the day in the life of a dynamic-air-removal steam sterilizer

82 December 2007MANAGING INFECTION CONTROL

Education & Training

ObjectivesAfter completion of this self-study activity, the learner will

be able to:1. Identify a dynamic-air-removal steam sterilization process.2. Develop a policy and procedure for sterilizer qualification

testing. 3. Develop a policy and procedure for routine monitoring of

dynamic-air-removal steam sterilization process.4. Document the monitoring and release of implants.

Test QuestionsTrue or False. Circle the correct answer.

1. Both prevacuum and steam-flush pressure-pulse sterilizersare considered dynamic-air-removal sterilizers.

True False

2. Test a dynamic-air-removal sterilizer with a biological indi-cator process challenge device (BI PCD) in three consecutive

Many thanks to the team at 3M Health Care for workingwith Managing Infection Control to provide the followingaccredited course. IAHCSMM has awarded one and one-half(1.5) contact points for completion of this continuing educa-tion lesson toward IAHCSMM recertification. The CBSPDhas preapproved this inservice for one and one-half (1.5)contact hours for a period of five (5) years from the date ofpublication, and to be used only once in a recertificationperiod. This inservice is 3M Health Care Provider approvedby the California Board of Registered Nurses, CEP 5770 forone (1) contact hour. This form is valid up to five (5) yearsfrom the date of publication. Instructions for submittingresults are on page 97.

Managing Infection Control and 3M Health Care willbe working collaboratively to provide continuing educationcourses in monthly editions of Managing Infection Control.

empty cycles followed by a Bowie-Dick (B-D) testpack in three consecutive empty cycles whenever thesterilizer is installed, relocated, malfunctions, hasmajor repairs, or after a sterilization process failure toensure the sterilizer is working and can be placed intoroutine use.

True False

3. Bowie-Dick tests should be placed on the floor of thesterilizer.

True False 4. If the medical device manufacturer recommends their

instrument tray be run for 8 minutes at 270-275°F (132-135°C) in a dynamic-air-removal sterilizer, you onlyneed to run the 4 minute cycle recommended by thesterilizer manufacturer because the device should besterile after 4 minutes.

True False

5. Read and initial the physical monitors after each cycleis completed to stop the use of the medical devices ifthe sterilization parameters were not reached or correctfor the load contents.

True False

6. Place internal chemical indicators (CIs) in eachpackage, tray or containerized system in areas deter-mined to be the greatest challenge to air removal andsteam penetration and not on the top of the tray.

True False

7. Implants can be routinely released before the biologicalindicator (BI) is negative if you have a Class 5 inte-grating indicator in the biological indicator processchallenge device.

True False

Continuing education self-study guide presented by 3M Health Care

by Martha Young, BS, MS, CSPDT

The Day in the Life of a Dynamic-Air-Removal Steam Sterilizer


8. Preferably a biological indicator should be routinely run dailyand definitely in any load containing implantable devices.

True False

9. Human errors (e.g., improper packaging and loading,choosing the wrong cycle for the load contents, etc.) arethe primary reason for sterilization process failures. True False

10. Do not perform product testing on loaner instrument trays.True False

IntroductionHello, I am a dynamic-air-removal steam sterilizer and

I am larger than two cubic feet in size. Do you recognize me?Dynamic-air-removal sterilizers use either a series of pressureand vacuum excursions (prevacuum cycle) or a series of steam flushes and pressure pulses above atmospheric pressure(steam-flush pressure-pulse [SFPP] cycle) to remove air.Typically my temperature runs at 132°C to 135°C (270°F-275°F). Don’t confuse me with a sterilizer that uses a gravityprocess where incoming steam displaces residual air through a port or drain near the bottom of the sterilizer chamber.Because of my large size, I am not usually used for flash steril-ization. In the Association for the Advancement of MedicalInstrumentation’s Comprehensive guide to steam sterilizationand sterility assurance in health care facilities, ANSI/AAMIST79: 2006 recommended practices, I have my own sectionunder routine sterilizer efficacy monitoring and qualificationtesting, as do table-top sterilizers and flash sterilization cycles.

I am the most versatile steam sterilization process avail-able with the most effective air removal system. I can process avariety of different packaging materials, instrumentation andfabrics. Let’s look at how I spend my day in your processingdepartment and how to effectively monitor my performance toimprove the outcome of the sterilization process.

Note: This inservice replaces the inservice by the sametitle published in March 2005.

First Day on the JobThe first day on the job is really scary and confusing. I

hope this healthcare facility worked with the service represen-tative and their in-house maintenance staff to ensure that I aminstalled correctly and have the correct utilities that I need tofunction consistently and properly.

Please make sure you follow the manufacturer’s specifica-tions for: Utility line sizes; Maximum and minimum pressures and dynamic flow

requirements of the required utilities;

Steam supply (saturated, condensate-free steam with aminimum dryness factor of 97 percent);

Specified water quality; Nominal electrical supply.

Before I am used routinely, AAMI recommends that I betested to ensure that I am in working condition and can functioneffectively. This testing is called sterilizer qualification testing.

Sterilizer Qualification TestingFor this testing, use an appropriate biological indicator

process challenge device (BI PCD). The BI PCD shouldcontain a BI with Geobacillus stearothermophilus spores thatcomply with ISO 111382,3 and can contain a chemical indicator(either a Class 4 multi-variable indicator or a Class 5 integrating indicator that complies with ANSI/AAMI/ISO11140-1:2005 because they provide more information than aClass 3 single-variable indicator).4 The BI should be incubatedin accordance with the manufacturer’s instructions and facilitypolicy and procedures.1 The BI PCD can be an AAMI 16 towelBI PCD or a “commercially available PCD that has beencleared by the FDA for their intended use.”1

Place the BI PCD in an empty chamber over the drain onthe bottom shelf of the transfer cart or rack because that isthe area inside the sterilizer that creates the greatest chal-lenge to air removal and steam penetration. An emptychamber is used to verify the function of only the sterilizerand the utilities without the influence of a load. Make sureyou use the transfer cart because if you do not I will get toohot (superheated) and will not be able to effectively killspores and do my job.

Run one BI PCD in three consecutive empty cycles. If atransfer cart is used, cool the cart between each cycle to alsoensure that superheating does not occur.1

Note: If I am designed to be used for multiple cycles theneach type of cycle must also be qualified: gravity-displacement at 132°C to 135°C [270°F to 275°F]; gravity-displacement at 121°C [250°F]; dynamic-air-removal at 132°C to 135°C [270°F to 275°F]; flash at 132°C to 135°C [270°F to 275°F]; flash with single wrapper or other packaging.1

Next run a Bowie-Dick (B-D) test pack if it is recom-mended by the sterilizer manufacturer. If the sterilizer hasboth a prevacuum cycle and a steam-flush pressure-pulsecycle, be sure to run the B-Dick test pack in the prevacuumcycle. I want to know I don’t have any air leaks, my vacuumis adequately removing air, I have adequate steam penetrationand appropriate steam quality (no non-condensable gases[i.e., air or gases from boiler additives]) which inhibit steampenetration. See Figure 1 for the test procedure and accept-


ance criteria for sterilizer qualification testing of dynamic-air-removal sterilizers.

Figure 1. Sterilizer Qualification Testing for Dynamic-Air-Removal Sterilizers

Test Procedure:1. Place one BI PCD in an empty chamber on the loading cart

or rack over the drain.2. Run the sterilization cycle.3. Read the physical monitors and initial the printout.4. At the end of the cycle, cool the BI PCD and BI according

to the manufacturer’s instructions.5. Read the CI and record the results.6. Incubate the test BI and a positive control BI (not

sterilized) from the same lot each day a test vial is incubated in each incubator.

7. Repeat this test for a total of three consecutive emptycycles for each sterilization cycle for which the sterilizer isdesigned for use.

8. If this is a dynamic-air-removal sterilizer, run a Bowie-Dick(B-D) test pack in three consecutive empty cycles for 3.5 to 4minutes at 270-275°F (132-135°C). All the test sheets mustshow a uniform color indicating a pass. See Figure 2 on page87 for more details on how to run a B-D test pack.

Acceptance Criteria:1. Appropriate reading from physical monitors.2. Appropriate readings from B-D test sheets.3. Appropriate reading from the CIs.4. Negative BI results from test BIs in all cycles tested.5. Positive BI control results in all incubators.

I want to perform my job properly every day so please donot start using me routinely until this sterilizer qualificationtesting is completed and all the results are acceptable. Alsomake sure my physical gauges are working properly and I havepaper for my printer.

The same sterilizer qualification testing should be performedafter an event occurs that may affect sterilizer performance toensure that the sterilizer is in working condition before it is placedinto routine use after any of the below events occurs.

These events include: sterilizer relocation; sterilizer malfunctions; sterilizer major repairs;

> a major repair is a repair outside the scope of normalmaintenance. This includes weld repairs of the pressurevessel, replacement of the chamber door or majorpiping assembly, or rebuilds or upgrades of controls.

Normal preventive maintenance, such as the rebuildingof solenoid valves or the replacement of gaskets, is notconsidered a major repair. Changes to the utilitiesconnected to the sterilizer such as those that result from a water-main break, annual boiler maintenance,additional equipment loads, and installation of newboilers should be treated as major repairs.

a sterilization process failure.1

Practical Application Perform sterilizer qualification testing in an

empty chamber after events take place that mayaffect the performance of the sterilizer.

One BI PCD should be run in three consecutivecycles followed by one B-D test pack in threeconsecutive cycles.

Also use a cool transfer cart for each load toavoid superheating which can result in positiveBIs and B-D test sheet failures.

Days of My LifeNow that the sterilizer qualification testing is completed,

I am ready to go to work but every day you need to routinelytest my performance to make sure I am still functioningcorrectly. Every time I am used is a new experience and it canget confusing because of the complexity of the process. Eachload is different because of the variety of packaging materialsand medical devices you process and the amount of items youplace in the load. These loads create different air removal andsteam penetration challenges and sometimes you have to setmy timer to a longer sterilization cycle and dry time for me tobe effective at sterilizing the load. Remember that the steriliza-tion process has many steps which include cleaning, packaging,loading, and choosing the appropriate sterilization time for theload contents. In addition, there is the function of the sterilizerand the utilities including quality and quantity of the steam. Soit is your responsibility to ensure that I am performing properlyeach day of my life in your department by following theserecommended practices and by ensuring that all the steps of thesterilization process are performed correctly.

Develop Policies, Procedures and TrainingANSI/AAMI ST79:2006 states, “Education and training

decrease the possibility of operator error during preparationand sterilization processing and help ensure that personnel areconversant with the latest data and techniques.” Train andmonitor personnel to ensure they are following policies andprocedures and not just doing what they have always done.Critical thinking skills are necessary to:



87December 2007 MANAGING INFECTION CONTROL

understand the science behind the policies and procedures; avoid human errors; improve the outcome of the sterilization process.

Develop policies and procedures based on the most stringent current scientific knowledge, accepted practice guidelines, and applicable laws, rules and regulations asrequired by The Joint Commission (JCAHO). Ensure that policies and procedures are consistent throughout the health-care facility. For steam sterilization the most stringentrecommended practice is published by the Association for theAdvancement of Medical Instrumentation’s Comprehensiveguide to steam sterilization and sterility assurance in healthcare facilities, ANSI/AAMI ST79: 2006.

I really want to do a good job so train and monitorpersonnel to ensure they are following these policies and procedures. Continuous training and competency assessmentshelp to minimize or eliminate human errors, which maycontribute to sterilization process failures that may not be my fault. Supporting the certification of employees so theyrecognize the importance of their role in improving patientsafety and properly performing the steps of the sterilizationprocess makes my job easier.

Practical Application1. Update policies and procedures when new

recommended practices and standards arepublished.

2. Continually educate, train and assess competenciesto reduce human error which is the primaryreason for sterilization process failures.

3. Provide resources and incentives for certification.

Select the Correct Sterilization Cycle and Drying Time forthe Load Contents

Check with the manufacturer of the medical devices beingprocessed for reprocessing instructions, especially devicessupplied in protective organizing cases and rigid sterilizationcontainers or containment devices.

I don’t want to run too short of a sterilization cycle or drytime that does not effectively process the medical device, souse the sterilization cycles and dry times recommended by themedical device manufacturer as they maybe longer than theminimum sterilization cycles recommended by the sterilizermanufacturer. Also, be sure to perform product testing asdescribed below in “When Something New Comes Along—Product Testing.”

Practical Application Obtain up-to-date instructions from the medical

device manufacturers to ensure that you arecorrectly processing medical devices.

Bowie-Dick Testing (Equipment Control) Make sure you use B-D type tests and physical monitors

to test my ability each day to operate to the set conditions oftime, temperature, pressure, air removal, moisture conditioningand sterilant exposure. This ensures that my equipment is under control.

For 270-275°F (132-135°C) prevacuum sterilizer, the first step of the day is to run a B-D test. Don’t forget that eliminating non-condensable gases is as important as eliminating air for proper steam penetration. See Figure 2Bowie-Dick Test Pack instructions and acceptance criteria.Always check with the manufacturer of the Bowie-Dick testpack and sterilizer for their specific instructions.

Figure 2. Bowie-Dick Test Pack Instructions1

1. Run an empty chamber cycle right before you run theBowie-Dick (B-D) test to preheat the sterilizer and purge airout of the lines, even if the sterilizer was never turned off.1

2. Place one B-D test pack horizontally in the front, bottomsection of the sterilizer rack or loading cart, near the doorover the drain, but not on the floor unless recommendedby the test pack manufacturer.

3. Run the test pack for 3.5 to 4 minutes at 270-275°F (132-135°C).

4. Read the physical monitors and initial the printout.5. If the test sheet has a uniform color change, use the sterilizer.6. If the test sheet does not have a uniform color change,

retest the sterilizer.7. If a second test sheet is run and has a uniform color

change, use the sterilizer.8. If the second test sheet does not have a uniform color change,

don’t use the sterilizer until the problem is identified.9. The supervisor needs to determine if the sterilizer needs to

be retested, serviced or remain in use. See section on“Sterilization Qualification Testing” for information onhow to test the sterilizer before it is placed back intoroutine use.

Acceptance Criteria:1. Appropriate readings from B-D test sheets.2. Appropriate readings from physical monitors.


Practical Application Correctly run a Bowie-Dick test pack every day

before the prevaccum sterilizer is placed intoroutine use.

Place the Bowie-Dick test pack on the rack orloading cart to avoid superheating.

Internal Chemical Indicator (Pack Control)Make sure you place an internal chemical indicator (CI)

(Class 4 multi-variable indicator or a Class 5 integrating indi-cator) inside each package, peel pouch, tray or containmentdevice in the area determined to be the least accessible to steampenetration.1,5 As I said before, each load is different becauseof the variety of packaging materials and medical devices andthe amount of items placed in the load. These loads createdifferent air removal and steam penetration challenges. Theonly way to know if you have properly followed the steps in theprocess and that I have done my job is by monitoring the condi-tions inside each pack with an internal chemical indicator.

AORN suggests the following placement of internal CIs.6 Place: a CI in the geometric center not on the top of a wrapped

pack or tray; two CIs inside rigid containers: one in each of two oppo-

site corners of the inside basket:> multi-level containers should have a CI placed in two

opposite corners (e.g., one in each of two corners) ofeach level;

a CI on each level of multi-level wrapped sets.

Train the OR staff to correctly read the results of internalchemical indicators when they open up the packs and to informthe processing department if they have not reached an accept-able endpoint. The ANSI/AAMI ST79 recommended practicestates, “If the interpretation of the CI suggests inadequatesteam processing, the contents of the package should not beused.”(1)

The complete unused package, including the load identifi-cation and the CI should be returned to the processingdepartment. The decision to recall the entire load should bebased on the results of physical monitoring, CI results fromother packs in the load, and the results of BIs if available. If BIresults will be available, quarantine the load until that time.Internal CIs will detect errors in packaging, loading, incorrectchoice of sterilization cycle for a particular load, and equip-ment malfunctions. Help me ensure that we detect anincorrectly processed package before it is used on a patient. Idon’t want anyone hurt because the process was not effective.

Practical Application Place a Class 4 multi-variable or Class 5 inte-

grating indicator inside each package, peelpouch, tray or containment device in the areadetermined to be the least accessible to steampenetration.

Do not use the package if the internal CI has notreached an acceptable endpoint.

External Chemical Indicator (Exposure Control)I want you to be able to tell as soon as a package comes

out of the load that it has been processed. The ANSI/AAMIST79 recommended practice states that a Class 1 process indicator (external chemical indicator) should be used on the outside of each hospital-assembled package, tray orcontainment device intended for sterilization unless the internalchemical indicator is visible.1 After unloading the sterilizer,check the external indicator for each package. Do not releasethe tray or package for use if the chemical indicator has notreached an acceptable endpoint.

Practical Application Place a Class 1 process indicator on the outside

of each package, tray or containment deviceunless the internal CI is visible to distinguishprocessed from unprocessed items.

Do not release the package, tray or containmentdevice for use if the internal chemical indicatorhas not reached an acceptable endpoint.

Physical Monitoring (Equipment Control)Physical monitoring is also a critical aspect of equipment

control. Remember I said to be sure my physical monitors areworking and I have paper for my printer. Also observe thedigital displays or gauges on the sterilizer and the recordings oftime, temperature and pressure, to identify an equipmentmalfunction before it becomes a problem.

Be sure to correctly set the cycle parameters on the sterilizerfor the load to be run. Mark the date, sterilizer number, and yourinitials on the printout at the beginning of the cycle unless it ispart of the printout. At the end of the cycle, read and record theresults of each cycle on the printout and initial to verify thecorrect results.1 Sterilizers without recording devices should notbe used.1

If the physical monitors indicate a malfunction, considerthe load nonsterile and do not distribute it. Do not put the



sterilizer back into routine use until the problem hasbeen identified, corrected and the sterilizer is retestedwith biological and chemical indicators which showthe correct results (see “Sterilizer QualificationTesting”). I only want to be on the job when I amworking properly.

Practical Application Train everyone on how to read and initial

each sterilization cycle printout beforethe load is released for use.

Do not release the load if the physicalmonitors are not correct.

Biological Indicators (Load Control)Now this is the test result I get excited about

because it tells me that I am killing spores which is my


goal! Load control is the process by which a load is monitored andreleased, based on the result of a biological indicator (BI) in a processchallenge device (PCD), commonly referred to as a BI test pack.

The ANSI/AAMI ST79 recommended practice states the BIshould be used in a PCD: to routinely monitor sterilizers at least weekly, but preferably

every day that the sterilizer is in use; to monitor every load containing implants. “The load should be

quarantined until the results of the BI testing are available.”1

Note: If I am designed to be used for multiple cycles then eachtype of cycle must also be routinely monitored with a BI PCD: gravity-displacement at 132°C to 135°C [270°F to 275°F]; gravity-displacement at 121°C [250°F]; dynamic-air-removal at 132°C to 135°C [270°F to 275°F]; flash at 132°C to 135°C [270°F to 275°F]; flash with single wrapper or other packaging.1

The BI PCD can be: an AAMI 16-towel pack;

Practical Application Run one BI PCD in each load to ensure all sterili-

zation cycles used are routinely tested in additionto implant loads.

Quarantine the loads until the BI result is negativeto eliminate recalls.

Quarantine each implant load until the BI is negative.

Routine Load Release For Nonimplant LoadsThe following monitoring should be done routinely for each

load before it is released for use to ensure that the sterilizationprocess was effective: physically monitor each load; label every package with an external process indicator; place an internal CI inside each package; if desired, place a PCD containing a BI and/or a Class 5 inte-

grating indicator or an enzyme-only indicator in the chamber; evaluate all quality control measures and data at the

conclusion of the sterilization cycle (this should be done byan experienced, knowledgeable person);

release loads only if the criteria for release are met.1

Release Criteria for ImplantsA BI PCD containing a BI and a Class 5 integrating

chemical indicator or an enzyme-only indicator should be used ineach load containing an implant.1 The load should be quarantineduntil the BI is negative to improve patient safety. The followingmonitoring should be done: physically monitor each load; label every package with an external process indicator; place an internal CI inside each package; monitor with a PCD containing a BI and a Class 5 inte-

grating CI or an enzyme-only indicator; evaluate all quality control measures and data at the

conclusion of the sterilization cycle (this should be done byan experienced, knowledgeable person);

quarantine implant until BI is negative; release loads only if the criteria for release are present.1

Practical Application The results of all load monitoring tools (e.g.,

physical monitors, BIs and CIs) should be evaluated and correct before the load is released.

Each load containing an implant should contain aBI PCD containing a BI and a Class 5 integratingCI or an enzyme-only indicator.

The implant should not be released until the BI is negative.



or a commercially available disposable PCD cleared bythe FDA for their intended use.1

The BI PCD should contain a BI with Geobacillusstearothermophilus spores and a CI (Class 4 multi-variableindicator or Class 5 integrating indicator). The BI should beincubated in accordance with the manufacturer’s instructionsand facility policy and procedures.1 See Figure 3 for the testprocedure and acceptance criteria for routine sterilizer efficacy resting of dynamic-air-removal sterilizers.

Figure 3. Routine Sterilizer Efficacy Testing ofDynamic-Air-Removal Sterilizers Larger than 2 Cubic Feet

Test Procedure:1. Place one BI PCD flat or according to the manufacturer’s

instructions on a rack or loading cart over the drain in a fullload. Do not place another pack or tray on top of the BIPCD. This will create too great of a challenge.

2. Run the load according to the sterilizer manufacturer’sinstructions.

3. Read the physical monitors and initial the printout.4. At the end of the cycle, cool the BI PCD and BI

according to the manufacturer’s instructions.5. Read the CI and record the results.6. Incubate the test BI and a positive control BI (not

sterilized) from the same lot each day a test vial is incubated in each incubator.

7. Read and record the results.

Acceptance Criteria: Appropriate reading from physical monitors. Appropriate readings from the CIs. Negative BI results from test BIs in all cycles tested. Positive BI control results in all incubators.

Using a self-contained biological indicator with a one- or three-hour readout in each load for routine sterilizerefficacy testing allows quarantining of all loads pending BI results, especially those containing implants. This helpseliminate recalls, reduces the risk to the patient and health-care facility due to the use of nonsterile medical devices andminimizes the costs associated with a sterilization processfailure and recall.7.8 This also ensures that each implant andsterilization cycle or mode used are tested. Check with thesterilizer and biological indicator manufacturer to make sureyou are using the correct BI and BI PCD for the cycles beingtested. I really want to know that the sterilization process I created was lethal or able to kill spores. That tells me I amdoing my job.


Record Keeping I have worked really hard today and I want you to docu-

ment all the materials that have been processed and themonitoring control evidence. In the event of a sterilizationprocessing failure, good records will help you trace each packbackward through the sterilization process, assist in a recall andhelp with troubleshooting of the sterilization process failure.

Each package should be labeled with a lot control identi-fier to enable retrieval of items in the event of a recall and fortracing of problems. An expiration date or statement on eachitem is important for stock rotation. Each item should beinspected and not used if damaged or opened.1

The ANSI/AAMI ST79 recommended practice states thatfor each sterilization cycle, the following information should berecorded and maintained:a) the lot number;b) the specific contents of the lot or load, including quantity,

department, and a description of the items (e.g., textilepacks, type/name of instrument packs);

c) the exposure time and temperature, if not provided on thesterilizer recording chart;

d) the name or initials of the operator;e) the results of biological testing, if applicable;f) the results of Bowie-Dick testing, if applicable;g) the response of the CI placed in the BI PCD, if applicable;

andh) any reports of inconclusive or nonresponsive CIs found

later in the load.1

In addition: time and temperature recording chart, printer or tape

should be dated and maintained; each cycle on the chart should be reviewed and signed by

the operator; records of repairs and preventive maintenance of the steril-

izer and utilities also should be kept for each sterilizer sothat you can determine if sterilizer qualification testingneeds to be performed.



AN

NE

X L

(In

vorm

ativ

e)All the foregoing information may be incorporated into a

sterilizer paper or electronic log system or filed as individualdocumentation records. All sterilizer records must be retainedin the central service department or another designated storagearea for a period of time not less than that specified by state orlocal statutes or, if statutes are nonspecific, by the infectioncontrol committee of the individual institution. Electronicrecords of each sterilization cycle, with item-specific identifi-cation, are recommended.

Practical Application Correctly document all sterilization process

monitoring results to facilitate recall and tracesteriliation process failures.

ImplantsThe sterilization process monitoring results of an implant

should be documented and fully traceable to the patient onwhom it is used or in whom it is implanted.1,5

The sterilizer operator should review and record the resultsof the physical monitors, BIs and CIs to determine if the resultsare appropriate and record this along with other data required inthe sterilizer records listed in Annex L.

“Patient safety could be adversely affected by theimplantation of a nonsterile device. The sterilization ofimplantables should be closely monitored and each loadcontaining implants should be quarantined until it is verifiedthat BI testing has yielded negative results.”1 This is whyeach load containing an implant should be monitored with aBI PCD. “The load should be quarantined until the results

Reprinted with permission from the Association for the Advancement of Medical Instrumentation, Inc. Copyright 2006 AAMI. www.aami.org. All rights reserved.

93MANAGING INFECTION CONTROL


December 2007

of the BI testing are available (CDC, 2003a).” The following explains theonly exceptions to the rule.

“When medical exceptions dictate (e.g., the need for trauma-relatedorthopedic screw-plate sets), it could be necessary to release an implantabledevice before the BI results are known. In this case, the release of the device before the BI results are known should be documented; the BI result obtained later should also be documented. (See Annex L for examplesof an implant log and exception form.) It is critical that this documentationbe fully traceable to the patient. Releasing implants before the BI results are known is unacceptable and should be the exception, not the rule.Emergency situations should be defined in written guidance developed inconsultation with infection prevention and control, the surgeon and riskmanagement. Steps should be taken to reduce the frequency of emergencyrelease of implantable items. For example, ongoing periodic reviews of the exception forms and implant logs could reveal consistent patterns of

Reprinted with permission from the Association for the Advancement of Medical Instrumentation, Inc.Copyright 2006 AAMI. www.aami.org. All rights reserved.

events that are causing emergency release and that could be corrected.”1

Premature release of implants before the BI result is available is unacceptable, should be the exception, not the rule,and each exception should be documented using an implantexception form. This form (see Annex L, Figure L.2 on page93) requires providing the following information each time animplant is prematurely released: Name of:

> implant prematurely released;> patient; > surgeon;

Reason for premature release; What could have prevented premature release of the

implant.

Practical Application Do not release implants until the BI result is

negative. Develop a policy and procedure that defines

emergency situations that would allow earlyrelease of implants before the BI results areavailable.

Document early release of implants using theimplant exception form provided in this inservice.

Recall-Positive Biological IndicatorsIf a positive BI is obtained, the appropriate supervisor and

infection control department should be notified immediately byphone or messenger. This notification should be followed by awritten report. As stated in ANSI/AAMI ST79:

“b) If it is determined that the sterilization failure was not the result of operator error (e.g., selection of the incorrectcycle), items processed in that sterilizer since the last negativeBI results should be considered unsterile. They should beretrieved, if possible, and reprocessed (see 10.11). The sterilizer in question should be taken out of service.

e) After the cause of the sterilization failure has beendetermined and corrected, the sterilizer in question should beimmediately rechallenged with a PCD (see 10.7.2.1, 10.7.3.1,or 10.7.4.1) in three consecutive empty-chamber cycles. Fordynamic-air-removal sterilizers, a Bowie-Dick test pack alsoshould be run in three consecutive empty-chamber cycles (see10.7.6) Until the results of retesting are satisfactory (threecycles with negative BIs and three cycles with acceptable colorchange in the Bowie-Dick indicator), the performance of thesterilizer should be considered in question”1

To summarize, all items processedsince the last negative BI should beconsidered nonsterile, retrieved and reprocessed even if the Class 5integrating indicator or enzyme-onlyindicator PCD in the other loadsshowed an acceptable cycle. Recalls can be avoided by running a biological indicator with a one- orthree-hour readout and quarantininguntil the BI is negative.

Remember that a sterilizer failure is only one reason for asterilization process failure. See Figure 4 for the variables thatcan affect the outcome of the steam sterilization process. Checkout the packaging, loading and cycle parameters first and retestthe sterilizer with BIs and CIs. If the testing results show thesterilizer is not functioning then call for a repair service or asteam sterilization investigation service which can check thefunction of the sterilizers and steam quality to determine thereasons for positive biological indicators. Don’t always assumethat I am the problem.

Figure 4. Variables that Affect Outcome of SteamSterilization Processes10

Human error (85 percent of failures):> Incorrect packaging or loading;> Choosing the incorrect biological indicator process

challenge device for the load;> Incorrectly placing the biological indicator process

challenge device in the load;> Choosing the incorrect cycle parameters for the load.

Equipment malfunctions (10 percent of the failures):> Low temperatures;> Inadequate air removal.

Utilities (5 percent of the failures):> Poor quality steam.





When Something New Comes Along—Product Testing

When you bring a new medical device or packaging mate-rial into the department or make other changes in thesterilization process, it is important to do additional testing toensure the sterilization process is still effective. This is becausethe BI PCDs discussed in the other sections present a knownchallenge to the sterilization process that does not necessarilyreflect the same challenge as items routinely processed.“Therefore, product testing is recommended as part of acomplete quality assurance program to ensure the effectivenessof the sterilization process and to avoid wet packs.”1

Routinely sterilized products should be tested periodicallyand testing should also occur when “major changes are made inpackaging, wraps, or load configuration, such as dimensionalchanges, weight changes, or changes in the type or material ofpackaging or wrapper.”1 This testing procedure should also beperformed on each loaner tray before it is put into routine useand whenever the contents change. Obtain in writing, from the

medical device manufacturer, the sterilization cycle to use forthe loaner instruments and the containment device.1 Furtherinformation on product testing is included in references 1 and11. I want to make sure I can still do my job after changes aremade in the process.

SummaryMy life as a dynamic-air-removal sterilizer is very

demanding because of my ability to process a variety ofmedical devices and the ever-increasing demand of aprocessing department to do more with less people, equipment and supplies. Follow the AAMI recommendedpractices related to sterilizer qualification testing, routine sterilizer efficacy testing and product testing to ensure that thesterilization process being used by your facility produces asterile medical device that improves patient outcomes. I wantto improve patient outcomes, so ensure that I am functioningproperly and that the steps of the sterilization process areperformed. I am depending on that.



Glossary of Terms: Dynamic-air-removal sterilizers: Type of sterilization

cycle in which “air is removed from the chamber and the load by means of a series of pressure and vacuumexcursions (prevacuum cycle) or by means of a series ofsteam flushes and pressure pulses above atmospheric pres-sure (steam-flush pressure-pulse [SFPP] cycle).”1

Sterilizer qualification testing: Testing the sterilizer with abiological indicator process challenge device and Bowie-Dick test after events (e.g., sterilizer installation,relocation, malfunction, major repair and sterilizationprocess failure) which could affect the ability of the steril-izer to perform.1

Biological indicator (BI): “Test system containing viable microorganisms providing a defined resistance to aspecified sterilization process.”1

Process challenge device (PCD): “Item designed to constitute a defined resistance to a sterilization processand used to assess performance of the process.”1

Chemical indicator (CI): “Device used to monitor thepresence or attainment of one or more of the parametersrequired for a satisfactory sterilization process, or used inspecific tests of sterilization equipment.”1

Bowie-Dick test: “Diagnostic test of a dynamic-air-removal steam sterilizer’s ability to remove air from thechamber and prevent air re-entrainment.”1

Noncondensable gases: Gas from air or boiler additivesthat enter the chamber with the steam and inhibit propersteam penetration.

Equipment control: Monitoring the sterilizer prior to, andduring, daily use to determine if the sterilizer is operatingto the set conditions of time, temperature, pressure, airremoval, moisture conditioning, and sterilant exposure.Includes physical monitors and Bowie-Dick tests.

Physical monitors: Time, temperature and pressurerecorders; displays; digital printouts; and gauges thatprovide real-time assessment of the sterilization cycleconditions and permanent records.1

Pack control: Use of internal chemical indicators tomonitor the conditions inside individual packs to determine that the sterilant has penetrated to the locationof the medical devices.

Containment devices: “Reusable rigid sterilizationcontainer, instrument case, cassette, or organizing trayintended for use in health care facilities for the purpose ofcontaining reusable medical devices for sterilization.”1

Acceptable endpoint of chemical indicator: Observablechange specified by the manufacturer that occurs after the indicator has been exposed to certain predefined physical conditions.4

Exposure control: Identifies processed medical devicesfrom unprocessed medical devices at a glance. Externalchemical indicators are used for Exposure Control.

Load Control: The process by which a load is monitoredand released based on the result of a BI and/or a Class 5 CIor enzyme-only indicator in a process challenge device.

Routine sterilizer efficacy testing: A regular pattern oftesting the efficacy of the sterilization process with physical monitors, Bowie-Dick tests, external and internalchemical indicators, and biological indicators.

Product testing: Routinely testing processed items with biological and chemical indicators whenever “major changes are made in packaging, wraps, or loadconfiguration, such as dimensional changes, weightchanges, or changes in the type or material of packaging or wrapper.”1 ✛

References 1. Association for the Advancement of Medical Instrumentation.

Comprehensive guide to steam sterilization and sterility assurancein health care facilities. ANSI/AAMI ST79: 2006.

2. International Standard. Sterilization of health care products-Biological indicators-Part 1: General requirements, ISO 11138-1:2006.

3. International Standard. Sterilization of health care products-Biological indicators-Part 3: Biological indicators for moist heatsterilization processes, ISO 11138-1:2006.

4. The Association for the Advancement of Medical Instrumentation.Sterilization of health care products-Chemical indicators-Part 1:General requirements, ANSI/AAMI/ISO 11140-1:2005.

5. Recommended Practices for Sterilization in Perioperative PracticeSettings. Association of periOperative Registered Nurses. AORNStandards, Recommended Practices, and Guidelines. 2007.

6. Recommended Practices for Selection and Use of PackagingSystems for Sterilization. AORN Standards, RecommendedPractices, and Guidelines. 2007.

7. Ross, Edwin. Using Biological Monitoring to Reduce Infection,Risk, and Costs. Surgical Services Management.Vol.4, No. 7,July:1998.

8. Murphy, Denise; Whiting, Joseph; and Hollenbeak, Christopher S.Dispelling the Myths: The True Cost of Healthcare-associatedInfections, www.apic.org, APIC. 2007.

9. Seavey, Rose. Loaner Instrumentation: Keeping Patient SafetyFirst! Managing Infection Control, April: 2007.


10. Hancock, Charles. Personal commu-nications, 2006.

11. Young, Martha. Condensation ofthe AAMI Steam SterilizationRecommended Practices, QualityControl (Section 10), Part 2,Comprehensive guide to steamsterilization and sterility assurancein health care facilities, ANSI/AAMI ST79: 2006), ManagingInfection Control, October:2006.

Martha Young, BS, MS, CSPDT,is a senior international technicalservice specialist in 3M MedicalDivision, St. Paul, Minn. She hasmore than 25 years of experiencein the area of sterilization anddisinfection. Ms. Young lecturesaround the world and hasnumerous publications on infectionprevention with an emphasis onimproving the performance of thesterilization process. She is amember of IAHCSMM, ASHCSP,AORN (Professional/Practice Issueschair for AORN speciality assemblyfor Sterile Processing MaterialsManagement) and APIC, and acertified central sterile processingand distribution technician. She is a member of several AAMIworking group committees that aredeveloping recommended practices.Ms Young was just named in 2007by HPN as one of the “30 Pros toKnow” who are the most influentialin healthcare sterile processing.


1. T2. T3. F4. F5. T

6. T7. T8. F9. T10. T

ANSWERS

Nursing CE Application FormThis inservice is approved by the California Board of Registered Nurses, CEP 5770

for one (1) contact hour. This form is valid up to one year from the date of publication.1. Make a photocopy of this form.2. Print your name, address and daytime phone number and position/title.3. Add the last 4 digits of your social security number or your nursing license number.4. Date the application and sign. 5. Answer the ture/false CE questions. 6. Submit this form and the answer sheet to: Workhorse Publishing Managing Infection Control PO Box 25310, Scottsdale, AZ 85255-99987. For questions or follow-up, contact [email protected]. Participants who score at least 70% will receive a certificate of completion

within 30 days of Managing Infection Control’s receipt of the application.

ApplicationPlease print or type.

Name______________________________________________________________

Mailing Address______________________________________________________

City, State, Country, Zip _______________________________________________

Daytime phone ( )__________________________________________

Position/Title_______________________________________________________

Social Security or Nursing License Number ________________________________

Date application submitted _____________________________________________

Signature __________________________________________________________

Offer expires December 2012

On a scale of 1-5, 5 being Excellent and 1 being Poor, please rate this programfor the following:

1) Overall content ___________________

2) Met written objectives ______________

3) Usability of content ________________

Sterile Process and Distribution CEU InformationCEU Applicant Name _________________________________________________

Address___________________________________________________________

City____________________________ State________ Zip Code ______________

The CBSPD (Certification Board for Sterile Processing and Distribution) haspre-approved this inservice for one and one-half (1.5) contact hours for a period offive (5) years from the date of publication. Successful completion of the lesson andpost test must be documented by facility management and those records maintainedby the individuals until recertification is required. DO NOT SEND LESSON OR TESTTO CBSPD.

For additional information regarding Certification contact: CBSPD, 121 StateHwy 31N, Suite 500, Flemington, NJ 08822 or call 908-788-3847 or visit the Web siteat www.sterileprocessing.org.

IAHCSMM has awarded one and one-half (1.5) Contact Points for completion ofthis continuing education lesson toward IAHCSMM recertification.

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the day in the life of a dynamic-air-removal steam sterilizer

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