CAA CAA Anesthesia Techniques & Airway Management 1 — Questions and Answers
Question 1: The LEMON mnemonic is used for predicting difficult direct laryngoscopy. What does the letter 'E' represent?
- Edema of the airway
- Evaluation of the 3-3-2 rule (Correct answer)
- Extension of the neck
- Epiglottis visualization
Correct answer: Evaluation of the 3-3-2 rule
In the LEMON airway assessment, 'E' stands for Evaluation of the 3-3-2 rule: ≥3 finger mouth opening, ≥3 finger thyromental distance, and ≥2 finger hyomental distance.
Question 2: Which laryngoscope blade design is recommended for patients with a long, floppy epiglottis?
- Macintosh curved blade
- Miller straight blade (Correct answer)
- McCoy levering blade
- Bullard blade
Correct answer: Miller straight blade
The Miller straight blade is used to directly lift the epiglottis, providing better exposure in patients with a long, floppy epiglottis that obscures the glottis.
Question 3: During rapid sequence induction (RSI), cricoid pressure (Sellick maneuver) is applied to:
- Open the glottis and facilitate intubation
- Compress the esophagus against the vertebral body to prevent passive regurgitation (Correct answer)
- Improve laryngoscopic view by displacing the larynx posteriorly
- Prevent vasovagal response during laryngoscopy
Correct answer: Compress the esophagus against the vertebral body to prevent passive regurgitation
Cricoid pressure compresses the esophagus between the cricoid cartilage and C6 vertebra to reduce the risk of passive regurgitation and pulmonary aspiration.
Question 4: The recommended cuff pressure for a standard endotracheal tube is:
- 5–10 cmH2O
- 20–30 cmH2O (Correct answer)
- 40–50 cmH2O
- 60–80 cmH2O
Correct answer: 20–30 cmH2O
ETT cuff pressure should be maintained at 20–30 cmH2O to seal the airway without compromising tracheal mucosal perfusion, which occurs above approximately 30 cmH2O.
Question 5: Which feature distinguishes a laryngeal mask airway (LMA) from an endotracheal tube?
- The LMA provides a definitive airway with protection against aspiration
- The LMA sits in the hypopharynx over the laryngeal inlet and does not pass through the vocal cords (Correct answer)
- The LMA requires neuromuscular blockade for insertion
- The LMA cannot be used during mechanical ventilation
Correct answer: The LMA sits in the hypopharynx over the laryngeal inlet and does not pass through the vocal cords
An LMA is a supraglottic airway device that seats in the hypopharynx over the laryngeal inlet; it does not pass through the cords and provides less aspiration protection than an ETT.
Question 6: Preoxygenation prior to induction of anesthesia is performed to:
- Reduce the dose of induction agent required
- Denitrogenate the functional residual capacity to extend the safe apnea time (Correct answer)
- Prevent bronchospasm during intubation
- Decrease the risk of post-operative nausea and vomiting
Correct answer: Denitrogenate the functional residual capacity to extend the safe apnea time
Breathing 100% oxygen for 3–5 minutes replaces nitrogen in the FRC with oxygen, creating an oxygen reservoir that extends the safe apnea period during intubation.
CAA CAA Anesthesia Techniques & Airway Management 1
The LEMON mnemonic is used for predicting difficult direct laryngoscopy.
What does the letter 'E' represent?