CGRN Infection Prevention and Control 2 — Questions and Answers
Question 1: According to the Spaulding classification, endoscopes that contact intact mucous membranes are categorized as which level of device?
- Critical
- Semi-critical (Correct answer)
- Non-critical
- Sterile
Correct answer: Semi-critical
Semi-critical devices contact intact mucous membranes and require high-level disinfection at minimum.
The Spaulding classification: Critical items (enter sterile tissue, require sterilization), semi-critical items (contact mucous membranes, require HLD), and non-critical items (contact intact skin, require low-level disinfection). Flexible endoscopes are semi-critical.
Question 2: What is the minimum contact time required for high-level disinfection of endoscopes using 2% glutaraldehyde at 25°C?
- 5 minutes
- 10 minutes
- 20 minutes (Correct answer)
- 45 minutes
Correct answer: 20 minutes
High-level disinfection with 2% glutaraldehyde requires a minimum of 20 minutes at 25°C.
For 2% glutaraldehyde, the FDA-cleared minimum contact time is 20 minutes at 25°C. Some AERs use different chemicals with shorter times (e.g., OPA requires 12 minutes at 20°C, peracetic acid may require only 5 minutes).
Question 3: Which step in endoscope reprocessing is considered the most critical for reducing bioburden?
- High-level disinfection
- Manual cleaning (brushing and enzymatic detergent) (Correct answer)
- Rinsing with sterile water
- Drying with forced air
Correct answer: Manual cleaning (brushing and enzymatic detergent)
Manual cleaning physically removes organic material and bioburden that can interfere with disinfection efficacy.
Manual cleaning is the most critical step because it physically removes blood, tissue, and secretions that can shield bacteria from chemical disinfectants. Proper cleaning achieves a 4-6 log10 bioburden reduction before HLD even begins.
Question 4: A patient scheduled for endoscopy has a known history of Creutzfeldt-Jakob disease (CJD). What is the recommended approach?
- Standard high-level disinfection is sufficient
- Use a disposable endoscope or quarantine the scope after use (Correct answer)
- Extended soaking in glutaraldehyde for 1 hour
- Autoclave the flexible endoscope at 134°C
Correct answer: Use a disposable endoscope or quarantine the scope after use
Prions are resistant to standard disinfection. Guidelines recommend disposable endoscopes or quarantining/destroying the scope.
CJD prions are extremely resistant to standard disinfection including glutaraldehyde and standard autoclaving. For known CJD patients, use single-use disposable endoscopes or quarantine the scope until diagnosis confirmed, with destruction if CJD is confirmed.
Question 5: What is the purpose of performing a leak test on an endoscope before reprocessing?
- To verify the disinfectant concentration
- To detect damage to the endoscope's internal channels and outer sheath (Correct answer)
- To confirm the AER is functioning properly
- To measure residual bioburden
Correct answer: To detect damage to the endoscope's internal channels and outer sheath
Leak testing detects holes or cracks that could allow fluid infiltration and damage internal components or harbor microorganisms.
Leak testing detects damage to the outer sheath, bending rubber, channel linings, or O-ring seals. If a leak is detected, the scope must NOT be immersed in liquid, as fluid can infiltrate internal components causing expensive damage. The scope should be sent for repair.
Question 6: Which organism is the most frequently reported pathogen associated with endoscope-related infections due to inadequate reprocessing?
- Staphylococcus aureus
- Pseudomonas aeruginosa (Correct answer)
- Clostridium difficile
- Escherichia coli
Correct answer: Pseudomonas aeruginosa
Pseudomonas aeruginosa is most commonly reported due to its ability to thrive in moist environments and form resilient biofilms.
Pseudomonas aeruginosa is most frequently implicated due to its ability to thrive in moist environments and form resilient biofilms within endoscope channels. Other organisms include Salmonella, H. pylori, and CRE associated with duodenoscopes.
CGRN Infection Prevention and Control 2
According to the Spaulding classification, endoscopes that contact intact mucous membranes are categorized as which level of device?