Lidocaine may be considered a suitable antiarrhythmic that can be used to treat cardiac arrest from VT/VF.
Lidocaine is now included in the AHA Cardiac Arrest diagram along with amdidoarne. Emphasis should not be on the use of medications and it is the AHA recommendation to place more emphasis on high quality CPR and early defibrillation.
Lidocaine indications for ACLS
- In ACLS, Lidocaine is used intravenously for the treatment of ventricular arrhythmias. (VT/VF)
- It is also useful for the treatment of stable monomorphic VT with preserved ventricular function and for stable polymorphic VT with preserved left ventricular function, normal QT interval, and correction of any electrolyte imbalances.
The overall benefits of lidocaine for the treatment arrhythmias in cardiac arrest has come under scrutiny. It has been shown to have no short term or long term efficacy in cardiac arrest.
Routine prophylactic use is contraindicated for acute myocardial infarction.
Side Effects
Lidocaine should be used with caution due to negative cardiovascular effects which include hypotension, bradycardia, arrhythmias, and/or cardiac arrest. Some of these side effects may be due to hypoxemia secondary to respiratory depression.
Lidocaine Toxicity
Symptoms of lidocaine toxicity progress in the following predictable pattern. It begins with numbness of the tongue, lightheadedness, and visual disturbances and progresses to muscle twitching, unconsciousness, and seizures, then coma, respiratory arrest, and cardiovascular depression.
There are several conditions that increase the potential for lidocaine toxicity:
- Liver dysfunction increases the risk of toxicity due to lidocaine being metabolized by the liver.
- Low protein increases the risk of toxicity because lidocaine is protein bound.
- Acidosis can also increase the risk of toxicity since acidosis increase the potential of lidocaine to dissociate from plasma proteins.
Dosing
Cardiac Arrest from VT/VF:
- Initial dose: 1 to 1.5 mg/kg IV/IO
- For refractory VF may give additional 0.5 to 0.75 mg/kg IV push, repeat in 5 to 10 minutes; maximum 3 doses or total of 3mg/kg
Perfusing Arrhythmia:
For stable VT, wide-complex tachycardia of uncertain type and significant ectopy:
- Doses Range from 0.5 to 0.75 mg/kg and up to 1 to 1.5mg/kg
- Repeat 0.5 to 0.75 mg/kg every 5-10 minutes with maximum total dose of 3 mg/kg
Maintenance infusion:
- 1 to 4 mg/min (30-50 mcg/kg/min)
Discontinue a lidocaine infusion immediately if signs of toxicity develop.