Ultrasound-guided intermediate cervical plexus block and perivascular local anesthetic infiltration for carotid...

Ultrasound-guided blocks of the cervical plexus are established anesthetic procedures for carotid endarterectomy. This randomized, double-blind, placebo-controlled study tested the hypothesis that an additional ultrasound-guided periarterial injection of local anesthetic leads to a lower frequency of periarterial supplementation by the surgeon.

A total of 40 patients were randomly assigned to 1 of 2 groups. In both groups an ultrasound-guided intermediate cervical plexus block (20 ml of 0.75 % ropivacaine) at the level of the fourth cervical vertebra was performed. In a second step, the needle was inserted from posterolateral to anteromedial (in-plane technique) relative to the internal carotid artery and then, depending on the randomized group assignment, 5 ml of 0.75 % ropivacaine (group 2) or 5 ml of 0.9 % saline (group 1) was injected. The parameters investigated included the need for supplementation, patient comfort, the incidence of side effects and circulatory changes.

The two groups did not significantly differ (p = 0.459) in terms of the need for intraoperative supplementation with 1 % prilocaine with a mean (range) in group 2 of 4.9 ml (0-20 ml), in group 1 of 3.7 ml (0-16 ml) and patient comfort (p = 0.144). In addition, a trend towards a higher complication rate was observed in group 2.

For ultrasound-guided intermediate blocks of the cervical plexus, an additional periarterial infiltration showed no advantage. Abandoning this technique leads to a relevant simplification of the blocking technique and tends to reduce block-related side effects.