Pre-Treatment with Intravenous Granisetron to Alleviate Pain on Propofol Injection: A Double Blind Randomised Controlled Study Using Normal Saline as Control

BACKGROUND: Pain on injection is one of the most commonly reported side effect of Propofol, there are numerous pharmacological and non pharmacological methods to reduce it. This study compares the efficacy of intra-venous Granisetron with normal saline pre-treatment to reduce pain on propofol treatment, measured on verbal rating pain scale. MATERIAL & METHODS: It was a double blind randomized controlled study. After approval from Institutional ethics committee 82 patients were randomly allocated into 2 groups. 41 patients were given intravenous Granisetron and other 41 were given normal saline pre-treatment before Propofol injection. RESULTS: Mean age in Granisetron group is 38.43+13.16 and 42.46+13.49. p=0.1756, using unpaired t-test indicating that the age of the patients in the NS group is significantly greater as compared to granisetron group. In the granisetron group 39% were male patients and 61% were female patients whereas NS group had 61% male patients and 39% female patients; with a p value of 0.0772 indicating the proportion of females in granisetron group is significantly greater as compared to that in normal saline group. The weight for patients in granisetron group was found to be 61.80±7.76 kg and for NS group was 67.16 ± 10.03 kg; with p value of 0.0978 indicating that the weight of the patients in the NS group is significantly greater as compared to granisetron group. p=0.1804, using chi-square test indicating no significant difference in the proportion of patients belonging to different ASA class in the two groups. Baseline heart rate was comparable in both the group at pre injection and 1 min post injection time points. However, at 3 min, heart rate was found to be significantly lower in granisetron group (79.22 ± 11.64) compared to normal saline group (88.41 ± 10.33). SpO2 at pre injection, 1 min and 3 min post injection was observed comparable in both granisetron and normal saline group. There was no statistical significance difference between observations of SpO2 up to 3 minutes of observation period. p<0.0001 indicating that the change in SBP was significantly higher in the NS group as compared to the granisetron group. p=<0.0001, indicating that the change in DBP was significantly higher in the NS group as compared to the granisteron group. p=0.0001, using Mann-Whitney test indicating that the pain score was significantly higher in the NS group as compared to the granisetron group. CONCLUSION: In conclusion, 1.) Granisetron pre-treatment decrease the heart rate, systolic and diastolic blood pressure and pain on injection of propofol. 2.) In comparison with normal saline granisetron was better to reduce the pain on propofol injection 3.) The results of this study were comparable with other studies, which also show similar results. 4.) It provides a simple and safe method of reducing the incidence of pain on injection of propofol with the added advantage of avoiding the administration of other drugs that may be undesirable in certain circumstances.