Effectiveness of prophylactic ondansetron in preventing spinal anesthesia induced hypotension and bradycardia in pregnant mother undergoing elective cesarean delivery: A double blinded randomized control trial, 2021

Abstract

Background: Spinal anesthesia is the most common techniques of regional anesthesia for cesarean section. However, hypotension is the most common complication associated with nausea and vomiting, altered mental status and risk of aspiration. Bradycardia is also a common feature of profound circulatory collapse under neuraxial anesthesia. After verification that, serotonin can induce BJR reflex and can causes bradycardia or hypotension, researchers started to evaluate the effect of ondansetron to decrease BJR reflex in human being. Objectives: To assess the effect of prophylactic ondansetron for prevention of spinal induced hypotension and bradycardia in parturients undergoing cesarean delivery from June 1, 2020 to January 30, 2021. Method: ology: A double blinded randomized control trial conducted in Dilla university referral hospital by recruiting 70 patients with systematic random sampling technique. Patients were randomized into ondansetron group (n = 35) and control group (n = 35). Mann Whitney U test was used for continuous non-normally distributed data and independent sample t-test for normally distributed data. Mixed ANOVA was used to analysis the interaction of the within and between factors. Categorical variable between the groups were analyzed using fisher exact and chi square test. p -value<0.05 is considered statically significant. Result: There were no significant differences in the incidence of hypotension between ondansetron (20(57) and saline group (21(60%)). There were no significant difference in incidence of bradycardia among the two groups p > 0.05. Perioperative Phenylephrine consumption was 36.43 ± 45.91 mcg and 32.14 ± 46.79 mcg in ondansetron and saline group respectively with P = 0.700. The incidence of shivering was lower in ondansetron group (11%) than saline group (45%) with (p = 0.04) and the perioperative rescue shivering requirement was higher in saline group (p = 0.00). Conclusion: and Recommendations: Prophylaxis administration of intravenous Ondansetron at a dose of 10 mg before spinal anesthesia was not effective in reducing the incidence of hypotension and bradycardia in pregnant women undergoing cesarean section. Highlights

Efficacy of Variable Doses of Prophylactic Intravenous Ondansetron in Attenuating Spinal Induced Hypotension in Parturients Undergoing Caesarean Delivery: A Randomised Control Trial

“…Ondansetron, a highly effective and specific 5-HT3 receptor antagonist, can block the binding of 5-HT to chemoreceptors, thus alleviating BJR. It also suppresses further expansion of peripheral vessels and increases venous return to the heart [23]. Although 4 mg of ondansetron preloading has been commonly used to reduce maternal hypotension and nausea, the dose-dependent effect of ondansetron on reducing maternal hypotension is still not established clearly and needs further studies [9][10][11]14,[20][21][22][23].…”

“…It also suppresses further expansion of peripheral vessels and increases venous return to the heart [ 23 ]. Although 4 mg of ondansetron preloading has been commonly used to reduce maternal hypotension and nausea, the dose-dependent effect of ondansetron on reducing maternal hypotension is still not established clearly and needs further studies [ 9 - 11 , 14 , 20 - 23 ].…”

“…Mohamed et al [ 23 ] did a double-blind randomised controlled trial and compared the use of prophylactic IV ondansetron 10 mg versus normal saline in a pregnant mother undergoing elective cesarean delivery. They found no effect of ondansetron in the prevention of maternal hypotension and bradycardia.…”

“…A number of studies conducted on both non-obstetric [6,7] and obstetric [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] populations suggest that 5-HT may be an important factor associated with cardiovascular responses via the BJR and this effect can be blocked at the 5-HT3 receptor by 5-HT3 receptor antagonists like ondansetron.…”

Ondansetron Reduces the Incidence of Hypotension after Spinal Anaesthesia: A Systematic Review and Meta-Analysis

“…However, in the aforementioned studies, the sample sizes were relatively small. Furthermore, significant resources have been utilised annually on clinical trials on this topic worldwide [6,7,[11][12][13][14]. Therefore, we conducted this systemic review and meta-analysis using trial sequential analysis (TSA) to investigate whether ondansetron prevents hypotension following spinal anaesthesia.…”