Influence of Alkalinization of Lidocaine on Epidural Anesthesia for Elective Cesarean Section in Mother and Fetus / 대한마취과학회지

ABSTRACT

BACKGROUND: The aim of study was to determine the influence of pH-adjusted lidocaine of epidural anesthesia on the maternal and fetal blood lidocaine concentration. METHODS: Thirty parturients having epidural anesthesia for cesarean section were assigned to two group. Plain group (n=15) received 18 ml of 1.8% lidocaine (2% lidocaine plus 1ml saline per 10 ml lidocaine) with added 1200,000 epinephrine. Patients in the alkalinized group (n=15) were given 18 ml of 1.8% lidocaine (2% lidocaine plus 1ml sodium bicarbonate per 10 ml lidocaine) with added 1200,000 epinephrine. The level of analgesia was assessed 5 min after injection and then reassessed every 1min in the middle line. Maternal and umbilical venous blood were obtained at birth and the concentrations of lidocaine in these samples were determined by Immunofluorescence assay. Apar score was also assessed. RESULTS: The peak level of sensory blockade were similiar (T5) but The time to peak level was significantly more rapid in alkalinized group than plain group. The plasma lidocaine levels in the maternal venous blood and umbilical venous blood were similar in both groups. The ratios of umbilical vein to maternal vein concentration of lidocaine were 0.76+/-0.36 in alkalinized group and 0.62+/-0.21 in plain group. CONCLUSIONS: We conclude that alkalinization of lidocaine in epidural anesthesia results in a faster onset of sensory block and more rapid time to peak level but no adverse effects on Apgar score. Alkalinization of lidocaine is therefore recommended when epidural anesthesia is planned for Cesarean section.