February 5, 2015 — This article presents Dr. Muscarella’s response submitted in August 2011 to the federal Food and Drug Administration (FDA), in reply to the Agency’s request earlier that same year that the public comment on its draft guidance document entitled:

“Draft Guidance: Processing/Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling.”

Click here to read this document, referred to herein as the “draft guidance document.”  The FDA’s invitation appeared in the Federal Register on July 28, 2011 (with the reference identifier: Docket No. FDA-2011-N-0294).

As its name suggests, the FDA’s draft guidance document focuses on a number of instrument-reprocessing issues, emphasizing the importance of effective reprocessing of reusable medical instruments like gastrointestinal (GI) endoscopes, whose contamination and inadequate reprocessing have been recently linked to several “superbug” outbreaks, with associated patient morbidity and mortality.

“Reprocessing” may be defined as the cleaning and either disinfection or sterilization of reusable medical instrumentation to prevent the transmission of infectious diseases in healthcare settings.

A federal senator’s involvement

Dr. Muscarella’s response, below, to the FDA’s draft guidance document becomes all the more timely and relevant because of a U.S. senator’s comments and actions detailed in the February 3, 2015, issue of The Seattle Times newspaper.

In the wake of a deadly superbug outbreak linked to contaminated GI endoscopes at Virginia Mason Medical Center (Seattle, WA), The Seattle Times reports that U.S. Sen. Patty Murray had just sent a letter to FDA Commissioner Margaret Hamburg urging the Agency to finalize this draft guidance document.

(On February 5, 2015, just two days later, Dr. Hamburg resigned as the FDA’s Commissioner for undisclosed reasons. There is no connection between her resignation and Senator Murray’s letter.)

Virginia Mason Medical Center’s ‘superbug’ outbreak linked to the inadequate reprocessing of contaminated GI endoscopes is only one of several recent outbreaks reported around the U.S. resulting in dozens of patient injuries and several patient deaths.

Click here to read Dr. Muscarella’s related article: “At Least Seven More Deaths Linked to GI Endoscopes in Seattle (WA): The Start of A National Discussion.”

Once it becomes finalized, a primary objective of the FDA’s draft guidance document will be to improve the effectiveness of the reprocessing of contaminated reusable medical equipment, thereby improving patient safety.


The following is written in the first person (“I”), referring to Dr. Muscarella, who wrote these comments and submitted them to the FDA.

Topic #1 – Rigid laryngoscope handles

The draft guidance document discusses rigid laryngoscope blades.

Action:  FDA, please clarify:

  • whether the Agency classifies rigid laryngoscope handles (which attach to semi-critical laryngoscope blades) as semi-critical devices that, no matter if covered with a protective cover during the clinical exam, require high-level disinfection (at a minimum) after each use; or,
  • alternatively (though less ideal), that the laryngoscope handle is a non-critical device for which intermediate- or low-level disinfection would be suitable. (The reader is directed to Reference #3, below.)

Note: Read Dr. Muscarella’s related articles:

  • “The Joint Commission’s Recommendation for Reprocessing Rigid Laryngoscopes: Is it Valid?” by clicking here; and
  • “Reprocessing the Handles of Rigid Laryngoscopes” by clicking here.

Topic #2 -Skin electrodes

The FDA’s draft guidance document classifies skin electrodes as non-critical devices.

Action: FDA, please consider re-classifying reusable skin electrodes as semi-critical devices, understanding that during routine use these devices may contact non-intact or abraded skin (e.g., scalp electrodes used during EEG).

Note: Read Dr. Muscarella’s related article:

Legal Reviews for Patients, Hospitals, Manufacturers:  Click here to read about Dr. Muscarella’s expertise and legal assessments of the causes of healthcare-associated infections, including “superbug” outbreaks linked to contaminated GI endoscopes and other reusable medical equipment.

Topic #3 – The FDA’s definition of “sterile”

The FDA defines “sterile” (refer to, for example, Page 32 of the FDA’s draft guidance document) as a “state of being free from viable microorganisms.”

This definition is arguably incomplete, however, because it permits a “sterile” surgical instrument to be contaminated and soiled with non-infectious debris – for example, endotoxins or other non-infectious, though potentially-harming, materials including contaminants, oils, and organic and non-organic compounds.

Toxic anterior segment syndrome, or “TASS,” is an example of a disorder of the eye that, caused by ophthalmic instruments contaminated with non-infectious debris, can result in blindness. According to the FDA’s definition in this draft guidance document, these ophthalmic instruments are considered “sterile,” despite their transmitting harming debris via contaminated surgical instruments.

Similarly, reports from almost a decade ago document a North Carolina hospital’s inadvertent use of elevator hydraulic fluid, thought to have been detergent, to clean surgical instruments. Although subsequently subjected to steam sterilization, the instruments remained contaminated with hydraulic fluid.

According to the FDA’s current definition, these surgical instruments, coated with potentially harming and toxic hydraulic fluid, would be deemed “sterile.”

Indeed, “sterile” implies the absence of any type of potentially harming material on a surgical instrument, not just infectious organisms.

Action: I recommend that the FDA consider re-defining “sterile” in the draft guidance document (and other relevant FDA documents) as a “state of being free of viable microorganisms and of non-infectious materials.”

Note: Read Dr. Muscarella’s related articles:

  • “FDA’s Definition of Sterility, Sterile: Is It Sound and Complete?” by clicking here; and
  • “Association of Toxic Anterior Segment Syndrome (TASS) with Ophthalmic Instrument Sterilization” by clicking here; and
  • “Impact of Hydraulic Fluid on the Steam Sterilization of Surgical Instruments” by clicking here.

Topic #4 – Ear-Nose-Throat (“ENT”) endoscopes

For background, in January of 2005, I wrote a letter to the FDA recommending that the Agency review, for clarity and consistency, a different guidance document finalized in 2000: “Guidance for Manufacturers Seeking Marketing Clearance of Ear, Nose, and Throat Endoscope Sheaths Used as Protective Barriers (Guidance for Industry)” (issue date: March 12, 2000) — click here to read it.

Under the heading “H. Sterility Information,” this finalized guidance document states that:

  • “Endoscopes, as used in ENT practice, are considered to be semi-critical devices as they come in contact with mucous membranes, which may or may not be intact. The Center for Disease Control (CDC) and Association of Practitioners in Infection Control (APIC) recommend high-level disinfection as the minimum acceptable level of reprocessing for semi-critical medical devices such as endoscopes …”; and
  • “Reprocessing of the endoscope after removal of the used sheath and before application of a new sheath must be recommended and described in the user’s information manual. If the applicant sufficiently demonstrates protective barrier properties of the finished device, a cleaning procedure followed by an intermediate disinfection step will be required”; and
  • “The applicant should direct the user to follow the cleaning procedure recommended by the endoscope manufacturer. This should include instructions to clean the entire endoscope, including the eyepiece and any hand attachments. This process serves two purposes: to clean the endoscope in case of a break in aseptic technique by the user and to mechanically remove any material that may have contacted the insertion tube of the endoscope during application or removal of the sheath”; and,
  • “In addition to cleaning, an intermediate disinfection step such as wiping with a 70% isopropyl alcohol soaked gauze pad should be recommended. This step is added to reduce the likelihood that any viable organisms remain on the endoscope prior to application of a new sheath. If the applicant wishes to propose a different cleaning regimen a full description and justification will be expected.”

Some of these statements in that finalized guidance document focusing on ENT endoscope sheaths (which has not been revised since it was issued in 2000) are not consistent with the FDA’s draft guidance document on the reprocessing of medical devices, which is awaiting finalization (i.e., the document entitled “Draft Guidance: Processing/Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling”).

Nor are these statements consistent with the FDA’s comments presented at its 2-day public workshop in Maryland on the reprocessing of reusable medical devices, on June 8-9, 2011.

As the FDA has acknowledged, ENT endoscopes, like other types of flexible endoscopes, are semi-critical devices (requiring high-level disinfection or sterilization after each use).

Further, on Page 10 of its draft guidance document, the FDA states (in the context of the cleaning of reusable devices and the use of protective covers) that “the cleaning and disinfection instructions for your device should assume that the device is used uncovered, because of the potential for loss of cover integrity during use.”

This a well taken point, but this instruction is not consistent with the FDA’s aforementioned guidance document from 2000 discussing ENT endoscope sheaths, which recommends the intermediate-level disinfection of ENT (semi-critical) endoscopes after removal of the used sheath or protective cover (i.e., “wiping with a 70% isopropyl alcohol soaked gauze pad”).

Action: FDA, please:

  • first, consider revising the Agency’s “Guidance for Manufacturers Seeking Marketing Clearance of Ear, Nose, and Throat Endoscope Sheaths Used as Protective Barriers” (and all other relevant documents) to be consistent with this draft guidance document issued in 2011 discussing the reprocessing of medical devices and awaiting finalization; and
  • second, clarify in all relevant documents that ENT endoscopes are semi-critical devices and, whether or not covered with a protective sheath during the procedure, would require high-level disinfection (at a minimum) – not intermediate-level disinfection as the FDA’s guidance document discussing ENT endoscope sheaths, published in 2000, currently recommends.[1,2]

As the FDA can appreciate, the mitigation, if not elimination, of inconsistent reprocessing instructions and device classifications is important to prevent confusion, improve the quality of instrument reprocessing, and minimize the likelihood of instrument reprocessing lapses that might result in disease transmission. The reader is directed to References #1 and #2, below.[1,2]

Note: Read Dr. Muscarella’s related article:

  • “The Reprocessing of Sheathed “ENT” Endoscopes, Cystoscopes, and Other Types of Flexible Endoscopes” by clicking here.

Topic #5 – Liquid chemical sterilization

As the FDA acknowledged in the Federal Register, “the adequate reprocessing of reusable medical devices is a critically important factor in protecting patient safety.”

Indeed, manufacturer instructions for reprocessing a reusable instrument that are unclear, incomplete, or impractical can adversely affect patient safety and the reusable device’s safe and effective reprocessing, resulting in an increased risk of disease transmission and healthcare-associated infections.

Clear, succinct, and validated reprocessing instructions are important to the FDA’s current efforts to improve public health and the quality of instrument reprocessing.

Action #1:  FDA, please clarify the Agency’s definition of “liquid chemical sterilization,” a term that this draft guidance document uses a number of times.

Several FDA documents provide somewhat unclear definitions of liquid chemical sterilization, the process’s effectiveness, and whether it is appropriate for use to reprocess critical devices used during invasive procedures.

Adding to this confusion, the FDA’s draft guidance document appears to equate the term liquid chemical sterilization with high-level disinfection, as if the two were indistinguishable processes that achieve the same outcome.

For example, under this draft guidance document’s heading “criterion 6,” subheading “drying,” the FDA uses these two terms together in the same context, writing that:

“active device drying is another post-processing procedure which may reduce or eliminate re-contamination of unwrapped devices after high level disinfection/liquid chemical sterilization reprocessing of devices because they will be wet at the end of reprocessing.”

According to the draft guidance document, processes labeled to achieve liquid chemical sterilization might be more like high-level disinfection than traditional sterilization processes, such as steam sterilization and ethylene oxide gas sterilization, both of which (unlike liquid chemical sterilization): (i) are associated with a sterility assurance level (SAL), (ii) can be monitored in the healthcare setting using resistant biological indicators (BIs), (iii) are not terminally rinsed with potentially un-sterile water, and (iv) render the sterile instrument wrapped (for safe handling, transportation and storage). (The reader is directed to References 4-14.)

In contrast, however, under the heading “criterion 4,” the FDA’s draft guidance document includes a discussion of liquid chemical sterilization in its description of steam, ethylene oxide gas, gas/plasma, dry heat, and chemical vapor sterilizers, as if the effectiveness of liquid chemical sterilization process is distinct from high-level disinfection and is like these other sterilization processes.

(Author’s note: This topic is all the more important today, because recent reports of ‘superbug’ outbreaks linked to GI endoscopes suggest that sterilization, in lieu of disinfection, may reduce the risk of disease transmission.)

Action #2: FDA, please mitigate confusion and clarify whether liquid chemical sterilization is akin to high-level disinfection or comparable to traditional sterilization.

The FDA is also asked to clarify whether it recommends that the wet, processed instruments be dried after completion of a liquid chemical sterilization cycle, not only before storage, but also between patient procedures (refer to Page 19 of the “draft guidance document).

Respectfully submitted, Lawrence F. Muscarella, Ph.D., President of LFM Healthcare Solutions, LLC (a quality improvement company)


1. Muscarella LF. Prevention of disease transmission during flexible laryngoscopy. Am J Infect Control. 2007 Oct;35(8):536-44.

2. Muscarella LF. Recommendations to resolve inconsistent guidelines for the reprocessing of sheathed and unsheathed rigid laryngoscopes. Infect Control Hosp Epidemiol. 2007 Apr;28(4):504-7.

3. Muscarella LF. Reassessment of the risk of healthcare-acquired infection during rigid laryngoscopy. J Hosp Infect. 2008 Feb;68(2):101-7.

4. Food and Drug Administration. Position statement: Liquid chemical sterilization. Accessed August 5, 2011. (See: <http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/GeneralHospitalDevicesandSupplies/ucm208018.htm>

5. Food and Drug Administration. Steris System 1E (SS1E) Liquid Chemical Sterilant – K090036. April 6, 2010.

6. Muscarella LF. Inconsistencies in endoscope-reprocessing and infection-control guidelines: the importance of endoscope drying. Am J Gastroenterol. 2006 Sep;101(9):2147-54.

7. Muscarella LF. The importance of bronchoscope reprocessing guidelines: raising the standard of care. Chest. 2004 Sep;126(3):1001-2; author reply 1002-3.

8. Muscarella LF. Contribution of tap water and environmental surfaces to nosocomial transmission of antibiotic-resistant Pseudomonas aeruginosa. Infect Control Hosp Epidemiol. 2004 Apr;25(4):342-5.

9. Muscarella LF. Leading a horse to water: are crucial lessons in endoscopy and outbreak investigations being learned? Infect Control Hosp Epidemiol. 2002 Jul;23(7):358-60; author reply 360.

10. Muscarella LF. Application of environmental sampling to flexible endoscope reprocessing: the importance of monitoring the rinse water. Infect Control Hosp Epidemiol. 2002 May;23(5):285-9.

11. Muscarella LF. Déjà Vu…all over again? The importance of instrument drying. Infect Control Hosp Epidemiol. 2000 Oct;21(10):628-9.

12. Muscarella LF. Are all sterilization processes alike? AORN J. 1998 May;67(5):966-70, 973-6.

13. Muscarella LF. Anticipated reliability of liquid chemical sterilants. Am J Infect Control. 1998 Apr;26(2):155-6.

14. Muscarella LF. High-level disinfection or “sterilization” of endoscopes? Infect Control Hosp Epidemiol. 1996 Mar;17(3):183-7.

Article by: Lawrence F Muscarella, PhD, President of LFM Healthcare Solutions, LLC. Click here for a list of his company’s services. Posted: 2/7/2015, Rev A.

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