Corner Pocket
Corner pocket supraclavicular block (Reg Anes and Pain Med 2007;32(1):94)
ultrasound guide supraclavicular block (Am J Emerg Med 2007;25;472)
1. Introduction
Emergency physicians often encounter patients who require anesthesia for the
treatment of acute traumatic or infectious processes. Direct infiltration of a
local anesthetic agent may be insufficient to obtain adequate anesthesia for
upper extremity fractures, dislocations, and abscesses. Although procedural
sedation can facilitate the treatment of these patients, it requires patients to
have fasted for 6 or more hours and still involves the risk of apnea,
hypotension, and other adverse effects.
Peripheral nerve blocks (of the median, ulnar, and radial nerves) in the upper
extremity are effective but require multiple injections and are unable to
provide effective anesthesia proximal to the forearm [1]. The success of
real-time ultrasound-guided supraclavicular brachial plexus nerve blocks has
been reported extensively in the anesthesiology literature [2], [3], [4], [5]
and [6]. These studies used both real-time ultrasound guidance and nerve
stimulation to confirm needle position.
We hypothesize that real-time ultrasound-guided brachial plexus nerve blocks can
be performed without nerve stimulation and can provide an excellent alternative
to procedural sedation for the management of upper extremity fractures,
dislocations, or abscesses in the emergency department (ED). We report a series
of 5 ED patients in whom supraclavicular brachial plexus nerve blocks were
performed using ultrasound guidance.
2. Methods
The procedure for ultrasound-guided supraclavicular brachial plexus nerve block
was modified from the technique originally described by Chan [4]. After written
informed consent was obtained, the supraclavicular fossa was prepared and draped
in sterile fashion. A sonographic view of the brachial plexus was obtained with
a 10 to 5.0 MHz linear transducer oriented transversely in the supraclavicular
fossa, just above the clavicle. In this view, the brachial plexus is superficial
and lateral to the subclavian artery and is visualized as a group of hypoechoic
nodules ( Fig. 1). Arterial flow was confirmed by pulsed wave Doppler flow to
ensure the correct identification of the subclavian artery. A 27-gauge or a
22-gauge noncutting spinal needle was inserted from the lateral aspect of the
linear transducer and directed in parallel with the transducer to allow
visualization of the full length of the needle throughout the procedure ( Fig.
2). When the needle tip was visualized adjacent to the hypoechoic nodules
representing the brachial plexus, 30 mL of lidocaine 1% with epinephrine was
instilled with frequent aspiration to avoid intravascular injection. The spread
of local anesthetic within the brachial plexus was visualized as an expanding
hypoechoic collection within the brachial plexus. This technique is similar to
the one described by Chan et al [4], yet does not involve the use of a nerve
stimulator needle given the lack of availability and familiarity with this
device in the ED.
