Clinical Practice and Cases in Emergency Medicine

Introduction: Lidocaine toxicity is a rare but potentially dangerous consequence of a frequently used medication. Most commonly, it has generalized neurologic and cardiac effects. Discontinuation of lidocaine is sufficient with less severe symptoms. With more severe symptoms, such as seizures and arrhythmia, intravenous (IV) lipid emulsion therapy can be used. To date, lidocaine toxicity presenting as focal neurologic deficits has rarely been documented in the literature. In the case reported here, the patient was receiving lidocaine injections when she developed palpitations and left arm and facial weakness and numbness, which resolved after IV lipid emulsion therapy. 

Case Report: A 52-year-old female with a past medical history of migraines, cholecystectomy, nephrolithiasis, and hypothyroidism presented to the emergency department (ED) via ambulance from her dental office with acute neurologic symptoms. While receiving an injection of lidocaine intraorally at the dental office, she experienced palpitations and left arm and left facial weakness with numbness. She continued to have symptoms upon arrival to the ED. Given concern for acute stroke, she underwent imaging, which was negative for large vessel occlusions or hemorrhage. She was given IV lipid emulsion therapy for suspected lidocaine toxicity with resolution of symptoms. She was cleared by oral and maxillofacial surgery and discharged with outpatient follow-up.

Conclusion: We identified a patient who developed neurologic symptoms during lidocaine administration, with no radiographic evidence for stroke. Given the timing of symptoms and lidocaine administration, we administered IV lipid emulsion therapy with resolution of the patient’s symptoms. Thus, we strongly suspect our patient had lidocaine toxicity with focal neurologic findings.