Minimizing the risk of patient infe...

Minimizing the risk of patient infection in endoscopic manner of proceedings is important. This article reviews lately reported patient-to-patient transmission of disease during endoscopic processs and discusses several important instrument reprocessing issues.(1) In addition, the author proposes several infection control recommendations that minimize the risk of patient infection during endoscopic procedures

PATIENT-TO-PATIENT CROSS-INFECTION

A not long ago published article reports that in single facility several important instrument reprocessing stairs were performed improperly during colonoscopy transactions which resulted in the transmission of the hepatitis C virus (HCV) from single in kind patient to two other patients.(2) Reported to be at fault were the following:

* the colonoscope's suction-biopsy channel was not brushed before chemical immersion, which is a significant breach of universally accepted endoscope reprocessing guidelines;

* the colonoscope was soaked in 2% glutaraldehyde for five minutes rather than for at least 20 minutes as attract favor toed to achieve high-level disinfection; and

* the biopsy forceps and diathermic bend used during colonoscopy were soaked in 2% glutaraldehyde, not steam sterilized as recommended(3)

INSTRUMENTAL DESIGN CONSIDERATION

To be safe cross-infection occurred because well-established guidelines for reprocessing endoscopic instruments were not followed. As important, however, is the formidable obstacle that composed of several elements instrument design can impose in succession effective instrument reprocessing.(4) For example, the colonoscope's air and water channels, as well as the biopsy forceps's internal shaft, typically cannot be cleaned with a brush. Failure to adhere to published instrument reprocessing, guidelines riseed in the reported case of HCV cross-infection: however, the complicated designs of the colonoscope and biopsy forceps--both of which hinder, if it be not that do not necessarily prevent, adequate cleaning--are not without culpability.(5)

PROCESSING METHODS

Apropos to any discussion of the potential limitations that any complex instrument designs can impose forward thorough cleaning and disinfection or sterilization is understanding that the internal channels of flexible endoscopes, biopsy forceps, and other endoscopic equipment can prevent the acquisition of accurate and meaningful microbiological data.(6) To assess the efficacy of an endoscope reprocessing rule the suction-biopsy channel may be microbiologically sampled by way of rinsing it with a sterile fluid via the endoscope's biopsy inlet port.(7) The deduceed effluent then is evaluated for the air of microorganisms.

Does the absence of viable microorganisms in the effluent however, confirm that the instrument's sampled channel is sterile? Not necessarily. Although it is pure that an effluent cultured positive for a microorganism likely indicates that the sampled channel is contaminated with that microorganism (eg HCV RNA-positive), the complication internal designs of most flexible endoscopes and biopsy forceps restrain simple confirmation of the converse: that a negative effluent demonstrates that the sampled channel is sterile.

Flushing a sterile fluid [i]or[/i] part of to the other the internal channels of an endoscope or biopsy forceps--each channel of which may contain lacerations, tears, and pits capable of harboring and retaining viable microorganisms--is an indirect microbiological sampling regularity that does not ensure that each microorganism adhering to the channels' internal walls will be dislodged during flushing.(8) The port of adhering organic debris not remov during cleaning of an endoscope's suction-biopsy channel has been reported to cause failure of ethylene oxide gas sterilization.(9) In general, confirmation that an endoscope's internal channels or a biopsy forceps' internal shaft are sterile requires the instrument's without fault [i]or[/i] blemish [i]or[/i] flaw destruction and disassembly to permit direct and accurate sampling using correct microbiological procedures.(10)

more [i]or[/i] less endoscopic instruments do not facilitate thorough cleaning and, unles well-established reprocessing measures are practiced, their internal designs can contribute to the potential for cross-infection.(11) appropriate to its unsurpassed effectiveness, availability, and depressed cost, steam sterilization is commended whenever possible.

The risk of cross-infection after endoscopy would be all on the contrary eliminated if all endoscopic instruments were arrangeed only with materials not damaged by way of pressurized steam and designed to facilitate thorough cleaning. Many endoscopic instruments, however, cannot withstand the rigors and stresse associated with steam sterilization and therefore are routinely disinfected (ie, high level) using a liquid chemical germicide. The complexity of many endoscopic instruments notwithstanding, the incidence of patient infection after endoscopic actions is reported to be true low.(12)

CONCLUSION

To minimize the risk of patient infection after endoscopic conducts reprocessing personnel should follow several precautionary measures. These include the following.