Background: This study compared the results of regional blocks containing a single anesthetic, bupivacaine, with those containing bupivacaine and 3 additives (buprenorphine, clonidine, and dexamethasone) in patients undergoing foot and ankle surgery.
Methods: Eighty patients undergoing foot and ankle surgery over a 9-month period were prospectively enrolled and randomized to receive a peripheral nerve block containing either a single anesthetic (SA) or one with 3 additives (TA). Patients, surgeons, and anesthesiologists were blinded to the groups. Patients maintained pain diaries and were evaluated at 1 and 12 weeks postoperatively. Fifty-six patients completed the study.
Results: The TA group had a longer duration of analgesic effect than the SA group (average 82 vs 34 hours, P < .05). Forty-eight hours after surgery, 93% of SA blocks, compared with 34% of TA blocks, had completely worn off. The TA group had a longer duration of sensory effects. At 3 months, 10 of 26 (38.5%) TA patients, compared with 3 of 30 (10%) SA patients, reported postoperative neurologic symptoms. Pain scores in both groups were not statistically different at 1 week or 3 months after surgery. Patients in both groups were similarly satisfied with their blocks.
Conclusion: Both types of nerve blocks provided equivalent pain control and patient satisfaction in patients undergoing foot and ankle surgery. The 3-additive agent blocks were associated with a longer duration of pain relief and a longer duration of numbness, as well as higher rates of postoperative neurologic symptoms. Longer pain relief may be obtained at the cost of prolonged sensory deficits.
Level of evidence: Level II, prospective comparative study.
Keywords: bupivacaine; buprenorphine; clonidine; dexamethasone; multimodal anesthesia; peripheral nerve block; regional anesthesia.