Clinical trial NCT04566224: Comparison of Intubation Rate of Macintosh Size 2 and 3 Blades in Asian Female: a Randomised Controlled Trial
Official title: Comparison of Intubation Rate of Macintosh Size 2 and 3 Blades in Asian Female: a Randomised Controlled Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Intubation;Difficult
Keywords: Intubation rate
Macintosh blade
Asian women
intubation difficulty scale
Lead sponsor: Mackay Memorial Hospital
Sponsor class: OTHER
First posted: 2020-09-28
Enrollment: 90
Sex: FEMALE
Minimum age (years): 20
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: 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: 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.

Eligibility criteria: 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

Primary outcomes:
measure: Intubation time
timeFrame: 0-10 minutes during induction
measure: Cormack-Lehane grade
timeFrame: 0-10 minutes during induction
measure: Intubation difficulty scale scores
timeFrame: 0-10 minutes during induction
measure: Tissue trauma
timeFrame: 0-10 minutes during induction
measure: Teeth trauma
timeFrame: 0-10 minutes during induction
Secondary outcomes:
Other outcomes:
Locations:
city: Taipei
country: Taiwan
facility: Mackay Memorial Hospital
Study officials:
affiliation: Mackay Memorial hospital, department of anesthesiology, attending physician
name: Nuan-Yen Su, MS
role: STUDY_DIRECTOR
References:
citation: Mellick LB, Edholm T, Corbett SW. Pediatric laryngoscope blade size selection using facial landmarks. Pediatr Emerg Care. 2006 Apr;22(4):226-9. doi: 10.1097/01.pec.0000210171.17892.7a.
citation: Ashfaque M, Mason J, Al-Shaikh B, Adegoke K. A comparison of the Laryngopharyngeal Examination blade and the English Macintosh laryngoscope blade using an intubating manikin: a prospective randomized crossover study. Eur J Anaesthesiol. 2009 Nov;26(11):917-22. doi: 10.1097/EJA.0b013e32832c7848.
citation: Asai T, Matsumoto S, Fujise K, Johmura S, Shingu K. Comparison of two Macintosh laryngoscope blades in 300 patients. Br J Anaesth. 2003 Apr;90(4):457-60. doi: 10.1093/bja/aeg086.
citation: Watanabe S, Suga A, Asakura N, Takeshima R, Kimura T, Taguchi N, Kumagai M. Determination of the distance between the laryngoscope blade and the upper incisors during direct laryngoscopy: comparisons of a curved, an angulated straight, and two straight blades. Anesth Analg. 1994 Oct;79(4):638-41. doi: 10.1213/00000539-199410000-00004.