Common Areas of Fluid Invasion

Fluid invasion can occur whenever a flexible endoscope is immersed in water, cleaning solution, disinfectant or other fluid if the scope’s outer water-resistant shell is compromised. Following are common areas for fluid to enter the scope and possible causes for the water-resistant seal or component to fail.

 

Bending Rubber - The bending rubber is the soft rubber-like material covering the bending section of the scope. It is thin and very flexible to maintain complete mobility of the bending section. The bending rubber is very susceptible to cuts, holes or tears from any sharp object. Damages to this area may occur most any time during the daily life cycle of the scope, including storage and transportation. The bending rubber can be protected by:

1. Using bite blocks to prevent patient bites on the bending rubber.
2. Keeping endoscopes separate from one another. The light guide connector ports have edges sharp enough to cut or tear the bending rubber. Do not stack scopes. Stacking typically occurs in cleaning areas on busy procedure days.
3. Keeping the light guide connector ports away from the bending rubber when transporting scopes.
4. Transporting scopes separately from accessories. Sharp edges on accessories can easily puncture the bending rubber.

Insertion Tube Cover - Layers of rubber-like material with a urethane outer surface comprise the insertion tube cover. The insertion tube cover is more cut and puncture resistant than the bending rubber but can be damaged in similar ways, such as biting and contact with sharp objects.

Control Body – The control body components are mostly solid plastic and metal parts. These parts are difficult to damage without severe impact damage; however, the o-ring seals where the different parts join together are much more delicate. Even slight impact to the control body may cause the o-ring seals to misalign. This can happen even if the impact was not severe enough to cause a dent or other indication of impact. A misaligned o-ring allows fluid to pass directly into the control body cavity. Common causes of control body impact are rough or poor handling in the cleaning sink, too small storage area or storage areas that are difficult to access.

Video Remote Switches – Video endoscopes have a series of rubber-covered video remote switches. The rubber cover is thicker than the bending rubber material, but it can still be damaged by sharp accessories or rough treatment in a sink or automated washer basin.

Light Guide Tube – The light guide tube is constructed similarly to the insertion tube and can be damaged in the same manner. Damage may also occur to the light guide tube if the scope is placed improperly in an automated reprocessing unit, particularly if it is placed where the cover may pinch or tear the outer cover. The entire scope, and especially the light guide tube, must be placed carefully inside any automated reprocessing unit.

Light Guide Connector – The light guide connector components are typically very sturdy and damaged only by severe impact. The most common fluid invasion area at the light guide connector is the video connection area on video endoscopes. The electrical contact/video connection area must be covered with a protective water-resistant cap in order to make video scopes completely water-resistant. Failure to install the cap securely prior to immersion may allow large amounts of fluid to directly enter the light guide connector. Damaged or misapplied water-resistant caps may also allow fluid invasion. Poorly installed or damaged caps can be detected during the pressure test.

Internal Instrument Channels – Internal channels can be damaged by using excess force when passing accessories or by passing damaged accessories. As a warning, this can occur during a cleaning activity performed after a successful pressure test, allowing for fluid invasion during subsequent reprocessing steps.

Next Page: Effects of Fluid Invasion

With its hollow make up, fluid entering one portion of the endoscope may travel and cause damage to multiple internal components..