A patient develops subcutaneous emphysema and tracheal stenosis 3 weeks after elective tracheostomy. Which complication is most likely responsible for the tracheal stenosis?

Explanation

## Post-Tracheostomy Tracheal Stenosis: Mechanism and Prevention **Key Point:** Tracheal stenosis after tracheostomy is primarily caused by **cuff-related ischemic injury** from excessive cuff pressure, NOT tube position or infection alone. ### Pathophysiology of Cuff-Induced Stenosis 1. **Normal tracheal capillary perfusion pressure:** 25–30 cm H₂O 2. **Cuff pressure > 30 cm H₂O** → mucosal ischemia → necrosis → fibrosis → stenosis 3. **Timeline:** Stenosis develops weeks to months after injury 4. **Subcutaneous emphysema** indicates cuff rupture or tube malposition with air leak, which may accompany high cuff pressures ### Comparison: Tracheostomy Complications by Timing and Cause | Complication | Timing | Primary Cause | Mechanism | |--------------|--------|---------------|----------| | **Tube obstruction** | Immediate | Secretions, blood clot | Mechanical | | **Subcutaneous emphysema** | Immediate–early | Cuff rupture, tube malposition | Air leak | | **Tracheal stenosis** | Weeks–months | High cuff pressure | Ischemic necrosis + fibrosis | | **Tracheoinnominate fistula** | Days–weeks | Tube erosion (low placement) | Vascular erosion | | **Tracheoesophageal fistula** | Weeks–months | High cuff pressure | Posterior wall necrosis | **Clinical Pearl:** The combination of **subcutaneous emphysema + tracheal stenosis** suggests cuff rupture with subsequent high-pressure cuff inflation attempts, leading to both air leak and mucosal injury. **High-Yield:** Cuff pressure should be maintained at **20–25 cm H₂O** (or 10–15 mm Hg). Use **minimal leak technique** or **minimal occlusion volume (MOV)** to prevent stenosis. **Mnemonic:** **CUFF** stenosis - **C**apillary perfusion pressure exceeded - **U**nder pressure (> 30 cm H₂O) - **F**ibrosis follows ischemia - **F**inal result: stenosis