Local anesthetic systemic toxicity in the pediatric patient

Lidocaine and prilocaine are local anesthetics, a class of medications which are frequently used in clinical medicine to minimize pain in a variety of procedures. They are commonly found in over-the-counter products such as topical anesthetic creams advertised to relieve localized muscle and joint pain. While safe and well-tolerated when used appropriately, an overdose of these anesthetics increases the risk for local anesthetic systemic toxicity (LAST), which in severe cases can present with seizures, cardiac dysrhythmias, and ultimately cardiovascular collapse. The reduced muscle mass of pediatric patients puts them at an increased risk of LAST due to the depot effect of the systemically absorbed anesthetic. Methemoglobinemia may also be associated with local anesthetic toxicity. Our case involves a previously healthy 15-month-old female who presented to one of our networks' emergency departments in status epilepticus following an accidental ingestion of a tube of 2.5% lidocaine/2.5% prilocaine cream. Her seizure activity was initially resistant to intraosseous benzodiazepine administration, but ultimately resolved following administration of lipid emulsion and sodium bicarbonate. Additionally, the patient had refractory hypoxia on the monitor which resolved shortly after administration of methylene blue. After stabilization, the patient was transferred to the Pediatric ICU and ultimately made a complete recovery. LAST is a life-threatening presentation which requires early recognition by clinicians, as well as an understanding of the appropriate treatment modalities. We review the assessment and management of LAST, with special focus on the pediatric patient.