제왕절개술을 위한 경막외 2% Lidocaine 용액의 알카리화

Abstract

Sixty parturients scheduled for elective cesarean section at term under epidural anesthesia were randomly divided into one of two groups. Group 1 patients were given a prepared 2% lidocaine solution with 1 ： 200,000 epinephrine plus lml of normal saline per 10ml of lidocaine； the solution pH was 2.45. Group 2 patients were given a prepared 2% lidocaine solution with 1 ：200,000 epinephrine plus lml(lmEq) NaHC03 per 10ml of lidocaine； the solution pH was 7.20. Just before injection, either 2ml normal saline(group l)or 2ml(2mEq) 8.4 % NaHC03 solution(group 2) was added to 20ml 2% lidocaine hydrochloride with 1:200, 000 epinephrine. The time to onset of the T5 sensory block (time between completion of injection and loss of cold sensation at T5 dermatome) was significantly more rapid in the group 2 that received the pH—adjusted solution. The mean onset time was 4.9士1.3 min in the group 2 and 6.4 土 2.0 min in the group 1. The time to peak level was also significantly more rapid in the group 2 at 10.5土2.7 min and group 1 at 13.3±4.0 min. But the peak level was not statistically significant between the two groups. The spread of sensory blockade was significantly more rapid in the pH — adjusted group at 5, 10 and 15 min after epidural injection. Incidence of maternal hypotension during the operation did not differ significantly between the two groups. The time from end of injection to Bromage scale 0 did not differ significantly between the two groups.

Key Words: Anesthetic techniques: spinal. Anesthetics, local: bupivacaine. Analgesics, opioid: fentanyl. Anesthesia, obstetric: cesarean section.