This study aims to compare the new-generation GMA laryngeal mask airway (LMA) with the traditional inflatable LMA in patients undergoing elective surgery under general anesthesia. The primary objectives are to evaluate the safety, effectiveness, stability, ease of use, and patient comfort of the GMA LMA, providing practical guidance for clinical airway management. Additionally, this research will analyze the anatomical positioning and sealing mechanism of the LMA to identify factors influencing proper alignment and airway sealing. The findings may contribute to future improvements in LMA design, enhancing patient safety and procedural success. This study is designed for healthcare providers, anesthesiologists, and researchers seeking evidence-based recommendations for LMA selection in clinical practice. Participation involves standard anesthesia procedures with close monitoring to ensure patient safety.
Eligible patients meeting the inclusion criteria were enrolled in the study and randomly assigned into two groups using a random number table: the traditional Inflatable Laryngeal Mask Airway Group (Group L) and the GMA Group (Group G). One day before surgery, the research team conducted preliminary screening of patients scheduled for elective surgery, followed by a preoperative visit to explain the study's purpose, anesthesia considerations, and obtain informed consent. Upon entering the operating room, standard monitoring (ECG, blood pressure, pulse oximetry, etc.) was applied. The research team recorded the patient's actual fasting duration, last intake (food/liquid type), and baseline characteristics, including age, sex, height, weight, BMI, comorbidities, ASA classification, surgical type, and preoperative anxiety level. Airway assessment was reconfirmed. Anesthesia induction was performed with intravenous etomidate, vecuronium, and sufentanil. After loss of consciousness and disappearance of the eyelash reflex, manual ventilation was initiated. Following induction, the laryngeal mask was inserted.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
1,384
The GMA-Tulip is a new single-use supraglottic airway device (SAD). Device size is selected based on the patient's weight and height, following manufacturer guidelines.
The comparator is a conventional inflatable Laryngeal Mask Airway (LMA) of appropriate size (selected by weight/height), inserted using standard clinical protocols.
The First affiliated Hospital, School of Medicine, Zhejiang University
Hangzhou, Zhejiang, China
RECRUITINGSuccess rate of anatomical alignment of laryngeal mask
Comparison of anatomical positioning success rates between inflatable LMA and GMA-Tulip LMA, assessed by fiberoptic bronchoscopy (FOB).
Time frame: During LMA placement (immediately after insertion)
Sealing pressure and positional stability of the GMA-Tulip versus inflatable LMA
Assess the stability and anti-displacement properties of special body positions (e.g. lateral decubitus, Trendelenburg position) and the laryngeal mask airway under pneumoperitoneum.
Time frame: Intraoperative period (from LMA insertion until removal at end of surgery)
First-attempt success rate of LMA
First-attempt success: Successful placement of the laryngeal mask airway on the first attempt without requiring reinsertion
Time frame: during procedure
Time to Successful Placement of LMA
Duration (in seconds) from LMA insertion into the oral cavity until final correct positioning is achieved
Time frame: during procedure
Hemodynamic response to LMA insertion and removal
Parameters: Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) (measured non-invasively or invasively).
Time frame: Intraoperative period
Oxygenation Stability (Intraoperative)
Peripheral oxygen saturation (SpO₂) (%) measured by continuous pulse oximetry
Time frame: From patient entry into operating room to the time for LMA removal
Ventilation Parameters (Intraoperative)
The measurement of Peak Airway Pressure (Ppeak) in cmH₂O is typically obtained through real-time monitoring by the anesthesia machine's ventilator system.
Time frame: from the start of mechanical ventilation after LMA placement to LMA removal
Feasibility of gastric tube insertion through LMA
Success rate: Proportion of cases with successful gastric tube placement
Time frame: During LMA placement (after confirmation of correct LMA position).
LMA-Related Complications
Immediate complications: Visible blood on removal (graded: none/mild/moderate/severe), sore throat , hoarseness, aspiration. Pain assessment: NRS for sore throat .
Time frame: Day 0
Patient Tolerance Score
Grade I (Excellent Tolerance) to Grade IV (Severe Intolerance)
Time frame: Within 60 minutes after LMA removal
Anesthesiologist Satisfaction Survey
Scale: 1-10 (1 = Very dissatisfied, 10 = Very satisfied)
Time frame: Within 30 minutes after surgery completion
Surgeon Satisfaction Assessment
Scale: 1-10 (1 = Very dissatisfied, 10 = Very satisfied)
Time frame: Within 30 minutes after surgery completion
Patient Satisfaction Survey
Scale: 1-10 (1 = Very uncomfortable, 10 = Very comfortable)
Time frame: Within 24 hours after surgery
Ultrasonographic Assessment of Gastric Antrum Cross-Sectional Area (CSA) in Supine Position for Monitoring Gastric Insufflation
This protocol utilizes point-of-care ultrasound (POCUS) to measure gastric antrum cross-sectional area (CSA) in supine patients, evaluating the risk of perioperative gastric insufflation caused by LMA.
Time frame: Baseline: Within 10 minutes before anesthesia induction; Post-intervention: Within 3 minutes after successful LMA placement; Postoperative: After surgical closure but before LMA removal
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