Comparison of Intubation Rate of Macintosh Size 2 and 3 Blades in Asian Female: a Randomised Controlled Trial

Study Overview
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Brief Summary
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Direct laryngoscope is a standard equipment for endotracheal intubation. To identify the differences between Macintosh size 3 and 2 blades, we will analysis the data collected from airway and intubation condition.

Detailed Description
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Selection the most appropriate size of laryngoscope blade size could not only increased intubation successful rate at the first time but also decrease the incidence of tissue trauma. Laryngoscope blade used in daily practice is usually Macintosh 3. However, compared with Caucasian people, Asian people are smaller and thinner especially in women. This study aims to confirm that the Macintosh 2 blade is not inferior to size 3 blade in laryngeal view and intubation rate. Female patients without known difficult airway will be enrolled and allocated into Macintosh blade size 2 and size 3 groups. The age, body weight, body height, Mallampati classification, mouth opening, thyromental distance, neck circumference, intubation time, Cormack-Lehane grade, intubation difficulty scale scores and associated teeth or tissue traumas will be recorded.

Official Title
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Comparison of Intubation Rate of Macintosh Size 2 and 3 Blades in Asian Female: a Randomised Controlled Trial

Conditions
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Intubation;Difficult

Intervention / Treatment
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* Device: Macintosh size 2 blade
* Device: Macintosh size 3 blade


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: with American Society of Anesthesiologists (ASA) physical status classification 1, 2, or 3 undergo elective surgery receive endotracheal intubation Exclusion Criteria: with known difficult airway (i.e. pathology of the neck, upper airway or alimentary tracts) with risks of pulmonary aspiration (i.e. emergent operation, pregnancy or inadequate nil per os) with previous difficult intubation history intubation attempts more than three times patient refusal

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Macintosh 2 group<br>Using Macintosh size 2 blade for direct laryngoscope intubation according to randomization | Device: Macintosh size 2 blade<br>* intubate with Macintosh size 2 blade<br>|
| Active Comparator: Macintosh 3 group<br>Using Macintosh size 3 blade for direct laryngoscope intubation according to randomization | Device: Macintosh size 3 blade<br>* intubate with Macintosh size 3 blade<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intubation time | Time from laryngoscope insertion to the first adequate lung insufflation | 0-10 minutes during induction | 
| Cormack-Lehane grade | Classification of glottis view during intubation | 0-10 minutes during induction | 
| Intubation difficulty scale scores | Scoring system to assess the difficulty of intubation in each patient | 0-10 minutes during induction | 
| Tissue trauma | Any tissue trauma event related to intubation | 0-10 minutes during induction | 
| Teeth trauma | Any dental damage event related to intubation | 0-10 minutes during induction | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Intubation rate, Macintosh blade, Asian women, intubation difficulty scale