An example of moist heat is?

Appeared in: DSSSB - 29 August 2019 (Shift-1)

Explanation

Moist heat sterilization uses water vapor or steam to kill microorganisms.
Steam under pressure, as used in an autoclave, is a classic and highly effective method of moist heat sterilization.
The high pressure allows the steam to reach temperatures above the normal boiling point of water (e.g., 121°C at 15 psi), which rapidly denatures and coagulates microbial proteins.
This method is efficient because steam has excellent penetrating power, ensuring all surfaces of the items being sterilized are reached.

Option A: Incineration is a method of dry heat sterilization. It involves burning materials at very high temperatures, reducing them to ash. It does not use water or steam.
Option C: A hot air oven is a form of dry heat sterilization. It uses heated dry air to kill microorganisms through oxidation. It lacks the moisture component.
Option D: Flaming is a dry heat method used for rapid sterilization of small instruments, like inoculation loops in a microbiology lab. It involves passing the object directly through a flame.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Sterilization Methods (Moist vs. Dry Heat) as background academic context rather than a clinical decision trigger.
Understanding the difference between moist and dry heat sterilization is critical for nurses to ensure patient safety by preventing healthcare-associated infections (HAIs).
Nurses are responsible for ensuring that medical equipment, especially critical items that enter sterile tissue (e.g., surgical instruments, urinary catheters), is properly sterilized before use.
Improper sterilization can lead to surgical site infections, sepsis, and other serious complications, increasing patient morbidity, mortality, and healthcare costs.

How to Approach the Question

First, identify the key concept in the question, which is "moist heat".
Recall the definition of moist heat sterilization: a process that uses steam or hot water to kill microbes.
Analyze each option to determine if it fits the definition of moist heat.
Option A (Incineration), Option C (Hot air oven), and Option D (Flaming) all use high temperatures without water, classifying them as dry heat methods.
Option B (Steam under pressure) explicitly involves steam, which is the hallmark of moist heat sterilization.
Therefore, conclude that Steam under pressure (Autoclave) is the correct example of moist heat.

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) pp. 126-128, 127-129

E6 Nursing Fundamentals Potter Perry 12e Part 2 p. 231-233

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Attempt every question from this paper in a timed mock, then review the full solution for each one.