Toxicity of local anesthetic drugs: a pediatric perspective.

The main mechanism of action of local anesthetics (LA) is to block sodium channels, thereby interrupting the propagation of nerve impulses. However, this action not only is localized to the sodium channels of nerve tissues involved with pain transmission but will have its effect on any tissue containing sodium channels. Thus, if there is a rapid absorption into the systemic circulation of locally injected LA or if LA inadvertently is injected into a blood vessel, then significant blockade of sodium channels in other tissues may also be blocked and serious complications may ensue. The two most important tissues associated with systemic toxicity of LA are the central nervous and the cardiovascular systems, which may lead to seizures, tachyarrhythmias, and ultimately death from apnea and cardiovascular collapse. The aim of this communication is to elucidate some issues that are associated with toxicity of LA and its treatment in the pediatric population.