Local Anesthesia Evaluator Practice Exam

Sodium bicarbonate is used in local anesthetic systemic toxicity mainly to correct metabolic acidosis that often accompanies the overdose. When acidosis is present, the body's tissues become less able to function properly, seizures may be more likely, and cardiovascular stability can worsen. By raising the blood pH, bicarbonate helps mitigate these issues and can improve CNS irritability and overall perfusion, making resuscitation more effective. It acts as a supportive measure rather than reversing the local anesthetic itself. The true antidote for LAST is lipid emulsion therapy, which directly helps sequester the local anesthetic and improves cardiac performance. Bicarbonate is added as an adjunct, typically considered when there is significant acidosis or persistent CNS symptoms despite lipid rescue. Dosing is typically a 1 mEq/kg IV bolus, with careful monitoring and repetition if acidosis persists. It is not used for allergic reactions, and it does not directly reverse the drug’s action.