Comparison of three video laryngoscopy devices to direct laryngoscopy for intubating obese patients: a randomized controlled trial.

Study Objective: To compare three different video laryngoscope devices (VL) to standard direct laryngoscopy (DL) for tracheal intubation of obese patients undergoing bariatric surgery.

Hypothesis: VL (vs DL) would reduce the time required to achieve successful tracheal intubation and improve the glottic view.

Design: Prospective, randomized and controlled.

Setting: Preoperative/operating rooms and postanesthesia care unit.

Patients: One hundred twenty-one obese patients (ASA physical status I-III), aged 18 to 80 years, body mass index (BMI) >30 kg/m(2) undergoing elective bariatric surgery.

Intervention: Patients were prospectively randomized assigned to one of 4 different airway devices for tracheal intubation: standard Macintosh (Mac) blade (DL); Video-Mac VL; Glide Scope VL; or McGrath VL.

Measurements: After performing a preoperative airway evaluation, patients underwent a standardized induction sequence. The glottic view was graded using the Cormack Lehane and percentage of glottic opening (POGO) scoring systems at the time of tracheal intubation. Times from the blade entering the patient's mouth to obtaining a glottic view, placement of the tracheal tube, and confirmation of an end-tidal CO2 waveform were recorded. In addition, intubation attempts, adjuvant airway devices, hemodynamic changes, adverse events, and any airway-related trauma were recorded.

Main Results: All three VL devices provided improved glottic views compared to standard DL (p < 0.05). Video-Mac VL and McGrath also significantly reduced the time required to obtain the glottic view. Video-Mac VL significantly reduced the time required for successful placement of the tracheal tube (vs DL and the others VL device groups). The Video-Mac and GlideScope required fewer intubation attempts (P< .05) and less frequent use of ancillary intubating devices compared to DL and the McGrath VL.

Conclusion: Video-Mac and GlideScope required fewer intubation attempts than standard DL and the McGrath device. The Video-Mac also significantly reduced the time needed to secure the airway and improved the glottic view compared to standard DL.