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Lidocaine is a tertiary amine class Ib antiarrhythmic agent primarily administered for local and topical anesthesia. In addition to its analgesic and antiarrhythmic effects, this drug can be used as an adjunct during tracheal intubation. Lidocaine's mechanism of action, dosing, pharmacokinetics, and relevant interactions are crucial for healthcare professionals to understand. By enhancing their knowledge of lidocaine's pharmacokinetics and potential adverse effects, healthcare professionals can make informed decisions and adjust dosage regimens to achieve optimal patient outcomes. This program provides evidence-based strategies and equips healthcare professionals with the knowledge to deliver safe and effective care involving lidocaine administration. Additionally, this educational activity emphasizes the importance of the interprofessional healthcare team in providing care to patients receiving lidocaine. Objectives: Evaluate the mechanism of action of lidocaine. Assess the various indications for the use of lidocaine. Identify the typical presentation of a patient with lidocaine toxicity. Implement effective collaboration and communication among interprofessional team members to improve outcomes and treatment efficacy for patients who might benefit from lidocaine therapy. Access free multiple choice questions on this topic.

Signs and Symptoms of Overdose Signs and symptoms of mild toxicity become apparent at plasma levels greater than 5 μg/mL, beginning with slurred speech, tinnitus, circumoral paresthesia, and lightheadedness. Above 10 μg/mL, the patient may experience seizures or loss of consciousness. The myocardium and central nervous system are further depressed at 15 μg/mL, progressing to cardiac arrhythmias, respiratory arrest, and cardiac arrest above 20 μg/mL.[32] Animal studies suggest that the dose of lidocaine required to cause cardiovascular collapse is 7.1 ± 1.1 times higher than the dose needed to induce central nervous system effects.[33] This so-called "(cardiovascular collapse/CNS (CC/CNS) ratio" is significantly higher than the ratio for other local anesthetic agents; bupivacaine has a CC/CNS ratio of around 2.0. In the event of toxic dosing in the conscious patient, lidocaine may be less likely than other local anesthetics to progress rapidly from neurological effects to complete cardiovascular collapse. By contrast, neurological signs and symptoms can often be masked if the patient is under the concurrent effects of sedation or general anesthesia, meaning that cardiovascular instability or arrhythmias may be the first manifestations.[34] Management of Overdose Lidocaine administration should be stopped immediately if toxicity or overdose is suspected. During cardiorespiratory collapse, airway support and breathing assistance should be prioritized to prevent the development of respiratory acidosis, which may exacerbate toxicity and potentiate lidocaine's negative chronotropic and inotropic effects.[35] Vital function support, including oxygen, IV fluids, and inotropes, should be instituted if required. Intravenous lipid emulsion is indicated as rescue therapy, especially if the cardiovascular collapse is refractory.[36]

All interprofessional healthcare team members, including clinicians, nurses, and pharmacists, should be knowledgeable about its toxicity and management. Lidocaine may cause significant pain during initial injection due to the agent stimulating nociceptors before it exerts its effects on sodium channels; this can be counteracted by buffering the lidocaine with small volumes of sodium bicarbonate shortly before use, making the solution less acidic.[37] Injection pain can also be reduced by warming the solution to body temperature, injecting more slowly, using narrow cannulas, and injecting perpendicular to the skin.[38] Patients receiving IV infusions of lidocaine should be regarded as high-risk; a 2020 consensus statement suggested that, when used outside of the operating room or post-anesthesia care unit, patients receiving IV lidocaine infusions should be managed in a high-dependency setting/intermediate care unit (IMC) with continuous monitoring. The infusion should be delivered through a separate, dedicated cannula using a tamper-proof pump.[17]