Intravenous Regional block with lidocaine and magnesium sulfate for below knee amputation in a high risk diabetic patient

Bier block anesthesia is an intravenous regional anesthesia technique in which an extremity is made numb for surgery by injecting a local anesthetic solution into a vein after the blood has been squeezed out of the extremity and a tourniquet has been placed on it. The tourniquet prevents the local anesthetic from leaving the extremity and blood from entering it, giving the patient a numb (anesthetic) extremity and the surgeon a bloodless field to work in. The technique is named for August Bier. The advantages of the technique is that it is simple to perform, and provides a bloodless field that is easy to work in and minimizes blood loss. The disadvantages are that there is a practical time limit on its use of about 1 hour due to tolerance of the awake patient for the pain of the tourniquet and 2 hours due to the maximum time blood flow can be restricted to the extremity without anoxic tissue damage. In this case we performed bier block in a high risk diabetic patient for below knee amputation. We added mg sulfate as an adjuvant drug in order to improve block quality and to prolong patient analgesia.