What is cavitation when used on surgical instruments.

cavitation and surgical instruments

Cavitation is used to clean in ultrasonic cleaners. What does that even mean, cavitation? 😀

  • Bubbles pop underwater against something a surgical instrument, an implant, a tray.
  • The force of the space of the old bubble closing and filling with water is energy.
  • Then, it creates energy that is both sound and physical against an instrument.
  • The bubble energy does this millions of times in a cycle “micro-scrubbing” instruments clean of bacteria a tiny bubble pop at a time. (Giarrizzo-Wilson)

The first cavitation experiment was in 1894 by Osborn Reynolds. (Eisenberg)

How do you make water boil at room temperature?

Lower the pressure. We know boiling water is hot and with heat creates bubbles that are the next phase of water becoming vapor. You can also boil water at room temperature by lowering pressure of the contained water. Air is sucked out and the water begins to boil and that’s also cavitation. Cavitation is not just the process of making bubbles. It is the measurement of the phenomenon water or a liquid changing into vapor at lower pressures. Its a similar result to boiling water but without heat.

Why would you want to boil water without heat?

Most disinfection uses heat as a primary source of “cleaning.” Right? I think it’s to reduce the after effects of super heating sensitive instruments. Let’s check to make sure that’s a, thing. Okay. After reading the Giarrizo-Wilson article cavitation and heat is not entirely like that.

What temperature does bacteria die at?

Cells colonize an area like well, Coachella. 😀 A bunch of people show up and people just keep showing up. Bacteria is a lot like Coachella its constantly dividing and then it grows to unsafe levels from its food source which is organic material. On surgical instruments that would be the body fluids from a patient the blood and fat and tissue from a procedure. We cannot see the tiny bacteria that remain and it doesn’t take much to get us infected or, sick.

Salmonella. Is in food. It is reduce when food reaches or stays above 150 degrees fahrenheit. (Wagner) It also depends on how long it stays above that temperature and the type of protein that is being made already comes with higher levels of bacteria before being cooked. What does that have to do with processing surgical instruments? A few of the similar bacteria that we ingest grow on surgical instruments after a medical procedure. The bacteria thrive on our bodies no matter how clean we appear and really don’t make a distinction between human or animal proteins to thrive. A steak, a chicken, or a person it doesn’t matter to bacteria. Not all bacteria die at 150 degrees they die in a range of 140 degrees to boiling.

Then, that makes cavitation less efficient than boiling.

Well. NO. On the surface of the item you have tiny cracks. You have, imperfections from the metal casting. You have daily uses or worn areas. Cavitation provides a way to find the bacteria that like to find these imperfections and stay and grow.

Bacteria are colonizing squatters.

They are the squatters on the surgical  instruments. They will stay and grow and make the instruments unsterile and harmful to use on the next patient without cavitation. Boiling, is a good alternative but not the best or most uniform cleaning solution. With cavitation, you have a sanitary fluid that can create millions of bubbles for a cycle to get to every part of the surgical instruments effectively. Boiling a pot and putting a surgical instrument in it will be effective in killing bacteria that the larger bubbles touch and explode next to the instrument. You also have no way to know how effective your pot is in making bubbles of a small size to explode. There is less of a procedure with boiling and more of a guess. So, cavitation with pressure control and temperature control on water is more efficient and effective in fighting bacteria on surgical instruments.


I make quizzes sometimes:

One Minute Sterile Surgery Area Quiz



Eisenberg, P “Cavitation.” Hydronautics Incorporated. Chapter link

Giarrizzo-Wilson, S. (2006) “Ultrasonic washers; instrument corrosion; one-stick rule.” AORN. Article link

LearnCax. “An Insight into Cavitation phenomenon” Learncax link

Wagner, A. (2008) “Food Technology and Processing Bacterial Food Poisoning.” Texas A&M System. Wagner article