SLR - September 2015 - Brett C. Chatman

Ultrasound-Guided Single-Penetration Dual-Injection Block For Leg and Foot Surgery: A Prospective, Randomized, Double-Blind Study

Reference: Børglum J, Johansen K, Christensen MD, Lenz K, Bendtsen TF, Tanggaard K, Christensen AF, Moriggl B, Jensen K. Ultrasound-guided Single-penetration Dual-injection Block for Leg and Foot Surgery: A Prospective, Randomized, Double-blind Study. Reg Anesth Pain Med. 2014 Jan-Feb;39(1):18-25.

Scientific Literature Review

Reviewed By: Brett C. Chatman, DPM
Residency Program: Washington Hospital Center

Podiatric Relevance: Complete anesthesia and analgesia of the leg, ankle and foot is often needed during complex foot and ankle surgery. Achieving this level of anesthesia can often lead to extended OR time, delayed cases, and inconvenient positioning techniques. The standard popliteal-sciatic approach utilized for podiatric surgery necessitates repositioning of the leg and often time causes pain to the injured leg of the patient. It also requires an extra injection for the saphenous nerve increasing the total performance time of the block. This article describes a new approach to blocking the sciatic and saphenous nerves using a single-penetration dual injection (SPEDI) technique. The overall aim of the study was to evaluate and see if this new technique would be an effective alternative and a possibly faster method for regional anesthesia before podiatric surgical intervention. This new technique would require one skin penetration in the proximal anterior thigh followed by two injections at different depths to deposit local anesthesia around the Sciatic and Saphenous nerves. This technique would not require repositioning of the patient and could potentially be significantly faster than the traditional popliteal block.

Methods: The study was conducted as a prospective, randomized, double-blind trial consisting of sixty patients undergoing leg and foot surgery under general anesthesia. The primary outcome measure was performance time. Positioning time, pain assessment, nausea in the post anesthesia care unit, sufentanil demand, dermatomal anesthesia, and degree of motor blockade were also recorded. Fifteen mL of ropivacaine 0.75 percent around the sciatic nerve and 5 mL of ropivacaine 0.75 at the saphenous nerve. Patients were randomized to the popliteal-sciatic/saphenous technique or the SPEDI technique and the blinding process was rigidly ensured at all times.

Results: Thirty patients were included in each group. Performance time was significantly faster with the SPEDI technique (median time, 110 seconds) vs. 246 seconds; (P < 0.0001). Positioning time was significantly shorter with the SPEDI technique (P < 0.0001). There were no other statistically significant differences recorded for pain assessment, nausea in the post anesthesia care unit, sufentanil demand, dermatomal anesthesia, and degree of motor blockade.

Conclusions: The SPEDI block is statistically an equally effective, faster, single penetration alternative to the traditional popliteal-sciatic/saphenous block combination in achieving complete anesthesia and analgesia of the leg, ankle and foot. This study found that the SPEDI block resulted in significantly faster performance time and reduced positioning time with statistically equal efficacy in relation to pain assessment, nausea, sufentanil demand, dermatomal anesthesia, and motor blockade. The authors also found that the SPEDI block was especially useful in podiatric surgical emergencies consisting of dislocated fractures of the ankle and foot where elevation of the leg or turning the patient in the lateral or prone position is contraindicated or extremely painful for the patient. 

Educational Opportunities