What are signs of local anesthetic systemic toxicity and initial management steps?

• A. Perioral numbness, tinnitus, metallic taste, seizures; stop local, ensure airway, give lipid emulsion therapy per protocol, and support hemodynamics
• B. Hypertension, chest pain; give opioids
• C. Drowsiness; administer caffeine
• D. Rash; administer antihistamines

Answer: (A)

Local anesthetic systemic toxicity occurs when the drug enters the bloodstream at a level that disrupts nervous system and heart function. Early signs are CNS-related and telltale: perioral numbness, a metallic taste, and tinnitus, often with dizziness or blurred vision, which can progress to seizures. If this happens, the priority is to stop the local anesthetic, secure the airway, provide 100% oxygen, and support breathing and circulation while preparing to treat seizures.

Lipid emulsion therapy is a primary treatment in this scenario. Administer a 1.5 mL/kg bolus of 20% lipid emulsion IV, then start an infusion at 0.25 mL/kg/min, adjusting per protocol if symptoms persist. Seizures are managed with benzodiazepines, and overall hemodynamic support is provided as needed. The approach focuses on rapidly removing the circulating anesthetic and stabilizing the patient.

The described signs and the stepwise management match this option because they include the early CNS symptoms and the correct initial interventions, including stopping the anesthetic, airway support, and lipid emulsion therapy. Other choices mention symptoms or treatments that do not align with LAST (hypertension and chest pain treated with opioids; drowsiness treated with caffeine; rash treated with antihistamines).