Which gas is most commonly used for daily work in the wards and operation theatres?

DSSSB 6 September 2024

Applied Microbiology & Infection control

Medium

Appeared in: DSSSB 6 September 2024

Explanation

Formalin is a 37-40% aqueous solution of formaldehyde, which is a gas at room temperature.
Formaldehyde gas is widely used for the fumigation of rooms, a process that involves filling an enclosed area with gaseous disinfectant to sterilize surfaces and air.
This method is effective for high-level disinfection of critical areas like operation theatres and isolation wards, as the gas can penetrate hard-to-reach areas.
Among the given choices, it is the only substance used as a gaseous disinfectant for large spaces.

Option A: Savlon is a liquid antiseptic solution containing chlorhexidine and cetrimide. It is used topically for skin and wound cleaning, not as a gas for room disinfection.
Option B: Chloroxylenol (the active ingredient in Dettol) is a phenolic compound used as a liquid antiseptic and disinfectant for skin and surfaces. It is not used in a gaseous form for fumigation.
Option D: Iodine is a halogen used as a liquid antiseptic, most commonly in the form of povidone-iodine. It is applied topically to the skin before surgical procedures. It is not used as a gas for environmental disinfection.

Clinical Relevance

Nursing practice connection: Knowing Gaseous disinfection in hospital settings helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the different types of disinfectants and their specific applications is crucial for infection control in healthcare settings.
Formaldehyde fumigation is a method of terminal disinfection, performed after a patient with a highly infectious disease is discharged or to prepare an OT for major surgeries. Nurses must ensure the area is properly sealed and that no one enters until the fumigation and subsequent neutralization/aeration are complete.
Due to formaldehyde's toxicity and carcinogenic properties, strict safety protocols are mandatory. Staff must be trained in handling, neutralization (e.g., with ammonia), and monitoring air levels before re-entry.

How to Approach the Question

First, identify the key requirements of the question: it asks for a 'gas' used for disinfection in 'wards and operation theatres'.
Evaluate each option based on its physical state (gas, liquid, solid) and its primary application in a hospital.
Consider Savlon. You may know it as a liquid antiseptic for wounds. This does not match the 'gas' requirement.
Consider Chloroxylenol (Dettol). This is also a liquid disinfectant for surfaces and skin. This does not match the 'gas' requirement.
Consider Iodine. This is typically used as a liquid solution (povidone-iodine) for skin antisepsis. This does not match the 'gas' requirement.
Consider Formalin. This is a solution that releases formaldehyde gas, which is used for fumigating rooms. This matches both the 'gas' and 'room disinfection' requirements.

Concept Tested & Keywords

QXT_VctufW_cTBtibUllGS

E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) pp. 128-130, 127-129

E6 Pharmacology KD Tripathi Essentials 9e Part 3 p. 242-244