Local anesthetic systemic toxicity: A narrative review for emergency clinicians

Abstract

Introduction: Emergency clinicians utilize local anesthetics for a variety of procedures in the emergency department (ED) setting. Local anesthetic systemic toxicity (LAST) is a potentially deadly complication.

Objective: This narrative review provides emergency clinicians with the most current evidence regarding the pathophysiology, evaluation, and management of patients with LAST.

Discussion: LAST is an uncommon but potentially life-threatening complication of local anesthetic use that may be encountered in the ED. Patients at extremes of age or with organ dysfunction are at higher risk. Inadvertent intra-arterial or intravenous injection, as well as repeated doses and higher doses of local anesthetics are associated with greater risk of developing LAST. Neurologic and cardiovascular manifestations can occur. Early recognition and intervention, including supportive care and intravenous lipid emulsion 20%, are the mainstays of treatment. Using ultrasound guidance, aspirating prior to injection, and utilizing the minimal local anesthetic dose needed are techniques that can reduce the risk of LAST.

Conclusions: This focused review provides an update for the emergency clinician to manage patients with LAST.

Keywords: Lipid emulsion; Local anesthetic systemic toxicity; Nerve block; Regional anesthesia; Toxicity.