How Do You Measure Immediate Use Steam Sterilization (IUSS)?

Immediate Use Steam Sterilization (IUSS)

Immediate Use Steam Sterilization (IUSS) is a sterilization cycle intended for use immediately after completion. Items are placed in approved transportation devices that allow transfer to the sterile field without contaminating the product, even though the contents may still be hot and not fully cooled.

Unlike standard sterilization cycles, the drying phase in IUSS is minimized or omitted, often limited to just a few minutes. As a result, instruments inside the transportation device are typically still wet at the time of use. Instruments processed using IUSS should be used only on the specific patient for whom they were sterilized.

Risk and Appropriate Use for IUSS Sterilization

IUSS (formerly known as flash sterilization) is considered to carry a higher risk to patient safety and therefore must be traced to the individual patient.

There is no national standard defining an acceptable percentage of instruments that may be sterilized using IUSS. The use of IUSS varies among hospitals and health systems. However, the overall goal is to minimize IUSS and restrict its use to urgent or emergent situations only.

Measuring IUSS Use

IUSS utilization is commonly measured by:

IUSS percentage = (Number of IUSS cycles) ÷ (Number of OR cases) during a defined period (usually monthly)

This method reflects the number of opportunities the facility had to potentially negatively impact the OR patient population.

Some facilities instead divide the number of IUSS trays by the total number of trays processed. This approach usually produces a much lower percentage and may underrepresent the risk associated with IUSS use.

Best Practices for Immediate Use Steam Sterilization

The key to safe and effective IUSS is strict adherence to Instructions for Use (IFUs) from:

• The sterilizer manufacturer

• The instrument manufacturer

• The transportation device manufacturer

  
  

Not all instruments are approved for IUSS, and not all transportation devices are validated for this type of cycle. As an additional safeguard, you may want to review the product’s FDA 510(k) clearance to confirm its approved indications for use.

Conclusion

While Immediate Use Steam Sterilization (IUSS) can be a critical tool in urgent or emergent situations, it should never replace robust instrument reprocessing practices or adequate instrument inventory. By closely monitoring IUSS rates, adhering to manufacturer IFUs, and ensuring only approved instruments and containers are used, facilities can reduce unnecessary reliance on IUSS and better protect patient safety. Ongoing education, process improvement, and clear policies are essential to keeping IUSS use as low as reasonably achievable while maintaining safe, efficient surgical care.