Sharath Padmanabhan, Supriya Kumari Madambikattil Chandrashekharan
BACKGROUND To test and compare LMA Classic, Ambu Aura40 and i-gel in terms of ease of insertion, efficacy and complications. MATERIALS AND METHODS 90 patients between 18-70 years of age of ASA I and II scheduled for short surgical procedures were enrolled into the study. They were randomly divided into 3 groups of 30 each. Ease of insertion was assessed by number of attempts for correct positioning of the device. Efficacy was assessed using fibre optic bronchoscope to visualise glottis through the supraglottic device. Oropharyngeal leak pressure was studied using an analogue manometer (Medisys) connected to the expiratory limb of the breathing circuit to measure the airway pressure. RESULTS The LMA Classic, Ambu Aura40 laryngeal mask and the I-gel are effective ways of securing the airway in patients undergoing elective short surgical procedures. LMA Classic required more attempts overall to secure the airway compared to the other two devices in this study. Glottic view scores were intermediate to the other two devices. It had the least Oropharyngeal Leak Pressure (OPLP) compared to the other devices. The Ambu Aura40 laryngeal mask required the least number of attempts to secure the airway among the devices studied. Therefore, in a ‘Cannot Ventilate, Cannot Intubate’ situation, this might be the better device compared to the other two devices in this study. The Glottic view as obtained with a fiberoptic bronchoscope was the best with the Ambu Aura40 laryngeal mask among the devices studied. This might be useful in guiding an airway exchange catheter into the trachea and using it as an intubation aid. The Oropharyngeal Leak Pressures (OPLP) was intermediate to the other two devices. The I-gel had the highest Oropharyngeal Leak Pressure (OPLP) among the devices studied. Therefore, this device would be preferable in situations requiring positive pressure ventilation. I-gel had the most sub-optimal positioning as determined by fiberoptic bronchoscopic positioning. Due to the buccal stabilizer of the I-gel, it is the most stable of the devices studied and therefore would be most suitable for surgeries in positions other than supine. The I-gel has an inbuilt bite guard which provides an additional measure of safety during emergence. The gastric channel also allows quick access to gastric contents when required. The incidence of complications was nil with the I-gel in this study. CONCLUSION Ambu Aura40 is the superior device in comparison to the other devices. The I-gel is useful in situations requiring positive pressure ventilation and added stability. LMA Classic was not as effective as the other two in securing an airway and was associated with minimal incidence of complication.
