Cardiac Resuscitation After Incremental Overdosage with Lidocaine, Bupivacaine, Levobupivacaine, and Ropivacaine in Anesthetized Dogs

Abstract

There were consistent differences among the local anesthetics, the sum of which suggests that larger doses and blood concentrations of ropivacaine (ROP) and lidocaine will be tolerated as compared with bupivacaine (BUP) and levobupivacaine (LBUP). Lidocaine intoxication results in myocardial depression from which resuscitation is consistently successful but will require continuing drug support. After BUP, LBUP, or ROP, resuscitation is not always successful, and the administration of epinephrine may lead to severe arrhythmias. The unbound plasma concentrations at collapse were larger for ROP compared with BUP, whereas the concentrations of LBUP and BUP were not significantly different from each other. Furthermore, larger plasma concentrations of ROP than BUP are present after resuscitation, suggesting a wider margin of safety when large volumes and large concentrations are used to establish upper or lower extremity nerve blocks for surgical anesthesia and during long-term infusions for pain management.