STERRAD rebuttal

Healthcare Purchasing News, Sept, 2003 by Martin S. Favero

To the Editor,

Michael Shaw's letter (Healthcare Purchasing News, June 2(X)3, pg. 82), which was in response to John Andrews' article ("Surgical preferences, sites driving sterilization trends," Healthcare Purchasing News, April 2003, pg. 42), contained a number of inacruracies that must be addressed.

Andrews' article touched on benefits and limitations of several sterilization modalities, including ethylene oxide (EtO), steam, and hydrogen peroxide gas plasma (HPGP), as well as other issues of interest to central service professionals. The article, however, did not claim that central service throughput time is "the gold standard by which all things are to be judged," as Shaw states in his letter, and in no way did it suggest that patient safety be traded for processing speed.

Despite Shaw's suggestions, there has been no increase in nosocomial infections due to the replacement of EtO with HPGP or the STERRAD System. While EtO is effective at killing microorganisms, the well-recognized problems with this method are toxicity and processing time. The STERRAD System is proven effective at killing microorganisms as well-laboratory tests have demonstrated that the system destroys a broad spectrum of microorganisms, including Gram negative and Gram positive vegetative bacteria, mycobacteria, yeasts, fungi, lipophilic viruses and hydrophilic viruses, as well as highly resistant aerobic and anaerobic bacterial spores-and it has the added benefits of being nontoxic and fast. (1)

The rate of hospital-acquired infections is not affected by whether EtO, steam autoclaves, or the STERRAD System is used. All three are valid and effective sterilization methods mad they all achieve at least a [10.sup.-6] sterility assurance level. The efficacy of the STERRAD) System has been proven by established validation methods, demonstrating its "ability to kill more than [10.sup.-6] Bacillus stearothermophilus (recently renamed as Geobacillus stearothermophilus) spores. The safety record of the STERRAD System speaks for itself-as of mid-year 2003, more than 6,000 units have been sold world wide, and more than 23.3 million processing cycles have been safely run to date.

The letter's author also provides inaccurate information about the materials compatibility of the STERRAD System. The STERRAD System is compatible with most medical devices and surgical instruments, and it has been tested by 250 device manufacturers on more than 1,500 devices. In addition, the system recently received expanded Food and Drug Administration label claims for processing items with narrow lumens (single stainless steel lumens with an inside diameter of 1mm or larger and a length of 125mm or shorter, or with an inside diameter of 2mm or larger and a length of 250mm or shorter). Finally, there is no evidence of increased instrument damage with HPGP sterilization. In fact, the STERRAD System has been shown to be gender on instruments than steam and peracetic acid.

Other statements in Shaw's letter are inaccurate as well. There is no question about the ability of HPGP to penetrate all areas of the sterilization load--as evidenced by extensive validation testing required by the FDA for marketing clearance. Peroxide leakage is prevented by a patented delivery system that ensures the cassette cannot be opened outside the closed system, and chemical leak indicators on the cassette provide further safety assurance. The byproducts of the system are harmless oxygen and water vapor. As a result, the Occupational Safety and Health Administration requires no protective gear, personnel monitoring, or venting for the STERRAD System. This contrasts with the long aeration time and extensive venting, monitoring, and protective gem- required with EtO in order to ensure staff and patient safety.

Statements about the STERRAD System's biological indicator also need to be corrected. The STERRAD CycleSure Biological Indicator, which uses Geobacillus stearothermophilus, recently received marketing clearance from the FDA. The system's previous BI used Bacillus atrophaeus in a test pack designed to have greater resistance to the STERRAD System sterilization process than G. stearothermophilus.

The most disturbing aspect of Shaw's letter is the reference to patient injuries caused by unapproved use of the AbTox Plazlyte System several years ago. Severe eye injuries occurred when peracetic acid in the AbTox system reacted with copper in lumened devices to term cupric acid, which remained after the cycle and was flushed into the eyes of patients. To suggest that this type of injury could occur with the STERRAD System shows a lack of understanding about the HPGP process. An April 1998 FDA Safety Alert about the AbTox system slams that the STERRAD System does not contain peracetic acid and can be safely used to sterilize instruments according to approved label claims. In fact, there are no known reports of any such occurrences with instruments processed in the STERRAD System and, given the chemistry involved, none would be expected.