Anesthesia Considerations 

Microlaryngoscopy & Airway Laser

 

 

Considerations

 

• Indication for surgery, location of airway lesion, presence of obstruction

• Potential for dynamic airway obstruction with induction, positive pressure ventilation & paralysis:

  • Double setup with rigid bronchoscope available 

• Shared airway with need to optimize surgical conditions/safety

• Individualized ventilation technique (communicate with surgeon): 

  • Closed system: laser-safe ETT

  • Open system: 

    • Low-frequency jet ventilation

    • High-frequency jet ventilation

    • Spontaneous ventilation (especially pediatrics) 

  • Total IV anesthetic (TIVA)

  • Motionless surgical field

• Complications:

  • Airway obstruction, laryngospasm 

  • Laser: airway fire, burns, venous air embolism with YAG laser (deeper), pneumothorax

  • Jet ventilation: barotrauma, abnormal ventilation/oxygenation

  • Unprotected airway & aspiration risk

 

 

Goals

 

• Optimize surgical conditions: motionless field, no risk of combustion

• Adequate oxygenation & ventilation, secure airway

• Depth of anesthesia sufficient to suppress hemodynamic response

• Clear, constant communication with surgery team

• Good postoperative care: prone to laryngeal spasm & edema

 

 

Conflicts

 

• Contraindication to jet ventilation & need for airway laser

• Full stomach & laser surgery: laser ETT vs jet ventilation

 

 

Airway Management Options

 

• Broadly classified into 1) closed system, 2) open system

• Closed system (intubation):

  • General anesthesia with ETT (microlaryngoscopy tube or laser tube)

• Open system (no intubation, tubeless technique):

  • Topical/local anesthesia with sedation

  • General anesthesia without intubation

    • Apnea & intermittent intubation/bag mask ventilation

    • Tubeless spontaneous ventilation technique

    • Jet ventilation with Sanders technique: supraglottic vs subglottic, via catheter/rigid scope

    • High-frequency jet ventilation

• Considerations:

  • ETT/microlaryngoscopy tube: ↑ risk of airway fire & obstructs surgeon's visualization

  • Jet ventilation avoids the risk of ETT complications (kinked, obstructed, displaced, damaged, ignited)

    • Risks/complications:

      • Difficulty maintaining oxygenation/ventilation in morbid obesity, stiff thorax, restrictive/obstructive pneumopathy, lung fibrosis, reduced alveolar-capillary diffusion capacity (pulmonary edema)

      • Risk of dynamic hyperinflation if obstructed airway with barotrauma (subcutaneous emphysema, pneumothorax/pneumomediastinum, tracheobronchial injury), hypoxemia, hypercarbia/hypocarbia, gastric distension & regurgitation due to scope malalignment, possible vocal cord motion if supraglottic, drying of laryngeal mucosa, distal spread of particulate matter with potential tracheobronchial viral or tumor seeding

 

 

Safety Precautions

 

• Locked doors, signs on doors 

• N95 mask for everyone if risk of viral particles 

• Eye protection for patient & personnel 

• Fire safety equipment (laser tube with methylene blue & saline into cuff/saline for extinguishing fire) 

• Difficult airway equipment 

• ENT surgeon present with rigid bronchoscopy 

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Further Reading 

• Patel, A. Ch 70: Anesthesia for Otolaryngologic and Head-Neck Surgery. In Miller's Anesthesia, 2-Volume Set 2210-2235 (Elsevier, 2020)