A Comparative Study of I-gel with Endotracheal Tube for Pressure Controlled Ventilation

Abstract

Background: Endotracheal intubation is considered to be the benchmark for controlled ventilation during general anaesthesia. But supraglottic airway devices are taking the place of endotracheal tubes in many scenarios and i-gel is one such airway device. Aim and Objectives: To assess whether i-gel is comparable to endotracheal tube for pressure controlled ventilation at different inspiratory pressures. Material and Methods: Forty American Society of Anaesthesiologists (ASA) III patients undergoing elective surgery were selected. Following induction, airway was secured with i-gel. Pressure controlled ventilation was initiated at four different pressures (10, 15, 20, 25 cm of H2O). Inspiratory and expiratory tidal volumes were measured and leak volume was calculated as thedifference of the two. Leak fraction was calculated by dividing leak volume by inspiratory tidal volume. Then i-gel was withdrawn, patient was intubated and the measurements repeated. Statistical analysis was done using two-tailed student's t test. Results: There was no significant difference on comparing the leak volume and leak fraction in the two groups at 10, 15 and 20 cm of H2O. However, at 25 cm of H2O, there was statistically significant difference in leak volume and leak fraction between the two groups. Conclusion: Igel can be considered as a safe alternative to endotracheal tube for pressure controlled ventilation at moderate pressures during anaesthesia.

Keywords

• airway leak test
• inspiratory airway pressure
• supraglottic airway devices
• tracheal intubation