Related Experiment Video
Updated: May 15, 2026
In Vitro Method to Control Concentrations of Halogenated Gases in Cultured Alveolar Epithelial Cells
Published on: October 23, 2018
Predicted end-tidal sevoflurane concentration for insertion of a Laryngeal Mask Supreme: a prospective observational
Matilde Zaballos1, Emilia Bastida, Consolación Jiménez
1Department of Toxicology, Complutense University, Madrid, Spain. mati@plagaro.net
Context:
The single-use Laryngeal Mask Airway (LMA) Supreme is a new supraglottic airway device. It has been reported to be reliable and easy-to-use in clinical practice; however, the anaesthetic techniques for its insertion are not standardised.
Objectives:
The purpose of this study was to determine the ED50 of end-tidal sevoflurane concentration for successful LMA Supreme insertion without the use of neuromuscular blockade.
Design:
A prospective observational study.
Setting:
A single tertiary care surgical centre.
Patients:
Thirty-one consecutive elective patients scheduled for minor elective surgery under general anaesthesia.
Intervention:
Patients were preoxygenated with 100% oxygen and anaesthetised using normal tidal volume inhalation of sevoflurane. The target sevoflurane concentration was determined using a modified Dixon's 'up-and-down' method (starting at 2.5% with 0.5% as the step size). After the predetermined end-tidal concentration had been established and maintained for 10 min, LMA Supreme insertion was attempted.
Main Outcome Measure:
The main outcome measure was the patient's response to LMA Supreme insertion, classified as either 'movement' or 'no movement'. The mean of the concentrations of seven cross-overs from 'movement' to 'no movement' was used to estimate the ED50.
Results:
The estimated sevoflurane concentration for successful LMA Supreme insertion in 50% of adults was 3.03 ± 0.75% (95% confidence interval 2.3 to 3.7%). The values of the ET50 and ET95 obtained by logistic regression were 2.83 and 5.30%, respectively.
Conclusion:
Sevoflurane alone can provide acceptable conditions for insertion of the LMA Supreme in adults, at an estimated minimum alveolar anaesthetic concentration of 3% with minimal adverse effects.
More Related Videos
03:02Application of Dixon's Up-and-Down Design to Estimate the Minimum Alveolar Concentration of Sevoflurane in Rats with Refined Movement Classification
Published on: July 25, 2025
09:36Halogenated Agent Delivery in Porcine Model of Acute Respiratory Distress Syndrome via an Intensive Care Unit Type Device
Published on: September 24, 2020
Related Concept Videos
01:20Inhalational Anesthetics: Overview
01:15Endotracheal Intubation I: Procedure
The ET tube comprises various components, including a standard adaptor to attach a bag-valve-mask (BVM) or ventilator, a cuff, a pilot balloon, and radiopaque markings along its length to measure the insertion distance. The tube sizes...
01:24Endotracheal Tube Extubation
Procedure
Extubation removes the endotracheal tube (ETT) from the patient on mechanical ventilation. It requires a well-coordinated, multidisciplinary approach involving physicians, nurses, respiratory therapists, and other healthcare professionals.
01:17Endotracheal Intubation II: Nursing Management
1. Nursing Care of Patients Before Intubation
Before the endotracheal intubation procedure, nurses play an essential role in ensuring the process goes smoothly. The nurses must be familiar with intubation...
01:17Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
01:30Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques