Ultrasound vs nerve stimulation multiple injection technique for posterior popliteal sciatic nerve block

Abstract

SummaryIn this prospective, randomised, observer-blinded study we evaluated whether ultrasound guidance can shorten the onset time of popliteal sciatic nerve block as compared to nerve stimulation with a multiple injection technique. Forty-four ASA I-III patients undergoing posterior popliteal sciatic nerve block with 20 ml of 0.75% ropivacaine were randomly allocated to nerve stimulation or ultrasound guided nerve block. A blinded observer recorded onset of sensory and motor blocks, success rates, the need for fentanyl intra-operatively, the requirement for general anaesthesia, procedure-related pain, patient satisfaction and side-effects. Onset times for sensory and motor blocks were comparable. The success rate was 100% for ultrasound guided vs 82% for nerve stimulation (p = 0.116). Ultrasound guidance reduced needle redirections (p = 0.01), were associated with less procedural pain (p = 0.002) and required less time to perform (p = 0.002). Ultrasound guidance reduced the time needed for block performance and procedural pain. The multiple twitch technique is based on searching and identifying the targeted nerve by eliciting each nerve's motor component with nerve stimulation [1][2][3]. It has been associated with a reduction in sensory and motor block onset and a greater efficacy than a single injection technique [2]. Recently, ultrasound guidance has been introduced in order to improve the efficacy of peripheral nerve blocks, to shorten procedural time, to reduce the minimum local anaesthetic volume required for a successful block and to lower the incidence of complications and side-effects [4][5][6]. Ultrasound guidance may, theoretically, offer an advantage over conventional technique (anatomical landmarks and nerve stimulation) since it allows direct visualisation of nerve structures, needle pathway and local anaesthetic spread in real time [7,8]. Ultrasound guidance for upper limb nerve blocks has been showed to have a greater success rate than nerve stimulation alone and it also allowed a reduction in local anaesthetic dose for femoral nerve block [6]. While its role for proximal sciatic nerve block has been widely described [9], some authors still argue about the feasibility of ultrasound guidance for sciatic block at the popliteal fossa [10,11].We conducted a prospective, randomised, observerblinded study to test the hypothesis that ultrasound guidance can shorten the onset of posterior popliteal sciatic nerve block as compared with nerve stimulation guidance for nerve location when using the multiple injection technique. MethodsWith Local Ethics Committee approval (University of Parma, Parma, Italy) and written informed consent, 44 American Society of Anesthesiologist physical status 1-3 patients undergoing foot and ankle surgery were enrolled in the study in January-March, 2008. Patients with clinically significant coagulopathy, infection at injection site, allergy to local anaesthetics, severe cardiopulmonary disease, body mass index > 35 kg.m 2 , diabetes mellitus, or known neuropathies, as well a...

Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis

“…A total of 508 articles were rejected for the following reasons: 448 did not evaluate ultrasound-guided nerve blocks in surgical procedures, 30 were not RCTs, 24 did not compare ultrasound alone versus control, 5 did not assess upper or lower extremity single-shot nerve blocks, and one did not assess surgical success rate. Table 1 provides a detailed overview of the studies included in the analysis [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Fig.…”

A randomised comparison between ultrasound and nerve stimulation for infraclavicular catheter placement

“…In their recent systematic review, Munirama and McLeod [15] reported no difference in postoperative neurological side effects, though they reported a reduced incidence of analgesic or anaesthetic rescue in the ultrasound group. Other authors have demonstrated comparable onset times and success rates with ultrasound and nerve stimulation guidance in other types of blocks [16]. Various cited studies in a review by Griffin and Nicholls showed faster onset times for ultrasoundguided nerve blocks in different locations [17].…”

Our Experience in Plexus Brachialis Block Using Ultrasonography and Nerve Stimulator

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