Ultrasound Guided Continuous Supraclavicular Block

Continuous Ultrasound-Guided Supraclavicular BlockThe ultrasound-guided continuous supraclavicular block is in many ways similar to the technique for interscalene catheter placement. Th e goal is to place the catheter in the vicinity of the trunks/divisions of the brachial plexus adjacent to the subclavian artery. Th e procedure consists of three phases: needle placement, catheter advancement, and securing of the catheter. For the fi rst two phases of the procedure, ultrasound can be used to assure accuracy in most patients. Th e needle is typically inserted in-plane from the lateral-to-medial direction so that the tip is just lateral to the brachial plexus sheath. Th e needle is then advanced to indent and transverse the sheath, followed by placement of the catheter.


Figure 9

		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. Th is 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 signifi cantly diff er from the single-injection technique. Th e 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 ( Figure 11 shows the preloaded needle with the catheter). 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. Th e catheter is secured by either taping to the skin or tunneling. Some clinicians prefer one over the other. Th e 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. Th e starting infusion regimen is typically 5 mL/hour of 0.2% ropivacaine with 5-mL patient-controlled boluses hourly.

Figure 11