Continuous popliteal sciatic nerve block: an original technique to provide postoperative analgesia after foot surgery

Our study describes an original technique of continuous popliteal sciatic nerve block (CPSB) (Group A, 60 patients) and compares its analgesic efficacy after foot surgery with intramuscular (IM) opioids (Group B, 15 patients) and intravenous patient-controlled analgesia (IV PCA) with morphine (Group C, 45 patients). CPSB was performed using Singelyn's landmarks. The sciatic nerve was localized with a short-beveled needle connected to a peripheral nerve stimulator. A 20-gauge catheter was placed at the same depth as the needle with a Seldinger technique. Thirty milliliters of 1% mepivacaine with epinephrine 1/200,000 was injected and followed by a continuous infusion of 0.125% bupivacaine with sufentanil 0.1 microgram/mL and clonidine 1 microgram/mL at 7 mL/h for 48 h. Postoperative analgesia (intravenous [IV] propacetamol [PRO] and/or IM piritramide [DIPI]) was standardized. Postoperative pain score (PPS), supplemental analgesia, and side effects were noted. CPSB was easy to perform in 55 patients (92%). In Group A, highest and mean PPS were significantly lower, and the mean dose of PRO was reduced by 62% and 36% when compared with Group B and C, respectively. Only 8% of patients required postoperative opioid in Group A compared with 91% and 100% in Groups B and C, respectively. No immediate or delayed complications other than postoperative technical problems (kinked or broken catheter 25%) were noted in Group A. In conclusion, CPSB is easy to perform, safe, and a more efficient technique than parenteral opioid for providing postoperative analgesia after foot surgery.