Cardiac or central nervous system toxicity may result when standard lidocaine doses are administered to patients with circulatory failure.This may be due to the following reason:

• A. There is a sudden out-burst of release of adreneline,noradreneline and dopamine in brain and heart
• B. Lidocaine is converted into a toxic metabolite due to its longer stay in liver.
• C. Lidocaine concentration are initially higher in relatively well perfused tissues such as brain and heart
• D. Histamine receptors in brain and heart gets suddenly activated in circulatory failure