An In Vitro Analysis of the Effects of Intravenous Lipid Emulsion on Free and Total Local Anaesthetic Concentrations in Human Blood and Plasma

Figure 1

Comparison of percent reduction in total-LA concentrations in human plasma treated with ILE at three concentrations (2%, 10%, and 20%). (a) Local anaesthetic concentration similar for all four agents (4 mg/L). Bupivacaine showed a significant reduction in concentration compared to all three other LAs. 2% ILE: . Bupivacaine significant compared to all other LAs. 10% ILE: . Bupivacaine significant compared to all other LAs. 20% ILE: . Bupivacaine significant compared to all other LAs. (b) Varying LA concentration for each agent dependent upon reported concentrations associated with clinical cases of severe CVS toxicity. Bupivacaine showed the greatest percent reduction in concentration across the three ILE groups. This was significant compared to all other LAs in all three ILE groups. 2% ILE: one-way ANOVA. Bonferroni’s posttest: bupivacaine significant compared to all other LAs, lignocaine and prilocaine significant to ropivacaine. 10% ILE: one-way ANOVA. Bonferroni’s posttest: bupivacaine significant compared to all other LAs, lignocaine significant to ropivacaine. 20% ILE: one-way ANOVA. Bonferroni’s posttest: bupivacaine significant compared to all other LAs. Mean ± S.E.M = mean values ± standard error of means of three experiments.

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