Why Do Bier Blocks Work for Hand Surgery … Most of the Time?

Abstract

surgical procedures because it provides anesthesia for short procedures and a bloodless field under tourniquet control. It is a safe and cost-effective alternative to general anesthesia, with patients who undergo IVRA leaving the hospital one hour sooner and having less postoperative nausea than those undergoing general anesthesia. 2,3 The success of IVRA for hand surgery is contingent on careful patient selection, maintenance of a bloodless field, and tolerance of the tourniquet. We will discuss why Bier blocks work well for hand surgery, and review some of the recent literature on technical modifications to improve intraoperative hemostasis and tourniquet tolerance. TRADITIONAL METHOD OF IVRA Traditionally, IVRA is performed by first applying a single or double lumen tourniquet to the proximal arm. For surgery less than 20 minutes duration, a single lumen tourniquet is usually chosen, whereas for surgery up to 60 minutes, a double lumen tourniquet provides a more extended period before tourniquet pain occurs. A 20- or 22-gauge cannula is inserted preoperatively into a vein on the dorsum of the hand. The extremity is then elevated and exsanguinated using an Esmarch bandage. Incomplete exsanguination can reduce the quality of anesthesia and hemostasis within the surgical field. The proximal lumen of the tourniquet is then inflated. Local anesthetic (LA) is then injected slowly. A dose of 3 mg/kg 0.5% lidocaine is used frequently. Rapid infusion can exceed the tourniquet pressure and LA may enter the systemic circulation. Surgical-level anesthesia is commonly reached within 5 to 10 minutes. The tourniquet’s proximal lumen remains inflated until the patient becomes uncomfortable. The distal lumen, which is over an anesthetized area, is then inflated, followed by release of the proximal lumen. Gradual release of the distal lumen at the end of the procedure is recommended to prevent systemic LA toxicity for procedures lasting less than 20 minutes. 4