 1 hr 

500 mL = 3 hrs

15 gtts = 1 mL

Equation for the rate in gtts:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 500 milliliters over 3 hours times 15 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. When the equation is solved, the answer is 41.6 which rounds to 42 drops for a flow rate of 42 drops per minute.

The initial flow rate is 42 gtts/min.

The nurse reassesses the flow rate of the IV fluid after 1 hour.  The amount of LR remaining in the bag is 250 ml.  The nurse will need to adjust the flow rate.  What is the new flow rate in gtts/min?

Equation for the new rate in gtts:

3 hrs total time – 1 hr time elapsed = 2 hours remaining

250 mL fluid remaining

The equation is 1 minute over 1 times 1 hour over 60 minutes times 250 milliliters over 2 hours times 15 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. When the equation is solved, the answer is 31.2 which rounds to 31 drops for a flow rate of 31 drops per minute.

The adjusted flow rate is 31 gtts/min.

 

Practice Problems

Module 7 Practice Problems

 

IV Infusions Delivered by a Pump

  1. A nurse working on a hospital medical unit has a client on IV fluids.  The healthcare provider has written a new prescription for 1500 mL D5W IV over 12 hours.  What flow rate in mL/hr will the nurse set on the IV pump?

  1.  A hospitalized client has a new prescription for 500 mL NS IV over 3 hours.  What flow rate in mL/hr will the nurse set on the IV pump?

  1. Your client has a prescription for Zosyn 3.375 g in 250 mL NS IV over 2.5 hours four times daily.  What flow rate in mL/hr will you set on the IV pump?

  1.  Your client has a prescription for 1000 mL LR IV over 8 hours.  What flow rate in mL/hr will you set on the IV pump?

  1. A hospitalized client has a new prescription for 2000 mL NS IV over 24 hours.  What flow rate in mL/hr will the nurse set on the IV pump?

  1.  A nurse working on a hospital medical unit has a client on IV fluids.  The healthcare provider has written a new prescription for moxifloxacin 400 mg in 1000 mL D5W IV over 9 hours daily for 14 days.  What flow rate in mL/hr will the nurse set on the IV pump?

 

IV Infusions Delivered by Gravity

  1. Your adult medical client has a new prescription for NS 1000 mL IV to infuse over 8 hours.  The drop factor of your IV set is 20 gtts/mL.  What is your flow rate in gtts/min? 

  1. The IV tubing for your client in problem 7 is now 4 days old and must be changed according to your hospital’s procedures.  Your new IV set has a drop factor of 10 gtts/mL.  You are starting a new bag of NS 1000 mL.  What is your flow rate in gtts/min? 

  1. A client has a new prescription for D5W 1000 mL IV to be given over 6 hours.  The drop factor of your IV set is 20 gtts/mL.  What is your flow rate in gtts/min? 

  1. A client has a prescription for 500 mL of NS to be given over 2 hours to deliver a medication.  The drop factor of your IV set is 15 gtts/mL.  What is your flow rate in gtts/min? 

  1. A client has a prescription for 250 mL of NS to be given over 1 hour to deliver a medication.  The drop factor of your IV set is 15 gtts/mL.  What is your flow rate in gtts/min? 

  1. A client has a prescription for LR 1000 mL IV to be delivered at the rate of 125 mL per hour.  The drop factor of your IV set is 15 gtts/mL.  What is your flow rate in gtts/min? 

  1. A client has a prescription for D5W 300 mL IV to be delivered at the rate of 100 mL per hour.  The drop factor of your IV set is 20 gtts/mL.  What is your flow rate in gtts/min? 

  1.  A client has a prescription for LR 500 mL IV to be delivered at the rate of 75 mL per hour.  The drop factor of your IV set is 20 gtts/mL.  What is your flow rate in gtts/min? 

 

 Time to Complete IV Infusion by Gravity

  1.  Your client has a prescription for 1000 mL NS IV.  You will need to use the gravity method of infusion.  Your IV tubing set has a drop factor of 20 gtts/mL.  You will use an infusion rate of 20 gtts/min.  What is the infusion time for the IV fluid in hours and minutes?

  1.  A nurse is administering 1500 mL D5W IV to a client by gravity using a rate of 40 gtts/min.  The IV tubing has a drop factor of 15 gtts/mL.   What is the infusion time for the IV fluid in hours and minutes?

  1.  A nurse is administering medication in 500 mL NS IV to a client by gravity using a rate of 35 gtts/min.  The IV tubing has a drop factor of 20 gtts/mL.   What is the infusion time for the IV fluid in hours and minutes?

  1.  Your client has a prescription for 1000 mL NS IV.  You will need to use the gravity method of infusion.  Your IV tubing set has a drop factor of 15 gtts/mL.  You will use an infusion rate of 20 gtts/min.  What is the infusion time for the IV fluid in hours and minutes?

  1.  A nurse is administering medication in 1000 mL LR IV to a client by gravity using a rate of 20 gtts/min.  The IV tubing has a drop factor of 10 gtts/mL.   What is the infusion time for the IV fluid in hours and minutes?

  1. A nurse is administering medication in 1000 mL NS IV to a client by gravity using a rate of 30 gtts/min.  The IV tubing has a drop factor of 20 gtts/mL.   What is the infusion time for the IV fluid in hours and minutes?

 

Adjusted Time to Complete IV Infusion by Gravity

  1.  A client is receiving 1000 mL D5W IV over 8 hours.  The IV tubing drop factor is 20 gtts/mL.  What is the initial flow rate in gtts/min?  The nurse reassesses the IV fluid after 3 hours and finds that 800 mL remain in the bag.   What would be the adjusted flow rate for the fluid in gtts/min? 

  1.  Your client is receiving 1000 mL NS IV over 8 hours.  The drop factor of your IV set is 15 gtts/mL.   What is the initial flow rate of the IV fluid?  You reassess the IV fluid after 2 hours and find 700 mL remaining in the bag.  What would be the adjusted flow rate for the fluid in gtts/min? 

  1.  A client is receiving 750 mL NS IV containing an antibiotic.  The fluid is to infuse over 6 hours.  The drop factor of your IV set is 10 gtts/mL.  What is the initial flow rate of the IV fluid?  You reassess the IV fluid after 2 hours and find 600 mL remaining in the bag.  What would be the adjusted flow rate for the fluid in gtts/min? 

  1.  Your client is receiving 1000 mL LR IV over 8 hours.  The drop factor of your IV set is 20 gtts/mL.   What is the initial flow rate of the IV fluid?  You reassess the IV fluid after 2 hours and find 625 mL remaining in the bag.  What would be the adjusted flow rate for the fluid in gtts/min?  

  1.  A client is receiving 500 mL NS IV containing an antibiotic.  The fluid is to infuse over 3 hours.  The drop factor of your IV set is 15 gtts/ml.  What is the initial flow rate of the IV fluid?  You reassess the IV fluid after 1 hour and find 400 mL remaining in the bag.  What would be the adjusted flow rate for the fluid in gtts/min? 

Answers to Practice Problems

Module 7 Practice Problems

 

IV Infusions Delivered by a Pump

  1. A nurse working on a hospital medical unit has a client on IV fluids.  The healthcare provider has written a new prescription for 1500 mL D5W IV over 12 hours.  What flow rate in mL/hr will the nurse set on the IV pump?

 

SF = 1 hr

AU = mL

Equivalent(s) needed:

1500 mL = 12 hrs

Equation:

The equation is 1 hour over 1 times 1500 milliliters over 12 hours. After cancelling hour, the remaining unit is mL. When the equation is solved, the answer is 125 milliliters for a flow rate of 125 milliliters per hour.

 

  1.  A hospitalized client has a new prescription for 500 mL NS IV over 3 hours.  What flow rate in mL/hr will the nurse set on the IV pump?

 

SF = 1 hr

AU = mL

Equivalent(s) needed:

500 mL = 3 hrs

Equation:

The equation is 1 hour over 1 times 500 milliliters over 3 hours. After the unit hour is cancelled, the remaining unit is milliliter. When the equation is solved, the answer is 166.6 which rounds to 167 milliliters for  flow rate of 167 milliliters per hour.

 

  1. Your client has a prescription for Zosyn 3.375 g in 250 mL NS IV over 2.5 hours four times daily.  What flow rate in mL/hr will you set on the IV pump?

 

SF = 1 hr

AU = mL

Equivalent(s) needed:

250 mL = 2.5 hrs

Equation:

The equation is 1 hour over 1 times 250 milliliters over 2.5 hours. After you cancel the unit hour, the remaining unit is milliliter. When the equation is solved, the answer is 100 milliliters for a flow rate of 100 milliliters per hour.

 

  1.  Your client has a prescription for 1000 mL LR IV over 8 hours.  What flow rate in mL/hr will you set on the IV pump?

 

SF = 1 hr

AU = mL

Equivalent(s) needed:

1000 mL = 8 hrs

Equation:

The equation is 1 hour over 1 times 1000 milliliters over 8 hours. After the unit hour is cancelled, the remaining unit is milliliter. When the equation is solved, the answer is 125 milliliters for a flow rate of 125 milliliters per hour.

 

  1. A hospitalized client has a new prescription for 2000 mL NS IV over 24 hours.  What flow rate in mL/hr will the nurse set on the IV pump?

 

SF = 1 hr

AU = mL

Equivalent(s) needed:

2000 mL = 24 hrs

Equation:

The equation is 1 hour over 1 times 2000 milliliters over 24 hours. After the unit hour is cancelled, the remaining unit is milliliter. When the equation is solved, the answer is 83.3 which rounds to 83 milliliters for a flow rate of 83 milliliters per hour.

 

  1.  A nurse working on a hospital medical unit has a client on IV fluids.  The healthcare provider has written a new prescription for moxifloxacin 400 mg in 1000 mL D5W IV over 9 hours daily for 14 days.  What flow rate in mL/hr will the nurse set on the IV pump?

 

SF = 1 hr

AU = mL

Equivalent(s) needed:

1000 mL = 9 hrs

Equation:

 

 

IV Infusions Delivered by Gravity

  1. Your adult medical client has a new prescription for NS 1000 mL IV to infuse over 8 hours.  The drop factor of your IV set is 20 gtts/mL.  What is your flow rate in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

1000 mL = 8 hrs

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 1000 milliliters over 8 hours times 20 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. When the equation is solved, the answer is 41.6 which rounds to 42 drops for a flow rate of 42 drops per minute.

 

  1. The IV tubing for your client in problem 7 is now 4 days old and must be changed according to your hospital’s procedures.  Your new IV set has a drop factor of 10 gtts/mL.  You are starting a new bag of NS 1000 mL.  What is your flow rate in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

1000 mL = 8 hrs

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 1000 milliliters over 8 hours times 10 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 20.8 which rounds to 21 drops for a flow rate of 21 drops per minute.

 

  1. A client has a new prescription for D5W 1000 mL IV to be given over 6 hours.  The drop factor of your IV set is 20 gtts/mL.  What is your flow rate in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

1000 mL = 6 hrs

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 1000 milliliters over 6 hours times 20 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. When the equation is solved, the answer is 55.5 which rounds to 56 drops for a flow rate of 56 drops per minute.

 

  1. A client has a prescription for 500 mL of NS to be given over 2 hours to deliver a medication.  The drop factor of your IV set is 15 gtts/mL.  What is your flow rate in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

500 mL = 2 hrs

15 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 500 milliliters over 2 hours times 15 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. When the equation is solved, the answer is 62.5 which rounds to 63 drops for a flow rate of 63 drops per minute.

 

  1. A client has a prescription for 250 mL of NS to be given over 1 hour to deliver a medication.  The drop factor of your IV set is 15 gtts/mL.  What is your flow rate in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

250 mL = 1 hr

15 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 150 milliliters over 1 hour times 15 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. When the equation is solved, the answer is 62.5 which rounds to 63 drops for a flow rate of 63 drops per minute.

 

  1. A client has a prescription for LR 1000 mL IV to be delivered at the rate of 125 mL per hour.  The drop factor of your IV set is 15 gtts/mL.  What is your flow rate in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

125 mL = 1 hr

15 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 125 milliliters over 1 hour times 15 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 31.2 which rounds to 31 drops for a flow rate of 31 drops per minute.

 

  1. A client has a prescription for D5W 300 mL IV to be delivered at the rate of 100 mL per hour.  The drop factor of your IV set is 20 gtts/mL.  What is your flow rate in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

100 mL = 1 hr

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 100 milliliters over 1 hour times 20 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 33.3 which rounds to 33 drops for a flow rate of 33 drops per minute.

 

  1.  A client has a prescription for LR 500 mL IV to be delivered at the rate of 75 mL per hour.  The drop factor of your IV set is 20 gtts/mL.  What is your flow rate in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

75 mL = 1 hr

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1 minute over 1 times 1 hour over 60 minutes times 75 milliliters over 1 hour times 20 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 25 drops for a flow rate of 25 drops per minute.

 

 Time to Complete IV Infusion by Gravity

  1.  Your client has a prescription for 1000 mL NS IV.  You will need to use the gravity method of infusion.  Your IV tubing set has a drop factor of 20 gtts/mL.  You will use an infusion rate of 20 gtts/min.  What is the infusion time for the IV fluid in hours and minutes?

 

SF = 1000 mL

AU = hrs

Equivalent(s) needed:

20 gtts = 1 min

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1000 milliliters over 1 times 20 drops over 1 milliliters times 1 minute over 20 drops times 1 hour over 60 minutes. After cancelling like units, the remaining unit is hour. When the equation is solved, the answer is 16.666 hours. Do not round at this point. Convert the partial hour to minutes by multiplying 0.666 times 60 to get 39.96 which rounds to 40 mins. The final answer is 16 hours 40 minutes.

 

  1.  A nurse is administering 1500 mL D5W IV to a client by gravity using a rate of 40 gtts/min.  The IV tubing has a drop factor of 15 gtts/mL.   What is the infusion time for the IV fluid in hours and minutes?

 

SF = 1500 mL

AU = hrs

Equivalent(s) needed:

40 gtts = 1 min

15 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1500 milliliters over 1 times 15 drops over 1 milliliter times 1 minute over 40 drops times 1 hour over 60 minutes. After cancelling like units, the remaining unit is hour. When the equation is solved, the answer is 9.375 hours. Do not round at this point. Convert the partial hour to minutes by multiplying 0.375 times 60 to get 22.5 which rounds to 23 mins. The final answer is 9 hours 23 minutes.

 

  1.  A nurse is administering medication in 500 mL NS IV to a client by gravity using a rate of 35 gtts/min.  The IV tubing has a drop factor of 20 gtts/mL.   What is the infusion time for the IV fluid in hours and minutes?

 

SF = 500 mL

AU = hrs

Equivalent(s) needed:

35 gtts = 1 min

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 500 milliliters over 1 times 20 drops over 1 milliliter times 1 minute over 35 drops times 1 hour over 60 minutes. After cancelling like units, the remaining unit is hour. When the equation is solved, the answer is 4.761 hours. Do not round at this point. Convert the partial hour to minutes by multiplying 0.761 times 60 to get 45.66 which rounds to 46 minutes. The final answer is 4 hours 46 minutes.

 

  1.  Your client has a prescription for 1000 mL NS IV.  You will need to use the gravity method of infusion.  Your IV tubing set has a drop factor of 15 gtts/mL.  You will use an infusion rate of 20 gtts/min.  What is the infusion time for the IV fluid in hours and minutes?

 

SF = 1000 mL

AU = hrs

Equivalent(s) needed:

20 gtts = 1 min

15 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1000 milliliters over 1 times 15 drops over 1 milliliter times 1 minute over 20 drops times 1 hour over 60 minutes. After cancelling like units, the remaining unit is hour. When the equation is solved, the answer is 12.5 hours. Do not round at this point. Convert the partial hour to minutes by multiplying 0.5 times 60 to get 30 minutes. The final answer is 12 hours 30 minutes.

 

  1.  A nurse is administering medication in 1000 mL LR IV to a client by gravity using a rate of 20 gtts/min.  The IV tubing has a drop factor of 10 gtts/mL.   What is the infusion time for the IV fluid in hours and minutes?

 

SF = 1000 mL

AU = hrs

Equivalent(s) needed:

20 gtts = 1 min

10 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1000 milliliters over 1 times 10 drops over 1 milliliter times 1 minute over 20 drops times 1 hour over 60 minutes. After cancelling like units, the remaining unit is hour. When the equation is solved, the answer is 8.333 hours. Do not round at this point. Conver the partial hour to minutes by multiplying 0.333 times 60 to get 19.98 which rounds to 20 minutes. The final answer is 8 hours 20 minutes.

 

  1. A nurse is administering medication in 1000 mL NS IV to a client by gravity using a rate of 30 gtts/min.  The IV tubing has a drop factor of 20 gtts/mL.   What is the infusion time for the IV fluid in hours and minutes?

 

SF = 1000 mL

AU = hrs

Equivalent(s) needed:

30 gtts = 1 min

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation is 1000 milliliters over 1 times 20 drops over 1 milliliter times 1 minute over 30 drops times 1 hour over 60 minutes. After cancelling like units, the remaining unit is hour. When the equation is solved, the answer is 11.111 hours. Do not round at this point. Convert the partial hour to minutes by multiplying 0.111 times 60 to get 6.66 which rounds to 7 minutes. The final answer is 11 hours 7 minutes.

 

Adjusted Time to Complete IV Infusion by Gravity

  1.  A client is receiving 1000 mL D5W IV over 8 hours.  The IV tubing drop factor is 20 gtts/mL.  What is the initial flow rate in gtts/min?  The nurse reassesses the IV fluid after 3 hours and finds that 800 mL remain in the bag.   What would be the adjusted flow rate for the fluid in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

1000 mL = 8 hours

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation for the intial flow rate is 1 minute over 1 times 1 hour over 60 minutes times 1000 milliliters over 8 hours times 20 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 41.6 which rounds to 42 drops for a flow rate of 42 drops per minute. Three hours later there is 800 milliliters remaining. There are 5 hours remaining to the infusion time. The equation for the adjusted flow rate is 1 minute over 1 times 1 hour over 60 minutes times 800 milliliters over 5 hours times 20 drops over 1 milliliter. After cancelling like units, the remaining unit drops. When the equation is solved, the answer is 53.3 which rounds to 53 drops for a flow rate of 53 drops per minute.

 

  1.  Your client is receiving 1000 mL NS IV over 8 hours.  The drop factor of your IV set is 15 gtts/mL.   What is the initial flow rate of the IV fluid?  You reassess the IV fluid after 2 hours and find 700 mL remaining in the bag.  What would be the adjusted flow rate for the fluid in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

1000 mL = 8 hours

15 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation for the initial flow rate is 1 minute over 1 times 1 hour over 60 minutes times 1000 milliliters over 8 hours times 15 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 31.2 which rounds to 31 drops for a flow rate of 31 drops per minute. After 2 hours, there are 700 milliliters remaining. There are 6 hours remaining of the infusion time. The equation for the adjusted flow rate is 1 minute over 1 times 1 hour over 60 minutes times 700 milliliters over 6 hours times 15 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 29.1 which rounds to 29 drops for a flow rate of 29 drops per minute.

 

  1.  A client is receiving 750 mL NS IV containing an antibiotic.  The fluid is to infuse over 6 hours.  The drop factor of your IV set is 10 gtts/mL.  What is the initial flow rate of the IV fluid?  You reassess the IV fluid after 2 hours and find 600 mL remaining in the bag.  What would be the adjusted flow rate for the fluid in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

750 mL = 6 hours

10 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation for the initial flow rate is 1 minute over 1 times 1 hour over 60 minutes times 750 milliliters over 6 hours times 10 drops over 1 milliliter. After like units are cancelled, the remaining unit is drops. When the equation is solved, the answer is 20.8 which rounds to 21 drops for a flow rate of 21 drops per minute. After 2 hours, there are 600 milliliters remaining. There are 4 hours left of the infusion time. The equation for the adjusted flow rate is 1 minute over 1 times 1 hour over 60 minutes times 600 milliliters over 4 hours times 10 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 25 drops for a flow rate of 25 drops per minute.

 

  1.  Your client is receiving 1000 mL LR IV over 8 hours.  The drop factor of your IV set is 20 gtts/mL.   What is the initial flow rate of the IV fluid?  You reassess the IV fluid after 2 hours and find 625 mL remaining in the bag.  What would be the adjusted flow rate for the fluid in gtts/min?  

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

1000 mL = 8 hours

20 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation for the initial flow rate is 1 minute over 1 times 1 hour over 60 minutes times 1000 milliliters over 8 hours times 20 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 41.6 which rounds to 42 drops for a flow rate of 42 drops per minute. After 2 hours, there are 625 milliliters remaining. There are 6 hours left of the infusion time. The equation for the adjusted flow rate is 1 minute over 1 times 1 hour over 60 minutes times 625 milliliters over 6 hours times 20 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 34.7 which rounds to 35 drops for a flow rate of 35 drops per minute.

 

  1.  A client is receiving 500 mL NS IV containing an antibiotic.  The fluid is to infuse over 3 hours.  The drop factor of your IV set is 15 gtts/ml.  What is the initial flow rate of the IV fluid?  You reassess the IV fluid after 1 hour and find 400 mL remaining in the bag.  What would be the adjusted flow rate for the fluid in gtts/min? 

 

SF = 1 min

AU = gtts

Equivalent(s) needed:

500 mL = 3 hours

15 gtts = 1 mL

1 hr = 60 mins

Equation:

The equation for the initial flow rate is 1 minute over 1 times 1 hour over 60 mins times 500 milliliters over 3 hours times 15 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 41.6 which rounds to 42 drops for a flow rate of 42 drops per minute. After 1 hour, there are 400 milliliters remaining. There are 2 hours left of the infusion time. The equation for the adjusted flow rate is 1 minute over 1 times 1 hour over 60 minutes times 400 milliliters over 2 hours times 15 drops over 1 milliliter. After cancelling like units, the remaining unit is drops. When the equation is solved, the answer is 50 drops for a flow rate of 50 drops per minute.

 

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