Decontamination
What this domain tests
Decontamination is the highest-risk area of the department. The exam asks how you protect staff, prevent cross-contamination, and clean items so later steps can work. Questions cluster around PPE, point-of-use care, manual and mechanical cleaning, high-level disinfection, and spill or sharps response.
Core rules and concepts
- Standard precautions apply to every item; there is no 'clean' patient.
- Keep the one-way workflow: receiving → decontamination → preparation/assembly → sterilization → sterile storage. Clean items never cross back through decon.
- Transport soiled items in closed, leak-proof, labeled containers; never in open bins or hands.
- PPE for decon: impervious gown over scrub suit, hair cover, mask, eye protection/face shield, and gloves; change gloves and perform hand hygiene between tasks. Remove PPE before leaving the room.
- Point-of-use treatment keeps soil moist. Use enzymatic foam or a damp towel; never soak in saline, which causes pitting and corrosion.
- Cleaning removes bioburden and must happen before disinfection or sterilization. Detergent choice, dilution, temperature, and contact time follow the manufacturer's IFU.
- Manual cleaning reaches hinges, lumens, and serrations with soft brushes and lumen brushes. Avoid metal brushes that scratch passivation.
- Washer-disinfectors use thermal disinfection; load items with hinges open and lumens connected to flush ports.
- Ultrasonic cleaning works by cavitation. Degas the solution, use a basket, avoid overloading, and follow the frequency and time in the IFU.
- High-level disinfection (HLD) is for semi-critical items such as flexible endoscopes. Verify minimum effective concentration (MEC) before each use, respect soak time and temperature, rinse with critical water, and dry thoroughly. Never top off a glutaraldehyde bath; discard it when it fails MEC or reaches its reuse limit.
Worked example
A flexible endoscope returns with visible blood in the suction channel. The tech leak-tests it, brushes every channel until no debris appears, runs enzymatic detergent through, rinses, then places it in HLD. The MEC strip shows the solution is below the minimum. Reasoning: the solution must be discarded and replaced, not topped off; the scope is reprocessed from the manual cleaning step with the new solution. Rinsing with filtered water and forced-air drying follow, and the scope is hung vertically. Documentation includes the MEC result, soak time, and reprocessing date.
Traps that cost marks
- Wearing decon PPE into the clean assembly area.
- Using saline soaks to 'keep instruments wet.'
- Skipping lumen brushing because the item will be sterilized.
- Relying on a chemical indicator or sterilizer to fix poor cleaning.
- Rinsing HLD items with tap water or storing them damp.