Flushing an IV Catheter

Your healthcare provider has told you that you need to flush your IV (intravenous) catheter. The exact flush method you use will depend on the type and size of your catheter, your medicine schedule, and your provider's policies and procedures. Also, IV flush methods for infants and children will be different than those for adults. Below is a general guide.

Check with your healthcare provider about how often you need to flush your IV catheter. You may need to flush your IV catheter after each use. Or you may need to flush it once a day if not in use. Some catheters need only weekly flushing when they are not being used. Always follow your healthcare provider's instructions. You will also be told what flush solution to use and how much to use. Usually, the flush solution is normal saline. This often comes in a prefilled syringe. You may also be told to flush your IV catheter with a heparin solution after the second saline flushing. The heparin solution helps keep clots from forming in the catheter.

Step 1. Prepare your supplies

  • Clean your hands with soap and water or alcohol-based hand sanitizer. Do this before you lay out your supplies on the work surface.

  • After cleaning your hands, only touch your supplies. If you do touch anything else, such as furniture or your clothes, clean your hands again. This is very important for preventing infection.

  • Place your supplies on the cleaned and dried work surface. Lay them out in the order you will be using them.

  • Know that you will likely use prefilled syringes that contain saline or heparin. If you are not using prefilled syringes, ask your healthcare team for instructions.

  • Keep syringes capped for now. This keeps the tips germ-free (sterile).

Step 2. Flush the catheter

  • Clean the injection cap on your catheter, using disinfectant wipes or other supplies, as directed by your healthcare team. Using friction, scrub the top, the tip (including the threaded edges), and the sides for 10 to 15 seconds. Then wait for the cap to dry completely (up to 30 seconds). Follow any specific instructions your healthcare team has given.

  • After cleaning the injection cap, don’t touch it. Instead, hold the end of the catheter securely. Make sure the cleaned injection cap doesn’t touch anything. If it does, germs could easily enter your body.

  • Uncap the syringe and remove air bubbles as directed by your healthcare team. If you’re flushing separately with saline and heparin, use the saline solution first.

  • If the tubing above the injection cap is clamped, unclamp it now.

  • Attach the syringe to the injection cap and twist to secure it.

  • Pull back on the syringe plunger and watch for blood to appear in the catheter. This is a sign that the catheter is working correctly. If you don’t see blood moving through the catheter, stop and call your healthcare team right away. (Note: Only check for blood during the first flush. If you’re infusing medicine and then flushing the catheter again, you don’t need to check for blood with the second flush.)

  • Push the plunger in slowly so the solution goes into the catheter. The plunger should be easy to push. If there is resistance, don’t force it. Make sure the syringe is twisted securely into the injection cap and the tubing above the cap is unclamped. If you still feel resistance, stop and call your healthcare team.

  • After injecting the solution, reclamp the tubing (if there is a clamp). Your healthcare team may give you specific instructions about this.

  • If you’re also flushing with heparin, repeat all of Step 2 using the heparin flush.

  • Place any used syringes in the sharps container.

  • Clean your hands again.

When to call your healthcare provider

Call your healthcare provider if you experience any of the following at or near the site where the catheter is inserted:

  • Redness

  • Swelling

  • Soreness

  • Drainage

  • Pain while flushing