With 10 mL of water remaining in the reservoir of a pre-filled bubble humidifier, the most appropriate action is to

• A. Refill the reservoir with sterile distilled water
• B. Replace the humidifier setup
• C. Refill the reservoir with sterile tap water
• D. Continue running the humidifier until the reservoir is empty

Answer: (B)

Pre-filled bubble humidifiers are designed for single-use; once the reservoir is low, the best and safest approach is to replace the entire humidifier setup. This preserves sterility and minimizes infection risk, because refilling—even with sterile water—can introduce contaminants or mineral deposits and the device may not be designed to be reused after the initial fill. Running the unit dry can also cause overheating or mechanical issues that affect humidification. By replacing the humidifier, you ensure a clean, reliably functioning airway humidifier and reduce the chance of neonatal infection or airway complications.