A Randomised Control Trial Comparing the Efficacy of LMA-Supreme and I-Gel as Rescue Ventilatory Device in Patients with Simulated Difficult Airway Undergoing Anaesthesia with Controlled Ventilation

Abstract

Introduction: In an unanticipated difficult airway or in an emergency situation of cannot-intubate-cannot-ventilate scenario, Supraglottic Airway Devices (SGD) are recommended as rescue devices for establishing airway quickly to prevent hypoxia. Aim: To compare efficacy of i-gel airway and Laryngeal Mask Airway supreme (LMA supreme) as ventilatory devices and the time taken for their insertion in anaesthetised and paralysed patients with simulated difficult airway. Materials and Methods: One hundred and eighty adult patients with simulated difficult airway were randomly allocated to two groups of 90 patients each. In group I: i-gel and in group S: LMA supreme was inserted. Primary outcome studied was time taken for insertion of SGD. Secondary outcomes were the number of attempts taken for insertion of device, oropharyngeal leak pressure, ease of gastric catheter insertion, fibreoptic bronchoscopic view of anatomical alignment of device with glottic opening. Quantitative variables were compared using unpaired t-test/Mann-Whitney Test, between the two groups. Qualitative variable were compared using Chi-Square test/Fisher’s-exact test. Results: Total time taken for successful insertion was significantly shorter with group i-gel as compared to group LMA supreme {median (IQR) {19 (18.25-21)} versus {24 (23-24)} with p-value ≤0.0001. Overall success rate of insertion (96.67% vs 97.78%, p=1.000) and oropharyngeal leak pressure (p-value=0.555) of i-gel and LMA-S were comparable. i-gel has better anatomic alignment with glottic opening as compared to LMA-S (p-value ≤0.0001). Gastric tube insertion was easy in all patients in both the groups. Conclusion: Shorter time for the insertion of i-gel was observed due to absence of inflatable cuff, although both LMA-S and i-gel are equally efficacious as ventilatory devices in patients with simulated difficult airway under general anaesthesia with controlled ventilation.