Comparison of gastric insufflation using LMA-supreme and I-gel versus tracheal intubation in laparoscopic gynecological surgery by ultrasound: a randomized observational trial

BACKGROUND: The application of bedside ultrasound to evaluate gastric content and volume can assist in determining aspiration risk. Applying positive pressure ventilation via supraglottic airway devices (SAD) can result in a degree of gastric insufflation. This study assessed and compared the antral cross-sectional area (CSA) in patients undergoing laparoscopic gynecological surgery when managed with different SAD. METHODS: One hundred American Society of Anesthesiologists I or II female patients were assessed for inclusion in this study and divided into three groups of different ventilation devices. Patients were randomly allocated into three groups to receive LMA-Supreme (Group S), I-gel (Group I) or tracheal tube (Group T). The primary outcome was the antral cross-sectional area and secondary outcomes included haemodynamic parameters and postoperative morbidity such as sore throat, hoarseness, dry throat, nausea and vomiting. RESULTS: The antral CSA was not significantly different among three groups before induction (P = 0.451), after induction (P = 0.456) and at the end of surgery (P = 0.195). The haemodynamic variables were significantly higher in the tracheal tube group than in the LMA-Supreme and I-gel groups after insertion (P < 0.0001) and after removal (P < 0.01). Sore throat was detected in none in the I-gel group compare to two patients (6.7%) in the LMA-Supreme group and fifteen patients (50%) in the tracheal tube group. Hoareness was detected in one (3.3%) in the I-gel group compare to two patients (6.7%) in the LMA-Supreme group and eleven patients (36.7%) in the tracheal tube group. CONCLUSIONS: The SADs do not cause obvious gastric insufflation. Thus, LMA-Supreme and I-gel can be widely used as alternative to endotracheal intubation for the short laparoscopic gynecological surgery. TRIAL REGISTRATION: This trial was registered at the Chinese Clinical Trial Registry (ChiCTR1800018212, data of registration, September 2018).