Certified Respiratory Therapist Practice Exam 2025 – Your Complete All-in-One Guide to Exam Success!

A clogged capillary tube in the nebulizer is indeed the most likely cause of low mist production. The function of the nebulizer relies on the capillary tube to effectively transport the liquid medication to the nebulization chamber, where it is aerosolized into mist. If this tube becomes obstructed due to medication residue or particulate matter, the flow of medication is restricted, significantly reducing the amount of mist that is produced.

Proper functioning of the nebulizer is contingent on unobstructed pathways for the medication, ensuring that it can adequately enter the nebulization area for conversion to mist. This is crucial for delivering the appropriate therapeutic dose to the patient. Since the other options do not directly impair the production of mist as significantly or specifically as a clogged capillary tube does, this reinforces why the capillary tube's condition is the primary factor in mist production challenges.