The use of a continuous popliteal sciatic nerve block after surgery involving the foot and ankle: does it improve the quality of recovery?

Abstract

Popliteal sciatic nerve block is a commonly used technique for surgery involving the foot and ankle. However, pain can be difficult to control as the local anesthetic block wears off. Therefore, we hypothesized that extending the block by using a continuous infusion of bupivacaine (0.25%) would provide improved pain management and might facilitate the recovery process after foot or ankle surgery. In this randomized, double-blinded, placebo-controlled study, 24 consenting patients undergoing foot or ankle surgery with a standardized general anesthetic technique were studied. Before surgery, a popliteal sciatic nerve block was performed in all patients with an 18-gauge Tuohy epidural needle and a peripheral nerve stimulator. After injection of bupivacaine 0.25% 30 mL and placement of a 20-gauge catheter, patients were randomly assigned to receive either 0.9% saline (control) or bupivacaine 0.25% at a constant rate of 5 mL/h for up to 48 h after surgery. An 11-point verbal rating scale (0 = no pain to 10 = worst pain imaginable) was used to assess the severity of pain. Opioid analgesic use was recorded at specific time intervals after surgery. Follow-up evaluations were performed at 24 h, 48 h, 72 h, and 1 week after surgery to assess pain scores, as well as patient satisfaction with their pain management and quality of recovery, by using a 100-point verbal rating scale (1 = highly dissatisfied to 100 = highly satisfied). In the bupivacaine group, there was a statistically significant reduction in the maximal pain scores (>50%) and in opioid use (>60%) during the postoperative period compared with the control group. Patient satisfaction with postoperative pain management (95 +/- 3 versus 77 +/- 13) and quality of recovery (96 +/- 7 versus 83 +/- 14) was significantly improved in the bupivacaine group (versus control). In addition, 40% of the patients in the bupivacaine group (versus none in the control group) were able to be discharged home on the day of surgery (P = 0.087). In conclusion, a continuous infusion of bupivacaine 0.25% decreased postoperative pain and the need for opioid analgesic rescue medication after orthopedic surgery involving the foot and ankle, leading to improved patient satisfaction and quality of recovery.

Implications: A continuous infusion of bupivacaine 0.25% (versus saline) at the popliteal fossa by using a simple elastomeric pump is an effective method of decreasing postoperative pain, reducing the opioid analgesic requirement, and increasing patient satisfaction with pain management after orthopedic surgery involving the foot and ankle. More importantly, the use of the continuous sciatic nerve block in the popliteal fossa facilitated an earlier discharge after lower extremity surgery.