Beginning IV Therapy and Flow Rate/ Learn
Elizabeth Bodman, Austin Community College
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IV Tubing

In order to connect an IV bag to a patient, tubing must be attached to the bag which is then attached to the catheter in the patient's vein. The IV bags do not come with tubing already connected. You will need to select both the bag and the tubing and assemble them.

Main IV Bag and IV Tubing
Main IV Bag and IV Tubing

Now look at the picture below, noticing the labeled items. We're going to investigate what each of these are.

Play video of roller clamp adjusting flow rate.

 

Press play to view the video of slide

 

The clamps on the tubing control the rate of flow for the fluid. The roller clamp will adjust the flow rate from a very slow rate to a "wide open" flow rate. The slide clamp, on the other hand, is used as an "on-off" switch. It provides an extra degree of safety if you want to be sure no fluid is moving in the IV tubing.

The drip chamber is part of any IV tubing which allows visual inspection of fluid movement. Drops (gtts)of fluid can be seen falling in the drip chamber, which allows you to actually to see how fast or slow the fluid is moving. Remember you can control this rate of flow with your roller clamp. The drip chambers are purposely manufactured to allow a specific size of drop to fall; some tubing allows small drops (gtts)to fall, while others allow larger drops (gtts)to fall. The manufacturer must label the IV tubing to tell you the size of the drops for that set of tubing. The difference in the size of the drops is always expressed in terms of how many drops it takes to equal 1 mL of fluid. This is the drop factor.

Examples of how the drop factor is expressed:

  • 60gtts/mL, meaning 60 small drops must fall in the drip chamber before 1 mL of fluid has moved through the tubing and into the patient.
  • 15gtts/mL meaning only 15 drops must fall before 1 mL of fluid has moved into the patient.
  • Drop factor is 10: this means that 10 drops must fall to equal on milliliter.

Because the drop factor is ALWAYS expressed in terms of how many drops equals one milliliter, the "one milliliter" may not actually be stated. For any IV tubing, you can never guess at the drop factor. You must always read this information as it is given by the manufacturer.

IV Tubing
IV Tubing

The drop factor is critical to know any time you must calculate a flow rate for an IV in gtts/minute. If you know how many drops equal one milliliter, and you count how many drops fall in a minute, you will know how much fluid -how many mLs of fluid the patient has received in one minute.

Next you'll view some simple IV orders and answer the questions about the orders.

 

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