The effect of epidural and general anesthesia on newborn rectal temperature at elective cesarean section.

Both epidural and general anesthesia can impair thermoregulatory mechanisms during surgery. However, there is lack of information about the effects of different methods of anesthesia on newborn temperature. The purpose of this study was to determine whether there are differences in newborn rectal temperature related to type of anesthesia. Sixty-three pregnant women were randomly assigned to receive general or epidural anesthesia. Maternal core temperature was measured three times with a rectal probe just before anesthesia, at the beginning of surgery and at delivery. In addition, umbilical vein blood was sampled for pH. The rectal temperatures of the babies were recorded immediately after delivery, and Apgar scores were determined 1, 5, and 10 min after birth. The duration of anesthesia and the volume of intravenous fluid given during the procedure (833 +/- 144 vs 420 +/- 215 mL) were significantly higher in the epidural group than in the general anesthesia group (P < 0.0001). Maternal rectal temperatures were not different in both groups at all measurements. In contrast, newborn rectal temperatures were lower in the epidural anesthesia group than in the general anesthesia group (37.4 +/- 0.3 vs 37.6 +/- 0.3 degrees C; P < 0.05) immediately after birth. Furthermore, the umbilical vein pH value (7.31 +/- 0.05 vs 7.33 +/- 0.01; P < 0.05) and Apgar scores at the 1st-min measurement (8.0 +/- 0.9 vs 8.5 +/- 0.7; P < 0.05) were lower in the epidural anesthesia group than in the general anesthesia group. Since epidural anesthesia requires more iv fluid infusion and a longer time for cesarean section, it involves a risk of a mild temperature reduction for the baby which, however, did not reach the limits of hypothermia.