Endotracheal Intubation MCQ — NEET PG Practice Question | NEETPGAI
Endotracheal Intubation
medium
syringe Anesthesia
A 68-year-old male with COPD is intubated in the ICU for acute respiratory failure. On day 5 of mechanical ventilation, he develops stridor and difficulty with tube passage during a planned reintubation. What is the most common site of endotracheal tube-related stenosis?
A. Subglottic region at the level of the cricoid cartilage
B. Posterior pharyngeal wall at the level of the soft palate
C. Trachea at the level of the tube cuff
D. Glottic inlet at the level of the vocal cords
Explanation
Endotracheal Tube-Related Stenosis: Site of Injury
Key Point
The subglottic region at the level of the cricoid cartilage is the most common site of post-intubation stenosis, accounting for 60–75% of cases.
Anatomical Basis
The cricoid cartilage forms a complete ring and is the narrowest part of the pediatric airway. In adults, the subglottic region is vulnerable because:
1.
The tube cuff exerts pressure on the soft tissues between the tube and the rigid cricoid ring
2.
The mucosa is thin and has limited collateral blood supply in this region
3.
Prolonged cuff pressure (>25 cm H₂O) causes mucosal ischemia and ulceration
4.
Healing by fibrosis leads to scar contracture and stenosis
Comparison of Sites of Injury
Table
Site
Frequency
Mechanism
Clinical Presentation
Subglottic (cricoid)
60–75%
Cuff pressure on mucosa
Stridor, difficulty with reintubation
Glottic (vocal cords)
10–15%
Direct tube trauma, vocal cord paralysis
Hoarseness, breathy voice
Tracheal (cuff site)
10–15%
Cuff pressure, tube movement
Dyspnea, stridor
Posterior pharynx
Rare
Tube pressure against wall
Dysphagia
High-YieldNEET PG
Subglottic stenosis is the most common serious complication of prolonged intubation and is preventable by maintaining cuff pressures <25 cm H₂O and minimizing tube duration.
Clinical Pearl
Subglottic stenosis typically presents 2–8 weeks after extubation as progressive stridor and dyspnea, whereas acute post-extubation stridor (within 24–48 hours) is usually due to laryngeal edema, not stenosis.
Mnemonic
CRICOID = Critical site for stenosis; Rigid ring; Ischemia from cuff; Contracture from fibrosis; Often overlooked in prevention; Injury preventable; Diagnosed late.
Prevention Strategies
Maintain cuff pressure 20–25 cm H₂O (check with manometer)
Minimize intubation duration; use tracheostomy if >7–10 days anticipated
Use high-volume, low-pressure cuffs
Avoid tube movement and self-extubation
Regular cuff pressure monitoring in ICU patients
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