ABSTRACT
Background: Bezold Jarisch reflex is important cause of hypotension and bradycardia which occur after spinal anaesthesia. This reflex is elicited by stimulation of peripheral serotonin receptors 5- hydroxytryptamine (5- HT3 type). These receptors have antinociceptive effect, which is confirmed by many studies.The two most commonly used 5HT3 antagonist are ondansetron and granisetrone. Very few comparative studies of the two drugs on the effect after spinal anaesthesia are available.Methods: Ninety adulted patients of either sex aged 18-58 years scheduled for elective infraumbilical surgeries were randomly allocated in three groups to receive intravenous ondansetron 4mg, granisetrone 2mg or normal saline in equal volume 5mins before spinal anesthesia. Hemodynamic changes and time to sensory motor onset and regression were evaluated.Results: There was statistically significant difference in fall of systolic diastolic and mean blood pressure among the three groups. Time to two segment regression of sensory block and time to regression to S1 was faster in ondansentron (76.6±17.2mins, 176±22mins) and granisetrone group (69±17.3mins, 165±19.2mins) in comparision to control group(77.4±24.3mins, 178±21mins) which was statistically significant also p value-0.019, 0.0001 respectively.Conclusions: The prophylactic therapy with 4mg i.v. ondansetron, given five minutes before spinal anaesthesia appears to be significantly most effective and safe for attenuating haemodynamic response after spinal anaesthesia without affecting the duration of sensory block in patients undergoing infraumbilical surgeries.
ABSTRACT
Background: In laparoscopic surgeries, insufflation with carbon dioxide triggers vagal afferents on the bowel and peritoneum which induces emesis by activating the vomiting center. It is hypothesized that combined antiemetics with different sites of activity would be more effective than one drug alone for the prophylaxis against PONV. So, the present study was planned to compare the efficacy of granisetron, dexamethasone and combination of granisetron with dexamethasone to prevent PONV.Methods: This randomized prospective double-blind study was performed on 120 patients, aged between 18 and 58 years of ASA physical status I and II of either sex undergoing laparoscopic surgeries under general anesthesia. Patients were randomized in three groups, group I (granisetrone 2 mg I.V.), group II (dexamethasone) 8 mg I.V., group III (granisetrone+dexamethasone) 2 mg+8 mg I.V. with 40 patients in each group. Complete response, incidence of nausea, vomiting, and rescue antiemetic were recorded at specified intervals.Results: A complete response (defined as no PONV and no need for another rescue antiemetic) was achieved in 75% of the patients given granisetron, 70% in dexamethasone and in 92.5% of the patients given granisetron plus dexamethasone (P <0.05). The overall cumulative incidences (0-24 hours) of PONV were 10 (25%) in the granisetron, 12 (30%) in the dexamethasone and 3 (7.5%) in the combination group. No difference in adverse events were observed in any of the groups.Conclusions: The prophylactic therapy of granisetron 2 mg plus dexamethasone 8 mg just before induction of anaesthesia is significantly effective in prevention of PONV in patients undergoing laparoscopic surgeries.