Evaluation of laryngoscopy and endotracheal intubation conditions in morbidly obese patients undergoing bariatric surgery

One of the anesthetist's most fundamental tasks is to maintain the airway safely open and ensure adequate ventilation. The primary condition for adequate ventilation is the provision of a secure airway, with endotracheal intubation being the gold standard for airway management. This study aimed to compare the glottic view quality, intubation success rate, intubation duration, and post-intubation hemodynamic responses and complication rates among three laryngoscopes—Macintosh direct laryngoscope, McGRATH video laryngoscope, and AUG Reusable video laryngoscope—in morbidly obese patients undergoing bariatric surgery, who were predicted to have difficult intubation. In our prospective, randomized controlled clinical study, after obtaining ethical committee approval, a total of 120 patients who provided written consent between 01/01/2023 and 01/01/2024 were included. Patients over the age of 18, classified as ASA III and scheduled for elective bariatric surgery, were included in the study. During the preoperative examination, the patients' age, height, weight, body mass index (BMI), American Society of Anesthesiologists (ASA) score, Mallampati classification, Cormack-Lehane grade, mouth opening, thyromental distance, sternomental distance, neck circumference, and pre-intubation heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial pressure were recorded. The patients were divided into three groups: Group 1, intubated with the Macintosh direct laryngoscope; Group 2, intubated with the McGRATH video laryngoscope; and Group 3, intubated with the AUG Reusable video laryngoscope. After standard monitoring and induction, intubation was performed using the respective laryngoscope. Intubation was carried out after evaluating the Cormack-Lehane score. The time from inserting the laryngoscope blade into the oral cavity to passing the intubation tube was considered the intubation duration. After intubation, the intubation duration and the number of intubation attempts were recorded. The patients' heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial pressure values were recorded at the 1st, 5th, and 10th minutes post-intubation. In Group 1, 90% of patients, in Group 2, 97.5% of patients, and in Group 3, 85% of patients were intubated on the first attempt, with no significant difference between the groups (p>0.05). The average intubation duration was 13.3±7.3 seconds in Group 1, 12.5±5.5 seconds in Group 2, and 15.0±8.5 seconds in Group 3, with no significant difference observed between the groups (p>0.05). In Group 1, 60% of patients had a Cormack-Lehane grade (CLD) of 1, 37.5% had a CLD of 2, and 2.5% had a CLD of 4. In Group 2, 67.5% had a CLD of 1, 25% had a CLD of 2, and 7.5% had a CLD of 3. In Group 3, 85% had a CLD of 1 and 15% had a CLD of 2. A significant difference was found between the groups in terms of CLD (p<0.05). The Intubation Difficulty Scale (IDS) was easy for 52.5% of patients in Group 1, 50% in Group 2, and 77.5% in Group 3, with a significant difference found between the groups (p<0.05). There was no significant difference among the three groups in terms of hemodynamic parameters (p>0.05). In cases predicted to have difficult intubation undergoing bariatric surgery, the group intubated with the AUG Reusable video laryngoscope showed a lower difficulty score for intubation, indicating the need for further research with larger studies. Keywords: Endotracheal intubation; bariatric surgery; morbid obesity; videolaryngoscope; hemodynamic parameters