Application of Visual Laryngeal Mask Airway Combined With Endotracheal Intubation in Non-head and Neck Surgery Under General Anesthesia
Phase: NA
Conditions: General Anesthesia, Laryngeal Mask, Endotracheal Intubation, Surgery
Sponsor: Peking Union Medical College Hospital

 
 
 
Study Protocol 
 
 
 
 
 
                             2021-1-18 
 
 

 
Project name 
Application of Visual Laryngeal Mask Airway Combined with 
Endotracheal Intubation in Non-head and Neck Surgery Under 
General Anesthesia 
Name 
of 
project 
leader 
Xia Ruan, Yahong Gong 
Title 
Associate 
Professor 
Department 
Department of Anesthesiology 
Telephone contact 
86-10-69152001 
Fax 
 
E-mail 
 sheyaruan@sina.com 
Research 
Cooperation Unit 
N/A 
Head 
of 
Research 
Cooperation Unit 
N/A 
Study Start Date 
February 1, 2021 
 
Estimated duration of the 
study 
1.5 Year 
Research site 
Peking Union Medical College Hospital 
Does this study include genetic analysis? 
□ yes ;■ no; 
Does this study include radiation? 
□ yes ;■ no; 
Does the researcher have a conflict of interest 
□ Yes (please specify): 
■ not; 
 
a. 
Background information on subjects: (Gender, age, health status, and other characteristics.) 
Patients undergoing non-head and neck surgery with endotracheal intubation under general 
anesthesia, ASA Ⅰ-Ⅱ. 
 
b. 
Number of subjects (sample size), inclusion criteria, exclusion criteria: 
50 subjects to be included 
Selection criteria: 
1. The operation of non-head and neck surgery with endotracheal intubation under general 
anesthesia.  
2. ASA Ⅰ-Ⅱ. 
3. Age 18~70 years old. 
4. Voluntary signature of informed consent. 
Exclusion criteria: 
1. ASA Ⅲ-Ⅳ; 
2. Weight <30kg or BMI>40kg/m2; 
3. Patients with high risk of regurgitation; 
4. Complicated with severe respiratory diseases; 
5. Complicated with oropharyngeal lesions affected laryngeal mask placement; 

6. Complicated with oropharyngeal pain in the last two weeks.  
 
c. 
Methods of intervention 
1. 
Preoperative 
The coordinators screen patient who meets the exclusion criteria before operation, visit the patient 
the day before operation, explain the research plan, and randomly divide the patient into visual 
group or non-visual group after the patient consents and signs the informed consent. 
2. 
Intraoperative 
After entering the operating room, the patient received routine general anaesthesia monitoring, 
and anesthesia induction was conducted after three-party verification. Propofol (plasma target-
controlled concentration: 3.5ug/ mL), midazolam (0.05mg/kg), fentanyl (2ug/kg) and rocuronium 
(0.6mg/kg) were used to induce the drugs. 
After anesthesia induction, visual laryngeal mask airway was placed in the visual group and 
endotracheal intubation was guided under visual conditions. In the non-visual group, after judging 
the position of laryngeal mask by clinical experience, endotracheal intubation was inserted blindly. 
Selection of laryngeal mask airway (LMA) model based on: the ideal body weight of the patient, 3 
was selected for the body weight of 30-50kg, 4 for the body weight of 50-70kg and 5 for the body 
weight > 70kg. The endotracheal tube intubation time, intubation times and intubation success 
rate of the two groups were recorded. 
During the operation, propofol and fentanyl are used for anesthesia maintenance, and the 
anesthesiologist adjusts the anesthesia depth according to his/her own experience. Ten minutes 
before the end of the operation, endotracheal intubation was removed and the laryngeal mask 
airway was retained. The displacement rate of the laryngeal mask airway, the volume of secretion 
in airway and the incidence of laryngeal spasm were compared between the two groups. 
3. 
Postoperation 
After the surgery, the residual muscle relaxation was antagonized, and the laryngeal mask was 
removed after the patient regained consciousness and reached the extubation criteria. The 
hemodynamic parameters and the severity of cough during laryngeal mask airway removal were 
recorded. The incidence and severity of oropharyngeal pain, oropharyngeal numbness, hoarseness, 
nausea, and vomiting were assessed immediately after the patient woke up and was followed up 
before leaving the recovery room and on the first day after surgery. 
 
d. Outcomes 
1) 
Compare the intubation time, intubation times and intubation success rate of endotracheal 
intubation through laryngeal mask airway under visual and non-visual conditions. 
2) 
Compare the displacement rate of laryngeal mask airway after endotracheal intubation 
removal under visual and non-visual conditions. 
3) 
Compare the incidence of oropharyngeal pain and hoarseness after endotracheal intubation 
through laryngeal mask airway under visual and non-visual conditions.