RESUMO
Clonidine has been shown to prolong sensory analgesia when given as an adjunct to peripheral nerve blocks but has not been evaluated when given in conjunction with a femoral-sciatic nerve block. The purpose of this investigation was to determine whether the addition of clonidine to a femoral-sciatic nerve block would prolong the duration of sensory analgesia in groups of patients undergoing anterior cruciate ligament (ACL) reconstruction. This prospective, randomized, double-blind investigation was performed on 64 subjects undergoing ACL reconstruction. Patients were assigned randomly to receive a femoral-sciatic nerve block using 30 mL of 0.5% bupivacaine with 1:200,000 epinephrine (control group) or 30 mL of 0.5% bupivacaine with 1:200,000 epinephrine and 1 microg/kg of clonidine (experimental group). Variables measured included demographics, timed pain intensity measurements, postoperative analgesic consumption, duration of analgesia, and patient satisfaction. No significant differences were noted between groups for pain intensity scores, duration of sensory analgesia, postoperative analgesic requirements, or overall patient satisfaction. Both groups reported minimal amounts of postoperative pain and high analgesic satisfaction scores. Based on our results, we do not recommend the addition of clonidine to a femoral-sciatic nerve block when given to facilitate postoperative analgesia in patients undergoing ACL reconstruction.