Ondansetron Prior to Spinal Anesthesia to Prevent Hypotension During Cesarean Delivery

Abstract

Regional anesthesia has made cesarean section surgeries much safer and tolerable for the obstetrical (OB) patient, however it does not come without risk. With elective cesarean sections, a subarachnoid block (SAB) is the gold standard, but commonly causes hypotension which may lead to many undesirable effects for the mother and baby.⁹ To combat the hypotension,  providers often administer vasoactive drugs, but this may affect the placental blood flow potentially compromising the fetus.⁶ This decrease in blood pressure is caused by the spinal anesthesia (SA)-induced sympathectomy and initiation of the Bezold-Jarisch reflex by intracardiac mechanoreceptors and chemoreceptors, specifically 5 hydroxytryptamine (5HT-3) receptors, which will cause bradycardia and further hypotension.^1-3 The purpose of this case report is to explore the effects of administering ondansetron, a 5HT-3 receptor antagonist, on spinal anesthesia-induced hypotension when administered prior to the SAB and synthesize recent literature to make recommendations for future practice.