[A comparative study between bupivacaine and clonidine associated with bupivacaine in cervical plexus block for carotid endarterectomy].

BACKGROUND AND OBJECTIVES

Neurological evaluation can be done during cervical plexus block for endarterectomy, which also maintains postoperative analgesia. The objective of this study was to compare the analgesic effects of clonidine associated with bupivacaine to those of bupivacaine in cervical plexus block.

METHODS

A randomized double-blind study was undertaken with 30 patients divided in two groups: G1 received 1.5 mg.kg-1 of 0.375% bupivacaine associated with 150 (1/4)g of clonidine (2 mL), and G2 received 1.5 mg.kg-1 of 0.375% bupivacaine associated with NS (2 mL). The following parameters were evaluated: heart rate and blood pressure at 0 (block), 30, 60, 90, and 120 minutes; the need for anesthetic supplementation; time until the first analgesic supplementation; amount of analgesic used; and pain severity at 0 (end of the surgery), 30, 60, 120, 240, and 360 minutes.

RESULTS

Group 1 received 3.8 mL of lidocaine for anesthetic supplementation, while G2 received 3.6 mL of lidocaine, but this difference was not statistically significant. In G1, the time until the first supplementation was 302.6 +/- 152.6 minutes, and in G2 it was 236.6 +/- 132.9 minutes, which was not statistically significant. Differences between the doses of dypirone and tramadol were not observed. Differences in pain severity between both groups were not observed either.

CONCLUSION

The association of 150 (1/4)g of clonidine and bupivacaine in cervical plexus block for carotid endarterectomy did not improve significantly the analgesic effects evaluated by pain severity, time until the first analgesic supplementations and amount of supplementary analgesics.