Association Between Fluid Administration, Oxytocin Administration, and Fetal Heart Rate Changes

Overview

Fetal heart rate patterns are an important parameter in the diagnosis of non-reassuring fetal status. Combined-spinal epidural analgesia is a method of initiating labor analgesia used by approximately 90% of the parturients at Prentice Women's Hospital. Optimizing the variables which could affect fetal heart rate patterns at the time of initiation of analgesia, such as fluid administration and oxytocin management, could help us provide better care for our patients and their fetuses. Hypotheses: Patients who receive a 1000 mL fluid bolus and lower rates of oxytocin administration will have fewer non-reassuring fetal heart rate (FHR) changes.

Informed, written consent will be obtained. At the time of request for labor analgesia, group assignment will be determined by opening an opaque envelope. Patients will be randomized to one of four groups. All subjects will receive a maintenance infusion of 125 mL Lactated Ringers (LR) solution throughout the study. For patients in Groups A or B, an intravenous bolus of 1000 mL LR will be initiated when the patient is positioned for epidural placement. The bolus will be administered through a free-flowing wide open intravenous catheter until complete. Patients in Groups C and D will not receive any additional fluid bolus and will only receive the maintenance infusion of 125 mL LR during the study period. Blinding will be maintained by the Labor and Delivery nurse by covering up the LR bolus fluid bag. If the patient is randomized to groups B or D, the dose of oxytocin currently being administered will be halved and not increased for the duration of the study period (60 minutes after the initiation of CSE).