4 Anesthesia in Hand Surgery
Many procedures in hand trauma can be performed under local anesthetic and patients can be managed in a day case setting. Some surgeons advocate surgery without a tourniquet using local anesthetic and adrenaline; however, this is not always suitable in complex multidigit injuries.
Wrist block can provide good local anesthesia; however, many patients suffer from significant tourniquet pain when this is performed without general anesthetic.
Most departments now use regional anesthesia in the form of brachial plexus anesthesia to provide effective postoperative pain relief. This avoids a general anesthetic (GA) and can be an efficient method of anesthesia if there is a block room available in the hand unit.
4.1 Wrist Block
The wrist block involves blocking the median nerve, ulnar nerve, and the sensory branch of the radial nerve. Key surface landmarks are identified for accurate placement of the injections (Fig. 4‑1). The aim is to inject close to but not directly into the nerves. Always withdraw on the plunger prior to infiltration to reduce the risk of intravascular injection.
The median nerve can be found deep in to the palmaris longus tendon and the ulnar nerve runs radial and deep to the flexor carpi ulnaris tendon (Fig. 4‑2, Fig. 4‑3). The dorsal branch of the ulnar nerve and palmar cutaneous branch of the median nerve often require separate injections (Fig. 4‑4). Finally, the sensory branch of the radial nerve should be blocked over the first extensor compartment (Fig. 4‑5).
Be careful to avoid an intraneural injection; sharp painful paresthesia in the distribution of a nerve territory upon siting the needle or during infiltration is suggestive of an intraneural injection. In such a case, the infiltration should be stopped and the needle should be repositioned prior to continuing.