Inclusion Criteria:  19 years of age or older. Patient receiving an uncomplicated, scheduled caesarean section Patient with a normal sinus rhythm  Exclusion Criteria:  Presentation with cardiac arrhythmia Contraindications to neuraxial analgesia (ex. patient refusal, infection at the site of injection, uncorrected hypovolemia, allergy, increased intracranial pressure, coagulopathy, sepsis, fixed cardiac output states, or indeterminate neurological status), or risk factors likely to affect placement or function of the spinal needle (ex. previous back surgery, significant uncorrected scoliosis, or morbid obesity (BMI >40)) History of hypersensitivity or idiosyncratic reaction to local anesthetics or opioids Current or historical evidence of any significant medical conditions, including diseases of pregnancy Clinical settings in which general anesthesia may be preferable (ex. patient with failed regional anesthetic, patient with history of bleeding, fetal shoulder dystocia etc.) Anticipated fetal abnormalities