AutoFlow® (volume-guaranteed mode) versus volume-controlled ventilation for the laparoscopic surgery with BlockBuster supraglottic airway: A randomized controlled trial

Background and Aims: Supraglottic airway devices used in laparoscopic surgeries must be efficient to counter the increased peak airway pressure (PAWP) and airway leakage that can occur in laparoscopic surgeries. Hence, the implication of AutoFlow in ventilator strategy is propounded nowadays that facilitates low PAWP and high dynamic compliance to achieve targeted tidal volume and end-tidal carbon dioxide (ETCO2). BlockBuster (TM) Laryngeal mask furnishing minimum airway leak. The primary objective was to compare PAWP using the two modes of ventilation through the BlockBuster LMA after intubation, pneumoperitoneum, and Trendelenburg position. The secondary objective was to observe hemodynamic vitals. Methodology: In this single-center randomized controlled trial, we recruited 80 American Society of Anesthesiologists grade I and II adult patients undergoing elective laparoscopic surgeries. They were randomized by computer-generated method into two groups: volume-controlled AutoFlow (R) (VCAF) and volume-controlled (VC) group. Ventilation settings for both groups set to tidal volume 5-6 ml/kg of predicted body weight, positive end-expiratory pressure 5 cm H2O, I: E ratio 1:2, and respiratory rate 12-16/min to maintain targeted ETCO2 of 30-35 cm H2O. Intraabdominal pressure was set to 14 mmHg during pneumoperitoneum and 15 degrees Trendelenburg position. Results: Mann-Whitney U-test for continuous variables and t-test for categorical variables. Data were presented as median (interquartile range). P <0.05 was considered statistically significant. During laparoscopic surgeries with BlockBuster (TM) PAWP at pneumoperitoneum was (20 cm H2O vs. 27 cm H2O) and Trendelenburg position (19 cm H2O vs. 27 cm H2O) was significant lower with VCAF (AutoFlow (R) ventilation) than with VC (P < 0.05). Conclusion: PAWP is significantly low in AutoFlow mode as compared to volume control mode with BlockBuster LMA. In addition, LMA BlockBuster provides good sealing pressure.