IAHCSMM Flexible Endoscope Reprocessing 1 — Questions and Answers
Question 1: According to ANSI/AAMI ST91, what is the FIRST step in flexible endoscope reprocessing after a procedure?
- Submerging the endoscope in high-level disinfectant immediately
- Point-of-use pre-cleaning: wiping the insertion tube and flushing channels with detergent solution or water at the procedure site (Correct answer)
- Sending the endoscope directly to the sterilizer
- Performing a leak test before any cleaning
Correct answer: Point-of-use pre-cleaning: wiping the insertion tube and flushing channels with detergent solution or water at the procedure site
Point-of-use pre-cleaning (wiping the insertion tube and flushing channels with enzymatic solution or water) must be performed immediately after removal from the patient to prevent soil from drying before formal reprocessing.
ANSI/AAMI ST91 (Flexible and semi-rigid endoscope processing in health care facilities) requires that point-of-use pre-cleaning begin immediately after withdrawal from the patient. This involves: wiping the external surface with a damp cloth or sponge, activating suction to flush channels with detergent or water, and capping the scope. Pre-cleaning prevents blood and tissue from drying in channels, which would be extremely difficult to remove later and could harbor pathogens through subsequent reprocessing.
Question 2: A leak test is performed on a flexible endoscope BEFORE manual cleaning primarily to:
- Verify the scope camera function is working properly
- Detect any damage to the outer sheath or internal channels that would allow fluids to enter the scope internal components (Correct answer)
- Confirm the scope has been pre-cleaned adequately
- Measure the scope channel diameter for brush selection
Correct answer: Detect any damage to the outer sheath or internal channels that would allow fluids to enter the scope internal components
The pre-cleaning leak test detects damage to the endoscope outer sheath or seals; if fluid enters during reprocessing through a breach, internal components can be permanently damaged.
Flexible endoscopes have a complex internal structure of channels, optics, and electronic components protected by an outer sheath. The leak test detects breaches in the sheath, channel perforations, or seal failures. Immersing a scope with an undetected leak in detergent or disinfectant solution causes fluid infiltration into internal components, leading to irreparable scope damage and potentially contaminating subsequent patients. The leak test is mandated before every reprocessing cycle per AAMI ST91.
Question 3: Which disinfection level is required for flexible endoscopes used in procedures that contact mucous membranes (e.g., upper GI endoscopes)?
- Low-level disinfection (LLD)
- Intermediate-level disinfection (ILD)
- High-level disinfection (HLD) (Correct answer)
- Sterilization
Correct answer: High-level disinfection (HLD)
Flexible endoscopes that contact mucous membranes are classified as semi-critical items under Spaulding Classification and require at least high-level disinfection (HLD).
Spaulding Classification categorizes flexible endoscopes that contact mucous membranes (e.g., gastroscopes, colonoscopes, bronchoscopes) as semi-critical devices requiring at minimum high-level disinfection. HLD eliminates all microorganisms except high concentrations of bacterial spores. Common HLD agents for endoscopes include glutaraldehyde (2%), ortho-phthalaldehyde (OPA, 0.55%), and peracetic acid. Endoscopes used in sterile body cavities (e.g., arthroscopes, laparoscopes) are critical items requiring sterilization when possible.
Question 4: What is the significance of minimum effective concentration (MEC) testing for high-level disinfectants used in endoscope reprocessing?
- MEC testing confirms the endoscope channel length is correct
- MEC testing verifies the disinfectant has not been diluted below the concentration required to achieve HLD (Correct answer)
- MEC testing measures the temperature of the disinfectant solution
- MEC testing is only required annually by AAMI
Correct answer: MEC testing verifies the disinfectant has not been diluted below the concentration required to achieve HLD
MEC testing verifies that the high-level disinfectant concentration has not dropped below the effective threshold due to repeated use or dilution, ensuring it remains capable of achieving HLD.
High-level disinfectants (e.g., glutaraldehyde, OPA) have a minimum effective concentration below which they cannot reliably achieve HLD. With repeated use, disinfectant solutions become diluted by carry-over water and lose active ingredient potency. MEC test strips specific to each disinfectant chemical must be used before every use or at frequency specified by manufacturer IFU to verify the solution is above the effective concentration threshold. Solutions testing below MEC must be discarded and replaced. AAMI ST91 requires MEC testing before each endoscope reprocessing cycle.
Question 5: After high-level disinfection, flexible endoscopes must be rinsed with:
- Tap water directly from the faucet to save time
- Sterile water or filtered water meeting bacterial quality standards, with each channel flushed completely (Correct answer)
- The same high-level disinfectant solution at a lower concentration
- Isopropyl alcohol only
Correct answer: Sterile water or filtered water meeting bacterial quality standards, with each channel flushed completely
AAMI ST91 requires rinsing endoscopes after HLD with sterile water or filtered high-quality water to remove disinfectant residues that could harm patients, flushing all channels completely.
After HLD, residual disinfectant must be removed by thorough rinsing to protect the next patient from chemical injury (e.g., glutaraldehyde colitis). The rinse water quality is critical: tap water can contain waterborne pathogens (Pseudomonas aeruginosa, Mycobacterium spp., Legionella) that can recontaminate the scope after HLD. AAMI ST91 recommends sterile water or filtered water (0.2 micron filter, meeting AAMI water quality standards) for the final rinse. All channels must be completely flushed.
Question 6: What is the recommended maximum hang-time for a reprocessed flexible endoscope stored in a ventilated drying cabinet?
- 6 months without restriction
- Per the facility validated written protocol, often 5 to 7 days in a ventilated cabinet; after which the scope must be reprocessed before use (Correct answer)
- 24 hours maximum regardless of cabinet type
- Indefinitely if kept in a sealed plastic bag
Correct answer: Per the facility validated written protocol, often 5 to 7 days in a ventilated cabinet; after which the scope must be reprocessed before use
Reprocessed endoscopes must be stored per a facility-validated hang-time protocol; AAMI ST91 allows facilities to establish validated hang-times, often 5 to 7 days in ventilated cabinets, after which reprocessing is required.
Unlike terminally sterilized packaged items (which use event-related sterility), HLD-reprocessed endoscopes are not in sterile packaging and are susceptible to environmental recontamination during storage. AAMI ST91 requires facilities to establish and validate endoscope hang-times based on storage cabinet design, drying adequacy, and contamination risk. Many facilities establish 5 to 7 day hang-times in drying and ventilated cabinets. After the validated hang-time expires, the scope must be reprocessed before patient use.
IAHCSMM Flexible Endoscope Reprocessing 1
According to ANSI/AAMI ST91, what is the FIRST step in flexible endoscope reprocessing after a procedure?