McGRATH MAC Video Laryngoscope

Keywords

• BMI < 50 kg/m2
• Mallampatti 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

Lead sponsor

The University of Texas Health Science Center, Houston is the lead sponsor of 880 studies on the registry; 209 are open to participants now.

Of its 170 completed or terminated interventional studies of FDA-regulated products, 140 (82%) have results posted.

Study arms

• Experimental
  McGrath Mac intubations

  All 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.

  Device: McGrath MAC enhanced direct laryngoscope

Interventions

• DeviceMcGrath MAC enhanced direct laryngoscope

  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

   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.

   Time frame: after successful endotracheal tube placement

Secondary outcomes

1. Glottic View With Direct 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

   Time frame: at the time of laryngoscopy

2. Glottic View With Indirect 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

   Time frame: at the time of laryngoscopy

3. Time for Direct View Laryngoscopy During the First Attempt

   Time from mouth opening to best direct laryngoscopic view

   Time frame: at the time of laryngoscopy

4. Time for Indirect View Laryngoscopy During the First Attempt

   Time from mouth opening to best indirect laryngoscopic view

   Time frame: at the time of laryngoscopy

5. Time for Intubation

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

   Time frame: at the time of laryngoscopy

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

   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.

   Time frame: at the time of laryngoscopy

10. Subjective Ease of Intubation

    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.

    Time frame: at the time of laryngoscopy

Baseline characteristics

Related links

• Device information ↗

Individual participant data

Plan to share: Undecided