The use of laparoscopic techniques in general surgery has gained increasing popularity. The small, limited incisions are well accepted by patients and there is the benefit of a faster recovery. But the contribution of N2O to nausea and vomiting is still controversial. This study was undertaken to evaluate the effect of N2O for airway pressure, blood gas and postoperative emesis in laparoscopic cholecystectomy.

Twenty ASA physical status I, II patients for elective laparoscopic cholecystectomy were randomly divided into two groups. First group (n=10) of patients was anesthetized with isoflurane(0.5~1.5 vol%)-O2 (2 l/min)-air (2 l/min). Second group (n=10) of patients was anesthetized with isoflurane (0.5~1.5 vol %)-O2 (2 l/min)-N2O(2 l/min). After induction of anesthesia, ventilation was controlled with tidal volume 10 ml/kg and respiratory rate 11/min and not changed throughout the operation. After measuring of control value of PaCO2, pH and airway pressures before CO2 insufflation, repeatedly measured at 20 min, 40 min after CO2 insufflation and 10 min after CO2 exsufflation. We observed the patients concerning nausea and vomiting for postoperative period.

There were no significant intraoperative differences between the both groups with respect to PaCO2, pH and airway pressures. In the both groups, PaCO2 and airway pressure throughout the operation are significantly increased in comparison to control values. The pH is significantly decreased in comparison to control values. The incidence of postoperative nausea and vomiting was similar in both groups.

N2O had no clinically apparent effects on airway pressure, blood gas and postoperation emesis during laparoscopic cholecystectomy.