[Effects of local anesthetics on fetal heart rate patterns and neonatal neurobehavior].

Changes in FHR after local anesthetic administration were analyzed and the neonatal neurobehavioral status was evaluated by the use of Amiel-Tison's NACS (Neurologic and Adaptive Capacity Scoring System). The following results were obtained. After the epidural administration of 35 mg bupivacaine transient ominous FHR changes were noted in 12 out of 99 cases, two of which followed maternal hypotension and five followed uterine hyperactivity. Among 13 out of 43 paracervical blocks by 200mg lidocaine transient FHR changes were noted; "post PCB bradycardia"/late deceleration with decreasing variability was seen after 7 blocks and variable deceleration with increasing variability after 6 blocks. The plasma bupivacaine level of the umbilical vein was 154.4 +/- 24.5 ng/ml (UV/MV 0.26) and of the neonatal vein at the 4th day was 15.1 +/- 3.8 ng/ml (in 71% of cases there was a trace). The score of NACS tended to be lower 3-6 hrs. after birth, but at the 4th neonatal day no significant difference was noted between groups with and without regional analgesics. Although local anesthetics might cause some FHR changes in cases with low fetal reserve, clinical effects are minimal in cases of term AGA. However, particular care must be taken in such high risk cases as IUGR.