From the Guidelines
Continuous lidocaine infusion for pain control should be initiated with a loading dose of 1.5 mg/kg administered intravenously over 10 minutes, followed by a maintenance infusion of 1.5 mg/kg/hour, with a maximum infusion rate of 120 mg/hour, as recommended by the most recent international consensus statement on efficacy and safety 1. The protocol for continuous lidocaine infusion involves several key considerations to ensure safe and effective pain management.
Key Considerations
- Ideal body weight should be used for dose calculation, and intravenous lidocaine should not be used in patients weighing less than 40 kg 1.
- A separate lidocaine monitoring chart should be used, and patients receiving i.v. lidocaine should ideally be managed in a monitored bedspace in a high dependency unit (level 2 care) 1.
- Clinicians should be aware of the possibility of toxicity and have lipid emulsion 20% readily available in case of an emergency 1.
Monitoring and Dose Adjustments
- Patients should be monitored for signs of toxicity, including perioral numbness, metallic taste, dizziness, tinnitus, visual disturbances, confusion, seizures, or cardiac arrhythmias 1.
- ECG monitoring is recommended during initiation and dose adjustments, and frequent changes of infusion rate should be discouraged 1.
- The duration of infusion should not generally exceed 24 hours, but may be extended in certain cases under the guidance of a consultant anaesthetist or intensivist 1.
Special Considerations
- Dose adjustments should be made for elderly patients, those with hepatic or cardiac dysfunction, and patients on medications that may interact with lidocaine 1.
- The infusion works by blocking voltage-gated sodium channels, reducing spontaneous neuronal firing and preventing pain signal transmission, making it particularly useful for neuropathic pain, postoperative pain, and refractory pain conditions 1.
From the FDA Drug Label
CLINICAL PHARMACOLOGY Mechanism of action: Lidocaine stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses, thereby effecting local anesthetic action. The FDA drug label does not answer the question.
From the Research
Protocol for Continuous Lidocaine Infusion
The protocol for continuous lidocaine infusion for pain control involves several key considerations, including:
- Loading dose: A loading dose of 1-2 mg/kg is typically administered, followed by a continuous infusion of 1-2 mg/kg/hr 2.
- Continuous infusion rate: The continuous infusion rate may vary depending on the patient's response to treatment, but a rate of 1-2 mg/kg/hr is commonly used 2, 3.
- Duration of infusion: The duration of the infusion may vary depending on the patient's needs, but infusions have been continued for several hours or even days in some cases 3, 4.
- Monitoring: Patients receiving continuous lidocaine infusions should be closely monitored for signs of toxicity, including hypotension, headache, and vomiting 2, 5.
Clinical Applications
Continuous lidocaine infusions have been used in a variety of clinical settings, including:
- Postoperative pain management: Lidocaine infusions have been shown to be effective in reducing postoperative pain and decreasing the need for other analgesics 2, 6.
- Cancer pain management: Lidocaine infusions have been used to manage cancer pain, particularly in patients who are refractory to other treatments 3.
- Palliative care: Lidocaine infusions have been used in palliative care settings to manage intractable headaches and other types of pain 4.
Safety Considerations
While continuous lidocaine infusions are generally considered safe, there are potential risks and side effects to be aware of, including:
- Toxicity: Lidocaine toxicity can occur, particularly at high doses or with prolonged infusions 2, 5.
- Cardiovascular effects: Lidocaine can cause hypotension and other cardiovascular effects, particularly in patients with pre-existing heart conditions 2.
- Neurological effects: Lidocaine can cause neurological effects, including headache, dizziness, and confusion 2, 3.