Comparison between ropivacaine 1.5 mg ml(-1) plus fentanyl 2 mg ml(-1) and ropivacaine 1.5 mg ml(-1) plus clonidine 1 mg ml(-1) as analgesic solution after anterior cruciate ligament reconstruction: a randomized clinical trial.

BACKGROUND

Ropivacaine is commonly used as local anesthetic for postoperative analgesia through an epidural catheter. Data show that several adjuvants influence the analgesic effect of local anesthetic potency.

OBJECTIVE

The aim of the study was to compare fentanyl and clonidine as adjuvants to 1.5 mg ml(-1) ropivacaine in terms of motor blockade, pain relief and side effects.

METHODS

In this single center, randomized, clinical trial, 52 patient scheduled for arthroscopic anterior cruciate ligament reconstruction were radomly allocated in two groups. At twenty-six patient a solution with ropivacaine 1.5 mg ml(-1) plus fentanyl 2 microg ml(-1) (group F) was administered through patient controlled epidural analgesia (PCEA) as postoperative analgesia and ropivacaine 1.5 mg ml(-1) plus clonidine 1 microg ml(-1) (group C) was administered at the remaining twenty-six patients. The VAS score, the Bromage scale and total solution consumption were documented and compared between the two groups for 24 hours after the end of the operation.

RESULTS

The mean patient control consumption of the solution was higher at group C respect group F (p = 0.007). At the 8th hour after the operation we register a statistical significant difference at the mean VAS score between the two groups (p < 0.05) with clonidine group achieving a higher score. At the 8th and 12th hour clonidine group register a lower Bromage score than fentanyl group (p < 0.005 and p = 0.002).

CONCLUSION

Ropivacaine 1.5 mg ml(-1) plus fentanyl 2 microg ml(-1) administred through PCEA compared with ropivacaine 1.5 mg ml(-1) plus clonidine 1 microg ml(-1) h guarantee higher quality analgesia after ACL reconstruction.