Comparison of Reverse and Normal Curve Techniques for ILMA-assisted Tracheal Intubation in Adult Patients: A Prospective Interventional Study

Introduction: Securing airway is the main task of Anaesthesiologist. Intubating Laryngeal Mask Airway (ILMA) was made to simplify blind intubation. Still the outcome can vary with orientation of endotracheal tube. Aim: To observe and compare the Normal Curve (NC) and Reverse Curve (RC) techniques of intubation through ILMA in adult patients with respect to success rate, intubation time, haemodynamic changes, and complications. Materials and Methods: The present prospective interventional study was done in the Department of Anaesthesiology, MGM Medical College and MY Hospital, Indore, Madhya Pradesh, India. A total of 128 adult patients American Society of Anaesthesiologists (ASA) I and II, aged 18-60 years, undergoing elective surgery under general anaesthesia were included in the study. Patients were divided into two groups, NC and RC according to orientation of endotracheal tube through ILMA. Demographic data, number of attempts, time taken for successful intubation, Heart Rate (HR), mean arterial pressue, SpO2 and postoperative complications were recorded. Statistical analysis was done with unpaired t-test and Chi-square test, p<0.05 considered significant. Results: Baseline profile like age, sex, ASA, Mallampati and weight were comparable in both groups. Intubation success was 100% in first attempt. Intubation time was longer in NC (86.9±4.9 s) than RC (76.5±6.7 s, p<0.001). HR and MAP showed slightly higher trend in NC but not significant. SpO2 stayed above 99% in all. Sore throat was more in NC (12.5% vs 4.7%) while hoarseness was rare and equal (1.6%). Conclusion: Both NC and RC gave full success for intubation. RC was faster and had less sore throat. Hoarseness was rare and equal. RC may be better choice when quick intubation and less airway irritation is desired. Larger studies are needed to confirm in wider group of patients.