Muscle Relaxants and Laryngeal Local Anesthetics for Laryngeal Mask Airway Insertion Decreasing Propofol in Elderly

Summary

Laryngeal mask airway (LMA) is currently the most widely used supraglottic airway device with advantages of simple and fast placement, reduced anesthesia drug use, more stable hemodynamics, and less throat discomfort after anesthesia compared to endotracheal intubation. Some studies claimed the use of muscle relaxants or local anesthetics (sprays or lubricants containing local anesthetics) for the throat before LMA placement can reduce the dosage of induction agents and postoperative throat complications.

In modern society, more and more elderly people undergo elective surgery with the need of general anesthesia. However, they are the more vulnerable population with tendency of greater hemodynamic changes with more induction agent usage. Propofol is one of the most used induction agents which may lead to a drop in blood pressure. The objective of this study is to observe whether the dose of propofol and the changes in hemodynamics can be reduced by using muscle relaxants or laryngeal local anesthetics in elderly who receiving general anesthesia with LMA insertion.

Conditions

• Anesthesia, General

Interventions

DRUG

10% lidocaine spray

10% lidocaine spray 3 puff for the throat before induction

DRUG

Placebo of lidocaine spray

Normal saline spray 3 puff for the throat before induction

DRUG

Cisatracurium

Intravenous cisatracurium 0.12 mg/kg during induction

DRUG

Placebo of cisatracurium

Intravenous normal saline during induction

DRUG

Propofol

The dosage of intravenous propofol for the first subjects was predetermined for each arm, and the dosage for the subsequent subjects would be determined according to the response of the previous subjects using the Dixon's up-and-down method with a step size of 0.25 mg/kg. If the subjects had no movement and stable hemodynamic status during and after the laryngeal mask airway (LMA) placement, the predetermined dosage of propofol for the subsequent subject would be decreased by 0.25 mg/kg. On the other hand, if the subjects had obvious movement, failure to LMA placement, and significant hemodynamic changes, the predetermined dosage of propofol for the subsequent subject would be increased by 0.25 mg/kg.

Sponsors & Collaborators

• Chang Gung Memorial Hospital

  lead OTHER

Principal Investigators

• Chung Yung-Tai, MD · Department of Anesthesiology, Chang Gung Memorial Hospital, Linkou Medical Center

• Hung Yu-Ting, MD · Department of Anesthesiology, Chang Gung Memorial Hospital, Linkou Medical Center

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

TRIPLE

Model

FACTORIAL

Eligibility

Min Age

65 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2022-04-12

Primary Completion

2023-08-24

Completion

2023-08-24

Countries

• Taiwan

Study Locations