NYSORA - The New York School of Regional Anesthesia: Ultrasound Guided Continuous Supraclavicular Block

Ultrasound Guided Continuous Supraclavicular Block
================================================================================
admin on 25/01/2012 04:52:00


Figure 1: A needle insertion for the continuous supraclavicular brachial plexus
block. The catheter is inserted 3–5 cm beyond the needle tip and injected with
3–5 mL of local anesthetic to document the proper dispersion of the local
anesthetic within the brachial plexus sheath.
http://www.amazon.com/Hadzics-Peripheral-Ultrasound-Guided-Regional-Anesthesia/dp/0071549617/ref=sr_1_1?ie=UTF8&qid=1334330534&sr=8-1
Continuous Ultrasound-Guided Supraclavicular Block
The ultrasound-guided continuous supraclavicular block is in many ways similar
to the technique for interscalene catheter placement. The goal is to place the
catheter in the vicinity of the trunks/divisions of the brachial plexus adjacent
to the subclavian artery. The procedure consists of three phases: needle
placement, catheter advancement, and securing of the catheter. For the first two
phases of the procedure, ultrasound can be used to assure accuracy in most
patients. The needle is typically inserted in-plane from the lateral-to-medial
direction so that the tip is just lateral to the brachial plexus sheath (Figure
1). The needle is then advanced to indent and transverse the sheath, followed by
placement of the catheter.
When the needle approaches the brachial plexus, extra force is required to
penetrate the prevertebral fascia and enter the brachial plexus "sheath". The
entrance of the needle into
the sheath is always associated with a distinct pop sensation as the needle
breaches the
fascial layer.
Proper placement of the needle can also be confirmed by obtaining a motor
response of the arm, forearm, or hand, at which point 4–5 mL of local
anesthetic is injected. This small dose of local anesthetic serves to assure
adequate distribution of the local anesthetic as well as to make the advancement
of the catheter more comfortable to the patient. This first phase of the
procedure does not significantly differ from the single-injection technique. The
second phase of the procedure involves maintaining the needle in the proper
position and inserting the catheter 2 to 3 cm into the sheath of the brachial
plexus. Care must be taken not to advance the catheter too far, which may result
in the catheter exiting the brachial plexus and the consequent failure to
provide analgesia. Insertion of the catheter can be accomplished by either a
single operator or a with a helper. The catheter is secured by either taping to
the skin or tunneling. Some clinicians prefer one over the other. The decision
about which method to use could be based on the patient's age, duration of the
catheter therapy, and anatomy. Tunneling could be preferred in older patients
with obesity or mobile skin over the neck and longer planned duration of the
catheter infusion. Two main disadvantages of the tunneling are the risk of
catheter dislodgment during the tunneling and the potential for scar formation.
A number of devices are commercially available to help secure the catheter. The
starting infusion regimen is typically 5 mL/hour of 0.2% ropivacaine with 5-mL
patient-controlled boluses hourly.