Intrathecal Dexmedetomidine vs Epinephrine

Several studies have shown that adding dexmedetomidine or epinephrine to single-dose spinal analgesia preparations improves the length and/or speed of onset of the sensory block and post-operative pain management without increased negative side effects. To date, however, no study has compared adjunctive intrathecal dexmedetomidine to adjunctive intrathecal epinephrine in single-dose spinal analgesia. The purpose of this study is to determine if adjunctive intrathecal dexmedetomidine is non-inferior to adjunctive intrathecal epinephrine in providing better single-dose spinal analgesia during cesarean section.

Inclusion Criteria: * Pregnant patients * aged 18-55 years * presenting for scheduled primary or secondary cesarean section * candidates for single shot spinal anesthesia singleton pregnancy Exclusion Criteria: * patient refusal of spinal anesthetic * if patient is not a candidate for spinal anesthesia due to history of coagulopathy, elevated intracranial pressure, infection at site of injection, etc. * emergency cesarean section * preexisting motor or sensory deficit * suspected pre-eclampsia * patient receiving combined spinal-epidural as anesthetic technique * BMI \> 40