Local anesthetic calculations: avoiding trouble with pediatric patients.

Local anesthetic systemic toxicity (LAST) is a rare but avoidable consequence of local anesthetic overdose. This article will review the mechanism of action of local anesthetic toxicity and the signs and symptoms of LAST. Due to physiologic and anatomic differences between children and adults, LAST occurs more frequently in children; particularly when 3% mepivacaine is administered. The calculation of the maximum recommended dose based on mg/lb body weight, Clark's rule, and the Rule of 25 in order to prevent LAST will also be reviewed, as well as the appropriate treatment procedures for a local anesthetic overdose.