Lateral Popliteal Nerve Block Research Articles

A 3-Dimensional Ultrasound Study of Local Anesthetic Spread During Lateral Popliteal Nerve Block

Recent clinical trials suggest that subfascial (sometimes termed subepineural) injections result in faster block onset and success compared with conventional techniques. This prospective, randomized, observer-blinded study measured and compared the 3-dimensional spread pattern and volume of perineural local anesthetic (LA) in contact with the sciatic nerve after subfascial versus extrafascial lateral popliteal injections. Sixty patients were randomly assigned to either the subfascial or the extrafascial injection group. All patients received a single-injection, US-guided lateral popliteal sciatic nerve block for postoperative pain. Depending on group assignment, the needle tip was placed outside or beneath the sciatic fascial sheath for a single injection of 30 mL of ropivacaine 0.5%. Using 3-dimensional ultrasound imaging, postblock scans were acquired to quantify the volume and spread pattern of perineural LA around the sciatic nerve in each group. The mean LA perineural volume for the extrafascial group was 1.48 (SD, 0.50) mL versus a mean of 5.57 (SD, 1.68) mL for the subfascial group, P < 0.05. The mean distance of longitudinal perineural LA spread (along the length of the nerve) for the subfascial group was 66% greater than that observed using the conventional technique (9.3 vs 5.6 cm, P < 0.01). Complete sensory block to pinprick for the extrafascial group was 63% versus 90% (P < 0.05) for the subfascial group. Placement of the needle tip beneath the complex fascial sheath of the sciatic nerve resulted in significantly greater perineural local anesthetic volume following a single-injection lateral popliteal approach at the nerve bifurcation and was associated with greater sensory blockade and a characteristic laminar LA spread pattern.

Preoperative Lateral Popliteal Nerve Block for Intraoperative and Postoperative Pain Control in Elective Foot and Ankle Surgery: A Prospective Analysis

Limiting postoperative pain and minimizing systemic narcotic complications are important considerations in foot and ankle surgery to maximize patient comfort and promote early discharge from the hospital. Nerve blocks are valuable additions to perioperative care. A variety of nerve blocks have been advocated, but few reports have evaluated a preoperative supine approach for popliteal block in foot and ankle surgery. We prospectively evaluated the effectiveness of a preoperative popliteal block in 25 consecutive patients undergoing a variety of foot and ankle procedures, as well as the length of block coverage, patient satisfaction, and any complications. Patients were monitored clinically and by a questionnaire at various time increments: preoperatively, in the post-anesthesia care unit (PACU), postoperative day one, and postoperative week one. Postoperatively, 15 of 25 patients had a complete block (motor and sensory), five of 25 patients demonstrated motor function, but denied sensation or pain, and the remaining five of 25 had sensation to light touch but no motor function or pain. None of the patients reported pain postoperatively in the PACU within an hour after surgery. The average time the block lasted was 14 hours. Overall satisfaction with the block on postoperative day one and week one was 4.8 out of 5. There were no intraneural injections, neurologic sequelae, or complications. We suggest that a preoperative nerve block for a sedated patient in the operating room saves time, avoids patient discomfort, augments general anesthesia, provides good postoperative pain control, and has high patient satisfaction with no significant complications.

Lateral Trans-Biceps Popliteal Block for Elective Foot and Ankle Surgery Performed after Induction of General Anesthesia

The purpose of this study was to determine safety and efficacy of lateral transtendinous popliteal blocks performed after induction of general anesthesia for intraoperative and postoperative pain control in elective foot and ankle surgery. The charts of 475 consecutive patients were retrospectively reviewed. The technique was a lateral transtendinous popliteal block under nerve stimulator direction (described in the text). Patient records were retrospectively evaluated from the postanesthesia care unit, as well as at followup on postoperative day 1 and weeks 2, 6, and 12. The block was complete in 398 patients (83.7%). An incomplete block was found in 77 patients (16.2 %). In the incomplete category, 21 patients (4.4%) had no pain but some motor function, 32 patients (6.5%) reported mild to moderate pain, and 24 patients (5.3%) had severe pain. The average block duration was 16.5 hours. There were no adverse effects documented in any patient at followup. Lateral popliteal nerve block after induction of general anesthesia appears to be safe and effective for intraoperative and postoperative pain control in elective foot and ankle surgery.

No Differences Between 20, 30, or 40 mL Ropivacaine 0.5% in Continuous Lateral Popliteal Sciatic-Nerve Block

The aim of this study was to compare the anesthetic and analgesic characteristics of the administration of an initial bolus of 20, 30, or 40 mL of ropivacaine 0.5% through a lateral popliteal sciatic catheter. Sixty patients scheduled for foot surgery under continuous sciatic lateral popliteal nerve block were included in this double-blinded study. Patients were randomly assigned to 1 of 3 groups: 20 mL, 30 mL, or 40 mL of ropivacaine 0.5%. Time to obtain a complete sensory block and duration of analgesia were recorded. Failure of the continuous block and complications such as technical or neurologic problems were noted. Data are presented as mean +/- SD, median and ranges, or percent of patients and were compared by application of analysis of variance or Kruskal-Wallis when required. Time to complete sensory block (31 [10-70] v 25 [5-50] v 25 [5-40] min), percentage of failure (5% v 5% v 0%), and duration of action (995 [278-1,800] v 967 [420-2,175] v 915 [190-1,900] min) were not statistically different between 20 mL, 30 mL, and 40 mL ropivacaine 0.5% groups, respectively. No complications were noted. This dose-response study shows that 20 mL of ropivacaine 0.5% injected through an indwelling lateral popliteal catheter is the optimal dose for foot surgery. Higher doses of 30 mL or 40 mL did not provide any further advantage.

98: Lateral popliteal nerve block with ultrasound guidance in children: our initial experience

98: Lateral popliteal nerve block with ultrasound guidance in children: our initial experience

Lateral popliteal nerve block with ultrasound guidance

Lateral popliteal nerve block with ultrasound guidance

Lateral approach to the sciatic nerve in the popliteal fossa: a comparison between 1.5% mepivacaine and 0.75% ropivacaine

Background and Objectives: Ropivacaine and mepivacaine are commonly used local anesthetics for peripheral nerve blockade. The purpose of the present study was to compare onset time, quality of anesthesia, and duration of analgesia with ropivacaine 0.75% and mepivacaine 1.5% for lateral popliteal nerve block. Methods: Fifty American Society of Anesthesiologists (ASA) physical status I or II patients scheduled for foot and ankle surgery with calf tourniquet under lateral popliteal sciatic nerve block were randomly assigned to receive 30 mL of either ropivacaine 0.75% or mepivacaine 1.5%. Time required for onset of sensory and motor block, resolution of motor blockade, onset of postsurgical pain, and time of first analgesic medication were recorded. Results: The 2 groups were similar with regard to demographic variables and duration of surgery. Onset of sensory and motor block was significantly shorter in the mepivacaine group (9.9 ± 3.3 min and 14.7 ± 3.6 min, respectively) than in the ropivacaine group (18.1 ± 6.1 min and 23.6 ± 5.5 min, respectively) ( P < 0.001). Resolution of motor block occurred later in the ropivacaine group than in the mepivacaine group ( P < 0.001), and duration of postoperative analgesia was significantly longer in the ropivacaine group (19 ± 3.4 h) compared with the mepivacaine group (5.9 ± 1.1 h) ( P < 0.001). Analgesic requirements were higher in mepivacaine group than in the ropivacaine group ( P < 0.001). There were 2 failed blocks, one in each group. Conclusions: Both ropivacaine and mepivacaine provided effective sciatic nerve blockade. Mepivacaine 1.5% displayed a significantly shorter onset time than ropivacaine 0.75%. Postoperatively, ropivacaine 0.75% resulted in longer-lasting analgesia and less need for oral pain medication.