In addition to potent analgesia, regional anesthesia may lead to reductions in the stress response, systemic analgesic requirements, opioid-related side effects, general anesthesia requirements, and, possibly, the development of chronic postoperative pain. Regional analgesia may accelerate postoperative convalescence.
Regional anesthetics must be administered in an area where standard anesthetic monitors, supplemental oxygen, and resuscitative medications and equipment are immediately available.
Over the past decade, fascial plane blocks have become a popular alternative to conventional peripheral nerve blocks or thoracic epidural analgesia. These blocks rely on depositing a large volume of local anesthetic into fascial planes in which target nerves are contained.
Local anesthetic may be deposited at any point along the brachial plexus, depending on the desired block effects: interscalene for shoulder and proximal humerus surgical procedures; and supraclavicular, infraclavicular, or axillary for surgeries distal to the mid-humerus.
A properly performed interscalene block almost invariably blocks the ipsilateral phrenic nerve, so careful consideration must be given to patients with severe pulmonary disease or preexisting contralateral phrenic nerve palsy. Bilateral interscalene blocks are always contraindicated.
Brachial plexus block at the level of the cords provides excellent anesthesia for procedures at or distal to the elbow. The upper arm and shoulder are not anesthetized with this approach. As with other brachial plexus blocks, the intercostobrachial nerve (T2 dermatome) is spared.
The axillary, musculocutaneous, and medial brachial cutaneous nerves branch from the brachial plexus proximal to where local anesthetic is deposited for an axillary brachial plexus block and thus are usually spared from blockade. The musculocutaneous nerve can be independently blocked to anesthetize the lateral forearm.
Often it is necessary to anesthetize a single terminal nerve, either for minor surgical procedures with a limited field or as a supplement to an incomplete brachial plexus block. Terminal nerves may be anesthetized anywhere along their course.
Intravenous regional anesthesia, also called a Bier block, can provide intense surgical anesthesia for relatively short (45–60 min) surgical procedures on an extremity.
A femoral nerve block alone will seldom provide adequate surgical anesthesia, but it is often used to provide postoperative analgesia for hip, thigh, knee, and ankle procedures.
Patients with continuous adductor canal catheters are able to ambulate further on the first day following total knee arthroplasty than patients with either femoral block (limited by weakness) or no block (limited by pain).
Blockade of the sciatic nerve may occur anywhere along its course and is indicated for surgical procedures involving the posterior thigh, knee, lower leg, ankle, and foot.
Popliteal nerve blocks provide excellent coverage for foot and ankle surgery while sparing much of the hamstring muscles, allowing lifting of the foot with knee flexion and thus facilitating ambulation. All sciatic nerve blocks fail to provide complete anesthesia for the leg and ankle, as the medial leg and ankle are innervated by the saphenous nerve. When a saphenous (or femoral) block is added, complete anesthesia below the knee is provided.
A complete ankle block ...