Local Anaesthetic Systemic Toxicity

Drugs that numb an area by preventing pain signals from reaching the brain.

A life-threatening complication that can occur after using local anaesthetics. It happens when the anaesthetic spreads to other parts of the body, affecting the heart, brain, and nervous system.

Local anaesthetics are made of water-soluble salts and fat-soluble alkaloids. This allows them to easily cross cell membranes in their unionized form.

Local anaesthetics work by blocking sodium channels in nerves, preventing pain signals from reaching the brain.

Different local anaesthetics have different abilities to dissolve in lipids. This affects how quickly they are absorbed and how easily they cause toxicity.

Local Anaesthetics are composed of both water-soluble salts and lipid-soluble alkaloids. This means they can dissolve in both water and fats, allowing them to easily cross cell membranes in their unionized form.

The ability of a Local Anaesthetic to dissolve in lipids is important because it affects its absorption and toxicity. More lipid-soluble anaesthetics like bupivacaine are more easily absorbed but also cause faster toxicity.

Local Anaesthetics work by blocking sodium channels in nerve cells. This stops pain signals from reaching the brain, causing numbness. However, blocking sodium channels can also affect the heart's ability to function properly.

The rapid early depolarization stage of an action potential requires sodium. Local Anaesthetics interfere with this process by blocking sodium channels, which can affect heart function and lead to serious problems.

Local Anaesthetics are most likely to cause problems in the first 10 minutes after being administered. These problems are caused by the anaesthetic spreading to the heart, brain, and nervous system. Symptoms are often related to abnormal heart function.