What is the preparation and dosing for a lidocaine (local anesthetic) intravenous drip?

From the Guidelines

Lidocaine drip preparation and dosing should be guided by a loading dose of no more than 1.5 mg.kg-1, given as an infusion over 10 min, followed by an infusion of no more than 1.5 mg.kg-1.h-1, for no longer than 24 h, as recommended by the international consensus statement on efficacy and safety 1. When preparing a lidocaine drip, it is essential to consider the patient's ideal body weight for dose calculation, and the infusion should not exceed 120 mg.h-1.

• Key considerations for lidocaine drip preparation and dosing include:
  • Using ideal body weight for dose calculation
  • Not using intravenous lidocaine in patients weighing < 40 kg
  • Avoiding concurrent use with other local anaesthetic interventions
  • Monitoring patients closely, particularly those with existing comorbidity, in a high dependency unit (level 2 care)
  • Having lipid emulsion 20% readily available in case of toxicity, as noted in the international consensus statement 1. The recommended dosing regimen is based on the latest consensus statement, which emphasizes the importance of careful patient selection, monitoring, and dose titration to minimize the risk of toxicity and ensure effective pain management 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION When 4% Lidocaine Hydrochloride Injection, USP is used concomitantly with other products containing lidocaine, the total dose contributed by all formulations must be kept in mind. The dosage varies and depends upon the area to be anesthetized, vascularity of the tissues, individual tolerance and the technique of anesthesia The lowest dosage needed to provide effective anesthesia should be administered. Dosages should be reduced for children and for elderly and debilitated patients Although the incidence of adverse effects with 4% Lidocaine Hydrochloride Injection, USP is quite low, caution should be exercised, particularly when employing large volumes and concentrations of lidocaine since the incidence of adverse effects is directly proportional to the total dose of local anesthetic agent administered.

The information provided does not directly support the preparation and dosing of a lidocaine drip. Key points:

• The label provides dosing information for various routes of administration (e.g., retrobulbar injection, transtracheal injection, topical application) but does not specifically address drip preparation and dosing.
• The label recommends reducing dosages for children and elderly or debilitated patients.
• The maximum recommended dose for normal healthy adults is 300 mg, not to exceed 4.5 mg/kg (2 mg/lb) body weight 2.

From the Research

Lidocaine Drip Preparation and Dosing

• The optimal dosing of lidocaine is not known, but a general consensus indicates that a loading dose of 1-2 mg/kg, followed by 1-2 mg/kg/hr continuous infusion, can achieve therapeutic levels of 0.5-5 mcg/kg and improve analgesia in the immediate postoperative period 3.
• Lidocaine is classified as a class Ib anti-arrhythmic that blocks voltage- and pH-dependent sodium channels, and its use as an anti-arrhythmic agent has been well investigated 4.
• The use of lidocaine for cardiac arrest caused by ventricular tachycardia or ventricular fibrillation is supported by American Heart Association Advanced Cardiac Life Support (ACLS) guidelines, with studies comparing amiodarone and lidocaine in adult populations with in-hospital VT/VF arrest showing that lidocaine may be associated with higher odds of return of spontaneous circulation, 24-hour survival, survival to hospital discharge, and favorable neurologic outcome 5.
• Comparative studies of intravenous amiodarone or lidocaine, or both, for inpatients with pulseless ventricular arrhythmias have shown varying results, with some studies indicating no difference in proportion of patients alive 24 hours post-cardiac arrest, while others suggest a decreased likelihood of survival in patients who received amiodarone as compared with lidocaine 6.
• Lidocaine is generally considered the agent of first choice against acute ventricular arrhythmias arising from many causes, due to its rapid onset of action, favorable electrophysiological profile, and lack of interaction with the autonomic nervous system 7.

Side Effects and Considerations

• Common side effects of lidocaine include hypotension, headache, and vomiting, while serious adverse effects include cardiovascular block and arrhythmias, neuro-excitability, and hypersensitivity 3.
• The pharmacokinetics and pharmacodynamics of lidocaine, especially with regard to optimal dosing to avoid side effects, are not yet fully understood 3.

Clinical Applications

• Lidocaine has been shown to be applicable in different clinical settings perioperatively, including following spinal, breast, ENT, and other surgeries, in addition to its initial use in laparoscopic and open abdominal surgeries 3.
• The use of lidocaine as an anti-arrhythmic agent has been well established, with its mechanisms of action still being investigated 4.