How can airway obstruction, such as tongue obstruction, be prevented in patients under anesthesia?

Prevention of Tongue Obstruction During Anesthesia

To prevent airway obstruction from tongue displacement during anesthesia, proper positioning of the patient's head and neck in the "sniffing position" along with appropriate use of airway adjuncts such as oropharyngeal or nasopharyngeal airways is essential. 1

Understanding Airway Obstruction During Anesthesia

Airway obstruction during anesthesia commonly occurs due to the loss of muscle tone that maintains airway patency in the awake state. The tongue is the most frequent cause of upper airway obstruction in anesthetized patients, as it falls backward against the posterior pharyngeal wall when muscle tone is reduced by anesthetic agents 2, 3.

Key factors contributing to tongue-related airway obstruction:

• Loss of pharyngeal muscle tone
• Relaxation of the genioglossus muscle
• Decreased protective reflexes
• Velopharyngeal narrowing

Prevention Strategies

1. Proper Patient Positioning

• Head and neck alignment: Position the patient in the "sniffing position" with:
  • Flexion of the neck
  • Extension of the head at the atlanto-occipital joint 1
  • Consider placing a roll under the shoulders for patients under 2 years of age 1

2. Airway Adjuncts

• Oropharyngeal airway: Insert when patient is adequately anesthetized to prevent gagging

  • Lifts the tongue away from the posterior pharyngeal wall
  • Choose appropriate size based on patient's age/size 1, 3

• Nasopharyngeal airway: Consider for patients where oral access is limited or when oropharyngeal airways are not tolerated 1

3. Airway Management Techniques

• Jaw thrust maneuver: Apply upward pressure behind the mandibular angles to lift the tongue forward 1
• Chin lift: Pull the chin forward to stretch the anterior neck tissues and lift the tongue 3
• CPAP (Continuous Positive Airway Pressure): Apply when necessary to maintain airway patency 1

4. During Emergence/Extubation

• Bite blocks: Use during emergence to prevent occlusion of the endotracheal tube if the patient bites down 1

  • Options include Guedel airways or rolled gauze (must be secured to prevent displacement)
  • If biting occurs, consider deflating the cuff to allow airflow around the tube 1

• Extubation technique: Choose based on patient risk factors:

  • Awake extubation: Safer for most patients as airway tone and protective reflexes return 1, 4
  • Deep extubation: Only for select patients with easy airways and no aspiration risk 1, 4

Special Considerations for High-Risk Patients

Identify patients at higher risk for tongue obstruction:

• Obesity
• History of obstructive sleep apnea
• Maxillary hypoplasia or mandibular retrusion
• Previous difficult airway management 2

For these patients:

• Consider using a supraglottic airway device (e.g., laryngeal mask airway) 1, 4
• Have advanced airway equipment immediately available
• Consider the "Bailey maneuver" (exchanging endotracheal tube for LMA before emergence) in high-risk cases 1, 4

Algorithm for Managing Unexpected Airway Obstruction

If tongue obstruction occurs despite preventive measures:

1. Optimize head position:

   • Reposition head and neck in sniffing position
   • Apply jaw thrust maneuver

2. Insert airway adjuncts:

   • Oropharyngeal or nasopharyngeal airway

3. If obstruction persists:

   • Apply CPAP
   • Deepen anesthesia if light anesthesia is causing laryngospasm
   • Consider inserting a supraglottic airway device (maximum 3 attempts) 1

4. If still unsuccessful:

   • Return to mask ventilation
   • Call for help
   • Consider tracheal intubation
   • In emergency situations, follow the "can't intubate, can't oxygenate" algorithm 1

By following these evidence-based approaches, the risk of tongue obstruction during anesthesia can be significantly reduced, improving patient safety and outcomes.