Endoscopic instruments are sterilized by:

BHU NO-2019

Applied Microbiology & Infection control

Medium

Appeared in: BHU NO-2019

Explanation

Endoscopes are classified as semicritical items because they come into contact with mucous membranes.
Semicritical items require high-level disinfection (HLD) or sterilization.
2% glutaraldehyde is a chemical sterilant (high-level disinfectant) that is effective against a broad spectrum of microbes, including spores, without using high heat.
This method, also known as cold sterilization, is ideal for delicate, heat-sensitive instruments like endoscopes, which would be damaged by methods like autoclaving or hot air ovens.

Option A: A hot air oven uses dry heat at temperatures (160–180°C) that would melt plastic components and destroy the delicate optics of an endoscope.
Option B: Autoclaving uses steam under high pressure and temperature (typically 121°C), which would damage the lenses, fiber optics, and seals of an endoscope.
Option C: Boiling water (100°C) does not kill all microbial forms, particularly bacterial spores, and therefore does not achieve sterilization. It is considered a method of disinfection.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Sterilization methods for medical equipment, specifically for heat-sensitive instruments as background academic context rather than a clinical decision trigger.
Proper sterilization of endoscopic equipment is critical to prevent healthcare-associated infections (HAIs). Failure to correctly sterilize can transmit pathogens like Pseudomonas aeruginosa or mycobacteria between patients.
Nurses are responsible for ensuring that equipment has been processed correctly before use and for handling it in a way that maintains its sterility or level of disinfection.
A nurse must be able to identify if an instrument is heat-sensitive and advocate for the correct sterilization method to ensure patient safety and prevent costly damage to equipment.

How to Approach the Question

First, identify the type of instrument mentioned in the question: an endoscope.
Recall the composition of an endoscope. It contains delicate, heat-sensitive components like lenses, fiber-optic cables, and plastic parts.
Consider the sterilization methods listed in the options. Evaluate each method based on its mechanism (heat, chemical, pressure).
Eliminate methods that use high heat, such as hot air ovens and autoclaving, as they would damage the endoscope.
Differentiate between disinfection and sterilization. Boiling disinfects but does not reliably sterilize because it doesn't kill spores.
Select the chemical method, 2% glutaraldehyde, which is a known high-level disinfectant/chemical sterilant suitable for heat-sensitive instruments.

Concept Tested & Keywords

Concept Tested: Sterilization methods for medical equipment, specifically for heat-sensitive instruments.
Stem keywords: Endoscopic instruments, sterilized
Lead-in keywords: BEST, MOST RELEVANT CLUE

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