The Nurse is giving oxygen therapy to a patient who should know that it has to be humidified Because?

Appeared in: PGIMER Sangrur NO - 2023

Explanation

Medical oxygen supplied from cylinders or wall outlets is an anhydrous (dry) gas.
Inhaling dry gas strips moisture from the respiratory mucous membranes.
This dehydration causes respiratory secretions (mucus) to become thick and viscous.
Thickened mucus impairs the function of cilia (mucociliary clearance), making it difficult for the patient to clear their airways, which can lead to mucus plugging and increased risk of infection.

Option A: Medical oxygen is not hot. It is stored as a compressed gas at ambient temperature. Any sensation of 'burning' is due to irritation from dryness, not from thermal heat.
Option C: Humidification does not clean or sterilize the oxygen. In fact, if the humidifier is not cleaned properly or if non-sterile water is used, it can become a reservoir for pathogens like bacteria.
Option D: Humidification adds water vapor (H₂O), not free hydrogen ions (H+). The process is physical (adding moisture), not chemical. It does not change the way oxygen is absorbed into the bloodstream via the alveoli.

Clinical Relevance

Nursing practice connection: Use the key finding related to Rationale for humidification in oxygen therapy to guide bedside assessment, documentation, and the next nursing action.
Ensuring proper humidification is a key nursing responsibility to prevent patient discomfort and iatrogenic complications like airway drying, thickened secretions, and potential mucus plugging.
Failure to humidify high-flow oxygen can lead to decreased patient compliance with the therapy due to discomfort, nasal dryness, and even epistaxis (nosebleeds).
What if? If the patient is on a very low flow rate, such as 1-2 L/min via nasal cannula, humidification is often considered optional. At these low flows, the oxygen mixes with a large volume of ambient air, which usually provides sufficient humidity, and the risk of significant mucosal drying is low.

How to Approach the Question

First, identify the core of the question, which is asking for the scientific reason ('Because?') for a common nursing practice (humidifying oxygen).
Consider the physical properties of medical oxygen. It is stored under pressure in cylinders or piped systems, which means it is a very dry gas.
Think about the physiological effect of breathing a dry gas directly into the respiratory system, which is naturally moist.
Evaluate each option against this understanding:
Option A (hot air): This is factually incorrect. Compressed gases cool upon expansion.
Option B (dry gas, thickens mucus): This aligns perfectly with the known effects of inhaling anhydrous gas on the respiratory mucosa.

Concept Tested & Keywords

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E6 Nursing Fundamentals Taylor p. 729-731

Practise the full PGIMER Sangrur NO - 2023

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