- Indications: short operative procedures for the extremities; pain therapy (e.g., treatment of recurrent complex pain syndrome); treatment of hyperhidrosis
- Local anesthetic: 12–15 mL of 2% lidocaine for upper extremities (or 30–40 mL of 0.5% lidocaine)
- Relative contraindications: crush injuries; inability to access peripheral veins; infections (skin, cellulitis); compound fractures; convincing history of allergy to local anesthetics (LAs); severe peripheral vascular disease; atrioventricular shunts; severe hepatic insufficiency; disrupted integrity of venous system; sickle cell disease
- Complexity level: Basic
Intravenous regional anesthesia: Injection of local anesthetic and placement of the tourniquet.
Intravenous regional anesthesia (IVRA) was first described in 1908 by the German surgeon A.G. Bier, hence the procedure name Bier block. Originally, anesthesia was obtained by the intravenous injection of procaine in a previously exsanguinated vascular space, isolated from the rest of the circulation by two Esmarch bandages used as tourniquets. After initial enthusiasm, the technique fell into obscurity for >50 years. In 1963, Holmes reintroduced the Bier block with the novel use of lidocaine, describing a series of 30 patients in The Lancet. Today, intravenous regional anesthesia of the upper limb remains popular because it is reliable, cost effective, safe, and simple to administer. It is a widely accepted technique well suited for brief minor surgeries such as wrist or hand ganglionectomy, carpal tunnel release, Dupuytren contractures, reduction of fractures, and others. Since the duration of anesthesia depends on the length of time the tourniquet is inflated, there is no need to use long-acting or more toxic agents. Its application for longer surgical procedures is precluded by the discomfort caused by the tourniquet, typically beginning within 30 to 45 minutes. Other disadvantages include incomplete muscle relaxation (where important) and lack of postoperative pain relief. With the implementation of a safety protocol and with meticulous attention to detail, concerns about local anesthetic (LA) toxicity should merely be a theoretical issue.
The only relevant anatomy is the location and distribution of peripheral veins in the extremity to be blocked. By preference, a vein as distal as possible is chosen. The antecubital fossa is an alternative only when more distal peripheral access is lacking.
The entire extremity below the level of the tourniquet is anesthetized. Numerous radiographic, radioisotope, and neurophysiologic studies looked into the site of action of IVRA. However, the exact mechanism still remains the subject of debate and controversy. The likely mechanism is that the local anesthetic, via the vascular bed, reaches both peripheral nerves and nerve trunks (vasae nervorum), and nerve endings (valveless venules). Diffusion of local anesthetic into the surrounding tissues also plays a role. Ischemia and compression of the peripheral nerves at the level of the inflated cuff is probably another contributory component of the mechanism of IVRA. Again, anesthesia achieved by intravenous regional anesthesia is limited only by the inevitable pain due to tourniquet ...