**Core Concept**
Tracheostomy tube blockage in a tracheostomised patient is a medical emergency due to risk of asphyxiation. The blockage is often caused by mucus plugging or foreign body obstruction, and immediate intervention is required to restore airway patency.

**Why the Correct Answer is Right**
In a tracheostomised patient with sudden complete blockage of the tracheostomy tube, the airway is fully occluded. Suctioning (even with saline or bicarbonate) or jet ventilation cannot bypass a complete physical obstruction. Immediate removal of the tube allows for rapid re-establishment of airway access, especially if the blockage is due to mucus plug or tube debris. This is a life-saving action in an emergency setting where ventilation is absent.

**Why Each Wrong Option is Incorrect**
Option B: Suctioning with sodium bicarbonate is ineffective in a **complete blockage**. It may only work in partial obstruction and does not overcome a full physical seal.
Option C: Suctioning with saline is similarly ineffective when the tube is completely blocked. Saline does not dissolve or dislodge a full obstruction.
Option D: Jet ventilation requires a patent airway and cannot be performed if the tracheostomy tube is completely obstructed. It is a **secondary** intervention, not a first-line option in complete blockage.

**Clinical Pearl / High-Yield Fact**
In a tracheostomy with complete obstruction, **immediate tube removal** is the first step to restore airway, followed by reinsertion of a new tube after clearing secretions. Never attempt to pass a catheter or perform suctioning in a completely blocked tube — it risks further complications or aspiration.

✓ Correct Answer: A. Immediate removal of the tracheostomy tube