Which pair of local anesthetics are commonly used for Bier blocks (IV regional anesthesia)?

Which pair of local anesthetics are commonly used for Bier blocks (IV regional anesthesia)?

• A. Lidocaine and Prilocaine
• B. Procaine and Tetracaine
• C. Bupivacaine and Ropivacaine
• D. Lidocaine and Bupivacaine

Answer: (A)

IV regional anesthesia relies on a local anesthetic that acts quickly when given intravenously and provides enough anesthesia for the duration of the surgical time while the tourniquet is in place. Lidocaine is the classic choice for a Bier block because its onset is rapid and its duration fits typical procedures, making it reliable and predictable when the limb is isolated from the rest of the circulation. Prilocaine has a similar onset and duration, offering a second option with a comparable safety profile in this setting. Together, these short- to intermediate-acting amide anesthetics align well with the goal of a fast, controllable block that resolves after the tourniquet is released. In contrast, agents like procaine or tetracaine bring different risk/duration profiles that are less suitable for IV regional use—procaine is less reliable, while tetracaine is long-acting and carries greater toxicity risk. Long-acting amides such as bupivacaine or ropivacaine are also avoided for Bier blocks because their effects persist longer after tourniquet release, increasing the chance of prolonged motor or sensory block and potential toxicity if the tourniquet fails.

IV regional anesthesia relies on a local anesthetic that acts quickly when given intravenously and provides enough anesthesia for the duration of the surgical time while the tourniquet is in place. Lidocaine is the classic choice for a Bier block because its onset is rapid and its duration fits typical procedures, making it reliable and predictable when the limb is isolated from the rest of the circulation. Prilocaine has a similar onset and duration, offering a second option with a comparable safety profile in this setting. Together, these short- to intermediate-acting amide anesthetics align well with the goal of a fast, controllable block that resolves after the tourniquet is released.

In contrast, agents like procaine or tetracaine bring different risk/duration profiles that are less suitable for IV regional use—procaine is less reliable, while tetracaine is long-acting and carries greater toxicity risk. Long-acting amides such as bupivacaine or ropivacaine are also avoided for Bier blocks because their effects persist longer after tourniquet release, increasing the chance of prolonged motor or sensory block and potential toxicity if the tourniquet fails.