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

Chang Gung Medical Foundation

Status: Completed

Conditions: Anesthesia, General

Treatments: Drug: 10% lidocaine spray; Drug: Propofol; Drug: Cisatracurium; Drug: Placebo of lidocaine spray; Drug: Placebo of cisatracurium

Study type: Interventional

Funder types: Other

Identifiers

NCT05310110

202200004A3

Details and patient eligibility

About

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.

Enrollment: 96 patients

Sex: All

Ages: 65+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• American Society of Anesthesiologists (ASA) physical status I-III
• Age: over 65 years
• Elective orthopedic surgery undergo general anesthesia in supine position

Exclusion criteria

• Anticipated difficult airway (Mallampati score 3-4), limited mouth opening, intra-oral and pharyngeal pathology
• Risk of pulmonary aspiration of gastric contents (full stomach)
• Obesity (Body mass index > 35)
• Significant lung abnormalities (low lung compliance, high airway resistance, impaired oxygenation)
• Loosening teeth
• Allergic to Cisatracurium or Lidocaine
• Failure in successful LMA insertion after second attempts

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Factorial Assignment

Masking: Triple Blind

---

96 participants in 4 patient groups, including a placebo group

10% lidocaine spray and cisatracurium group

Experimental group

Description:

The subjects received laryngeal local anesthetics (10% lidocaine spray), intravenous cisatracurium 0.12 mg/kg, and propofol before laryngeal mask airway placement. The predetermined dosage of propofol for the first subject is 1 mg/kg.

Treatment:

Drug: 10% lidocaine spray

Drug: Propofol

Drug: Cisatracurium

10% lidocaine spray and placebo of cisatracurium group

Experimental group

Description:

The subjects received laryngeal local anesthetics (10% lidocaine spray), intravenous normal saline as a substitute for cisatracurium, and propofol before laryngeal mask airway placement. The predetermined dosage of propofol for the first subject is 1.25 mg/kg.

Treatment:

Drug: 10% lidocaine spray

Drug: Propofol

Drug: Placebo of cisatracurium

Placebo of lidocaine spray and cisatracurium group

Experimental group

Description:

The subjects received normal saline spray as a substitute for laryngeal local anesthetics (10% lidocaine spray), intravenous cisatracurium 0.12 mg/kg, and propofol before laryngeal mask airway placement. The predetermined dosage of propofol for the first subject is 1 mg/kg.

Treatment:

Drug: Propofol

Drug: Cisatracurium

Drug: Placebo of lidocaine spray

Placebo group

Placebo Comparator group

Description:

The subjects received normal saline spray as a substitute for laryngeal local anesthetics (10% lidocaine spray), intravenous normal saline as a substitute for cisatracurium, and propofol before laryngeal mask airway placement. The predetermined dosage of propofol for the first subject is 2 mg/kg.

Treatment:

Drug: Propofol

Drug: Placebo of cisatracurium

Drug: Placebo of lidocaine spray