Dex vs SLNB in Spontaneous Breathing Via THRIVE for Laryngeal Surgery

Kaohsiung Veterans General Hospital

Status: Completed

Conditions: Endoscopic Laryngeal Surgery

Treatments: Drug: Dexmetedomedine infusion; Procedure: Ultrasound-Guided Superior Laryngeal Nerve Block (SLNB)

Study type: Interventional

Funder types: Other

Identifiers

NCT05581485

KSVGH22-CT8-38

Details and patient eligibility

About

This prospective, randomized controlled trial evaluated the efficacy and safety of two anesthetic strategies-dexmedetomidine infusion and ultrasound-guided superior laryngeal nerve block (SLNB)-in patients undergoing non-intubated endoscopic laryngeal surgery under spontaneous breathing supported by Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE). The primary outcome was the arterial partial pressure of carbon dioxide (PaCO₂), measured at three time points: before oxygenation, at the end of surgery, and in the post-anesthesia care unit (PACU). Secondary outcomes included other arterial blood gas parameters, hemodynamic variables, and surgeon satisfaction scores.

Full description

Detailed Description:

This prospective, single-center randomized controlled trial was conducted to compare two anesthetic strategies-Dexmedetomidine infusion and ultrasound-guided bilateral superior laryngeal nerve block (SLNB)-for non-intubated endoscopic laryngeal surgery performed under spontaneous respiration with high-flow nasal oxygenation (THRIVE). The study was carried out at Kaohsiung Veterans General Hospital, Taiwan.

Patients aged 20 to 80 years scheduled for elective microlaryngeal surgery were enrolled and randomly assigned to either the Dexmedetomidine (Dex) group or the SLNB group. Both groups received total intravenous anesthesia (TIVA) with propofol and oxygenation via transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) to facilitate tubeless anesthesia. The Dex group received a loading dose of Dexmedetomidine (1 µg/kg over 10 minutes) followed by continuous infusion (1 µg/kg/h), while the SLNB group underwent bilateral ultrasound-guided nerve blocks with 1% lidocaine.

The primary outcome was the arterial partial pressure of carbon dioxide (PaCO₂) measured at three time points: before oxygenation (baseline), at the end of surgery, and 15 minutes after arrival in the post-anesthesia care unit (PACU). Secondary outcomes included arterial blood gas parameters (PaO₂, pH), intraoperative hemodynamic variables (HR, SBP, DBP, MAP), and surgeon satisfaction scores.

The goal of this study was to evaluate whether Dexmedetomidine, which offers both sedative and analgesic properties while preserving spontaneous breathing, could serve as a viable alternative to regional nerve block in the context of shared-airway surgery. Particular attention was given to the risk of carbon dioxide accumulation and respiratory acidosis associated with Dexmedetomidine.

This trial provides important insights into the safety and efficacy of two distinct anesthetic modalities for performing non-intubated endoscopic laryngeal surgery and contributes to the ongoing optimization of airway management strategies in tubeless anesthesia.

Enrollment: 46 patients

Sex: All

Ages: 20 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Subjects are between 20-80 years old.
• Patients undergoing endoscopic laryngeal surgery.
• Anesthesiologists rated ASA as between I and III.

Exclusion criteria

• Having drug dependence and drinking habits.
• Abnormal heart, liver and kidney function.
• Allergic reactions to narcotic drugs.
• Emergency surgery.
• pregnancy.
• Refuse to participate.
• BMI ≥ 35 kg/m2.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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46 participants in 2 patient groups

Dexmedetomidine Infusion Arm for Non-Intubated Laryngeal Surgery Using THRIVE

Experimental group

Description:

This arm involves patients undergoing endoscopic laryngeal surgery under non-intubated general anesthesia with spontaneous breathing, supported by transnasal humidified rapid-insufflation ventilatory exchange (THRIVE). Patients receive an intravenous loading dose of dexmedetomidine (1 µg/kg over 10 minutes), followed by a continuous infusion (1 µg/kg/h) for sedation and analgesia. No regional nerve blocks are performed in this arm. Supplemental propofol is titrated via target-controlled infusion (TCI) to maintain BIS levels between 40-60. Topical 10% lidocaine is applied to the airway before insertion of the laryngoscope. Intraoperative fentanyl may be given as needed based on hemodynamic responses.

Treatment:

Drug: Dexmetedomedine infusion

Superior Laryngeal Nerve Block (SLNB)

Active Comparator group

Description:

This arm includes patients undergoing non-intubated endoscopic laryngeal surgery with spontaneous breathing, supported by transnasal humidified rapid-insufflation ventilatory exchange (THRIVE). After induction with propofol (via TCI) and standard premedication, bilateral ultrasound-guided superior laryngeal nerve blocks are performed using 5 mL of 1% lidocaine on each side for regional analgesia. No dexmedetomidine is administered in this group. Anesthesia is maintained with propofol titrated to a BIS range of 40-60. Additional fentanyl may be administered intraoperatively as needed to control sympathetic responses. Topical 10% lidocaine is applied to the airway prior to laryngoscope insertion.

Treatment:

Procedure: Ultrasound-Guided Superior Laryngeal Nerve Block (SLNB)