Evaluation of the Feasibility and Safety of Laryngoscopic Microsurgery Under Non-intubation Anesthesia
Condition: Spontaneous Breathing; Laryngomicrosurgery; Superior Laryngeal Nerve Block
MeSH terms: Respiratory Aspiration
Study type: Interventional

Summary: 
      Nonintubated anesthesia applied in combination with high-flow nasal oxygen (HFNO) is an
      alternative strategy for laryngeal microsurgery (LMS). LMS is a common procedure in
      otolaryngology that typically requires endotracheal tube intubation under general anesthesia.
      Endotracheal tube intubation causes complications; a nonintubated strategy can avoid these
      complications and provide a clearer surgical field of vision, enabling vocal cord inspection
      and disposal. Administering a muscle relaxant can also help prevent bucking during surgery
      but can engender apnea and hypercapnia, which may have negative effects on hemodynamics.
      Therefore, the investigators assessed the effectiveness of a superior laryngeal nerve block
      (SLNB) with intravenous general anesthesia in maintaining spontaneous breathing and improving
      safety during LMS with nonintubated anesthesia.
    

Detailed description: 
      Laryngeal microsurgery (LMS) is among the most common operations in otolaryngology and
      typically requires general anesthesia administered through endotracheal tube intubation.
      Endotracheal tube intubation provides stable gas exchange, protects the airways by preventing
      secretions from falling into the lower respiratory tract, and enables the monitoring of
      parameters such as tidal volume and end-tidal CO2.

      Nonintubated anesthesia applied in combination with transnasal humidified rapid-insufflation
      ventilatory exchange or high-flow nasal oxygen (HFNO) is another option for LMS. LMS with
      nonintubated anesthesia can avoid the complications caused by endotracheal tube intubation
      such as oral tissue trauma, tracheal trauma, and dental injury. Furthermore, LMS with
      nonintubated anesthesia can provide a clearer surgical field of vision that allows the vocal
      cords to be inspected and disposed of completely. Current practice in LMS with nonintubated
      anesthesia is to administer a muscle relaxant to help avoid bucking during the procedure.
      However, the administration of a muscle relaxant can lead to apnea and hypercapnia, which may
      negatively affect hemodynamics. Therefore, the investigators investigated the use of a
      superior laryngeal nerve block (SLNB) with intravenous general anesthesia to help the patient
      maintain spontaneous breathing and provide higher surgical safety during LMS with
      nonintubated anesthesia.
    

Intervention name(s): Non-intubated Laryngomicrosurgery
Intervention type(s): Procedure
Intervention description(s): Non-intubated LMS was performed with assistance of Optiflow (HFNO).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Nonintubated; Spontaneous breathing; Laryngomicrosurgery; Superior laryngeal nerve block