Determining the effect of intravenous ondansetron in pereventing hypotension in patients under elective cesarean section

Spinal anesthesia is an efficient method of providing intra operative analgesia and a safe alternative to general analgesia in many cesarean patients. Despite its advantages, SA is not free from adverse effects, which include unwanted cardiovascular events, in most cases: hypotension and bradycardia. Ondansetron is a 5HT3 receptor antagonist, with known efficacy on preventing nausea and vomiting. Maybe ondansetron given intravenously attenuates the fall of blood pressure and heart rate, by 5HT3 blocking in vagal nerve endings and effect on BJR.(Bezold jarish Reflex). In this clinical trial 102 healthy pregnant women that were candidate for elective cesarean in hamedan fatemieh hospital during 3 months in 1390, studied. They were randomized into 2 groups: the ondansetron group, n= (51) received (4miligram) ondansetron intravenously before performing spinal anesthesia, and placebo group n= (51): received 2cc sterile water before spinal anesthesia. Spinal anesthesia was performed with hyperbaric bupivacaine (0/5Percent) 10 mg and sufentanil (5 µg(BP and HR were measured and recorded before and after anesthesia immediately. If hypotension happened, ephedrine 5- 10mg injected. Itching and nausea recorded every 10 min during operation by observation and question. There were no significant differences in SBP, DBP, MAP, HR and itching in both groups. Nausea and vomiting, and mean consumed ephedrine was siginificantly different in both groups.(p=0.001, p=0.009). Ondansetron given intravenously with antiemetic dose (4miligram), decreases mean consumed ephedrine and nausea and vomiting after spinal anesthesia, but doesnt have an influence on BP, HP and pruritus