Flush the catheter

In some cases, it may be necessary to flush the indwelling catheter. This should only be done if you think it is necessary to restore flow. The reason may be the viscosity of the pleural effusion or ascites.

Information about flushing the catheter

You do not need to flush the catheter as a preventative measure. The suction in the vacuum bottles usually prevents the catheter from clogging. This is because the vacuum sucks out any particles stuck in the catheter. Do this if the catheter still gets blocked:

  1. Consider the option that there is no fluid.
  2. If you think there is liquid and if bags have been used for drainage, first try using a vacuum bottle to get rid of any particles.
  3. If there is no flow in the bottle, you can flush the catheter using sterile saline solution, see instructions below.

Only doctors, or nurses on doctor’s orders, are allowed to flush the catheter and aseptic technique is used.

If the fluid does not start to drain after flushing, the patient should be X-rayed to see what is causing it (compartmentalisation or lack of fluid).

Necessary material


1 | Connect the 3-way tap with the syringe containing NaCl 0.9% to the flushing line. Then fill the entire flushing line with 0.9% NaCl to remove the air.

2 | Remove the cap from the catheter and discard it.

3 | Disinfect the safety valve.

4 | Connect the flushing line to the safety valve on the catheter and flush with 0.9% NaCl. Then aspirate to see if the fluid starts to drain.

5 | Disconnect the flushing line with accessories from the catheter safety valve. Then drain the liquid using a drainage kit (or drainage bag/bottle) according to the instructions.

6 | Disinfect the safety valve.

7 | Put on a new cap.

Do you have any questions?

Here are some of our frequently asked questions.