LMA Protector vs I-Gel in Low-Flow Anesthesia for Laparoscopic Cholecystectomy

Comparison of LMA Protector and I-Gel Use in Low-Flow Anesthesia for Laparoscopic Cholecystectomy: A Prospective Randomized Study

This prospective randomized study aims to compare two second-generation supraglottic airway devices (SGAs), the I-Gel and the laryngeal mask airway (LMA) Protector, in patients undergoing laparoscopic cholecystectomy under low-flow desflurane anesthesia. The study evaluates the devices in terms of respiratory mechanics (dynamic compliance, peak inspiratory pressure, plateau pressure, and airway resistance), non-invasive perfusion parameters (oxygen reserve index, perfusion index, and pleth variability index), hemodynamic stability, ease of insertion, oropharyngeal leak pressure, and postoperative complication rates.

Study Overview

• Status: Completed
• Conditions: Anesthesia, General; Laparoscopic Cholecystectomy
• Intervention / Treatment: Device: I-Gel supraglottic airway; Device: LMA Protector supraglottic airway

Detailed Description

Sixty-two patients (ASA I-II, aged 18-65 years) scheduled for elective laparoscopic cholecystectomy were randomized into two groups: Group I (I-Gel) and Group P (LMA Protector). General anesthesia induction was standardized, and maintenance was provided with desflurane at a fresh gas flow of 1 L/min to achieve low-flow anesthesia. Peak inspiratory pressure (PIP), plateau pressure (Pplato), dynamic compliance (Cdyn), and airway resistance were recorded at six distinct intraoperative time points: 5 minutes after SGA insertion (T1), 1 minute after pneumoperitoneum insufflation (T2), 1 minute after the 30-degree reverse Trendelenburg position (T3), 10 minutes after insufflation (T4), 1 minute after desufflation (T5), and immediately before SGA removal (T6). Oropharyngeal leak pressure (OLP) was measured after insertion and before removal. Postoperative complications such as sore throat, cough, hoarseness, dysphagia, and nausea-vomiting were monitored postoperatively.

• Study Type: Interventional
• Enrollment (Actual): 62
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye), 34752
    • Fatih Sultan Mehmet Training and Research Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients aged 18-65 years
• American Society of Anesthesiologists (ASA) physical status I or II
• Scheduled for elective laparoscopic cholecystectomy

Exclusion Criteria:

• Known or predicted difficult airway or history of difficult intubation
• Body Mass Index (BMI) greater than 35 kg/m²
• High risk of gastroesophageal reflux or aspiration
• Severe cardiac, respiratory, renal, or hepatic disease
• Pregnancy
• Patient refusal to participate

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group I: I-Gel; Patients managed with the I-Gel supraglottic airway device during low-flow desflurane anesthesia for laparoscopic cholecystectomy.	Device: I-Gel supraglottic airway; Placement of an appropriate size of i-gel supraglottic airway device for airway management during general anesthesia. Anesthesia maintenance is provided with desflurane in a fresh gas flow of 1 L/min (low-flow anesthesia).; Other Names: i-gel
Experimental: Group P: LMA Protector; Patients managed with the LMA Protector supraglottic airway device during low-flow desflurane anesthesia for laparoscopic cholecystectomy.	Device: LMA Protector supraglottic airway; Placement of an appropriate size of LMA Protector supraglottic airway device for airway management during general anesthesia. Anesthesia maintenance is provided with desflurane in a fresh gas flow of 1 L/min (low-flow anesthesia).; Other Names: Laryngeal Mask Airway Protector

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dynamic Lung Compliance (Cdyn)	Dynamic compliance of the respiratory system, calculated automatically by the ventilator as tidal volume divided by (peak inspiratory pressure minus positive end-expiratory pressure).	Measured intraoperatively at 6 specific time points from 5 minutes after device insertion until immediately before device removal.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak Inspiratory Pressure (PIP)	Maximum airway pressure generated during the inspiratory phase, monitored to assess airway dynamics under general anesthesia.	Measured intraoperatively at 6 specific time points from 5 minutes after device insertion until immediately before device removal.
Plateau Pressure (Pplateau)	Pressure applied to the small airways and alveoli during a period of zero gas flow, monitored to assess risk of barotrauma.	Measured intraoperatively at 6 specific time points from 5 minutes after device insertion until immediately before device removal.
Airway Resistance	The resistance of the respiratory tract to airflow during mechanical ventilation, calculated using peak and plateau pressures.	Measured intraoperatively at 6 specific time points from 5 minutes after device insertion until immediately before device removal.

Collaborators and Investigators

• Sponsor: Fatih Sultan Mehmet Training and Research Hospital
• Collaborators: Masimo Corporation

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2020
• Primary Completion (Actual): October 31, 2020
• Study Completion (Actual): October 31, 2020

Study Registration Dates

• First Submitted: July 5, 2026
• First Submitted That Met QC Criteria: July 11, 2026
• First Posted (Actual): July 16, 2026

Study Record Updates

• Last Update Posted (Actual): July 16, 2026
• Last Update Submitted That Met QC Criteria: July 11, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Respiratory Mechanics; LMA Protector; I-Gel; Supraglottic Airway Device; Low-Flow Anesthesia
• Other Study ID Numbers: FSM KAEK-2020/79

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No