All the following agents are acceptable for use in a Bier block EXCEPT

All the following agents are acceptable for use in a Bier block EXCEPT

• A. 0.5% Lidocaine
• B. 0.5% Mepivacaine
• C. 0.5% Procaine
• D. 0.25% Bupivacaine

Answer: (D)

In a Bier block the goal is to produce rapid, reliable anesthesia in the limb by injecting a local anesthetic into the venous system with a tourniquet in place, so the drug acts quickly but has a predictable, limited duration while the tourniquet holds it in the limb. Bupivacaine, even at 0.25%, is not suitable because it has a slower onset and a longer, more cardiotoxic duration if it enters the systemic circulation, which can happen when the tourniquet is released. This makes it a higher risk for intravenous regional anesthesia. Lidocaine 0.5%, mepivacaine 0.5%, and procaine 0.5% are favored for this technique due to their faster onset and more favorable safety profile within the limited confines of a Bier block.

In a Bier block the goal is to produce rapid, reliable anesthesia in the limb by injecting a local anesthetic into the venous system with a tourniquet in place, so the drug acts quickly but has a predictable, limited duration while the tourniquet holds it in the limb.

Bupivacaine, even at 0.25%, is not suitable because it has a slower onset and a longer, more cardiotoxic duration if it enters the systemic circulation, which can happen when the tourniquet is released. This makes it a higher risk for intravenous regional anesthesia.

Lidocaine 0.5%, mepivacaine 0.5%, and procaine 0.5% are favored for this technique due to their faster onset and more favorable safety profile within the limited confines of a Bier block.