Endoscopic catheters are sterilized by?

WCL Staff Nurse - 2019

Applied Microbiology & Infection control

Medium

Appeared in: WCL Staff Nurse - 2019

Explanation

Endoscopic catheters are classified as semi-critical items because they contact mucous membranes.
These instruments are heat-labile, meaning their delicate components (lenses, fiber optics, adhesives) are easily damaged by high temperatures.
Therefore, they cannot be sterilized using heat-based methods like autoclaving or a hot air oven.
2% Glutaraldehyde is a liquid chemical sterilant that works at room temperature (a process known as 'cold sterilization'), making it the appropriate choice for heat-sensitive equipment.
While it provides high-level disinfection in a shorter time (around 20 minutes), true sterilization requires prolonged immersion for up to 10 hours to eliminate all microbial life, including spores.

Option A: Autoclaving uses steam under high pressure and temperature (typically 121°C or higher), which would destroy the delicate optical and electronic components of an endoscopic catheter.
Option B: A hot air oven uses dry heat at very high temperatures (160-180°C), which would melt, warp, and irreversibly damage the plastic, rubber, and adhesive parts of an endoscope.
Option D: Boiling water at 100°C is a method of disinfection, not sterilization. It kills most vegetative bacteria but is not effective against resilient bacterial spores and some viruses.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Sterilization methods for heat-sensitive medical equipment as background academic context rather than a clinical decision trigger.
Proper sterilization of endoscopic equipment is critical in preventing healthcare-associated infections (HAIs). Failure to follow correct protocols can lead to the transmission of serious pathogens like Pseudomonas aeruginosa, Clostridium difficile, or hepatitis viruses between patients.
Nurses are often responsible for overseeing or performing the initial stages of decontamination and ensuring that equipment is sent for reprocessing correctly. They must understand the principles to ensure patient safety.
What if? If an endoscope is not rinsed properly with sterile water after being soaked in glutaraldehyde, the residual chemical can cause severe chemical burns and inflammation (colitis, esophagitis) to the patient's mucous membranes during the procedure.

How to Approach the Question

First, identify the key terms in the question: 'Endoscopic catheters' and 'sterilized'.
Recall the physical properties of an endoscope. It is a complex instrument with delicate, heat-sensitive components like lenses, fiber optics, and plastic.
This key property (heat sensitivity) immediately rules out any sterilization methods that rely on high temperatures.
Evaluate the options: Autoclaving and Hot air oven both use high heat, so they are incorrect.
Differentiate between the remaining options. Boiling is disinfection, not sterilization, because it doesn't kill spores. Sterilization requires killing all microbial life.
This leaves 2% Glutaraldehyde, a chemical sterilant used for heat-sensitive items, as the only correct and logical answer.

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