Pulse Pressure and Post-epidural Fetal Heart Rate Changes

Epidural anesthesia, the most common method of pain control in labor, can contribute to alterations in maternal blood pressure and/or fetal heart rate changes. As a result, the administration of an IV fluid bolus ("preload") is standard prior to epidural placement. However, the optimal volume of preload is unknown and no clinical trials have evaluated a risk-factor based approach to dosing. Studies in the critical care, trauma, and obstetric literature have suggested that a narrow pulse pressure (difference between systolic and diastolic blood pressures) is a marker of reduced intravascular volume status and may identify women at a higher risk for new onset fetal heart rate changes after epidural placement. Therefore, the purpose of this study is to assess if an increased IV fluid preload bolus among women with a narrow pulse pressure reduces the risk of new onset fetal heart rate changes after epidural placement.