374 - Quantification of Topical Anesthesia

Purpose: The purpose of this study is to estimate the amount of topical anesthesia utilized in pediatric patients.

Methods: We determined the amount of two topical anesthetics used by scooping it from the jar using a IRM plastic measuring spoon and weighing it on ME203A Mettler Toledo scale. High Performance Liquid Chromatography (HPLC) was used to detect the exact amount of topical anesthetic present in each sample as labelled.

Results: The results are consistent with the labelled concentration of commercially available topical anesthetics. A uniform volume/weight that is appropriate for clinical use was evaluated and found to contain 61.2-74.8 mg of benzocaine per application. 

Conclusions: Most topical anesthetics use benzocaine in concentrations of 18-20%. The concentration of benzocaine present in the bottle coincides with manufacturer labelling. The concentration of benzocaine present in a uniform volume/weight is within a safe dose for a child greater than 4kg. Staff education regarding uniform volume/weight dispensing is encouraged, and further studies on high concentration prescription based topical anesthetics is warranted.