From the Guidelines
Treatment for lidocaine toxicity primarily involves supportive care and symptom management, with the immediate cessation of lidocaine administration being the first step, as recommended by recent guidelines 1. The management of lidocaine toxicity is crucial to prevent morbidity and mortality. Key factors to consider include the dose and speed of intravenous lidocaine administration, as well as patient factors such as acid-base status, hypoxaemia, and hypoalbuminaemia, which can influence lidocaine toxicity 1. Some important considerations in the treatment of lidocaine toxicity include:
- Maintaining the airway, breathing, and circulation with oxygen supplementation and cardiac monitoring
- Administering benzodiazepines such as diazepam (5-10 mg IV) or midazolam (2-5 mg IV) for seizures
- Treating hypotension with IV fluids and, if necessary, vasopressors like norepinephrine (starting at 0.1-0.5 mcg/kg/min)
- Managing severe cardiac arrhythmias with specific interventions, such as atropine (0.5-1 mg IV) for bradyarrhythmias or amiodarone (150 mg IV over 10 minutes) for ventricular arrhythmias
- Using lipid emulsion therapy (20% lipid emulsion, 1.5 mL/kg bolus followed by 0.25 mL/kg/min infusion for 30-60 minutes) for life-threatening toxicity, as it creates a "lipid sink" that draws lidocaine from tissues into the bloodstream 1. It is essential to note that the correlation of plasma levels with signs and symptoms of toxicity is not linear, and systemic toxicity reflects the unpredictable interaction between patient factors and the pharmacokinetic and pharmacodynamics properties of the drug 1. Therefore, a thorough understanding of the factors influencing lidocaine toxicity and the appropriate management strategies is crucial to minimize morbidity and mortality.
From the FDA Drug Label
If local anesthetics must be used in these patients, close monitoring for symptoms and signs of methemoglobinemia is recommended. Signs of methemoglobinemia may occur immediately or may be delayed some hours after exposure, and are characterized by a cyanotic skin discoloration and/or abnormal coloration of the blood Methemoglobin levels may continue to rise; therefore, immediate treatment is required to avert more serious central nervous system and cardiovascular adverse effects, including seizures, coma, arrhythmias, and death. Discontinue lidocaine hydrochloride and any other oxidizing agents. Depending on the severity of the signs and symptoms, patients may respond to supportive care, i.e., oxygen therapy, hydration. A more severe clinical presentation may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen.
The treatment for lidocaine toxicity involves:
- Discontinuation of lidocaine hydrochloride and other oxidizing agents
- Supportive care, such as oxygen therapy and hydration, for mild cases
- Methylene blue, exchange transfusion, or hyperbaric oxygen for more severe cases 2
- Monitoring for signs of methemoglobinemia, such as cyanotic skin discoloration, and immediate treatment if necessary 2
From the Research
Treatment for Lidocaine Toxicity
The treatment for lidocaine toxicity involves several approaches, including:
- Supportive care with the Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach 3
- Use of intravenous lipid emulsion as an antidote 4, 5
- Management of symptoms and prevention of further toxicity
Mechanism of Action of Lipid Emulsion Therapy
The mechanism of action of lipid emulsion therapy is not well defined, but it is postulated to work by:
- Creating a "lipid sink" to decrease circulating amounts of lidocaine 4
- Providing a direct "energy source" to the myocardium 4
Role of Benzodiazepines in Lidocaine Toxicity
Benzodiazepines may play a role in alleviating lidocaine toxicity by:
- Safeguarding nerve cells from the toxicity of lidocaine via the miR-133a-3p/EGFR pathway 6
- Increasing cellular viability and reducing apoptosis in PC12 cells treated with lidocaine 6
Clinical Implications
The treatment of lidocaine toxicity requires prompt recognition and management of symptoms, as well as the use of antidotes such as intravenous lipid emulsion. Clinicians should be aware of the potential hazards of lidocaine use and the importance of monitoring for signs of toxicity 7, 5