The Effect of 50% Nitrous Oxide on Postoperative Nausea- Vomiting in Patients Undergoing Laparoscopic Cholecystectomy

Background: Postoperative nausea and vomiting (PONV) is a common problem and its cause is multifactorial. The relationship between PONV and nitrous oxide is under debate. Aim: To evaluate the relationship between nitrous oxide and PONV in patients undergoing laparoscopic cholecystectomy. Methods: We randomly divided 60 female patients, ASA I or II, age 18-60 years and weighing between 50-100 kg, scheduled for elective laparoscopic cholecystectomy into two groups. Anaesthesia was induced in all patients with propofol, nalbuphine and atracurium. Anaesthesia was maintained with sevoflurane, nitrous oxide in oxygen in group I and sevoflurane in oxygen in group II. Perioperatively paracetamol was infused in all patients. The patient’s PONV and pain scores were assessed 24 hours postoperatively. Results: In group I, PONV scores were significantly higher at 1 st and 6 th hour postoperatively; however, there was no significant difference in group II. However there was no significant difference in PONV and pain scores and the percentage of patients needing antiemetics between two groups. We could not find any correlation between PONV and use of 50% Nitrous oxide. Conclusion: Our data concludes that 50% nitrous oxide does not increase the incidence or severity of PONV in patients undergoing laparoscopic cholecystectomy.