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

Registration Number
NCT05310110
Lead Sponsor
Chang Gung Memorial Hospital
Brief 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.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
96
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
FACTORIAL
Arm && Interventions
GroupInterventionDescription
10% lidocaine spray and placebo of cisatracurium group10% lidocaine sprayThe 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.
10% lidocaine spray and placebo of cisatracurium groupPlacebo of cisatracuriumThe 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.
Placebo of lidocaine spray and cisatracurium groupPlacebo of lidocaine sprayThe 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.
Placebo groupPlacebo of lidocaine sprayThe 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.
10% lidocaine spray and cisatracurium group10% lidocaine sprayThe 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.
Placebo groupPlacebo of cisatracuriumThe 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.
10% lidocaine spray and cisatracurium groupPropofolThe 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.
10% lidocaine spray and cisatracurium groupCisatracuriumThe 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.
Placebo of lidocaine spray and cisatracurium groupCisatracuriumThe 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.
10% lidocaine spray and placebo of cisatracurium groupPropofolThe 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.
Placebo of lidocaine spray and cisatracurium groupPropofolThe 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.
Placebo groupPropofolThe 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.
Primary Outcome Measures
NameTimeMethod
Propofol requirementone minute after propofol infusion

The minimal propofol requirement dose was defined as the median effective dose (ED50) of movement or increased mean arterial pressure (MAP) to no movement or stable MAP. The ED50 is the average of the crossover midpoints found during conducting the Dixon's up-and-down method.

Secondary Outcome Measures
NameTimeMethod
Coughing or gaggingWithin 1 minute after LMA placement

Symptoms which suggest non-optimal condition of LMA insertion

Oxygen saturation (SpO2)0 minute, 1 minute, 2 minute, 3 minute, 4 minute, 5 minute, 10 minute after LMA placement

Using the pulse oximeter to collect the real-time oxygen saturation

Ease of LMA insertionProcedure (At the same time of LMA placement)

A factor for evaluating the condition of LMA insertion

Non-invasive blood pressure (NIBP)0 minute, 1 minute, 2 minute, 3 minute, 4 minute, 5 minute, 10 minute after LMA placement

Using the non-invasive blood pressure machine to collect the systolic blood pressure, diastolic blood pressure, and mean arterial pressure

Heart rate (HR)0 minute, 1 minute, 2 minute, 3 minute, 4 minute, 5 minute, 10 minute after LMA placement

Using the electrocardiogram monitor to collect the real-time heart rate

Head or body movementWithin 1 minute after LMA placement

Symptoms which suggest non-optimal condition of LMA insertion

Peak pressure (P peak) of the airway0 minute after LMA placement

One of the monitoring parameter demonstrated on the mechanical ventilator

HiccupsWithin 1 minute after LMA placement

Symptoms which suggest non-optimal condition of LMA insertion

Mean pressure (P mean) of the airway0 minute after LMA placement

One of the monitoring parameter demonstrated on the mechanical ventilator

Ease of jaw openingProcedure (At the same time of LMA placement)

A factor for evaluating the condition of LMA insertion

Attempts for LMA insertionProcedure (At the same time of LMA placement)

The number of attempts for LMA insertion

ComplicationsOne hour after LMA removal

Including sore throat, dysphagia, dysphonia

LaryngospasmWithin 1 minute after LMA placement

Laryngospasm is defined as airway obstruction with assumption that LMA is correctly placed, which is also a factor for evaluating the condition of LMA insertion

Trial Locations

Locations (1)

Linkup Chang Gung Memorial Hospital

🇨🇳

Taoyuan City, Taiwan

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