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Completed

NCT Number: NCT02250521

McGRATH MAC Video Laryngoscope

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.

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Key information

Conditions

Intubation; Difficult

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

The University of Texas Health Science Center at Houston

Houston, Texas, 77030, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

McGrath MAC enhanced direct laryngoscope

Device

The McGRATH® MAC enhanced direct laryngoscope (EDL) combines the familiarity of direct laryngoscopy with an inline video camera for an enhanced view.

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.

Primary outcomes

  1. Number of Participants Successfully Intubated on First Attempt With Use of Either a Direct or Indirect Laryngoscopic View

    Time frame: after 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 outcomes

  1. Glottic View With Direct Laryngoscopy

    Time frame: at 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

  2. Glottic View With Indirect Laryngoscopy

    Time frame: at 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

  3. Time for Direct View Laryngoscopy During the First Attempt

    Time frame: at the time of laryngoscopy

    Time from mouth opening to best direct laryngoscopic view

  4. Time for Indirect View Laryngoscopy During the First Attempt

    Time frame: at the time of laryngoscopy

    Time from mouth opening to best indirect laryngoscopic view

  5. Time for Intubation

    Time frame: at the time of laryngoscopy

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

  6. Number of Intubation Attempts

    Time frame: at the time of intubation

  7. Number of Participants Who Received External Laryngeal Manipulation During the First Attempt

    Time frame: at the time of intubation

  8. Number of Participants on Whom Bougie (Introducer) Was Used to Facilitate Intubation on the First Attempt

    Time frame: at the time of intubation

  9. Subjective Ease of Laryngoscopy

    Time frame: at 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.

  10. Subjective Ease of Intubation

    Time frame: at 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.

Sponsors and collaborators

Lead sponsor

The University of Texas Health Science Center, Houston

Other

Collaborators

  • Medtronic - MITG

Registry information

Official study title

McGRATH MAC Video Laryngoscope - To View or Not To View?

Important dates

Study start
2014
Primary completion
2016
Study completion
2016
First posted
Sep 26, 2014
Registry last updated
Nov 9, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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