Thyroid Cartilage Plane VS Superior Laryngeal Nerve Space Block in Awake Tracheal Intubation

Official title

Thyroid Cartilage Plane Versus Superior Laryngeal Nerve Space for Ultrasound-guided Superior Laryngeal Nerve Block in Awake Tracheal Intubation: a Randomised Non-inferiority Clinical Trial

Overview

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

Detailed description

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.

Interventions

• 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.
• Procedure Ultrasound-guided bilateral Superior Laryngeal Nerve Space 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 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.

Primary outcome measures

• The proportion of patients with acceptable intubation conditions (AIC) [Time frame: Upon intubation]

Secondary outcome measures (12)

• Quality of airway anesthesia [Time frame: Upon intubation]
• Mean Arterial Pressure [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: immediately after tracheal tube insertion,T3: 5 minutes after successful intubation]
• Ramsay Sedation Score [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 [Time frame: Before intubation]
• The time needed for blockade procedure [Time frame: From ultrasounography localization to completion of local anesthetic administration]
• Record coughing in patients when the fiberoptic bronchoscope touches the glottis [Time frame: Before intubation]
• The tolerance score after the tube insertion [Time frame: Five minutes after successful intubation]
• Adverse reactions such as coughing and nausea/vomiting [Time frame: During intubation]
• Occurrences of sore throat and lowered pitch [Time frame: Post-extubation,24 hours after surgery]
• Total procedure time needed for awake intubation [Time frame: From the initiation of topical anesthesia to the accomplishment of tracheal intubation]
• Airway hemorrhage or nerve damage [Time frame: During intubation]

Eligibility criteria

Inclusion criteria

• Patients scheduled for awake tracheal intubation under general anesthesia.
• Patients with difficult airways (e.g., limited cervical spine mobility, full stomach, partial airway obstruction, craniofacial deformities or trauma, micrognathia, mouth opening <3cm, Mallampati III or IV classification) posing challenges for mask ventilation or intubation.
• Age between 18 and 85 years old.
• Gender is not restricted.
• ASA classification of I - III.

Exclusion criteria

• Cardiovascular dysfunction or arterial aneurysms.
• Mental or neurological disorders or concomitant arterial aneurysms.
• Infection at the puncture site.
• Allergy to local anesthetics.
• Continuous use of antiplatelet or anticoagulant medications preoperatively.
• Hoarseness or coughing while drinking water.
• Bronchial asthma.
• Participation in other clinical trials within the previous 3 months before enrollment 9.r current participation in other clinical trials.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Triple blind

Primary purpose

Health services research

Study locations

China · 2 centers

• Nanjing First Hospital — Nanjing
• Nanjing First Hospital — Nanjing

Identifiers

NCT: NCT07397234 · KY20260108-04

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗