Sterilization of endoscope is done:

OSSSC Nursing Officer-2021

Applied Microbiology & Infection control

Medium

Appeared in: OSSSC Nursing Officer-2021

Explanation

Endoscopes are classified as semi-critical items as they come into contact with mucous membranes, requiring at least high-level disinfection.
These instruments are heat-sensitive due to their delicate optical and electronic components, making heat-based sterilization methods like autoclaving unsuitable.
2% glutaraldehyde is a high-level disinfectant and chemical sterilant that is effective against a wide range of microorganisms, including spores.
It is a standard and appropriate choice for sterilizing or disinfecting heat-sensitive equipment like endoscopes.

Option A: Autoclaving uses high-pressure steam at temperatures that would destroy the delicate fiber optics, lenses, and electronic components of an endoscope.
Option B: UV radiation is a form of surface disinfection. It cannot penetrate the long, narrow, and complex internal channels of an endoscope, leaving internal surfaces contaminated.
Option C: Phenol is an intermediate-level disinfectant that is not sporicidal. It is not potent enough for high-level disinfection required for semi-critical instruments and is also considered corrosive and toxic.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Sterilization and disinfection methods for medical instruments as background academic context rather than a clinical decision trigger.
Proper reprocessing of endoscopes is a critical patient safety measure to prevent the transmission of healthcare-associated infections (HAIs), including from multidrug-resistant organisms.
Nurses play a key role in ensuring adherence to the multi-step cleaning and disinfection protocol, including verifying correct chemical concentration, temperature, and immersion time.
What if? If the facility uses an Automated Endoscope Reprocessor (AER), the principle remains the same, but the machine automates the disinfection, rinsing, and drying steps. AERs often use other chemicals like peracetic acid, which can offer faster cycle times and reduced staff exposure to fumes.

How to Approach the Question

First, identify the item in question: an endoscope.
Recall the key characteristics of an endoscope: it is a delicate, complex instrument with lenses, fiber optics, and long internal channels, making it sensitive to heat.
Categorize the instrument based on its use. Since it contacts mucous membranes, it is a 'semi-critical' item requiring at least high-level disinfection.
Evaluate each option based on the instrument's properties. Eliminate autoclaving due to heat sensitivity.
Eliminate UV rays due to its inability to penetrate internal channels.
Compare the chemical agents. Phenol is an intermediate-level disinfectant, whereas glutaraldehyde is a high-level disinfectant/sterilant.

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