Ultrasound Guidance for Lateral Midfemoral Sciatic Nerve Block: A Prospective, Comparative, Randomized Study

Abstract

Block of the sciatic nerve at the midfemoral level is usually performed using nerve stimulation techniques. We investigated the efficacy of ultrasound, combined with nerve stimulation, to locate and block the sciatic nerve at the lateral midfemoral level compared to nerve stimulation alone. Sixty-one patients scheduled for foot and ankle surgery were enrolled in this prospective, randomized study. Thirty patients underwent a lateral block of the sciatic nerve at the midfemoral level guided by ultrasound (group US) and 31 patients received the block without ultrasound (group ES). Once an adequate motor response was obtained using nerve stimulation, 35 mL of ropivacaine 0.5% was administered. The main end-points of the study were: number of attempts to obtain an adequate motor response, success rate of nerve location at the first attempt, quality and duration of both sensory and motor blocks, and anesthetic distribution. The success of sciatic nerve location at the first attempt was significantly more frequent in the US group than in the ES group (76.6% versus 41.9%; P < 0.001). The quality of the sensory block and the tolerance to the pneumatic tourniquet were also significantly better in the US group (P < 0.01). We conclude that ultrasound combined with nerve stimulation improved the quality of the sensory block and the tolerance to the pneumatic tourniquet, reducing the number of attempts to perform sciatic nerve block at the midfemoral level.

Can ultrasound-guided nerve block be a useful method of anesthesia for arthroscopic knee surgery?

“…The usefulness of regional nerve block under US guidance has been reported by several authors [2,5,6,12]. It has numerous advantages, such as precise targeting, less needle pain due to the short procedure duration, more rapid anesthesia, higher anesthesia success rate, fewer postoperative complications, and extended postoperative pain-free duration.…”

A review of approaches and techniques for lower extremity nerve blocks

“…50,59,60 Ultrasonography, in combination with neurostimulation, has been successfully used as an adjunct in one RCT pertaining to the lateral midfemoral approach. 55 Further RCTs are required to determine its role in other approaches. Finally, the best method for anesthesia of the posterior tibial nerve is a neurostimulation-guided injection around the medial malleolus.…”

“…In the second RCT, adjunctive neurostimulation was compared to neurostimulation combined with echoguidance. 55 In 61 patients undergoing foot and ankle surgery, Domingo-Triado et al 55 found that, with the combination of the two modalities, fewer attempts were required (1 vs 2; P = 0.001) and a denser sensory block was achieved (P = 0.01). However performance, onset and offset times were not significantly different between the two groups.…”

Comparison of femoral-sciatic nerve blocking in lower extremity orthopedic surgery combined with neurostimulation technique and ultrasound technique

“…Domingo-Triado ve ark. 'nın [16] , alt ekstremite cerrahisi uygulanan 61 hasta üzerine yapılan çalışmala-rında, ilk girişimde siyatik sinirin konumunu bulma başarıları karşılaştırılmış, ultrason grubundaki başarı, nörostimülator grubundakine göre istatistiksel olarak anlamlı derecede yüksek bulunmuş (%76.6 versus %41.9; p<0.001). Yine aynı çalışmada, duyusal blok kaliteleri karşılaştırılmış, ultrason grubunda nörostimülator grubuna göre istatistiksel olarak anlamlı derecede yüksek bulunmuş (p<0.001).…”