Ultrasonic Cleaning of Surgical Instruments
Most surgical instrument suppliers recommend using an ultrasonic cleaner to remove contaminants after surgery. Following is a standard step-by step procedure, along with a rough explanation of how the process works…
Ultrasonic cleaning works by creating and then imploding millions of microscopic bubbles inside the ultrasonic tank – this process, known as cavitation, releases a tremendous amount of kinetic energy. The fact that the frequencies involved are so high (normally 40-45 kHz) means that the wavefront is small, and that we can remove very tiny particles, and clean out crevices that would be impossible to reach manually.
This is especially important when we are dealing with instruments that have hinges, clasps, serrations or other detailed parts.
A typical procedure for cleaning instruments using ultrasonics follows:
1. Prepare the ultrasonic tank properly. This means that it is up to temperature and fully degassed*.
2. Ensure that you are using the right chemical and concentration for your instruments.
3. Rinse off the instruments with warm water.
4. To avoid the possibility of a chemical reaction, do not place dissimilar metals into the cleaner at the same time. Do not use ultrasonic on chrome plated instruments.
5. Ensure that ‘sharps” are positioned so that they do not touch other instruments.
6. Make sure that anything that “opens” like hemostats or scissors is opened to allow the ultrasonic energy full access, and that everything is completely submerged.
7. Ensure that each item is completely “wetted” inside and out. Your may have to re-position long tubular instruments to ensure complete interior wetting.
8. Change the cleaning solution frequently, and remember that is must be degassed after you do, to eliminate trapped gases that interfere with cleaning.
9. Instruments should be thoroughly rinsed post cleaning to remove ultrasonic cleaning solution residue.
10. When you are finished, you should drain, clean, and rinse out the inside of the tank.
Recommended ultrasonic tank is the Branson PC620. The long narrow tank and high energy ultrasonics lend themselves perfectly to this application.
As in any cleaning activity, you’ll want to check with your facility manager and make sure that you are following the proper procedures with respect to solution disposal.
*Degassing is done each time an ultrasonic tank is filled with fresh solution to eliminate trapped gases in the liquid. The procedure is simple – just run the ultrasonics for about 10 minutes after adding new liquid. You do not have to degas each time you use the cleaner, just when you add new solution.