Endotracheal Tube Placement Using McGrath MAC® Video Laryngoscope Versus Macintosh Laryngoscope

A Prospective, Randomized, Single Center Study to Compare Endotracheal Tube Placement Using McGrath MAC® Video Laryngoscope Versus Macintosh Laryngoscope in Bariatric Surgery Patients

This study aims...

• To assess the difference in intubation difficulty scale (IDS) score following ETT placement using McGrath MAC® video laryngoscope versus conventional intubation with Macintosh laryngoscope for bariatric surgery patients
• To assess the difference in hemodynamic stimulation (airway manipulation) events in both groups
• To assess the overall difference of the duration (seconds) of ETT placement between both groups
• To assess the difference of the duration (seconds) of ETT placement during every attempt (maximum of three attempts) between both groups.
• To assess the difference of STOP BANG score between both groups
• To assess the number of intubation attempts between both groups

The failure to place properly an endotracheal tube (ETT) and to secure the airway is still significantly impacting morbidity and mortality in surgical and critical care settings. In addition, no assertive predictor factor will foresee the presence of difficult airway, most of them being acknowledged after anesthesia induction. The incidence of difficult intubation reported in different studies varies from 0.1% to 13%.

The gold standard device to place an ETT that has been used since 1943 is the Macintosh laryngoscope (ML). However, in contemplation of addressing these challenging factors related to endotracheal intubation failure, modern airway devices technology has been developed in order to improve orotracheal visualization, reduce orotracehal manipulation and ensure airway patency.

As part of these novel devices, several video laryngoscopies (VL) have s been developed to secure the airway and improve the management of difficult intubation. Difficult Airway Society (DAS) guidelines recognizes the usefulness of VL in difficult intubation by providing an improved view of the airway to clinicians and directly observe/report the effects of laryngeal manipulation.

Among several VL introduced recently, a McGrath MAC® VL was announced in 2012. McGrath MAC® is a self-contained VL with a single-use blade; its structure is similar to the ML, but without the channel that guides the tube and a mounted LCD screen on the handle that is connected to a miniature camera with a light source at the tip of the blade, allowing the clinicians to directly observe surrounding anatomical airway structures during a tracheal intubation. These features have shown a better glottis visualization and to be supportive during tracheal intubation of difficult airways.

The McGrath MAC® VL and ML are standard of care devices used according to anesthesia care providers' criteria at our institution.

A single-center, prospective, randomized, double arm study, will be conducted in order to test the following hypothesis:

Reduced manipulation of the airway using McGrath MAC® VL will lead to less hemodynamic stimulation events following intubation when compared to ML.

The non-disposable portion of the McGrath MAC® VL (upper mounted reusable video camera and the optic guide) will be cleaned between usages in accordance to manufacture catalogue and institutional policy (using disinfectants such as CIDEXTM OPA, a 0.08% paracetic acid solution or disinfecting wipes).

2.2. Inclusion Criteria

1. Patients (male or female) admitted for elective bariatric surgery under general anesthesia with orotracheal intubation
2. Age > 18 years old
3. American Society of Anesthesiologists (ASA) score 1-3
4. Patients capable of consenting in English language

2.3. Exclusion Criteria

1. Potential or history of difficult airway (see pages 11 and 12)
2. Past medical history of confirmed uncontrolled gastrointestinal diseases including delayed gastric emptying, dysphagia, or other gastrointestinal motility disorders that according to the investigator will not qualify for the study
3. Patients with uncontrolled metabolic disorders (e.g., diabetes mellitus, chronic kidney disease) or conditions that according to the investigator will not qualify for the study
4. Pregnant women
5. Prisoners
6. Surgery requiring patient positioning other than supine
7. Other mental, physical, and medical conditions where subject participation is inadvisable according to the investigator judgment