Pressure Supporting Ventilation and EEG-guided Emergence for Free of Unwanted Complications

Study Overview
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Brief Summary
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This study aims to assess whether pressure supporting ventilation and electroencephalogram (EEG)-guided emergence can reduce airway complications after thyroid surgery compared with conventional emergence. Patients will be randomly assigned to either pressure supporting ventilation and EEG-guided emergence group (intervention group) or conventional emergence group (control group). Co-primary outcomes are the incidence of emergence coughing and lowest percutaneous oxygen saturation (SpO2) after emergence. Secondary outcomes included severity of emergence cough, emergence time, blood pressure and heart rate during emergence, Richmond Agitation-Sedation Scale (RASS) immediately after extubation and upon post-anesthesia care unit (PACU) arrival, incidence of desaturation during PACU stay, hoarseness, sore throat during PACU stay, duration of PACU stay, surgeon satisfaction regarding emergence process, postoperative pain score, and patient satisfaction score regarding emergence process.

Detailed Description
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Adult patients aged ≤ 60 years scheduled to undergo thyroid surgery will be screened for eligibility. Patients will be randomly allocate to either the intervention group or control group. In the intervention group, pressure support ventilation will be applied from the start of subcutaneous suture until extubation. At the end of surgery, sevoflurane will be discontinued, and the attending anesthesiologist will perform tracheal extubation after observing the 'zipper opening' pattern on the EEG spectrogram, indicating the patient's recovery of consciousness. For safety reason, extubation will also be guided by the following processed EEG indices thresholds: 95% spectral edge frequency (SEF) ≥ 23 Patient state index (PSI) ≥ 64 In the control group, conventional full-awake extubation will be performed based on the routine practice of our institution. At the end of surgery, sevoflurane will be stopped, and the attending anesthesiologist will lead the emergence process, allowing the patient to breathe spontaneously and providing intermittent manual assistance if necessary. Extubation will be performed when the patient meets the following criteria: obeys commands such as eye-opening or hand-grip, tidal volume > 5 ml/kg, end-tidal carbon dioxide < 45 mmHg, spontaneous respiratory rate 10 to 20 breaths/min. In both groups, the Oxygen Reserve Index (ORi) will be monitored. Blinded investigator will assess the incidence of emergence coughing and the lowest SpO2 after emergence.

Official Title
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Pressure Supporting Ventilation and Electroencephalography-guided Extubation for Free of Unwanted compLications (PEACEFUL): a Randomised Controlled Trial

Conditions
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Thyroid Surgery

Intervention / Treatment
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* Procedure: PSV
* Procedure: Intermittent Manual Assistance
* Procedure: EEG-Guidance
* Procedure: Obey Command
* Procedure: Spontaneous Respiration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients aged under 60 years who are scheduled to undergo thyroid surgery. Exclusion Criteria: Patients scheduled for radical neck dissection Patients scheduled for lymph node biopsy Patients with an anticipated difficult airway Patients experiencing difficulty during intubation Patients with a fasting time not meeting institutional policy Patients with a body mass index (BMI) greater than 30 kg/m² Patients with sleep apnea Pregnant or breastfeeding women Patients unable to communicate

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Prospective, single-blinded, parallel-group, randomized clinical study
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pressure Supporting Ventilation (PSV) and EEG-guided Emergence group<br>Pressure support ventilation will be applied from the start of subcutaneous suture until extubation. At the end of surgery, sevoflurane will be discontinued, and the attending anesthesiologist will perform tracheal extubation after observing the 'zipper opening' pattern on the EEG spectrogram, indicating the patient's recovery of consciousness. For safety reason, extubation will also be guided by the following processed EEG indices thresholds: 95% spectral edge frequency (SEF) ≥ 23 Patient state index (PSI) ≥ 64 | Procedure: PSV<br>* Pressure support ventilation applied from the start of subcutaneous suture until extubation.<br>Procedure: EEG-Guidance<br>* Extubation criteria based on EEG findings:Zipper opening pattern observed in the spectrogram 95% spectral edge frequency (SEF) ≥ 23 Patient state index (PSI) ≥ 64<br>Procedure: Spontaneous Respiration<br>* Extubation criteria include: Tidal volume > 5 ml/kg End-tidal carbon dioxide (ETCO2) < 45 mmHg Spontaneous respiratory rate (RR) 10 to 20 breaths/min<br>|
| Active Comparator: Conventional Emergence group<br>Conventional full-awake extubation will be performed based on the routine practice of our institution. At the end of surgery, sevoflurane will be stopped, and the attending anesthesiologist will lead the emergence process, allowing the patient to breathe spontaneously and providing intermittent manual assistance if necessary. Extubation will be performed when the patient meets the following criteria: obeys commands such as eye-opening or hand-grip, tidal volume > 5 ml/kg, end-tidal carbon dioxide < 45 mmHg, spontaneous respiratory rate 10 to 20 breaths/min. | Procedure: Intermittent Manual Assistance<br>* Volume-controlled mode during surgery, with intermittent manual assistance from the end of surgery until extubation.<br>Procedure: Obey Command<br>* Extubation criteria include obeying commands (eye-opening or handgrip).<br>Procedure: Spontaneous Respiration<br>* Extubation criteria include: Tidal volume > 5 ml/kg End-tidal carbon dioxide (ETCO2) < 45 mmHg Spontaneous respiratory rate (RR) 10 to 20 breaths/min<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of emergence coughing | Incidence of emergence coughing (defined as coughing during the time period from sevoflurane off until 5 minutes after extubation) | During the time period from sevoflurane cessation until 5 minutes after extubation | 
| Lowest SpO2 after emergence | Lowest SpO2 after emergence (defined as the lowest SpO2 value during the time period from sevoflurane off to post-anesthesia care unit (PACU) discharge) | During the time period from sevoflurane cessation until post-anesthesia care unit (PACU) discharge, an average of 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Severity of Emergence coughing | The severity of emergence coughing will be assessed using the modified 4-point Minogue scale, with grades assigned as follows: grade 1 (none), grade 2 (mild), grade 3 (moderate), or grade 4 (severe). A higher score indicates a more severe cough. | During the time period from sevoflurane cessation until 5 minutes after extubation. | 
| Incidence and severity of coughing during PACU stay | Incidence and severity of coughing during PACU stay evaluated using a modified 4-point Minogue scale. | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Emergence time | Time from sevoflurane cessation until tracheal extubation (minutes) | During the time period from sevoflurane cessation until tracheal extubation, an average of 20 minutes | 
| Time to leave operating room | Time from sevoflurane cessation until leaving operating room | During the time period from sevoflurane cessation until leaving operating room, an average of 30 minutes | 
| Blood pressure during emergence | systolic, diastolic, mean blood pressure (mmHg) | during the time period from sevoflurane off until 5 minutes after extubation | 
| Heart rate during emergence | Heart rate (beats per minute) | during the time period from sevoflurane off until 5 minutes after extubation | 
| Incidence of endotracheal tube biting | Biting of the endotracheal tube; The investigator will observe whether the patient bites the endotracheal tube or not. | During the time period from sevoflurane cessation until tracheal extubation, an average of 20 minutes | 
| Hypoventilation after extubation (RR <8/min) | Hypoventilation defined as Respiratory Rate <8/min | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Richmond Agitation-Sedation Scale (RASS) immediately after extubation and upon PACU arrival | The Richmond Agitation-Sedation Scale (range : +4 to -5) | RASS will be assessed at two time points; (1) immediately after tracheal extubation, and (2) immediately after PACU arrival | 
| Incidence of desaturation during PACU stay | Incidence of desaturation | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Hoarseness | Patients will be specifically asked about the existence of a hoarse voice | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Incidence and severity of sore throat | Incidence and severity of pain or irritation of the throat. | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Duration of PACU stay | Duration of PACU stay (minutes) | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Surgeon satisfaction regarding emergence process encompassing smoothness/safety/speed | Surgeon satisfaction regarding emergence process encompassing smoothness/safety/speed (0: totally unsatisfied, 10: totally satisfied) | Immediately after the transfer of the patient from operating room to PACU | 
| Incidence of awareness with recall | Patients will be specifically asked whether they experienced intraoperative consciousness, explicit recall of intraoperative events, or the emergence process. | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Pain score during PACU stay | pain score assessed by numeric rating scale; from 0 (no pain) to 10 (worst pain) | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Patient satisfaction score regarding emergence process | 0: totally unsatisfied, 10: totally satisfied | During the time period from PACU admission until PACU discharge, an average of 40 minutes | 
| Incidence of Postoperative hematoma | hematoma formation | After operation, through the hospitalization, an average of 3 days. | 
| Incidence of wound dehiscence | dehiscence of the surgical wound | After operation, through the hospitalization, an average of 3 days. | 
| reoperation | reoperation of thyroid surgery | After operation, through the hospitalization, an average of 3 days. | 
| Oxygen Reserve Index | Index of the patient's oxygen reserve, with a unit-less scale between 0.00 and 1.00. | During the period from sevoflurane cessation until PACU discharge, an average of 1 hour |