7.2 Inspection for Cleanliness: Methods

The Methods, From Simple to Sensitive

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Magnification Is the Working Standard

The bulletin's own example for cleanliness inspection method is a magnifying lamp, and it is the right one. The features where soil hides — serration valleys, box-lock interiors, tooth interstices, ratchet teeth, threaded areas, cannulation openings — are at or below the limit of unaided vision.

Practical technique:

1. Work under a lighted magnifier, typically in the 2x to 5x range, with the instrument dry.
2. Inspect the jaw faces and serrations, then rotate to view them from the side.
3. Open and close the instrument fully so the box lock interior and the mating surfaces are exposed at multiple positions.
4. Inspect the ratchet teeth and the shank surfaces around them.
5. Inspect screws, threads, and any joint.
6. Inspect tips under higher magnification on micro and fine instruments.
7. Look for cracks and corrosion, which magnification reveals at the same time as soil.

Magnification also enables the rest of the inspection domain: sharpness edges, jaw alignment, insulation surface defects, and tip damage are all magnification-dependent judgements.

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Borescopes for Channels

A borescope is a small-diameter rigid or flexible optical inspection scope with its own illumination, used to look inside a lumen. It is the only method that directly answers "is the inside of this channel clean and undamaged?"

What borescope inspection typically reveals that nothing else does:

• Retained soil and biofilm at bends and at the far end of long channels
• Internal corrosion, pitting, and scratches in suction lumens and endoscope channels
• Debris trapped at the junction of a channel and a port
• Damage to the internal surface of flexible endoscope channels

Borescopes are used routinely on flexible endoscopes and increasingly on other lumened devices. They are also an investigative tool: when a residue test fails, the borescope shows where and why.

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Residue Chemistry Tests

These are swab or flush tests that develop a colour or a luminescent reading in the presence of specific residues.

They are used to verify the cleaning process and to investigate suspected failures, not as a substitute for looking at every instrument. Results are documented and trended; a rising trend is a signal to examine detergent concentration, water temperature, washer mechanical action, load configuration, or point-of-use practice.

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Actuation: Inspecting What You Cannot See at Rest

Soil hides in the parts of an instrument that move. Inspection therefore includes making them move:

• Hinged instruments: open and close fully; inspect the box lock interior at several positions.
• Ratcheted instruments: run through every tooth.
• Take-apart instruments: inspect disassembled; an assembled take-apart Kerrison or laparoscopic instrument cannot be assessed.
• Rotating and articulating instruments: rotate through full travel; articulate robotic and laparoscopic wrists.
• Stopcocks and valves: turn through all positions and inspect the plug and body.
• Spring instruments: open and release, watching the spring region.

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Lumen Patency Verification

For any channelled device, cleanliness inspection includes confirming the channel is open and clean:

1. Pass a correctly sized brush completely through so it exits the far end.
2. Flush with water and observe clear, unobstructed flow from the distal end.
3. Pass the stylet where the device has one, confirming free travel over the full length.
4. Borescope the channel where the device and policy call for it.
5. Dry the lumen — with filtered compressed air where permitted — because retained moisture causes corrosion and contributes to wet packs.

A lumen that flushes slowly, that produces cloudy or particulate effluent, or through which a brush binds is failing inspection and goes back to decontamination — or, if the obstruction is damage rather than soil, to repair.

Lighting, Ergonomics and the Inspector

Inspection quality is limited by the conditions the inspector works in, and this is a legitimate content area rather than a comfort issue.

Illumination at the assembly bench must be strong and even. Under-lit benches hide exactly the low-contrast findings — a film of dried protein, a faint haze in a box lock — that inspection exists to catch. A lighted magnifier provides both magnification and shadow-free light at the working distance and is the practical standard for routine inspection.

Magnification is normally in the region of 3 to 8 times for general work. Very high magnification is counterproductive for routine scanning because the field of view becomes too small to cover an instrument efficiently; it is reserved for examining a specific suspect feature or for micro-instruments.

Fatigue measurably degrades detection. Inspection is a sustained-attention task, and the rate at which real defects are missed rises through a long shift. Departments manage this with task rotation, adequate break scheduling, correct bench height and seating, and by not making a single technician inspect at speed under production pressure. A technician who is rushed will pass instruments.

Building a Defensible Verification Program

The periodic testing that sits alongside per-instrument inspection needs to be organised, not ad hoc.

Define what is tested: washer-disinfector cleaning efficacy with a commercial soil-challenge indicator, ultrasonic cavitation with a foil test or commercial equivalent, and residual-soil detection on sampled instruments using protein or ATP methods. Define how often — cleaning-efficacy and cavitation checks are typically performed at least daily, and after any repair or relocation of the equipment. Define who performs, reads, and records them, and define what happens on a failure: the equipment is taken out of service, the loads processed since the last acceptable test are identified and reprocessed, and the failure and corrective action are documented.

Records must be retained and retrievable. The value of the program is realised only when a question is asked later about a specific date, and the record either answers it or does not.

Matching the Method to the Device

Choose the method by what you need to see. Direct visual inspection handles external surfaces. Magnification handles serrations, box locks, teeth, and tips. A borescope is the only way to see inside a long lumen or channel and is increasingly expected for flexible endoscope channels and long rigid lumens. Chemical residue tests detect what no optical method can see. Actuation — opening, closing, rotating, and disassembling — exposes surfaces that are simply not visible at rest, and is the step most often skipped.