Continuous Popliteal Sciatic Nerve Block Research Articles

Case report of anesthesia for free fibula flap reconstruction in Ewing sarcoma: Safety and efficacy of continuous popliteal sciatic nerve block and very low doses of intravenous heparin

A child with a maxillary Ewing sarcoma was operated for tumor asportation and reconstruction with free fibula flap. Adequate anticoagulation was achieved with lower doses of heparin and monitored with multiple ACT values. We used NIRS monitoring to avoid hypoperfusion. Post‐operative pain relief was guarantited by local anestethic continous infusion.

Color Doppler ultrasonography of an agitated solution is predictive of accurate catheter placement for a continuous popliteal sciatic nerve block

BackgroundContinuous peripheral nerve catheters (PNCs) have been shown to provide superior postoperative analgesia, decrease opioid consumption, and improve patient satisfaction compared with single injection techniques. In order to achieve success and reliability, accurate catheter positioning is an essential element of PNC placement. An agitated solution of normal saline, D5W, or a local anesthetic solution can be produced by the introduction of air to the injectate, creating air bubbles that can enhance ultrasonographic visualization and possibly improve block success.MethodsEighty-three patients were enrolled. Ultrasound-guided continuous popliteal sciatic nerve blocks were performed by positioning the tip of a Tuohy needle between the tibial and common peroneal branches of the sciatic nerve and threading a catheter. An agitated local anesthetic solution was injected through the catheter, viewed with color Doppler ultrasound and video recorded. A peripheral block score (lower score = greater blockade, range 0-14) was calculated based upon the motor and sensory testing at 10, 20, and 30 min after block completion. The color Doppler agitation coverage pattern for the branches of the sciatic nerve was graded as follows: complete (> 50%), partial (> 0%, ≤ 50%), or none (0%).ResultsThe degree of nerve blockade at 30 min as judged by median (10th, 90th percentile) peripheral block score was significant for partial or complete color Doppler coverage of the sciatic nerve injectate compared to no coverage [3 (0, 7) vs 8 (4, 14); p < 0.01] and block onset was faster (p = 0.03). The block success was higher in groups with partial or complete coverage of the branches of the sciatic nerve vs no coverage (96% vs 70%; p = 0.02).ConclusionsInjection of an agitated solution through a popliteal sciatic perineural catheter is predictive of accurate catheter placement when partial or complete coverage of the sciatic nerve branches is visualized with color Doppler ultrasound.Trial registrationNCT01591603

Mean effective volume of local anesthetics by nerve conduction technique

BackgroundThis study aimed to investigate whether nerve conduction could be used to objectively evaluate mean effective volume of 1.5% lidocaine after subparaneural or extraparaneural injection.MethodsTwenty patients undergoing unilateral foot or ankle surgery were randomized into either subparaneural or extraparaneural injection group, and ultrasound-guided continuous popliteal sciatic nerve block was performed. The action potential amplitude of the distal gastrocnemius muscle was monitored. The time of anesthesia onset and dosage of lidocaine were recorded when amplitude declined to 0.5 mV. The operative analgesic effect, score of numeric rating scales, patient’s satisfaction, and movement or sensation were recorded during or after surgery.ResultsPreoperative dose of local anesthetics (10.7±1.6 vs. 16.2±1.2 mL) and the time of onset (19.4±3.3 vs. 30.4±2.5 min) reduced significantly in the subparaneural group (P<0.05). The intra-operative analgesic effect (1.2±0.422 vs. 1.3±0.483) and the score of resting numeric rating scales (0.6±1.0 vs. 1.9±2.1 and 0.4±0.7 vs. 1.2±1.1) 24 and 48 h after surgery were comparable between groups, but the subparaneural group had markedly lower scores of activity numeric rating scales (0.3±0.6 vs. 2.1±2.0, 0.7±1.2 vs. 2.2±1.9 and 0.5±0.8 vs. 1.5±1.2) at 6, 24 and 48 h, and significantly higher satisfaction (9.7±0.5 vs. 8.8±0.8) (P<0.05). There were no obvious symptoms of movement or sensation within 3 days in two groups.ConclusionsThe nerve conduction can be used to objectively evaluate the mean effective volume of 1.5% lidocaine in different injection groups, and subparaneural injection has more advantages as compared to extraparaneural injection for continuous popliteal sciatic nerve block.

Effect of Intraoperative Sedation with Dexmedetomidine Versus Propofol on Acute Postoperative Pain Following Major Foot Surgery under Popliteal Sciatic Nerve Block: A Randomized Controlled Trial.

Intravenous (IV) dexmedetomidine is reported to prolong analgesia following peripheral nerve blocks. Popliteal sciatic nerve block provides effective postoperative analgesia, but some patients still experience severe pain during the early postoperative period. We aimed to evaluate the postoperative analgesic effects of IV dexmedetomidine versus propofol in patients undergoing foot surgeries under popliteal sciatic nerve block. Forty patients were enrolled and randomly assigned to receive either IV propofol (n = 20) or IV dexmedetomidine (n = 20) for intraoperative sedation. All the patients received continuous popliteal sciatic nerve block. The corresponding drug infusion rate was adjusted to achieve a modified observer’s assessment of alertness/sedation score of 3 or 4. The primary outcome was postoperative cumulative opioid consumption during the first 24 h after surgery. Thirty-nine patients were analyzed. The median (interquartile ranges) postoperative cumulative opioid consumption during the first 24 h after surgery was significantly lower in the dexmedetomidine group (15 (7.5–16.9) mg) than in the propofol group (17.5 (15–25) mg) (p = 0.019). The time to first rescue analgesic request was significantly greater in the dexmedetomidine group than in the propofol group (11.8 ± 2.2 h vs. 10.0 ± 2.7 h, p = 0.030) without the prolonged motor blockade (p = 0.321). Intraoperative sedation with dexmedetomidine reduced postoperative opioid consumption and prolonged analgesic duration after a popliteal sciatic nerve block.

Suture-method versus Through-the-needle Catheters for Continuous Popliteal-sciatic Nerve Blocks

The basic perineural catheter design has changed minimally since inception, with the catheter introduced through or over a straight needle. The U.S. Food and Drug Administration recently cleared a novel perineural catheter design comprising a catheter attached to the back of a suture-shaped needle that is inserted, advanced along the arc of its curvature pulling the catheter past the target nerve, and then exited through the skin in a second location. The authors hypothesized that analgesia would be noninferior using the new versus traditional catheter design in the first two days after painful foot/ankle surgery with a primary outcome of average pain measured with the Numeric Rating Scale. Subjects undergoing painful foot or ankle surgery with a continuous supraparaneural popliteal-sciatic nerve block 5 cm proximal to the bifurcation were randomized to either a suture-type or through-the-needle catheter and subsequent 3-day 0.2% ropivacaine infusion (basal 6 ml/h, bolus 4 ml, lockout 30 min). Subjects received daily follow-up for the first four days after surgery, including assessment for evidence of malfunction or dislodgement of the catheters. During the first two postoperative days the mean ± SD average pain scores were lower in subjects with the suture-catheter (n = 35) compared with the through-the-needle (n = 35) group (2.7 ± 2.4 vs. 3.4 ± 2.4) and found to be statistically noninferior (95% CI, -1.9 to 0.6; P < 0.001). No suture-style catheter was completely dislodged (0%), whereas the tips of three (9%) traditional catheters were found outside of the skin before purposeful removal on postoperative day 3 (P = 0.239). Suture-type perineural catheters provided noninferior analgesia compared with traditional catheters for continuous popliteal-sciatic blocks after painful foot and ankle surgery. The new catheter design appears to be a viable alternative to traditional designs used for the past seven decades.

Intermittent bolus versus continuous infusion popliteal sciatic nerve block following major foot and ankle surgery: a prospective randomized comparison

Background and objectivesFoot and ankle surgery is associated with severe pain that can be reduced with continuous popliteal sciatic nerve block. We tested the hypothesis that programmed intermittent bolus (PIB)...

Two different placement paths in popliteal fossa with a novel nerve block needle for postoperative analgesia after foot and ankle surgery.

Previous studies have documented that single injection nearby the sciatic nerve bifurcation would influence the anesthesia and analgesia effect. But this is uncertain for preoperative continuous popliteal sciatic nerve block. This trial was conducted to compare two paths (proximal to the bifurcation and at the bifurcation) of ultrasound-guided continuous popliteal sciatic nerve block in foot and ankle surgery. Forty recruited objects were randomly assigned to receive ultrasound-guided continuous popliteal sciatic nerve block at the puncture path proximal to the nerve bifurcation either at the nerve bifurcation. Subjects received an injection using a novel nerve block needle with external indwelling cannula guided by ultrasound invented by the corresponding author. The external indwelling cannula was inserted for postoperative analgesia. The primary outcome was NRS scores (at rest and during movement) times at 24 hours after surgery. The secondary outcomes included the measurements related to the performance of the nerve block and efficacy of analgesia, such as anesthesia effect grade, grade of nausea and vomiting, case number of patients with cannula leaking, occlusion or slipping, patient satisfaction, etc. RESULTS: During the surgery, six subjects in the proximal group needed additional analgesic, significantly different from one in the at bifurcation group (P<0.05). There was significant difference on anesthesia effect rating, 1.6±0.8 in the proximal group and 1.1±0.4 in another (P<0.05). The proximal group got 2.1±1.6 of NRS on rest at 24 hours and 1.7±1.5 at 48 hours, and the at bifurcation group got 0.9±1.4 at 24 hours and 0.7±1.1 at 48 hours (P<0.05). The proximal group got more PCA times during 6-24 hours and 24-48 hours and lower satisfaction scores. Continuous popliteal sciatic nerve block at nerve bifurcation could receive better analgesia effect and more patients' satisfaction, rather than proximal to the bifurcation.

Liposomal Bupivacaine versus Continuous Popliteal Nerve Block in Total Ankle Arthroplasty

Category: Ankle, Ankle Arthritis Introduction/Purpose: The use of liposomal bupivacaine (LB) has recently gained popularity in joint arthroplasty. Despite it’s proven safety and efficacy, there is little reported on the use of LB in foot and ankle surgery. Catheter placement for a continuous popliteal sciatic nerve block (CPSNB) has an excellent track record for pain relief, and is commonly used by our group for major foot and ankle reconstructions. The purpose of this study was to compare the use of intraoperative LB injection to CPSNB as a regional anesthetic for total ankle arthroplasty (TAA), with attention to postoperative pain scores, narcotic use, and complications. Methods: Retrospective review of TAA patients treated by two fellowship-trained orthopedic foot and ankle surgeons was performed. Patient demographic data, operative, and postoperative details were collected, including type of regional anesthetic used. Patient’s received either preoperative single-shot popliteal sciatic nerve block with 0.25% bupivacaine followed by intraoperative injection of LB, or preoperative CPSNB alone. Outcomes examined were VAS pain score at 8 hours, 24 hours, 1 week, and 3 weeks following surgery, need for opioid pain medication refill, physician office notification for pain issues or other adverse events, and complications within the first 90 days following surgery. Standard statistical analysis was performed and p &lt; 0.05 was considered significant. Results: 75 patients were identified who underwent TAA and met inclusion criteria. 41 received LB and 34 received CPSNB. No statistical difference was seen between groups with regard to complications, emergency department visits, readmissions, reoperations, VAS pain score at any time point, physician office contacts, and narcotic refills. Mean VAS with LB use was 1.8, 3.5, 2.6, and 2.2 at 8 hours, 24 hours, 1 week, and 3 weeks respectively, compared with mean VAS 2.1, 3.2, 2.2, and 1.9 at similar time points for CPSNB (p=0.59, 0.65, 0.27, and 0.40, respectively). 16 of 41 LB patients needed narcotic refills, versus 12 of 34 CPSNB patients (p=0.81). 3 of 41 LB patients had a complication postoperatively, versus 4 of 34 CPSNB patients. Conclusion: This is the first study evaluating the use of LB for total ankle arthroplasty. LB was both safe and effective for postoperative pain control, with comparable results to CPSNB. As LB gains more widespread use in foot and ankle surgery, further investigation is warranted to determine potential unseen complications and cost-effectiveness.

Continuous Popliteal Sciatic Blocks: Does Varying Perineural Catheter Location Relative to the Sciatic Bifurcation Influence Block Effects? A Dual-Center, Randomized, Subject-Masked, Controlled Clinical Trial

Multiple studies have demonstrated that, for single-injection popliteal sciatic nerve blocks, block characteristics are dependent upon local anesthetic injection relative to the sciatic nerve bifurcation. In contrast, this relation remains unexamined for continuous popliteal sciatic nerve blocks. We, therefore, tested the hypothesis that postoperative analgesia is improved with the perineural catheter tip at the level of the bifurcation compared with 5 cm proximal to the bifurcation. Preoperatively, subjects having moderately painful foot or ankle surgery were randomly assigned to receive an ultrasound-guided subepimyseal perineural catheter inserted either at or 5 cm proximal to the sciatic nerve bifurcation. Subjects received a single injection of mepivacaine 1.5% either via the insertion needle preoperatively or the perineural catheter postoperatively, followed by an infusion of ropivacaine 0.2% (6 mL/h basal, 4 mL bolus, and 30-min lockout) for the study duration. The primary end point was the average pain measured on a numeric rating scale (0-10) in the 3 hours before a data collection telephone call the morning after surgery. The average numeric rating scale of subjects with a catheter inserted at the sciatic nerve bifurcation (n = 64) was a median (10th, 25th to 75th, and 90th quartiles) of 3.0 (0.0, 2.4-5.0, and 7.0) vs 2.0 (0.0, 1.0-4.0, and 5.0) for subjects with a catheter inserted proximal to the bifurcation (n = 64; P = 0.008). Similarly, maximum pain scores were greater in the group at the bifurcation: 6.0 (3.0, 4.4-8.0, and 9.0) vs 5.0 (0.0, 3.0-8.0, and 10.0) (P = 0.019). Differences between the groups for catheter insertion time, opioid rescue dose, degree of numbness in the foot/toes, catheter dislodgement, and fluid leakage did not reach statistical significance. For continuous popliteal sciatic nerve blocks, a catheter inserted 5 cm proximal to the sciatic nerve bifurcation provides superior postoperative analgesia in subjects having moderately painful foot or ankle surgery compared with catheters located at the bifurcation. This is in marked contrast with single-injection popliteal sciatic nerve blocks for which benefits are afforded to local anesthetic injection distal, rather than proximal, to the bifurcation.

A randomized, triple-masked, active-controlled investigation of the relative effects of dose, concentration, and infusion rate for continuous popliteal-sciatic nerve blocks in volunteers

It remains unknown whether local anaesthetic dose is the only factor influencing continuous popliteal-sciatic nerve block effects, or whether concentration, volume, or both exert an influence as well. Bilateral sciatic catheters were inserted in volunteers (n=24). Catheters were randomly assigned to ropivacaine of either 0.1% (8 ml h(-1)) or 0.4% (2 ml h(-1)) for 6 h. The primary endpoint was the tolerance to transcutaneous electrical stimulation within the tibial nerve distribution at hour 6. Secondary endpoints included current tolerance at other time points and plantar flexion maximum voluntary isometric contraction (22 h total). At hour 6, tolerance to cutaneous stimulation for limbs receiving 0.1% ropivacaine was [mean (standard deviation)] 27.0 (20.2) vs26.9 (20.4) mA for limbs receiving 0.4% [estimated mean difference 0.2 mA; 90% confidence interval (CI) -8.2 to 8.5; P=0.02 and 0.03 for lower and upper boundaries, respectively]. Because the 90% CI fell within the prespecified tolerance ±10 mA, we conclude that the effect of the two concentration/volume combinations were equivalent. Similar negative findings were found for the secondary outcomes. For continuous popliteal-sciatic nerve blocks, we found no evidence that local anaesthetic concentration and volume influence block characteristics, suggesting that local anaesthetic dose (mass) is the primary determinant of perineural infusion effects in this anatomic location. These findings suggest that for ambulatory perineural local anaesthetic infusion-for which there is usually a finite local anaesthetic reservoir-decreasing the basal rate while increasing the local anaesthetic concentration may allow for increased infusion duration without compromising postoperative analgesia. NCT01898689.

Safety and effectiveness of bilateral continuous sciatic nerve block for bilateral orthopaedic foot surgery

Severe postoperative pain is a major problem after unilateral and bilateral foot surgery. Continuous regional anaesthesia is often used for unilateral surgery. However, for bilateral surgery, the incidence of complications of continuous bilateral compared with unilateral regional anaesthesia is unknown. To assess the incidence of catheter-related complications of bilateral compared with unilateral continuous regional anaesthesia. A prospective observational study. Bellinzona Regional Hospital, a tertiary teaching hospital. Patients (n = 130) scheduled for elective bilateral or unilateral hallux valgus repair treated with continuous popliteal sciatic nerve block using a continuous infusion of ropivacaine 0.15% at 5 ml h for each popliteal catheter by elastomeric pumps. The incidence of catheter-related complications, effectiveness, pain levels at rest and with motion, patient satisfaction for the first three postoperative days and the incidence of ambulatory visits or readmissions after discharge were measured. A follow-up for neurological or other complications related to regional anaesthesia was performed 6 to 8 weeks after surgery. The incidence of catheter-related complications comparing bilateral with unilateral continuous sciatic popliteal nerve block. There were no differences in the incidence of catheter-related complications between the groups. Pain scores at rest and with motion were comparable between the groups. All patients were fit for discharge home 3 days after surgery. Patient satisfaction was similar between the groups. There were no unplanned ambulatory visits or readmissions due to complications in either group. No complications related to regional anaesthesia were reported during the follow-up. The complication rate, effectiveness and patient satisfaction of bilateral continuous popliteal sciatic nerve block was comparable with unilateral continuous sciatic popliteal nerve block. The follow-up showed that bilateral continuous sciatic popliteal nerve block does not increase the complication rate. However, an outpatient-based study should confirm these data prior to introduction in the ambulatory setting.

Chronic pain 1 year after foot surgery: Epidemiology and associated factors

BackgroundMost studies of chronic postoperative pain focussed on major surgical procedures. Chronic postoperative pain occurred in 10% to 50% of patients and exhibited neuropathic features in 5% to 68% of cases. The objectives of this prospective single-centre study were to determine the rates of occurrence and associated factors of any chronic pain and of neuropathic chronic pain 1year after orthopaedic surgery on the foot. MethodsWe included consecutive patients who underwent scheduled orthopaedic surgery on the foot or ankle at a university hospital centre between 2009 and 2011. All patients received a multimodal analgesia regimen that usually combined a continuous popliteal sciatic nerve block, paracetamol, and ketoprofen, with additional ketamine if deemed appropriate. A telephone interview was conducted 1year after the surgical procedure. The main outcome measures were moderate-to-severe pain (numerical rating scale score>3/10) 1year after surgery at rest and during walking, and presence of neuropathic pain (defined using the DN2 score). Multivariate analysis was performed to look for associations of various perioperative clinical variables with pain. ResultsOne year after surgery, 55 of 260 (21%) patients reported moderate-to-severe pain at rest, 111 (43%) moderate-to-severe pain during walking, and 9 (3%) neuropathic pain. By multivariate analysis, factors independently associated with moderate-to-severe pain at rest and/or during walking 1year after surgery were moderate-to-severe pain during the first postoperative night (P=0.048) and/or day (P=0.043) and revision surgery (P=0.001). DiscussionThe rate of occurrence of moderate-to-severe pain 1year after orthopaedic foot surgery is similar to that seen after major surgical procedures, whereas neuropathic pain seems rare. Orthopaedic surgery on the ankle or hindfoot is not more likely to be followed by chronic pain compared to surgery for hallux valgus or toe abnormalities. There is some evidence that earlier surgery might be beneficial. Level of evidenceIV, prospective observational longitudinal cohort study.

The effect of continuous popliteal sciatic nerve block on unplanned postoperative visits and readmissions after foot surgery – a randomised, controlled study comparing day‐care and inpatient management

Regional anaesthesia has been shown to have several advantages over general anaesthesia in reducing the need for, and hence cost of, unscheduled outpatient visits or readmission to hospital. However, the benefit has not been evaluated in a direct comparison between day-care patients and inpatients. We randomly allocated 120 patients undergoing unilateral foot surgery to either inpatient (two-day postoperative stay) or day-care management under continuous regional anaesthesia, and compared the impact on unscheduled postoperative outpatient visits, readmissions to hospital and the associated costs. The operations were performed under popliteal sciatic nerve block. A perineural catheter was inserted before surgery and removed from all patients on the third postoperative day. We found no significant difference in the incidence of outpatient visits (3.3% day-care vs 5.0% inpatient, p=0.640), readmissions (6.7% day-care vs 3.3% inpatient, p=0.395) or complications between the two groups. Costs were also significantly lower in the day-care group (net difference €8011 (£6684; $10 986) per patient, p<0.001). We conclude that continuous regional anaesthesia allows foot surgery to be performed as a day-care procedure more cheaply than in inpatients, without an increase in clinical complications.

The Efficacy and Safety of Continuous Popliteal Sciatic Nerve Block for the Relief of Pain Associated with Critical Limb Ischemia: A Retrospective Study

Background: Patients with critical limb ischemia (CLI) often suffer from severe pain. A continuous peripheral nerve block has been shown to provide effective analgesia for patients having lower limb surgery. We have been administering continuous sciatic nerve block (CSNB) for patients with CLI whose pain could not be relieved by other analgesic tools. The aim of this retrospective study was to investigate the efficacy and safety of CSNB for patients with CLI. Method: We retrospectively investigated 99 patients who received CSNB for the relief of severe pain in the lower limb associated with CLI. Patient demographics, neurological history, complications, and subjective evaluation of the effectiveness of CSNB were investigated from their clinical records. The distal tips of 108 catheters were cultured. Result: One hundred and seventy-two catheters were placed in 99 patients. More than 90% of the patients enjoyed considerable relief of severe pain. The analgesic effect of CSNB was greater in patients with older age and hemodialysis. Thirty-one catheters had positive bacterial colonization. However, no severe infectious complication was found. There was no relationship between the co-existence of diabetes and positive bacterial colonization. We encountered a patient with ASO and diabetes who suffered from persistent motor weakness and hypesthesia even after 3 months of CSNB placement. Conclusions: CSNB provided good pain control for patients with severe pain caused by CLI. Although catheters were frequently found to be colonized, infection at the catheter site was self-limiting even in patients with diabetes.

Ultrasound Guidance Improves a Continuous Popliteal Sciatic Nerve Block When Compared With Nerve Stimulation

Continuous sciatic nerve blockade at the popliteal level effectively alleviates postoperative pain after major foot and ankle surgery. No randomized controlled trials have previously compared the success rate of continuous sciatic nerve sensory blockade between ultrasound and nerve stimulation guidance. In the current study, we tested the hypothesis that ultrasound-guided catheter placement improves the success rate of continuous sciatic nerve sensory blockade compared with catheter placement with nerve stimulation guidance. After research ethics committee approval and informed consent, 100 patients scheduled for elective major foot and ankle surgery were randomly allocated to popliteal catheter placement either with ultrasound or nerve stimulation guidance. The primary outcome was the success rate of sensory block the first 48 postoperative hours. Successful sensory blockade was defined as sensory loss in both the tibial and common peroneal nerve territories at 1, 6, 24, and 48 hrs postoperatively. The ultrasound group had significantly higher success rate of sensory block compared with the nerve stimulation group (94% versus 79%, P=0.03). Ultrasound compared with nerve stimulation guidance also entails reduced morphine consumption (median of 18 mg [range, 0-159 mg] versus 34 mg [range, 0-152 mg], respectively, P=0.02), fewer needle passes (median of 1 [range, 1-6] versus 2 [range, 1-10], respectively, P=0.0005), and greater patient satisfaction (median numeric rating scale 9 [range, 5-10] versus 8 [range, 3-10)] respectively, P=0.0006) during catheter placement. Ultrasound guidance used for sciatic catheter placement improves the success rate of sensory block, number of needle passes, patient satisfaction during catheter placement, and morphine consumption compared with nerve stimulation guidance.

Perisciatic infusion of ropivacaine and analgesia after hallux valgus repair

Moderate to severe pain after hallux valgus repair can be successfully treated with a continuous popliteal sciatic nerve block in ambulatory patients. Different anesthesiologists use various infusion rates for this purpose. The aim of this study was to compare the analgesic efficacy of two infusion rates of ropivacaine 2 mg/ml: 5 and 8 ml/h. Forty ambulatory patients who underwent chevron osteotomy for hallux valgus were randomized to receive perisciatic infusion of ropivacaine 2 mg/ml at a rate of either 5 ml/h (5 ml group) or 8 ml/h (8 ml group). All patients received standard general anesthesia for surgery after the sciatic popliteal and the single-shot saphenus nerve blocks were performed. Verbal rating scale (VRS) scores for pain, sleep disturbances, opioid consumption and side effects were monitored for 3 post-operative days. No significant difference was found in the primary end point worst pain on the first post-operative day with VRS scores of 2.5 (0-8) vs. 5.5 (0-10) for the 5 and 8 ml/h groups, respectively (P=0.53). Post-operative pain was satisfactory in both groups, with an average VRS score ≤4 for 60-62 h. We found no significant difference in the analgesic effect between two perisciatic infusion rates of ropivacaine 2 mg/ml (5 vs. 8 ml/h) in ambulatory patients who underwent chevron osteotomy.

Continuous popliteal sciatic nerve block for postoperative pain control at home: A prospective study in patients undergoing hallux valgus repair

Continuous popliteal sciatic nerve block for postoperative pain control at home: A prospective study in patients undergoing hallux valgus repair

Major complications after 400 continuous popliteal sciatic nerve blocks for post‐operative analgesia

A continuous popliteal sciatic nerve block (CPSNB) has been performed with increasing frequency for post-operative analgesia after foot surgery. Major complications associated with the placement of a perineural catheter remain rarely studied. The aim of this study was to prospectively determine the incidence of major complications (neurological and infectious) in post-operative adult patients with a continuous popliteal catheter inserted by the anatomical posterior approach for analgesia after foot surgery. All popliteal catheters were placed pre-operatively under sterile conditions with the aid of a nerve stimulator technique. The primary outcome measure was the incidence of major complications including infection and neuropathy. As a secondary outcome, adverse effects as well as other complications were also evaluated. Data were expressed as median [25th-75th percentiles]. A total of 400 patients were included in the study during a 2-year period. The median time the catheter remained indwelling was 47 h [23, 54]. Major complications included three events (0.75%) with one infection (0.25%) and two neuropathies (0.50%). Three blocks were unsuccessful and the catheter insertion was difficult in 12 patients (3%). During the CPSNB procedure, one patient reported slight paraesthesia during stimulation. Patient satisfaction was scored at 4 for 89%, 3 for 6% and 2 for 5% on the analogue scale. Major complications after the use of CPSN are not in fact rare. The incidence of severe neuropathy or infection complications is, respectively, 0.50% and 0.25%. However, the insertion of CPSN could be considered effective and is associated with only a few minor complications.

The Effects of Local Anesthetic Concentration and Dose on Continuous Infraclavicular Nerve Blocks: A Multicenter, Randomized, Observer-Masked, Controlled Study

It remains unclear whether local anesthetic concentration or total drug dose is the primary determinant of continuous peripheral nerve block effects. The only previous investigation, involving continuous popliteal-sciatic nerve blocks, specifically addressing this issue reported that insensate limbs were far more common with higher volumes of relatively dilute ropivacaine compared with lower volumes of relatively concentrated ropivacaine. However, it remains unknown if this relationship is specific to the sciatic nerve in the popliteal fossa or whether it varies depending on anatomic location. We therefore tested the null hypothesis that providing ropivacaine at different concentrations and rates, but at an equal total basal dose, produces comparable effects when used in a continuous infraclavicular brachial plexus block. Preoperatively, an infraclavicular catheter was inserted using the coracoid approach in patients undergoing moderately painful orthopedic surgery distal to the elbow. Patients were randomly assigned to receive a postoperative perineural ropivacaine infusion of either 0.2% (basal 8 mL/h, bolus 4 mL) or 0.4% (basal 4 mL/h, bolus 2 mL) through the second postoperative day. Both groups, therefore, received 16 mg of ropivacaine each hour with a possible addition of 8 mg every 30 min via a patient-controlled bolus dose. Our primary end point was the incidence of an insensate limb during the 24-h period beginning the morning after surgery. Secondary end points included analgesia and patient satisfaction. Patients given 0.4% ropivacaine (n = 27) experienced an insensate limb, a mean (sd) of 1.8 (1.6) times, compared with 0.6 (0.9) times for subjects receiving 0.2% ropivacaine (n = 23; estimated difference = 1.2 episodes, 95% confidence interval, 0.5-1.9 episodes; P = 0.001). Satisfaction with postoperative analgesia (scale 0-10, 10 = highest) was scored a median (25th-75th percentiles) of 10.0 (8.0-10.0) in Group 0.2% and 7.0 (5.3-8.9) in Group 0.4% (P = 0.018). Analgesia was similar in each group. For continuous infraclavicular nerve blocks, local anesthetic concentration and volume influence perineural infusion effects in addition to the total mass of local anesthetic administered. Insensate limbs were far more common with smaller volumes of relatively concentrated ropivacaine. This is the opposite of the relationship previously reported for continuous popliteal-sciatic nerve blocks. The interaction between local anesthetic concentration and volume is thus complex and varies among catheter locations.

Infectious Risk of Continuous Peripheral Nerve Blocks

Infectious Risk of Continuous Peripheral Nerve Blocks