The Optimal Time to Put Laryngeal Mask Airway in the Mouth Under General Anesthesia (LMA)

The Optimal Time of Insertion of Laryngeal Mask Airway With Propofol Induction

Laryngeal mask airway (LMA) is routinely used for some patients who have surgery under general anesthesia. LMA is placed in the mouth and allow the anesthesia to be given without having to put a breathing tube in the throat. Previous studies have focused on the effect of different anesthesia medicines on optimal condition for LMA use. The objective of the present study is to find the optimal time for LMA insertion.

Study Overview

• Status: Completed
• Conditions: General Anesthesia
• Intervention / Treatment: Procedure: Insertion of Laryngeal Mask Airway

Detailed Description

This is a randomized, controlled, blinded trial. Midazolam, 2 mg and fentanyl 1.0 µg/kg, would be given prior to induction with propofol, 2.5 mg/kg.

The investigator who does the induction of general anesthesia will also be responsible for the timekeeping. For this reason, it is not possible for this investigator to be blinded to randomization. The induction would conclude after loss of eyelash reflex (LER). At that point insertion of the LMA (#4 for females, #5 for males) will occur 0, 60 and 90 seconds after LER. The LMA will be lubricated with a water soluble gel and will be inserted with a deflated cuff according to the technique described by Brain.

The investigator who inserts the LMA (Inv1) will be in the operating room and blinded to randomization groups by not seeing the induction of general anesthesia. This investigator will insert the LMA only when called by the investigator who induces general anesthesia (Inv2). Inv1 will also grade ease of LMA insertion.

The primary outcome is Jaw opening at the time of LMA insertion, defined as full 1, partial 2, and nil 3.

Secondary outcomes include:

1. Insertion of LMA (easy, difficult, impossible)
2. Coughing or gagging (none, some, significant)
3. Head or body movement (none, some, significant)
4. Laryngospasm or airway obstruction (none, partial, total)

• Study Type: Interventional
• Enrollment (Actual): 198
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02111
      • Tufts Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• subjects 18 years or older
• ASA status 1-3

Exclusion Criteria:

• high risk of aspiration
• anticipated difficult airway
• use of sedative drugs
• patient refusal

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: 0 sec, 60 sec, 90 sec; LMA will be inserted at 0, 60, and 90 seconds after eyelash reflex disappears	Procedure: Insertion of Laryngeal Mask Airway; The LMA will be inserted at 0 sec, 60 sec. and 90 sec. after induction of general anesthesia; Other Names: Laryngeal Mask Airway

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Ease of Mouth opening	From Induction of general anesthesia to satisfactory LMA insertion

Collaborators and Investigators

• Sponsor: Tufts Medical Center
• Investigators: Principal Investigator: Pei-shan Zhao, MD,PhD, Tufts Medical Center

Study record dates

Study Major Dates

• Study Start: September 1, 2009
• Primary Completion (Actual): December 1, 2013
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: September 3, 2009
• First Submitted That Met QC Criteria: September 4, 2009
• First Posted (Estimate): September 7, 2009

Study Record Updates

• Last Update Posted (Estimate): December 4, 2013
• Last Update Submitted That Met QC Criteria: December 3, 2013
• Last Verified: December 1, 2013

More Information

Terms related to this study

• Other Study ID Numbers: IRB-8910

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No