Using Instrument Air in the Decontamination Area

By Nancy Chobin, RN, AAS, ACSP, CSPM, CFER

Q:  I am wondering if there is guidance supporting clean air on the assembly side to blow out lumens. Also, do you have a recommendation for using 70 percent alcohol or sterile water to flush out lumens during the assembly of instruments prior to sterilization? 

A: First, let’s discuss the need for air. Instruments are usually relatively dry when they are removed from mechanical washers. However, it is important to ensure that there is no excess moisture in sets to be steam sterilized (because wet packs can occur). All excess moisture must also be removed from sets that are to be sterilized by low-temperature sterilization processes (e.g., EO, hydrogen peroxide gas plasma). (This is especially important when lumened instruments are part of the set). For manually cleaned instruments, drying is important as well because they are very wet after cleaning and rinsing.

Recently, AAMI introduced the term “instrument air.” This air should be used to dry instruments. The Association for the Advancement of Medical Instrumentation (AAMI) states, “Using methods other than instrument air for drying can adversely affect the device or contaminate it.”  Excess moisture from cleaning and rinsing should be removed using filtered, instrument air (formerly called medical-grade, compressed air). Excess moisture should be removed because it can adversely affect the drying process; using methods other than instrument air drying can adversely affect the device or contaminate it. AAMI recently reviewed recommendations for medical air. The most recent information is that traditional medical grade air USP should not be used for anything other than human respiration or the calibration of equipment used in human respiration. Instrument air: (Previously called compressed air or medical air) is defined as a medical gas that falls under the general requirements for medical gases as defined by the National Fire Protection Agency NFPA 99: Health Care Facilities Code, is not respired, is compliant with the ANSI/ISA S-7.0.01, Quality Standard for Instrument Air, and is filtered to 0.01 micron, free of liquids and hydrocarbon vapors, and dry to a dew point of -40 degrees F (-40 degrees C.). Instrument air may be supplied from cylinders, bulk containers and/or medical air compressors.

The definition of a medical air compressor (per NFPA) is a compressor that is designed to exclude oil from the air stream and compression chamber and that does not, under normal operating conditions or any single fault, add toxic or flammable contaminants to the compressed air.”

This air is needed in the decontamination area to “blow out” debris and in the prep and packaging area to help dry lumened devices and sets that are still wet. Items should be dried for steam as well as low temperature sterilization methods unless otherwise directed by the sterilizer manufacturer.  If the device manufacturer (e.g. semi-rigid endoscope) recommends drying, refer to the IFU to see if there is a specific pressure that is recommended to prevent damaging the device.  A pressure gauge would have to be installed on the hose to monitor the pressure.  It is also recommended to have available a set of adapters to fit various size lumens. Therefore, instrument air should be available in the Decontamination Area to “blow” out lumens as well as in the Preparation and packaging area to dry lumens and any residual moisture on sets.

Regarding the use of sterile water or 70 percent alcohol to flush out lumens during the assembly of instruments prior to sterilization that is a totally different issue.  In the “old days” SPD personnel frequently flushed out lumens with alcohol thinking it would dry the lumens and disinfect them at the same time. We also used sterile water to flush lumens prior to sterilization because it was thought that in a pre-vacuum steam or gravity displacement sterilizer, the process of the steam reaching inside the lumens was not certain.

Unless recommended by the manufacturer, devices with lumens (e.g., needles and catheters) need not be flushed with water before prevacuum steam sterilization. If the manufacturer does recommend flushing of the device (which might be the case if a gravity-displacement cycle is to be used), distilled or deionized water should be used and sterilization should follow immediately after packaging. (Regular tap water, which can contain pyrogens, should not be used.) The distilled or deionized water will become steam as it heats during the sterilization cycle and help sterilize the inside of the lumen. When a bottle of sterile distilled water is used, it should be labeled with the date it was opened. Any unused water should be discarded 24 hours after the bottle is opened. If the sterile water is poured into a bowl, the bowl should be kept covered to prevent contaminants from entering the water.

Lumens should always be checked for cleanliness and blockages. Small lumened devices (e.g., Frazier suction catheters) can be flushed with water to verify that the water flows through. A cotton-tipped applicator or a non-linting pipe cleaner, moistened with sterile distilled water, should be passed through the lumen; care should be taken to rub the walls. The applicator or non-linting pipe cleaner should not show any evidence of soil after it is removed (see photo below). If soil is seen, the instrument should be returned to the decontamination area for re-cleaning. Some pipe cleaners and cotton-tipped applicators leave residual behind. Non-linting pipe cleaners are now commercially available.

 
Debris found inside a laparoscopic suction catheter

Regarding the use of alcohol, a manufacturer’s IFU should never be modified. Additional chemicals (e.g., alcohol, hydrogen peroxide, disinfectant wipes) should never be used to “enhance” the cleaning unless the device manufacturer has specified their use. Alcohol can be a fixative and make cleaning more difficult.  If cleaning is performed exactly as the manufacturer specifies, even if the cleaning is done manually, the device will be safe to handle without PPE in the preparation and packaging area.  Remember, a manufacturer, by law, must provide you with specific instruments for use.  You, as the processor, must replicate those instructions exactly.  When you modify the instructions in any way (even though you might think it will enhance the process), you are using the product “off label.” 

In summary, it is important to remain current with changes in practices and standards. The fact that you are questioning these practices is a good thing!  Keep yourself updated by attending Seminars or webinars. Make sure your department purchases the ST-79 update as soon as it is available so you can continue to provide the best practices for your patients.

Nancy Chobin, RN, AAS, ACSP, CSPM, CFER, is a sterile processing consultant and educator.

References:

ANSI/AAMI:  ST79:2010 & A1:2010 & A2:2011 & A3:2012   A4:2013Comprehensive Guide to Steam Sterilization and Sterility Assurance in Healthcare Facilities.

Basics of Sterile Processing 6th Edition.  Sterile Processing University, LLC.  Lebanon, NJ.