Background: Unpredicted Difficult Tracheal Intubation (DTI) with Macintosh occurs frequently in obese patients. We investigated the incidence of DTI using an algorithm based on preoperative assessment with the El-Ganzouri Risk Index (EGRI) and Glidescope® routine use.
Methods: We prospectively enrolled morbidly obese patients undergoing abdominal surgery. Patients were scheduled for Glidescope® intubation under general anesthesia if EGRI was <7 or awake Flexible Fiber-optic Intubation if EGRI was ≥7. The primary outcome was the DTI rate, defined as Cormack and Lehane grades ≥III, Intubation Difficulty Scale >5 and modified Intubation Difficulty Scale >5. Secondary outcomes included intubation success on the first attempt, the Time to Cormack, the time to intubation, failure to intubate, oxygen desaturation and difficult ventilation.
Results: Of the 214 patients enrolled, 212 (99%) were intubated with Glidescope® and 2 (1%) with awake Flexible Fiber-optic Intubation (one electively, one after a Glidescope® failure). There were no cases of DTI assessed using Cormack and Lehane and Intubation Difficulty Scale, and 3 cases (1.4%; 95% CI 0.45-4.29%) assessed using modified Intubation Difficulty Scale. Of the 213 patients intubated with Glidescope®, 185 (87%) had successful intubation on the first attempt. Mean Time to Cormack and time to intubation were 13.1 (SD 9.6) and 38.1 seconds (SD 21.1) respectively. We had one case (0.5%) of failed Glidescope® intubation and no cases of clinically significant complications.
Conclusions: The incidence of DTI and Intubation Failure was reduced to near-zero using Glidescope® and the Besta Airway Algorithm in this sample of morbidly obese patients.