Ultrasonic cleaners have become standard equipment in most sterile processing departments. They provide a thorough cleaning of all parts of surgical instruments, from hinges to lumens to the housing on your robotic instruments. How can you make sure your ultrasonic cleaner is doing its best? Here are a few things to keep in mind.

Use manufacturer-recommended products

Ultrasonic cleaners use detergent and accessories that are designed to meet the operational requirements of the machine. For instance, Ultra Clean Systems’ Sanizyme detergent is effective at 85°F–95°F, the recommended water temperature in our ultrasonics; other detergents may need hotter water. At 85°F–95°F, the water is warm enough that the sonic frequency is not disturbed, and cold enough that proteins will not bake onto the instruments. By using products the manufacturer recommends in the instructions for use (IFU), you prevent unnecessary repairs.

Another example is the Ultra Clean Systems’ accessory kits, which come with everything needed to connect lumen instruments to the tray manifold safely and securely for irrigation. Not all instruments can connect directly to the manifold. Instead, they may require an irrigation hose and hose nozzle. Suction and orthopedic instruments often require an extension or direct coupler and hose nozzle. Instruments with a luer lock require a hose with a luer lock connector. These hoses, couplers, and nozzles are all included in the kit and are specific to the machine and tray manifold used in our ultrasonic cleaning systems.

Don’t overload the tray with instruments

Ultrasonic energy needs to get into small crevices, hinges, joints, and lumens to effectively scrub biofilm and soil. If instruments are stacked on top of one another, sonication cannot be distributed evenly through them. Think of it as though you are washing dishes by hand. If all the plates are stacked on top of one another in the sink, water and detergent cannot reach every part of each plate; they require separation for thorough cleaning. To ensure the same for your instruments, place them in the tray so that you can see the entire device.

Perform routine maintenance

Routine maintenance is crucial to your ultrasonic cleaner’s usefulness and longevity. During the cleaning cycle, debris is lifted from the instruments and goes through the drain/irrigation system. Each machine has a drain/irrigation filter and drain screen that catch this debris, preventing damage to internal components. For the system to be effective, the filter needs to be replaced after every 8-hour shift (or when visibly dirty) and the drain screen cleaned.

It may be tedious and time consuming, but it’s necessary. There is no magic in maintenance. No one wakes up wanting to change their car’s oil or clean their bathtub—we do it to ensure we don’t have serious issues later. Review the maintenance section of the operator manual for instructions on what should be done daily, monthly, and annually.

Avoid using rubber mats in the trays

Sonic energy works best against hard surfaces. When ultrasonic energy occurs, it creates cavitation bubbles that implode on impact with surfaces. When this implosion contacts rubber, it softens the blow. If a rubber mat is placed under the instruments, it blocks the sonication from cleaning the instruments effectively. Ultra Clean’s trays are perforated for the efficacy of the ultrasonics; if there are any concerns about instruments falling through the openings, use the instrument holders.

Use wash monitors to test your ultrasonic cleaner

Ultra Clean Systems uses Wash-Checks U or Getinge Assured wash monitors to validate our equipment. Each coupon has a blue square that mimics the bioburden found on instruments after surgery, allowing us to determine whether all five factors involved are working together to properly remove it. Those five factors are:

  1. Water temperature: If the water temperature is not 85°F–95°F, it can impact the amount of inert gases within the water, the detergent performance, and the cleaning efficacy. Excessive water temperatures (above 110°F) can cause proteins in the enzymatic detergent to denature onto the instrument and affect its cleanliness.
  2. Detergent: The type and amount of detergent matters. Ultrasonic baths require detergent with enzymatic, low-foaming agents and water conditioning agents. Too little detergent is not effective compared to the volume of water and too much may oversaturate the water. If you are unsure of the proper dilution, Ultra Clean recommends 1 ounce of detergent per gallon of water as a good baseline.
  3. Cycle time: Water conditions are different throughout the country, and what may have been good water quality three months ago may have changed because of water tables or changes in municipal water sources. Water quality can affect ultrasonic cleaning efficacy. The Wash-Checks U is a guide to determine the cycle time for a passing result. If at the end of an 8-minute cycle, the test soil result is marginal, a longer cycle may be required. If the next test passes at the end of a 10-minute cycle, then this is the new recommended cycle time baseline going forward.
  4. Degassing: Degassing is the process of removing inert gases from the water. The first area cavitation attacks is inert gases (dissolved oxygen, carbon dioxide, etc.). Cavitation energy is at its highest level, attacking the proteins on the instruments once the inert gases are removed.
  5. Tray type: Per the IFUs for Ultra Clean Systems’ ultrasonic cleaners, if a tray’s openings are smaller than 1/2 cm2, the amount of energy that can pass through the tray to the instruments is reduced. Using trays with very small mesh openings also increases the number of air pockets on the tray when it is submerged in the detergent solution, increasing the amount of inert gases and the degassing time.