The gas most commonly used in Cryosurgery is?

NHM UP Staff Nurse - 2019

Medical Surgical Nursing

Easy

Appeared in: NHM UP Staff Nurse - 2019

Explanation

Liquid Nitrogen (N2) is the most common cryogen used in cryosurgery, particularly for dermatological applications.
It achieves the lowest temperature among common cryogens, -196°C (-321°F), ensuring rapid and effective freezing and destruction of abnormal tissue.
Its effectiveness, low cost, and ease of availability make it the standard choice for treating a wide variety of skin lesions like warts, actinic keratoses, and some skin cancers.
The mechanism of action involves intracellular ice crystal formation, which disrupts cell membranes and leads to cell death (cryonecrosis).

Option A: Oxygen (O2) is not used as a cryogen. It is a highly reactive gas that supports combustion and does not have the extreme cold properties required for cryosurgery.
Option C: Carbon Dioxide (CO2), in its solid form (dry ice), can be used as a cryogen, but it is less common and significantly less cold (-78.5°C) than liquid nitrogen. Its lower efficacy limits its use.
Option D: Hydrogen (H2) is a highly flammable gas and is not used in cryosurgery. Its use would pose a significant safety risk in a clinical environment.

Clinical Relevance

Nursing practice connection: Knowing Commonly used agents in cryosurgery helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses frequently assist with or perform cryosurgery in dermatology and primary care settings, making knowledge of the agents and procedure essential.
Post-procedure care and patient education are key nursing responsibilities to ensure proper healing and prevent complications like infection or scarring.
What if? If a patient has a lesion on a cosmetically sensitive area like the face, the provider might use a more controlled application technique (e.g., a fine spray tip or a cotton-tipped applicator) and a shorter freeze time to minimize scarring, which the nurse should be prepared for and can reinforce during patient education.

How to Approach the Question

First, identify the core subject of the question: 'cryosurgery' and the specific detail required: 'most commonly used gas'.
Analyze the options provided: O2, N2, CO2, H2.
Recall or deduce the properties of these gases in a medical context. Eliminate options that are clearly unsafe or unsuitable. Hydrogen (H2) is flammable, and Oxygen (O2) supports combustion, making them dangerous choices.
This leaves N2 (Nitrogen) and CO2 (Carbon Dioxide) as plausible cryogens.
Differentiate between N2 and CO2 based on common clinical practice. Liquid nitrogen (N2) is widely known for its use in dermatology for 'freezing' warts and other lesions due to its extreme cold.
Conclude that N2 is the 'most commonly used' agent, as it is more effective (colder) and prevalent than CO2 for these procedures.

Concept Tested & Keywords

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E6 Nursing Brunner Adult Health 3SA Vol 1 Part 4 p. 91-93

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