An interventional study of Ultrasound-guided bilateral Thyroid Cartilage Plane Block and Ultrasound-guided bilateral Superior Laryngeal Nerve Space Block in Superior Laryngeal Nerve Block, sponsored by Nanjing First Hospital, Nanjing Medical University. Recruiting at 2 sites in China. Open to participants aged 18 Years to 85 Years. Per ClinicalTrials.gov, last updated 2026-07-28.
Sponsored by Nanjing First Hospital, Nanjing Medical University · Not applicable, Interventional, and Health services research
The aim of this clinical trial is to compare the effectiveness and safety of ultrasound-guided thyroid cartilage plane approach with the superior laryngeal nerve space approach for superior laryngeal nerve block in awake tracheal intubation. Patients were randomized into the thyroid cartilage plane block group (T group) or the superior laryngeal nerve space block group (C group). In Group T, bilateral thyroid cartilage plane block was performed under ultrasound with thyroid cartilage as the landmark, and local anesthetic was injected on the surface of the thyroid cartilage. In Group C, local anesthetic was injected into the space between the thyrohyoid membrane and muscle groups above.
The investigators aim to evaluate whether the thyroid cartilage plane approach is not inferior to the superior laryngeal nerve space approach for ultrasound-guided superior laryngeal nerve block in awake tracheal intubation
After entering the operation room, ECG, SPO2, and invasive blood pressure were monitored. Sedation was facilitated. The proper anaesthesia depth was maintained at 60-80 using the bispectral index. Additionally, 0.5 mg of Penehyclidine Hydrochloride was injected intravenously once the venous access was established. 100% oxygen 4 L min-1 was administered with a nasal cannula throughout the procedure. All patients received topical pharyngeal anesthesia using lidocaine spray. The investigators used a 5-12 MHz linear probeto perform bilateral block. The probe was placed parasagittally to locate the thyroid cartilage and superior laryngeal nerve space. After identification of related structure, the investigators advanced a 22-gauge needle medial to the transducer at the upper half of the thyroid cartilage laminae until it touched the laminae or superior laryngeal nerve space using the out-of-plane technique. The correct location of the needle tip in the fascial deep to the muscle groups was confirmed by injecting 0.5-1 ml saline. A total of 2% lidocaine 2.5 ml was administered after negative aspiration bilaterally. "Spray-as-you-go" technique guided by a fiberoptic bronchoscope was performed to the tracheal with 5 ml of 2% lidocaine. After airway anesthesia, intubation completed.
The primary outcome was the proportion of acceptable intubation conditions (AIC). Secondary outcomes were the performance time, Ramsay sedation score, the patient's cough condition, comfort score, and tracheal tube tolerance score and other perioperative complications including airway hemorrhage and superior laryngeal nerve damage.
Nanjing First Hospital, Nanjing Medical University is the lead sponsor of 213 studies on the registry; 106 are open to participants now.
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All patients received topical oral and pharyngeal anesthesia using 2.4% lidocaine spray. The pharyngeal surface was sprayed twice, with each spray lasting one second, and repeated after a 5-minute interval. Under ultrasound guidance, the needle was advanced step by step into the potential space between the relevant muscle groups and the thyrohyoid membrane. When the needle tip contacted the surface of the thyrohyoid membrane and slightly penetrated the submembranous tissue, negative aspiration was confirmed, and 2.5 mL of 2% lidocaine was injected into the space on each side. Subsequently, performing fiberoptic bronchoscope-guided subglottis and tracheal surface topical anesthesia using 5ml of 2% lidocaine. After completing surface anesthesia, performing fiberoptic bronchoscope-guided tracheal intubation.
Procedure: Ultrasound-guided bilateral Superior Laryngeal Nerve Space Block
All patients received topical oral and pharyngeal anesthesia using 2.4% lidocaine spray. The pharyngeal surface was sprayed twice, with each spray lasting one second, and repeated after a 5-minute interval. Ultrasound-guided bilateral Thyroid Cartilage Plane Block is performed using the thyroid cartilage as an anatomical landmark. 2.5ml of 2% lidocaine is injected on the surface of the thyroid cartilage each side. Subsequently, performing fiberoptic bronchoscope-guided subglottis and tracheal surface topical anesthesia using 2% lidocaine 5ml. After completing surface anesthesia, performing fiberoptic bronchoscope-guided tracheal intubation.
Procedure: Ultrasound-guided bilateral Thyroid Cartilage Plane Block
Use a SonoSite high-frequency linear array transducer (5-13 MHz, SonoSite, USA). Placing the transducer parallel to the spine on one side of the neck, ensuring clear visualization of the thyroid cartilage under ultrasound. Using the out-of-plane technique to visualize the needle insertion path and tip. Once the needle tip contacts the cranial half of the thyroid cartilage, injecting 2.5ml of 2% lidocaine on the surface of the thyroid cartilage each side.
Use a SonoSite high-frequency linear array transducer (5-13 MHz, SonoSite, USA). Placing the transducer parallel to the spine on one side of the neck, ensuring clear visualization of the superior laryngeal nerve space under ultrasound. Using the out-of-plane technique to visualize the needle insertion path and tip. 2% lidocaine 2.5ml was injected into the space between the thyrohyoid membrane and muscle groups above.
The proportion of patients with acceptable intubation conditions (AIC)
The evaluation of the intubation condition was based on the Cormack-Lehane classification, vocal cord movement, 5-point reaction scale, and severity of coughing. Clinically, AIC was defined when each part was scaled to Grade 1 or Grade 2. The proportion of AIC = number of participants with AIC/number of participants who received ATI in each group.
Time frame: Upon intubation
Quality of airway anesthesia
The quality of airway anesthesia assessed on a 5-point scale,Quality of airwayanesthesia was graded as: 0=no coughing or gagging in response to intubation, 1=mild coughing and/or gaggingthat did not hinder intubation, 2=moderate coughing and/or gagging that interfered minimally with intubation,3=severe coughing and/or gagging that made intubation difficult and 4=very severe coughing and/or gaggingthat required additional local anesthetic and/or change in technique.The lower grade means a better quality of airway anesthesia.
Time frame: Upon intubation
Mean Arterial Pressure
Stable blood pressure indicates a good neural blockade effect.
Time frame: T0: upon entry to the operating room,T1: before insertion of the tracheal tube,T2: immediately after tracheal tube insertion,T3: 5 minutes after successful intubation
Heart Rate
Time Frame: T0: upon entry to the operating room,T1: before insertion of the tracheal tube,T2: immediatelyafter tracheal tube insertion,T3: 5 minutes after successful intubation
Time frame: T0: upon entry to the operating room,T1: before insertion of the tracheal tube,T2: immediately after tracheal tube insertion,T3: 5 minutes after successful intubation
Ramsay Sedation Score
The Ramsay Sedation Score is as follows: 6 points for unarousable, 5 points for slow response to stimulus, 4points for asleep but easily aroused, 3 points for quiet and cooperative with orientation, 2 points for asleep,anxious, restless, and 1 point for asleep, agitated, and restless. Satisfactory sedation falls within 2-4 points,while oversedation is indicated by 5-6 points.
Time frame: T0: upon entry to the operating room,T1: before insertion of the tracheal tube,T2: immediately after tracheal tube insertion,T3: 5 minutes after successful intubation
The number of patients with lowered pitch
A lowered pitch might indicate a good neural blockade effect.
Time frame: Before intubation
The time needed for blockade procedure
The neural blockade procedure time reflects the ease of the operation, with a shorter time indicating a simpler neural blockade procedure.
Time frame: From ultrasounography localization to completion of local anesthetic administration
Record coughing in patients when the fiberoptic bronchoscope touches the glottis
The patient's coughing upon contact of the fiberoptic bronchoscope with the vocal cords before intubation reflects the effectiveness of neural blockade. A lower degree of coughing indicates a better neural blockadeeffect. 1 point for no response, 2 points for mild cough, 3 points for severe cough.
Time frame: Before intubation
The tolerance score after the tube insertion
The tolerance of the tube reflects the patient's tolerance to awake tracheal intubation. A higher score indicates a better outcome. 3 points for severe resistance requiring immediate general anesthesia, 2 points for restlessness and mild resistance, 1 point for cooperation.
Time frame: Five minutes after successful intubation
Adverse reactions such as coughing and nausea/vomiting
The lower the incidence of coughing, nausea, and vomiting, the better the neural blockade effect.
Time frame: During intubation
Occurrences of sore throat and lowered pitch
Pharyngeal pain and decreased vocal tone are used to assess postoperative complications of neural blockade.
Time frame: Post-extubation,24 hours after surgery
Total procedure time needed for awake intubation
The total procedure time reflects the ease of the operation, with a shorter time indicating a simpler procedure.
Time frame: From the initiation of topical anesthesia to the accomplishment of tracheal intubation
Airway hemorrhage or nerve damage
Observation of bleeding of the laryngeal mucosa via fiberoptic bronchoscope or observation of bloody secretions via coughing or suction
Time frame: During intubation
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Nanjing First Hospital, Nanjing Medical University