Lessons from the bronchoscope case: What happened at Allegheny General?

by Lawrence F. Muscarella, PhD

In March 2002, several patient infections at Johns Hopkins Hospital in Baltimore were linked by the hospital to a medical device that had been recalled several months earlier. The injuries were attributed to a defective component of a bronchoscope — a flexible, fiber-optic device used to examine the lungs and sample their tissues — that had become colonized with Pseudomonas aeruginosa (referred to as “P aeruginosa”).

Several national and local news sources reported this recall and outbreak. Although most were fair and objective, some of these reports were misleading, suggesting that the reported infections might have been due, not to a design defect, but instead to an inherent inadequacy in current guidelines for reprocessing bronchoscopes and other types of flexible endoscopes. 

This episode raises an important question: What lessons, if any, were learned as a result of this bronchoscope recall and well-publicized P aeruginosa outbreak at Johns Hopkins? The answer to this question appears potentially grim. Last October, a Pittsburgh newspaper reported that an outbreak of P aeruginosa at Pittsburgh’s Allegheny General Hospital had been investigated and determined to be responsible for multiple patient injuries and at least one death following bronchoscopy. Although reportedly not due to a defective bronchoscope, Allegheny General’s outbreak shares many similarities with the P aeruginosa outbreak at Johns Hopkins, as well as several other outbreaks including a P aeruginosa outbreak following bronchoscopy at a hospital in New York City. While bacterial infections following endoscopy can have many different causes, ranging anywhere from defective components to inadequate cleaning or ineffective drying of the endoscope, one reprocessing fact is clear, consistent and incontrovertible: There are no reports of a patient infection from a bronchoscope, gastrointestinal endoscope or endoscopic accessory that was reprocessed in accordance with and as instructed by the guidelines published by several professional organizations.

So, what went wrong at Allegheny General? After having reviewed hundreds of papers in this field of instrument reprocessing, the prevention of nosocomial infection following endoscopy, outbreak management, aseptic technique, instrument design and both disinfection and sterilization, and having written several published papers myself on these topics, I posit the following suggestions and conclusions:

It is my opinion that, although the development of future endoscope designs that facilitate more efficient cleaning and provide unhindered access to every potentially contaminated surface is certainly encouraged, years of experience and a plethora of data have taught us that new endoscope reprocessing guidelines are not needed. Rather, what is needed is strict adherence to the guidelines already published. Simply put, to further minimize the low risk of infection following bronchoscopy (and gastrointestinal endoscopy), I suggest that healthcare staff ensure their endoscopy unit is in complete compliance with published guidelines that describe in step-by-step detail the three crucial steps of endoscope reprocessing: 1) cleaning, 2) high-level disinfection, followed by rinsing with water of a high quality (e.g., bacteria-free) and 3) drying, which is typically achieved by rinsing the endoscope’s channels with 70 percent alcohol, followed by forced-air. Provided each of these steps is performed properly, there is virtually no risk of disease transmission via an endoscope.

Reports suggest that the outbreak at Allegheny General was due in part to the transmission of P aeruginosa via bronchoscopes rinsed with contaminated water during reprocessing. Because P aeruginosa and other waterborne bacteria require moisture for their transmission, bacterial outbreaks like Allegheny General’s suggest that, among other possible reprocessing missteps, the bronchoscope was not dried (step 3, above) before reuse. This possibility raises an inevitable question: During its P aeruginosa outbreak, was Allegheny General drying its bronchoscopes after each reprocessing cycle? And if not, why not? Was there anything in the labeling of the bronchoscope or the automated device used by Allegheny General to reprocess its bronchoscopes that would suggest that the terminal drying step could (or should) be skipped or ignored? These are important questions that warrant an investigation and response. To be sure, drying the endoscope readily destroys P aeruginosa, preventing its transmission during endoscopy.

Further, I also suggest medical facilities consider dedicating more resources to the recruiting, education, training and support of their nurses and reprocessing staff. Never should a medical facility minimize or overlook the importance of endoscope reprocessing to the prevention of patient infection. It is crucial during training to stress the importance of understanding the potentially unique internal design presented by different endoscope models; accounting for and reprocessing each of the endoscope’s channels and potentially contaminated surfaces; and remembering that each reprocessing step is as important as the other.

Due to improper training, some healthcare facilities may be unaware of the importance of thoroughly drying the endoscope after each reprocessing cycle, having concluded that this practice not only is superfluous but also violates the presumed aseptic condition of the endoscope. As previously stated, endoscope drying is recommended by virtually every endoscope reprocessing guideline, and its omission can increase the risk of bacterial infection during endoscopy. Healthcare facilities are also encouraged to evaluate the merits of routine monitoring of the water used to rinse endoscopes during reprocessing (especially if the rinse water is claimed to be sterile), because P aeruginosa and other waterborne bacteria cultured in hospitals’ water supplies have been shown to be the cause of many bacterial outbreaks.

Certain to be heard will be calls to use only disposable endoscopes to prevent disease transmission. Would a disposable bronchoscope have prevented this outbreak at Allegheny General? Yes, but so presumably would drying the bronchoscope (as well as cleaning and high-level disinfection), a simple and inexpensive practice. When given a choice, one would always prefer a new and sterile instrument. But rising healthcare costs in an environment driven toward reducing expenses is a trend likely to continue. Therefore, it is recommended to perform a cost-benefit analysis whenever a more expensive device such as a disposable endoscope is being considered. If a more expensive device demonstrates a clinically significant advantage over a reusable one, then its use, despite its higher price, should be considered. But, to date, data supporting the claim that a disposable endoscope is safer than a reusable endoscope reprocessed according to published guidelines are lacking. (Whether medical facilities would feel pressured, like with many other expensive disposable devices, to reuse disposable endoscopes to reduce costs is unclear.)

Finally, I suggest that we learn from our mistakes and ask ourselves why lessons from published P aeruginosa outbreaks following endoscopy are apparently not being learned. Unfortunately, probably because something in the message about the causes and prevention of bacterial outbreaks in the endoscopic setting is confusing or is being misinterpreted or improperly conveyed to healthcare staff, more outbreaks caused by the transmission of P aeruginosa and other bacteria during bronchoscopy are likely to be reported.

Are we all to blame for this apparent miscommunication? Perhaps. But we can all contribute to reducing the risk of disease transmission during endoscopy, among other considerations, by encouraging the FDA and Centers for Disease Control and Prevention to adhere more diligently to their intended respective missions and ensure that reusable endoscopic instrumentation is safe and effective (I say this notwithstanding my being employed by a company that manufacturers automated endoscope reprocessors and is regulated by the FDA). It is further suggested that the FDA review the current labeling of liquid chemical sterilants, flexible endoscopes and automated endoscope reprocessors to safeguard the public and make certain the labeling of these devices does not in any way mislead users or confuse healthcare staff into skipping or omitting an essential reprocessing step. There are lessons out there to be learned. Let’s all go back to school and learn them.

Lawrence F Muscarella, PhD, is director of research and development and chief of infection control for Custom Ultrasonics Inc., Ivyland, PA. Dr. Muscarella also serves as editor-in-chief of the newsletter, The Q-Net Monthly. He can be reached at 215-364-8577, or at editor@myendosite.com.

HPN

March