The effect of epinephrine on reversing bupivacaine-induced asystole in isolated rat heart

Abstract

Objective To study the influence of epinephrine on reversing bupivacaine-induced asystole in isolated rat heart. Methods Twenty-four adult male SD rats were randomly divided into four groups according to the table of random number(n=6): group B40, EB40, B50 and EB50. Langendorff isolated heart perfusion model was used. Continuous infusion with 100 μmol/L bupivacaine until asystole had been induced for 3 min, then the model was completed. Group B40, perfused with K-H solution containing 40 μmol/L bupivacaine for 20 min. Group EB40, perfused with K-H solution containing 0.15 mg/L epinephrine and 40 μmol/L bupivacaine for 20 min. Group B50, perfused with K-H solution containing 50 μmol/L bupivacaine for 20 min. Group EB50, perfused with K-H solution containing 0.15 mg/L epinephrine and 50 μmol/L bupivacaine for 10 min, then epinephrine was increased to 0.3 mg/L for 10 min. The situation of recovery of heart beat was recorded and the following cardiac functional parameters were monitored during 20 min perfusion: HR, heart rate-pressure product (RPP) and coronary flow (CF). Results The recovery rate of heart beat(100%) in the group EB40 was higher than which in other groups(0)(P<0.01). The recovery time of heart beat in the group EB40 was (35±9) s and the asystole time after recovery of heart beat was (568±182) s. The CF in the groups EB40 and EB50 were higher compared with the groups B40 and B50 (P<0.01). Conclusions The ability of epinephrine on reversing asystole induced by bupivacaine in isolated rat heart is related to the concentration of bupivacaine. When drug concentration of bupivacaine was 40-50 μmol/L, the ability of epinephrine could not be displayed. Key words: Epinephrine; Bupivacaine; Asystole; Resuscitation