A Comparative Study of Cuff Pressure Changes of Endotracheal Tube with the Use of Air Versus Nitrous Oxide in the Anaesthetic Gas Mixture During Laparoscopic Surgery

OBJECTIVE: Cuffed endotracheal tube remains the standard of care during laparoscopic surgeries. Nitrous oxide is widely used as a carrier gas in anaesthesia practice. Cuff pressure greater than 30 cm H2O impairs tracheal mucosal perfusion leading to necrosis. This study aimed to compare the endotracheal tube cuff pressure while using air versus nitrous oxide in the anaesthetic gas mixture during laparoscopic surgeries. METHODS: Sixty patients aged 18-70 years undergoing laparoscopic surgery were randomized into 2 groups of 30 each. Group 1 patients received air and oxygen in the anaesthetic gas mixture and group 2 patients received nitrous oxide and oxygen. Cuff pressure changes were measured throughout the surgery and perioperative hemodynamic parameters were recorded. The incidence and severity of postoperative sore throat were also evaluated postoperatively for 24 hours. RESULTS: The increase in cuff pressure was more in the group using nitrous oxide (40.80 ± 8.78 cm H2O) when compared to the group using air (26.93 ± 2.69 cm H2O) (P < .001). Trendelenburg position was associated with a significant increase in cuff pressure when compared to other positions. The incidence and severity of postoperative sore throat were more at 2 hours (P=.0099) and 4 hours (P=.0105) postoperatively in the group using nitrous oxide. The hemodynamic parameters were comparable between the 2 groups. CONCLUSION: The use of nitrous oxide in the anaesthetic gas mixture causes an increase in endotracheal tube cuff pressure and increased severity of postoperative sore throat during laparoscopic surgeries.