Which measure helps prevent nasal mucosa dryness for a patient on nasal cannula oxygen?

• A. Increase oxygen concentration to 100%
• B. Apply water-soluble lubricant to nostrils
• C. Use a mouthguard to keep lips moist
• D. Place the patient on the prone position

Answer: (B)

Nasal cannula oxygen can dry the nasal mucosa because the inspired air is drier than the normal air we breathe. Keeping the nasal passages moisturized helps prevent irritation, crusting, and nosebleeds, which is why applying a water-soluble lubricant inside the nostrils provides a protective film and reduces friction from the airflow. Water-based lubricants are preferred for safety with respiration and potential aspiration, unlike petroleum-based products. Increasing oxygen concentration to 100% would not fix dryness and can carry additional risks; keeping lips moist with a mouthguard doesn't address the nasal mucosa, and changing to a prone position doesn't affect dryness of the nasal passages. If available, using humidified oxygen can also help maintain mucosal moisture.