Introduction:

1. Introduction: The patient with the predicted difficult airway presents a challenge to the anesthesia provider. While many devices can be useful, it is not clear which devices are most favorable as a primary intubation technique. We therefore conducted a prospective randomized clinical trial in order to compare conventional and video-laryngoscopy regarding success, ease of use and complications in patients with a predicted or documented difficult airway presenting for surgery. We hypothesize that the videolaryngoscope will improve the success rate of tracheal intubation on first attempt. Secondary outcomes include laryngeal view achieved, time to intubate, and complications such as arterial oxygen desaturation and airway trauma. A power analysis targeted a goal recruitment of 300 patients. Interim analysis is conducted at this point. The sample is analyzed using Fischer exact test for success rate and Student’s t-test for laryngoscopy time. Results: Clinical Evaluation of the Storz CMAC Video Laryngoscope in the Known or Predicted Difficult Airway Michael Aziz, MD. Dawn Dillman, MD. Ansgar Brambrink, MDDepartment of Anesthesiology & Perioperative Medicine. Oregon Health & Science University. Portland, OR In the first 245 patients the primary intubation success rate was 109/124 (88%) for direct laryngoscopy and 112/121(93%) for CMAC (p=NS). For patients with a documented history of difficult intubation, the primary intubation success rate for direct laryngoscopy was 7/9 (78%) and 12/15 (80%) for CMAC(p=NS). Laryngeal view was better in the CMAC group compared to direct laryngoscopy. Intubation times were slower in the CMAC group (35 seconds) compared to direct laryngoscopy (29 seconds) (p<0.05). • Methods: • Following IRB approval, We included patients predicted to pose difficulties for endotracheal intubation according to established predictors based on the preoperative evaluation and previous anesthetic records. By physical examination, we included patients with a Mallampati classification 3 or 4 airway, those with small mouth opening (<3cm), and those with limited cervical spine motion. We also included patients with a history of multiple intubation attempts or direct laryngoscopy achieving only a Cormack-Lehane laryngeal grade 3 or 4. Patients were randomized to direct laryngoscopy with a regular Macintosh blade (#3-4) or CMAC #3-4. The primary outcome assessed was success rate of tracheal intubation on first attempt. Conclusion: This preliminary analysis demonstrates an improved laryngeal view with the videolaryngoscope (CMAC). However, with the limited number of patients included at this point this benefit does not translate into a significant improvement of intubation success on first attempt in patients with predicted difficult airway. The continuation of the trial will allow determining whether the improved laryngeal view can improve intubation success and will point towards the role of video laryngoscopy in the management of the difficult airway in the perioperative period.