Drug of choice for high-level disinfection of heat-sensitive endoscopes and surgical instruments in a hospital setting is:
A. Ethyl alcohol
B. Povidone-iodine
C. Glutaraldehyde
D. Chlorhexidine
Explanation
High-Level Disinfection of Heat-Sensitive Equipment
Key Point
Glutaraldehyde is the gold standard high-level disinfectant for heat-sensitive instruments that cannot tolerate autoclaving, particularly endoscopes and arthroscopes.
Mechanism of Action
Glutaraldehyde is a dialdehyde that cross-links bacterial proteins and nucleic acids, providing broad-spectrum antimicrobial activity against bacteria, viruses, fungi, and spores.
Comparative Disinfectant Profile
Table
Disinfectant
Level
Heat-Sensitive Use
Sporicidal
Contact Time
Drawbacks
Glutaraldehyde
High
Yes
Yes (2%)
3–10 hrs
Toxic fumes, irritant
Ethyl alcohol (70%)
Intermediate
Yes
No
Minutes
No sporicidal activity
Chlorhexidine
Intermediate
Yes
No
Variable
Limited against spores
Povidone-iodine
Low-Intermediate
Yes
No
Minutes
Stains, allergic reactions
High-YieldNEET PG
Glutaraldehyde 2% is the preferred choice for endoscopes because it:
Achieves high-level disinfection in 3–10 hours
Is sporicidal (kills bacterial spores)
Penetrates biofilms on instrument lumens
Allows reuse of expensive heat-sensitive equipment
Clinical Pearl
Glutaraldehyde requires proper ventilation and personal protective equipment due to respiratory irritation and sensitization risk. Alternatives like ortho-phthalaldehyde (OPA) are being adopted in some centres for faster action and lower toxicity.
Warning
Ethyl alcohol alone is NOT suitable for high-level disinfection of endoscopes because it lacks sporicidal activity and does not penetrate instrument channels adequately.
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