Lidocaine

As a clinician skilled in Advanced Cardiac Life Support (ACLS), it is important to have a deep understanding of the drugs used in the algorithms, how they work, and why they are a good choice for treating certain conditions.

Lidocaine is one such drug, and has uses both as a local anesthetic and as an antiarrhythmic. The drug was discovered in 1943 by Swedish chemist Nils Lofgren and was approved and available for use in 1949. It is sold under the trade names Xylocaine, Ztildo, and others.

Lidocaine Uses

Lidocaine is a drug with many uses that comes in several different preparations and routes of administration.

It is a commonly used local anesthetic, and as such can be injected into the tissue or applied topically via a cream or spray. These types of anesthetic preparations are used by physicians for numbing during procedures and in more diluted over-the-counter medications for sore throats and sunburns. Dosage for anesthetic administration varies widely, depending on the route and type of procedure. Dosages featuring a 1-2% Lidocaine solution are the most commonly distributed.

Lidocaine is also used as a cardiac antiarrhythmic, which is the primary focus of this article. It works by blocking sodium channels and thus decreasing the rate of heart contractions.

Specific situations where Lidocaine is indicated for cardiac use include:

• Ventricular fibrillation
• Pulseless ventricular tachycardia
• Stable monomorphic ventricular tachycardia with preserved ventricular function
• Stable monomorphic ventricular tachycardia with preserved left ventricular function, normal QT interval, and after correction of any electrolyte imbalances

Note that the first two situations typically accompany a sudden cardiac arrest, while the second two situations would require background knowledge of the patient’s condition(s) and a hospital environment. These second two scenarios of Lidocaine usage are cardiac in nature, but not quite as emergent (allowing more time for targeted treatment plans).