Application of Visual Laryngeal Mask Airway Combined With Endotracheal Intubation in General Anesthesia

To study the advantages of visual laryngeal mask combined with endotracheal intubation in general anesthesia surgery, we compared intubation time, intubation times and intubation success rate of endotracheal intubation through laryngeal mask airway under visual and non-visual conditions, at the same time, the laryngeal mask displacement rate, volume of secretion in airway, the incidence of laryngeal spasm, the incidence and severity of postoperative oropharyngeal pain were also compared between two groups.

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.

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.

Eligibility Criteria:
Inclusion Criteria:

* Aged 18-70
* American Society of Anesthesiologist physical status (ASA) Ⅰ-II
* Undergoing non-head and neck surgery under general anesthesia with endotracheal intubation
* Sign the informed consent voluntarily;

Exclusion Criteria:

* Not willing to participate in the study or not able to sign the informed consent
* American Society of Anesthesiologist physical status (ASA) Ⅲ-Ⅳ
* Weight \<30kg or BMI\>40 kg/m2
* High risk of reflux aspiration
* Combined with severe respiratory disease
* Combined oropharyngeal lesions affect the laryngeal mask insertion
* Oropharyngeal pain in the last two weeks.