Which anesthetic is typically injected during a bier block?

A Bier block, also known as intravenous regional anesthesia (IVRA), typically utilizes lidocaine as the anesthetic agent for the procedure. This technique involves the injection of lidocaine into a vein in a limb after the circulation to that limb has been temporarily occluded. Lidocaine is favored because of its rapid onset and adequate duration of action for procedures on the extremities, making it ideal for this type of regional anesthesia.

Utilizing lidocaine alone allows for effective anesthesia without the risk of prolonged effects which can occur with longer-acting agents like bupivacaine. This property of lidocaine is particularly useful in outpatient settings or for short surgical procedures, where quicker recovery and fewer side effects are desirable.

Although bupivacaine can be used in various anesthesia techniques, it is generally not preferred for Bier blocks due to its longer duration of action which can lead to complications when used in this manner since the anesthetic should clear from the limb quickly after the procedure. Therefore, lidocaine stands out as the most appropriate choice for the Bier block technique.