COMPARATIVE SYSTEMIC TOXICITY AND A MECHANISM FOR LETHALITY OF INTRAVENOUSLY INFUSED COCAINE, LIDOCAINE, AND BUPIVACAINE IN SPONTANEOUSLY AND MECHANICALLY BREATHING UNCONSCIOUS PIGS
Jr. Kambam et al., COMPARATIVE SYSTEMIC TOXICITY AND A MECHANISM FOR LETHALITY OF INTRAVENOUSLY INFUSED COCAINE, LIDOCAINE, AND BUPIVACAINE IN SPONTANEOUSLY AND MECHANICALLY BREATHING UNCONSCIOUS PIGS, Research communications in substance abuse, 14(2-3), 1993, pp. 97-112
We investigated systemic toxicity and possible mechanisms for lethalit
y of intravenously (iv) infused cocaine (C), lidocaine (L), and bupiva
caine (B) in 24 spontaneously and mechanically breathing unconscious p
igs. Pigs were given sodium thiopental and ventilated with 70% nitrous
oxide in 30% oxygen. Pigs in groups 1, 2, and 3 pigs were allowed to
breathe spontaneously and groups 4, 5, and 6 were mechanically ventila
ted. The animals in groups 1 and 4 were infused iv with C (0.8 mg/kg/m
in), groups 2 and 5 were infused with B (0.8 mg/kg/min), and groups 3
and 6 were infused with L (3.2 mg/kg/min). Respiratory and cardiovascu
lar parameters, blood temperature, sodium and potassium levels were mo
nitored. The times of occurrences of respiratory (RA) and cardiac arre
sts (CA), and convulsions were recorded. Our results showed that RA is
the primary cause of death in spontaneously breathing pigs and that m
echanical ventilation significantly delayed the occurrence of CA (p <
0.05). Significant decreases in cardiac output, mean blood pressure, a
nd heart rate and significant increases in systemic and pulmonary vasc
ular resistances, central venous and pulmonary wedge pressures, and bl
ood K+ levels were noticed in mechanically ventilated pigs (p < 0.05).
Our experiments demonstrated that all three local anesthetic drugs pr
oduced similar systemic effects with continuous iv administration of l
ethal doses.