Chapter 80E: Axillary Brachial Plexus Block

INTRODUCTION

Brachial plexus block at the level of the axilla is typically chosen for anesthesia of the distal upper limb. Axillary block is one of the most common approaches to brachial plexus blockade. Easy landmarks and simplicity make this block suitable for a wide range of surgical procedures.

HISTORY

The surgical technique of this block was first described by William Hallstead¹ in New York City (Roosevelt Hospital, also the clinical affiliation for NYSORA 1995-2014) in 1884, whereas the percutaneous technique was described by Georg Hirschel² in 1911. In 1958, Preston Burnham³ recognized that filling the neurovascular “sheath” with local anesthetic could simplify the axillary block. He also described the characteristic fascial “click” felt upon needle entry into the axillary sheath. In 1961, while using the formula for a cylinder volume, Rudolph De Jong⁴ calculated that in an average adult, 42 mL of local anesthetic (LA) was necessary to fill the fascial compartment to the level of the cords and block all terminal nerves to the arm. A year later, Ejnar Eriksson and Skarby,⁵ in an effort to promote the proximal spread of LA, advocated wrapping a rubber tourniquet around the arm, distal to the needle. In 1979, Alon Winnie and coworkers⁶ found the tourniquet ineffective and painful and recommended firm distal digital pressure on the neurovascular sheath instead. In addition, they also recommended arm adduction after LA injection, thinking that the head of the abducted humerus com pressed the neurovascular sheath. Both maneuvers were later proved to be clinically ineffective.^7,8,9 Gale Thompson and Duane Rorie,¹⁰ in 1983, studied brachial plexus using computed tomograms and suggested that the median, ulnar, and radial nerves lie in separate fascial compartments within the neurovascular sheath; this hypothesis provided a rational explanation for incomplete blocks. However, anatomic studies by Lassale and Ang¹¹ in 1984 and Vester-Andersen and coworkers¹² in 1986 did not confirm the existence of a true neurovascular sheath. The interfascial space they found contained the median and the ulnar nerves, infrequently the musculocutaneous, and occasionally the radial nerves. Moreover, the space was suggested to communicate proximally only with the medial cord of the plexus. In 1987, Partridge and coworkers¹³ found the interneural septa, which were easily broken by injection of dyed latex. In 2002, Oivind Klaastad and coworkers¹⁴ were the first to investigate the spread of the LA through the axillary catheter in studies using magnetic resonance imaging (MRI) scanning. They found that in most patients the spread of LA was uneven and the clinical effect inadequate.

Until the 1960s, the prevalent block techniques were double or multiple axillary injections. After the concept of the neurovascular sheath had been established by De Jong⁴ in 1961, the single-injection technique, being the simplest, became standard. However, Vester-Andersen and coworkers^15,16 demonstrated in 1983 and 1984 that despite ...