Seizure following in-office lidocaine administration: a case report on local anesthetic systemic toxicity

Local anesthetics have a broad application for minor and major surgeries, in outpatient and inpatient settings. Drug dosing, frequency, duration of action, and coadministration with other drugs, are some of many factors that must be considered for each patient, before drug administration. Like other medical treatments, the use of local anesthetics has potential complications, such as local anesthetic systemic toxicity (LAST). LAST primarily affects the cardiac and central nervous systems (CNS), seizures and cardiac arrest being some of the more time-sensitive symptoms requiring immediate treatment. Patients should be briefed on potential symptoms if LAST occurs and physicians should be aware of the warning signs, treatment, and prevention. In our case study, a 40-year-old, 51 kg woman was administered a lidocaine dosage of 760 mg in an outpatient setting. She presented to the emergency department with diffuse tremors, paresthesias of the mouth and face, spasticity, irritability, and a single generalized tonic–clonic seizure. The patient was successfully treated with Ativan along with lipid emulsion. We review this case and perform a literature review to identify key points in the use of local anesthetics. Healthcare providers should be trained in LAST treatment and prevention. Our case study therefore serves to reduce the frequency of LAST and other adverse outcomes associated with local anesthetic administration.