Comparison of intermediate vs subcutaneous cervical plexus block for carotid endarterectomy.

BACKGROUND: Carotid endarterectomy surgery can be performed under regional anaesthesia alone or under general anaesthesia. However, there are several types of regional block available and reported complication rates after superficial cervical plexus blocks are significantly lower than deep blocks. It is not known if subcutaneous and intermediate blocks are equally effective, although anatomical evidence suggests that the latter (where the injectate diffuses below the deep cervical fascia) might provide superior quality of intraoperative anaesthesia. METHODS: Forty-four patients were randomized to receive either subcutaneous or intermediate cervical plexus blocks for carotid endarterectomy. The primary endpoint was supplemental lidocaine requirement during surgery. Secondary outcome measures included: total amount of fentanyl administered during surgery, recall of pain scores during surgery, complications, and patient and surgeon satisfaction. RESULTS: There was no statistically significant difference for median (range) lidocaine supplementation between the subcutaneous and intermediate groups 65 (20-170) mg vs. 85 (30-345) mg, respectively; P=0.31. There were no statistical differences in the secondary outcome measures and no major complications during the study. CONCLUSIONS: Intermediate and subcutaneous cervical plexus blocks are equally effective for carotid endarterectomy. This study adds to the body of evidence supporting the safe use of superficial blocks for this type of surgery.

Prospective, randomized comparison of deep or superficial cervical plexus block for carotid endarterectomy surgery.

BACKGROUND: Carotid endarterectomy may be performed under cervical plexus block with local anesthetic supplementation by the surgeon as necessary during surgery. It is unclear, however, whether deep or superficial cervical plexus block offers the best operating conditions or patient satisfaction. Therefore, the authors compared the two in patients undergoing carotid endarterectomy. METHODS: Forty patients undergoing carotid endarterectomy were randomized to receive either a superficial or a deep cervical plexus block with 20 ml bupivacaine, 0.375%. Outcomes subjected to statistical analysis included supplemental anesthetic supplementation with lidocaine, 1%, by the surgeon, dermatomes affected by the block, paresthesia during block placement, postoperative pain scores, and analgesic requirements. RESULTS: Median supplemental lidocaine requirements were 6 ml (range, 0.5 to 20 ml) in the deep block group and 6 ml (range, 0 to 20 ml) in the superficial block group (P = 0.7323). Patients in the deep block group who reported paresthesia during block placement required less lidocaine supplementation (median, 2; range, 0.5 to 20 ml) than the 9.5 ml (range, 6 to 15.5 ml) required by those who did not experience paresthesia (P = 0.0113). Compared with patients in the superficial block group, those in the deep block group were less likely to need analgesia in the first 24 h after operation (P = 0.047), and those who required analgesia received it later (6.6 +/- 4.1 vs. 3.9 +/- 1.4 h after operation; Student's t test, P = 0.02). One patient in each group expressed dissatisfaction with the technique. CONCLUSIONS: Carotid endarterectomy may be performed satisfactorily during superficial or deep cervical plexus block placement with no differences in terms of supplemental local anesthetic requirements, although this is influenced by whether paresthesia is elicited during placement of the deep block. Therefore, the clinician's decision to use one block rather than another need not be based on any assumed superiority of one block based on intraoperative conditions or patient satisfaction.