CMDRT - Certified Medical Device Reprocessing Technician Decontamination Processes Questions and Answers 2 — Questions and Answers

Question 1: What is the primary purpose of enzymatic detergent in the decontamination process?

To sterilize instruments
To break down organic soil such as blood and tissue (Correct answer)
To lubricate instrument joints
To disinfect work surfaces

Correct answer: To break down organic soil such as blood and tissue

Enzymatic detergents contain specific enzymes (proteases, lipases, amylases) that break down organic matter like blood, tissue, and body fluids on instruments before further cleaning steps.

Enzymatic detergents are a critical component of the decontamination process in medical device reprocessing. They contain biological enzymes — commonly proteases (for protein), lipases (for fats), and amylases (for starches) — that chemically break down organic soil at the molecular level. This is essential because organic residue left on instruments can shield microorganisms from subsequent disinfection or sterilization, compromise patient safety, and cause biofilm formation. Per CSA Z314.8, enzymatic cleaning is a recommended step before mechanical or manual cleaning of reusable medical devices.

Question 2: According to CSA standards, what is the recommended water temperature range for pre-soaking instruments in enzymatic solution?

Cold water below 10°C
Lukewarm water between 20°C and 43°C (Correct answer)
Hot water above 60°C
Boiling water at 100°C

Correct answer: Lukewarm water between 20°C and 43°C

CSA standards recommend lukewarm water (20°C to 43°C) for enzymatic solutions because temperatures above 43°C can denature the enzymes, reducing their effectiveness, while very cold water slows enzyme activity.

The temperature of water used with enzymatic detergents is critical to their performance. CSA Z314.8 specifies that the water should be lukewarm, typically between 20°C and 43°C. Water that is too hot (above 43°C) causes thermal denaturation of the enzymes, rendering them ineffective at breaking down organic soil. Conversely, water that is too cold significantly slows the enzymatic reaction rate. Additionally, hot water can cause proteins in blood and tissue to coagulate and fix onto instrument surfaces, making them harder to remove. This is why instruments should never be rinsed in hot water as a first step.

Question 3: What is the correct sequence of steps in the decontamination workflow?

Sterilization → Cleaning → Disinfection → Rinsing
Pre-cleaning at point of use → Transport → Cleaning → Rinsing → Disinfection/Sterilization (Correct answer)
Packaging → Sterilization → Cleaning → Storage
Transport → Sterilization → Cleaning → Inspection

Correct answer: Pre-cleaning at point of use → Transport → Cleaning → Rinsing → Disinfection/Sterilization

The standard decontamination workflow follows a logical progression: pre-cleaning at point of use to prevent soil from drying, safe transport to the reprocessing area, thorough cleaning, rinsing, and then disinfection or sterilization.

The decontamination workflow in Canadian medical device reprocessing follows a well-defined sequence established by CSA Z314.8 and provincial health authority guidelines. It begins with pre-cleaning at the point of use, where gross soil is removed or kept moist to prevent drying. Instruments are then transported safely in closed, puncture-resistant containers to the Medical Device Reprocessing Department (MDRD). Upon arrival, they undergo thorough cleaning (manual or mechanical), followed by rinsing to remove cleaning agents. Only after cleaning can effective disinfection or sterilization occur, as residual organic matter can interfere with these processes. Each step builds on the previous one.

Question 4: What type of water should be used for the final rinse of instruments after cleaning?

Tap water
Distilled or treated water meeting CSA specifications (Correct answer)
Saline solution
Soapy water

Correct answer: Distilled or treated water meeting CSA specifications

The final rinse should use distilled, deionized, or reverse-osmosis treated water to prevent mineral deposits (spotting) on instruments and to avoid introducing contaminants that may be present in tap water.

The quality of rinse water is an important factor in medical device reprocessing. While tap water may be acceptable for initial rinses, the final rinse should use treated water — distilled, deionized (DI), or reverse-osmosis (RO) water — as specified in CSA Z314.8. Untreated tap water contains dissolved minerals (calcium, magnesium, iron) that can leave deposits on instrument surfaces, causing spotting and staining. These mineral deposits can also interfere with sterilization by creating a barrier between the sterilant and the instrument surface. In addition, tap water may contain microbial contaminants that could recontaminate cleaned devices.

Question 5: Why must instruments with lumens receive special attention during decontamination?

Lumens are more expensive to replace
Soil and biofilm can accumulate inside narrow channels where standard cleaning cannot reach (Correct answer)
Lumens do not need sterilization
Instruments with lumens are always single-use

Correct answer: Soil and biofilm can accumulate inside narrow channels where standard cleaning cannot reach

Lumened instruments have narrow internal channels where blood, tissue, and biofilm can accumulate and are difficult to reach with standard cleaning methods. They require specific brushing, flushing, and sometimes ultrasonic cleaning to ensure adequate decontamination.

Instruments with lumens (such as endoscopes, suction tips, and cannulas) present unique decontamination challenges because their internal channels create areas that are difficult to access during routine cleaning. Organic soil and moisture trapped in these channels provide an ideal environment for biofilm formation, which is highly resistant to chemical disinfection and sterilization. CSA Z314.8 and CAN/CSA-Z314.8 require that lumened devices be flushed with enzymatic solution and rinsed thoroughly, with channel brushes of appropriate size used for manual cleaning. Ultrasonic cleaners with lumen adapters may also be employed. Failure to adequately clean lumens is one of the most common causes of reprocessing failures.

Question 6: What action should be taken if an instrument arrives at the decontamination area with dried-on soil?

Proceed directly to sterilization
Discard the instrument immediately
Soak in enzymatic solution to soften the dried soil before cleaning (Correct answer)
Scrub with an abrasive pad without soaking

Correct answer: Soak in enzymatic solution to soften the dried soil before cleaning

Dried-on soil is harder to remove and can harbor microorganisms. Soaking in enzymatic solution rehydrates and loosens the dried organic matter, making it accessible for effective cleaning without damaging the instrument surface.

When instruments arrive at the decontamination area with dried-on soil, it indicates that pre-cleaning at the point of use was inadequate or delayed. Dried organic matter forms a hardened layer that is difficult to remove through standard cleaning alone and can shield microorganisms from disinfectants and sterilants. The correct approach is to soak the instruments in an appropriately diluted enzymatic solution for the manufacturer's recommended contact time (typically 1-10 minutes). This allows the enzymes to rehydrate and break down the dried soil. Abrasive cleaning tools should be avoided as they can scratch instrument surfaces, creating harbourage sites for bacteria. CSA standards emphasize pre-cleaning at point of use to prevent soil from drying in the first place.

CMDRT - Certified Medical Device Reprocessing Technician Decontamination Processes Questions and Answers 2

What is the primary purpose of enzymatic detergent in the decontamination process?