Sampling methods for flexible endoscopes without a working channel: a scoping review

A diagnostic flexible laryngoscopy using a flexible endoscope (FE) without a working channel can become contaminated when inserted through the nose to inspect the throat. Microbiological surveillance is necessary to ensure adequate reprocessing. A lack of knowledge exists about the most accurate way to assess microbiological contamination on the surface of FEs without a working channel. A scoping review of research on sampling techniques for FEs without a working channel was done to identify frequently used sampling techniques and to determine the best way to assess microbiological contamination.

PubMed, Embase, Cochrane Library, and CINAHL databases were searched. Data related to the sampling technique and bacterial contamination were extracted.

Twelve of the 378 studies met the inclusion criteria. None compared sampling techniques, most studies investigated the efficacy of several disinfection methods. Retrieved sampling techniques were immersion, swabbing, and wiping. Immersion and wiping could detect bacterial contamination on contaminated FEs without a working channel. Two out of six studies using a swabbing method found bacterial contamination on contaminated FEs without a working channel. Three studies using the swabbing method detected bacterial contamination after disinfection. One study did not retrieve microorganisms after disinfection using the swabbing method.

Three different sampling techniques were extracted: immersion, wiping, and swabbing, which could all detect microbiological contamination on contaminated FEs without a working channel. However, this scoping review identified significant gaps in literature. Additional research is needed to determine the best sampling technique(s) for FEs without a working channel to detect microbiological contamination.