Which is the most appropriate method for sterilizing flexible endoscopes used in clinical procedures?

RML PRE 2025

Applied Microbiology & Infection control

Medium

Appeared in: RML PRE 2025

Explanation

Flexible endoscopes are classified as semi-critical items because they come into contact with mucous membranes.
These instruments are made of heat-sensitive materials like plastics, rubber, and delicate fiber optics that cannot withstand high temperatures.
Glutaraldehyde is a chemical sterilant (often called a 'cold sterilant') that effectively kills all microorganisms, including spores, without using heat.
Immersing the endoscope in a glutaraldehyde solution (e.g., 2% Cidex) for a specified contact time achieves high-level disinfection or sterilization, making it the appropriate method.

Option A: Autoclaving uses high-pressure steam at temperatures (121-134°C) that would melt, warp, and destroy the heat-sensitive components of a flexible endoscope.
Option B: Boiling water (100°C) is not hot enough to kill all bacterial spores, so it does not achieve sterilization. Additionally, this temperature is still high enough to damage the delicate materials of an endoscope.
Option D: Dry heat sterilization uses very high temperatures (160°C or higher) for extended periods, which would completely destroy a flexible endoscope.

Clinical Relevance

Nursing practice connection: Knowing Sterilization and disinfection methods for medical equipment helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Proper reprocessing of endoscopes is critical for patient safety. Failure to correctly sterilize or high-level disinfect endoscopes can lead to the transmission of serious infections between patients, including Hepatitis B, Hepatitis C, and multidrug-resistant bacteria.
Nurses are responsible for ensuring that equipment is properly decontaminated according to hospital policy and manufacturer guidelines before it is used on a patient.
What if the item was a stainless steel surgical scalpel? Since a scalpel is a critical item (enters sterile tissue) and is heat-resistant, the most appropriate method would be autoclaving (steam sterilization), not chemical immersion.

How to Approach the Question

First, identify the specific equipment mentioned in the question: a 'flexible endoscope'.
Recall the physical properties of this equipment. Flexible endoscopes are complex instruments containing heat-sensitive components like fiber optics, lenses, plastics, and adhesives.
Next, evaluate each sterilization method listed in the options based on its mechanism and temperature.
Eliminate the high-temperature methods: Autoclaving (high-pressure steam), Boiling (100°C water), and Dry heat (160°C+ air) would all cause thermal damage to the endoscope.
Identify the remaining option, Glutaraldehyde, as a chemical or 'cold' sterilization method, which is specifically designed for heat-sensitive instruments.
Conclude that glutaraldehyde immersion is the most appropriate choice for sterilizing a flexible endoscope.

Concept Tested & Keywords

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