Effects of narcotic and non-narcotic continuous epidural anesthesia on intrapartum fetal heart rate tracings as measured by computer analysis

OBJECTIVE: To evaluate the effect of narcotic and non-narcotic continuous epidural anesthesia on intrapartum fetal heart rate (FHR) tracings as measured by computer analysis. METHODS: We studied 37 women with uncomplicated pregnancies at term with reactive FHR tracings. The women were randomized to receive epidural anesthesia with either bupivicaine with fentanyl or bupivicaine alone. One-hour FHR tracings were obtained before epidural anesthesia. Thirty minutes after the initial bolus of the epidural a repeat computer analysis of 60-minute FHR tracing was obtained. Median values are reported for FHR parameters with statistical analysis performed by the Mann-Whitney U and Wilcoxon signed rank tests where appropriate. A power calculation was performed using a power of 90% to determine a required sample size of 28 patients. Statistical significance was set at P < .05. RESULTS: In early first stage of labor, there was no significant difference in pre- and postepidural anesthesia FHR baseline, accelerations of 10 and 15 beats per minute, episodes of high and low variation, and short- and long-term variation when using either narcotic or non-narcotic anesthetic agents. CONCLUSIONS: Thus, the clinician can consider the use of narcotic as well as non-narcotic continuous epidural anesthesia in the dosages used in our study with its attendant advantages without fear of obscuring the fetal heart rate tracing.