The Effect of Clonidine Premedication on Hemodynamic Changes Following Tracheal Intubation and Co2 Gas Insufflation and Postoperative Shivering In Patients Undergoing Laparoscopic Cholecystectomy; a Randomized Clinical Trial.

BACKGROUND: Laparoscopic cholecystectomy is a proper treatment for cholecystitis but the Carbon dioxide gas which is used in surgery stimulates the sympathetic system and causes hemodynamic changes and postoperative shivering in patients undergoing operations. This study was conducted to evaluate the effects of clonidine on reducing hemodynamic changes during tracheal intubation and Carbon dioxide gas insufflation and postoperative shivering in patients undergoing laparoscopic cholecystectomy. MATERIAL AND METHODS: This prospective, randomized, triple-blind clinical trial was conducted on 60 patients between the 18-70 years-old age group, who were candidates of laparoscopic cholecystectomy surgery. The patients randomized into two groups (30 patients received 150 µg oral clonidine) and 30 patients received 100 mg oral Vitamin C). Heart rate and mean arterial pressure of patients were recorded before anesthesia, before and after laryngoscopy, before and after Carbon dioxide gas insufflation. Data were analyzed using Chi-2, student t-test, and analysis of variance by repeated measure considering at a significant level less than 0.05. RESULTS: The findings of this study showed that both heart rate and mean arterial pressure in clonidine group after tracheal intubation and Carbon dioxide gas insufflation were lower than patients in the placebo group, but there was not any statistically significant difference between the two groups (p>0.05) and also postoperative shivering was not different in groups. There was no significant statistical difference in postoperative shivering between the two groups (p>0.05). CONCLUSION: Using 150 µg oral clonidine as a cheap and affordable premedication in patients undergoing laparoscopic cholecystectomy improves hemodynamic stability during operation.

The Effect of Granisetron, Ondansetron, and Meperidine in Preventing Postoperative Shivering: Controlled Clinical Trial.

BACKGROUND: Recently, use of HT35 receptor antagonists to prevent postoperative shivering has attracted a great deal of attention. This study was conducted with the aim of investigating the effectiveness of granisetron as an HT35 antagonist when compared with ondansetron and meperidine in preventing postoperative shivering. MATERIAL AND METHODS: In this triple blind random clinical trial study, 90 patients 18-50 years of age with ASA Class I and II undergoing general anesthesia were randomly assigned into one of the three drug groups: O (4-mg ondansetron), G (40 µg/kg of granisetron), and P (25 mg meperidine), immediately before induction of anesthesia. After anesthesia induction, at the end of the surgery, after the entrance and after leaving the recovery state, central temperature, peripheral temperature, heart rate, systolic blood pressure, diastolic blood pressure, and shivering were measured and documented. Two-tailed P < 0.05 was considered significant. RESULTS: In the meperidine, ondansetron, and granisetron groups, 4 (13.3%), 3 (10%), and 10 (33.3%) of patients experienced shivering during recovery, where the difference between the ondansetron and granisetron groups was significant (p-value=0.02). The variations in the mean arterial pressure during the investigation stages only in the ondansetron group were not significant (p>0.05). At the beginning of recovery, the reduction of peripheral temperature significantly was lower in the ondansetron group (p<0.05), while reduction of the central temperature was significantly (p<0.05) higher in the granisetron group. By the end of the recovery, the variations in the peripheral temperature across the three groups were consistent with the changes at the beginning of recovery, but variations of the central temperature across the three groups was not significantly diverse. CONCLUSION: Granisetron was not found to be much effective in preventing postoperative shivering. Ondansetron and meperidine were equally effective in preventing postoperative shivering. Ondansetron also causes less hemodynamic changes compared to other drugs, while granisetron is more effective in terms of preventing nausea and vomiting.