Describe the intravenous regional anesthetic technique (Bier block) for surgery on the extremities

Describe the intravenous regional anesthetic technique (Bier block) for surgery on the extremities.

The intravenous regional anesthetic (Bier block) is an easily performed and extremely predictable method for providing anesthesia of the extremities. It is best reserved for procedures on the upper extremity below the elbow, although it can provide anesthesia for surgery on the distal lower extremity as well. The technique of intravenous regional block requires little technical skill other than the placement of an additional intravenous catheter in the hand or foot of the extremity to be anesthetized. The block has a rapid onset, and the success rate approaches 100% in most hands. Only minor patient discomfort occurs during performance of the block. After the arm is exsanguinated, by wrapping it in an Esmarch bandage, the tourniquet is inflated to 100 mmHg over systolic pressure, and the elastic bandage is then removed. Fifty milliliters of 0.5% preservative-free lidocaine is then injected through the previously placed intravenous catheter. Surgical anesthesia is achieved within approximately 10 minutes.

Because a significant proportion of the infused medica-tion may enter the systemic circulation, the anesthesiologist must remain vigilant at all times for the development of subtle central nervous system changes. Frank seizures may occur if the tourniquet fails shortly after the drug is injected.

Usually, little or no intraoperative sedation or adjunc-tive analgesia is required. On release of the tourniquet, anesthesia rapidly dissipates. Therefore, the Bier block is recommended where postoperative surgical pain is apt to be minimal. It is ideal for procedures such as ganglion excision, trigger finger repair, removal of foreign bodies, and carpal tunnel release.