A number of years ago this blog’s founder – Dr. Lawrence F Muscarella – wrote the Food and Drug Administration (FDA) requesting the Agency review for clarity and consistency, among other documents, its published guidance document for manufacturers seeking to market disposable sheaths used as protective barriers to cover ear, nose, and throat (“ENT”) endoscopes.[10]

Entitled “Guidance for Manufacturers Seeking Marketing Clearance of Ear, Nose, and Throat Endoscope Sheaths Used as Protective Barriers,”[11] this guidance document (which has not been updated or revised as of the writing of this blog) was issued on March 12, 2000.

This and four other important infection-control topics, along with Dr Muscarella’s suggested “action” to resolve each of the topic’s potential deviation, may be read by downloading the more complete PDF version of this article at clicking here.

In this correspondence with the FDA,[10] Dr. Muscarella focused on the following statements in this guidance document about sheaths used to cover ENT endoscopes (and comparable flexible endoscopes that may be used with a protective cover or sheath, to reduce the risk of contamination):[11]

  • ENT endoscopes are “semi-critical devices as they come in contact with mucous membranes, which may or may not be intact”; and
  • the federal Centers for Disease Control and Prevention (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.”

FDA Guidance

Suggesting that the use of an effective protective sheath, however, would “lower” the ENT endoscope’s infection-control device classification from semi-critical to non-critical, this same FDA guidance document also states that:[11]

  • “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 (e.g., labeling). If the applicant (i.e., the manufacturer) sufficiently demonstrates protective barrier properties of the finished device, a cleaning procedure followed by an intermediate disinfection step will be required”; 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.”

Dr. Muscarella questions this recommendation to “wipe” an instrument’s surfaces with a gauze pad soaked with 70% isopropyl alcohol to achieve intermediate-level disinfection.*

[* Note: The suggestion to “wipe” an instrument’s surfaces with a gauze pad soaked with 70% isopropyl alcohol to achieve intermediate-level disinfection is questioned. Whereastext continued in the footnote at the end of this article.]

Discussion

These statements in this FDA guidance document raise a number of questions, in part because they are seemingly inconsistent with:

  1. the FDA’s current advice, which is provided in the Agency’s aforementioned draft guidance document on the reprocessing of medical devices (issued May, 2, 2011) – click here to read it;[9]
  2. the FDA’s stated goal to improve the quality of instrument reprocessing and prevent HAIs; and
  3. the CDC’s published guideline for the disinfection and sterilization of instruments in healthcare facilities (click here to read it).[3]

A Worst-Case Paradigm

As previously noted, the FDA acknowledges that ENT endoscopes are semi-critical devices.[11] But, whereas its guidance document discussing the clearance of protective sheaths (finalized on March 12, 2000; – click here to read it) recommends intermediate-level disinfection of the endoscope after removal of the used sheath,[11] the FDA asserts in its draft guidance document on the reprocessing of medical devices[9] that a reusable instrument’s reprocessing instructions “should assume (that) the device is used uncovered” (i.e., as if no sheath had been used during the procedure), “because of the potential for loss of cover integrity during use”[9]—which is an instruction that requires the reusable semi-critical instrument be at least high-level (not intermediate-level) disinfected after the sheath’s removal.

The FDA writes in a draft guidance document that a reusable instrument’s reprocessing instructions “should assume (that) the device is used uncovered” … “because of the potential for loss of cover integrity during use.”[9]

CDC Recommendations

The CDC would agree, having similarly stated in its guideline on disinfection and sterilization that the use of a protective (single-use) sheath to cover a reusable instrument neither lowers the instrument’s infection-control classification (e.g., from semi-critical to non-critical) nor reduces its required level of disinfection (e.g., from high-level to either intermediate– or low-level disinfection).[3]

In its 2008 guideline on disinfection and sterilization, the CDC writes that the use of a protective sheath to cover a reusable semi-critical instrument (e.g., an “ENT endoscope, a flexible cystoscope) does not reduce the instrument’s required level of disinfection – namely, from high-level to either intermediate– or low-level disinfection.[3]

Whether confusion about the minimum reprocessing requirement of an “ENT” endoscope, cystoscope, or other type of  flexible endoscope sheathed during the procedure has been linked to HAIs is unclear.

Yet, according to the CDC, the use of a protective sheath does not reduce a reusable semi-critical instrument’s minimum level of disinfection from high-level to intermediate-level.[3,9]

Click here to read the abstract of Dr. Muscarella’s article in the peer-reviewed medical literature entitled: “Recommendations to resolve inconsistent guidelines for the reprocessing of sheathed and unsheathed rigid laryngoscopes.”

Corrective Action

The FDA is respectfully requested to consider updating its published “Guidance for Manufacturers Seeking Marketing Clearance of Ear, Nose, and Throat Endoscope Sheaths Used as Protective Barriers” (and all other relevant documents):

  • to prevent user confusion;
  • to clarify for manufacturers the minimum labeling requirements for reprocessing their marketed reusable, semi-critical instruments;
  • improve the quality of instrument reprocessing; minimize the risk of disease transmission; and
  • to be consistent both with the FDA’s draft guidance document discussing the reprocessing of medical devices[9] and with CDC guidelines.[3]

The revised FDA guidance document would no longer recommend intermediate-level disinfection of ENT endoscopes (and other comparable types of flexible endoscopes, including cystoscopes) after removal of the used sheath.

Instead, it would reiterate that ENT endoscopes are semi-critical devices that require high-level disinfection (or sterilization), no matter whether covered with a protective sheath.[9,12]

Remember that this and four other controversial infection-control topics may be read by downloading the more complete PDF version of this article at clicking here.

Manufacturers

And, too, manufacturers that market their “ENT” endoscopes (and comparable flexible endoscopes, including cystoscopes) as devices that do not require high-level disinfection, because the device is covered with a a single-use sterile sheath to prevent any contact with the patient — click here for an example of one such marketed product — might have to be revised to require high-level disinfection (or sterilization), to prevent disease transmission, no matter whether covered with a protective sheath.[9,12]

The FDA is respectfully request to resolve this confusion.

The references to this article, which are not in sequence, are available by clicking here.

[* Note: The suggestion to “wipe” an instrument’s surfaces with a gauze pad soaked with 70% isopropyl alcohol to achieve intermediate-level disinfection is questioned. Whereas this practice might achieve low-level disinfection, wiping does not ordinarily provide a sufficient exposure time to achieve intermediate-level disinfection, defined to destroy most types of microorganisms, including fungi, viruses, and mycobacteria, but not bacterial endospores.]

Article by: Lawrence F Muscarella PhD; posted on 1-16-2013; revised: 10-22-2014, Rev A.

Leave a Reply

Your email address will not be published.