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McGRATH MAC Video Laryngoscope

Not Applicable
Completed
Conditions
Intubation; Difficult
Interventions
Device: McGrath MAC enhanced direct laryngoscope
Registration Number
NCT02250521
Lead Sponsor
The University of Texas Health Science Center, Houston
Brief Summary

This study was designed to determine the first attempt success rate of tracheal intubation with the McGRATH™ MAC laryngoscope using direct visualization in patients with known difficult airways, as well as exploring the possibility of identifying a particular direct Cormack-Lehane (C-L) grade view where indirect (video) visualization can be most beneficial during laryngoscopy and intubation.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
100
Inclusion Criteria
  • BMI < 50 kg/m2
  • Two or more of the following inclusion criteria: Mallampati class: III-IV; Reduced mouth opening < 4 cm; Neck circumference > 40 cm for females and > 43 cm for males; Thyromental distance < 6 cm; Ratio of the patient's height to thyromental distance ≥ 23.5; Sternomental distance < 12 cm
Exclusion Criteria
  • BMI ≥ 50 kg/m2
  • emergency status
  • cervical injury or pathology
  • neck irradiation
  • known difficult airway
  • risk of gastric aspiration
  • hemodynamic instability
  • requiring rapid sequence intubation

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
McGrath Mac intubationsMcGrath MAC enhanced direct laryngoscopeAll 100 patients will be intubated using the McGRATH® MAC video laryngoscope, either through direct or indirect vision laryngoscopy. The liquid crystal display (LCD) monitor of the McGRATH™ MAC was initially covered; if the anesthesiologist visualized a modified C-L grade 1-3 view, the patient was intubated utilizing this direct view. If the anesthesiologist observed a modified C-L grade 4 view during their initial direct view, the patient was intubated using the indirect method. If intubation via direct laryngoscopy was unsuccessful on the first attempt, the patient was intubated using the indirect view. If both methods of laryngoscopy were unsuccessful, the rescue intubation technique was performed at the discretion of the anesthesiologist.
Primary Outcome Measures
NameTimeMethod
Number of Participants Successfully Intubated on First Attempt With Use of Either a Direct or Indirect Laryngoscopic Viewafter successful endotracheal tube placement

All 100 patients will be intubated using the McGRATH® MAC video laryngoscope, either through direct or indirect vision laryngoscopy. The LCD monitor of the McGRATH™ MAC was initially covered; if the anesthesiologist visualized a modified C-L grade 1-3 view, the patient was intubated utilizing this direct view. If the anesthesiologist observed a modified C-L grade 4 view during their initial direct view, the patient was intubated using the indirect method. If intubation via direct laryngoscopy was unsuccessful on the first attempt, the patient was intubated using the indirect view. If both methods of laryngoscopy were unsuccessful, the rescue intubation technique was performed at the discretion of the anesthesiologist.

Secondary Outcome Measures
NameTimeMethod
Glottic View With Direct Laryngoscopyat the time of laryngoscopy

Glottic view as described by Cormack and Lehane, scored as follows- Grade 1. Full view of glottis Grade 2a. Partial view of glottis Grade 2b. Arytenoids or posterior portion of cords just visible Grade 3. Only the epiglottis visible Grade 4. Neither epiglottis nor glottis visible

Glottic View With Indirect Laryngoscopyat the time of laryngoscopy

Glottic view as described by Cormack and Lehane (Samsoon GL, Young JR. Difficult tracheal intubation: A retrospective study. Anesthesia 1987; 42:487), scored as follows- Grade 1. Full view of glottis Grade 2a. Partial view of glottis Grade 2b. Arytenoids or posterior portion of cords just visible Grade 3. Only the epiglottis visible Grade 4. Neither epiglottis nor glottis visible

Number of Participants on Whom Bougie (Introducer) Was Used to Facilitate Intubation on the First Attemptat the time of intubation
Time for Intubationat the time of laryngoscopy

Time for laryngoscopy (either direct or indirect) plus the time for endotracheal tube (ETT) cuff to pass vocal cords.

Number of Intubation Attemptsat the time of intubation
Time for Indirect View Laryngoscopy During the First Attemptat the time of laryngoscopy

Time from mouth opening to best indirect laryngoscopic view

Number of Participants Who Received External Laryngeal Manipulation During the First Attemptat the time of intubation
Time for Direct View Laryngoscopy During the First Attemptat the time of laryngoscopy

Time from mouth opening to best direct laryngoscopic view

Subjective Ease of Laryngoscopyat the time of laryngoscopy

The anesthesiologists rated the McGRATH™ MAC's ability in managing airways as "very easy," "easy," "slight resistance," "difficult," or "not possible." The difficulty of laryngoscopy was evaluated during the insertion and placement of the McGRATH™ MAC, from the patient's lips, into their oropharynx, until a glottic view was obtained.

Subjective Ease of Intubationat the time of laryngoscopy

The anesthesiologists rated the McGRATH™ MAC's ability in managing airways as "very easy," "easy," "slight resistance," "difficult," or "not possible." The difficulty of endotracheal tube (ETT) delivery (that is, intubation) was evaluated during the insertion of the ETT into the patient's mouth, until the ETT passed the vocal cords.

Trial Locations

Locations (1)

The University of Texas Health Science Center at Houston

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Houston, Texas, United States

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