[Comparison of the effects of sciatic nerve block combined with continuted femoral nerve block or continuted adductor canal block on pain and motor function after total knee arthroplasty]

Objective

To compare the effect of sciatic nerve block (SNB) combined with continuted femoral nerve block (FNB) or continuted adductor canal block (ACB) on pain and motor function after total knee arthroplasty (TKA).

Methods

A total of 60 patients with TKA-treated osteoarthritis of the knee who met the selection criteria were enrolled between November 2020 and February 2021 and randomised allocated into the study group (SNB combined with continuted ACB) and the control group (SNB combined with continuted FNB), with 30 cases in each group. There was no significant difference in gender, age, body mass, height, body mass index, preoperative Hospital for Special Surgery (HSS) score, femoral tibial angle, and medial proximal tibial angle between the two groups ( P>0.05). The operation time, the initial time to the ground, the initial walking distance, and the postoperative hospital stay were recorded. At 2, 4, 6, 12, 24, and 48 hours after operation, the numerical rating scale (NRS) score was used to evaluate the rest pain around the knee joint, the quadriceps femoris muscle strength was evaluated by the freehand muscle strength method, and the knee flexion and extension angles were measured.

Results

There was no significant difference in the operation time and initial walking distance between the two groups ( P>0.05); the initial time to the ground and postoperative hospital stay of the study group were significantly shorter than those of the control group ( P<0.05). Except for the 48-hour postoperative NRS score of the study group, which was significantly lower than that of the control group ( P<0.05), there was no significant difference in the NRS scores between the two groups at the remaining time points ( P>0.05). The quadriceps femoris muscle strength from 4 to 24 hours postoperatively and the knee extension angle from 2 to 6 hours postoperatively of the study group were significantly better than those of the control group ( P<0.05); the differences in the quadriceps femoris muscle strength and knee extension and flexion angles between the two groups at the remaining time points were not significant ( P>0.05).

Conclusion

SNB combined with either continuted ACB or continuted FNB can effectively relieve pain in patients after TKA, and compared with combined continuted FNB, combined continuted ACB has less effect on quadriceps femoris muscle strength, and patients have better recovery of knee flexion and extension mobility.

The Gluteus Deep Investing Fascia Compartment Block: A Novel Technique for Posterior Femoral Cutaneous Nerve Block

Purpose

The posterior femoral cutaneous nerve (PFCN) block is used in regional anesthesia for lower extremity surgery. This study introduces a new ultrasound-guided technique called the "Gluteus-Deep Investing Fascia compartment Block (GDIF block)" for blocking the PFCN. This approach involves injecting local anesthetic into the potential space between the gluteus maximus muscle and the deep investing fascia, named the 'Gluteus Deep Investing Fascia Compartment'. The study discusses the anatomical and sonographic features crucial for identifying this compartment and explores the potential benefits of this approach for achieving effective PFCN block. Additionally, it examines the clinical application of the GDIF block for PFCN block as part of the Complete Lower Extremity Fascia Tri-compartment Block technique, named "CLEFT Block." This technique combines the suprainguinal fascia iliaca block with GDIF compartment block for PFCN and a sciatic nerve block as exclusive anesthesia technique.

Patients and Methods

Nine patients with weapon-related lower limb injuries underwent surgery at district hospitals supported by the International Committee of the Red Cross. Between October and December 2023, seventeen above-knee procedures were performed for the nine patients using the GDIF block as part of a CLEFT block technique. Anesthesia was performed with a CLEFT block technique using a volume ratio of 1:1 of 1% lidocaine and 0.5% levobupivacaine.

Results

The GDIF block technique for PFCN blockade was performed successfully in all patients without complications, achieving complete PFCN blockade. The CLEFT block technique proved effective as the sole anesthetic technique for seventeen above-knee procedures. All surgeries were completed successfully without additional pain medication or conversion to general anesthesia.

Conclusion

The GDIF block appears to be a promising technique for anesthetic management, alone or as part of the CLEFT block. Further research with a larger patient population is necessary to validate these findings.

The Successful Use of an Ultrasound-Guided Mid-Femur Sciatic Nerve Block in a Juvenile Emu (Dromaius novaehollandiae) under General Anaesthesia

The current case report describes a successful ultrasound-guided mid-femur sciatic nerve block in an emu. A 2-month-old emu suffering from acute-onset lameness was referred to the University Clinic of Liège, where he was diagnosed with a lateral luxation of the Achilles tendon on both hind limbs. Two surgical procedures were performed for treatment. Both surgical procedures were performed under general anaesthesia with butorphanol, ketamine, midazolam and isoflurane in oxygen. The anaesthesia was continuously monitored. An ultrasound-guided sciatic nerve block was performed to prevent and treat surgically induced nociception. The technique was adapted from what is already described in other species. Levobupivacaine was injected perineurally under ultrasound-guidance. Intraoperative nociception was assessed based on the heart rate and mean arterial pressure changes. The recovery was uneventful and with no clinical signs of postoperative pain.

Combined Lumbar Plexus-Sciatic Nerve Block for Urgent Lower Limb Surgery: A Good Alternative in Patients With High Anesthetic Risk

The use of peripheral nerve blocks has grown significantly in recent years not only because of the progress and availability of the materials necessary for its realization but also for enhancing patient safety. Anesthesia in the elderly or individuals with high anesthetic risk is always a challenge for the practitioner. Hence, the importance of peripheral nerve blocks in avoiding the side effects associated with general or spinal anesthesia. In this report, we present a case series of five patients with high anesthetic risk (classified American Society of Anesthesiologists (ASA) III or IV) who underwent different lower limb surgeries under a combined lumbar plexus-sciatic nerve block. The goal of this case series was to evaluate the effectiveness of this technique as an anesthetic alternative for these different types of surgical procedures.

The use of granisetron on bupivacaine induced sciatic nerve block in rats

PURPOSE

The effects of the 5-hydroxytryptamine (5-HT3) receptor antagonists on regional anaesthesia are complex and unclear. The present study was designed to test the hypothesis that granisetron, a selective 5-HT3 receptor antagonist, would decrease the duration of motor block, sensory block, and proprioception in a dose-dependent fashion in a rat model of bupivacaine-induced sciatic nerve blockade.

MATERIALS AND METHODS

Thirty-eight male Wistar Albino rats that received unilateral sciatic nerve blocks were randomly divided into five experimental groups. Group B received a perineural of 0.3 ml of bupivacaine alone; Group BG800 received perineural 0.3 ml of bupivacaine and 800 µg of granisetron 10 min later; Group BG1200 received perineural 0.3 ml of bupivacaine and 1200 µg of granisetron 10 min later; Group BG1200IP received a perineural 0.3 ml of bupivacaine and an intraperitoneal injection of 1200 µg of granisetron 10 min later; and Group S was sham operated. A blinded investigator assessed motor, sensory and proprioception function every 10 min until the return of normal function.

RESULTS

The medians for recovery times in Group B, Group BG800, Group BG1200, and Group BG1200IP were 105, 64, 85, and 120 min for motor function, respectively; 80, 64, 84, and 104 min for sensory function; 80, 63, 85, and 108 min were calculated for the proprioception function. The time to the return of normal motor, sensory, and proprioception function was not statistically significantly different between the groups (p > 0.05). Motor block did not develop in any of the rats in Group S.

CONCLUSIONS

Local and systemic application of granisetron was not significantly decrease the duration of bupivacaine induced motor, sensory, and proprioception block of sciatic nerve in rat.

Comparative Efficacy of iPACK vs Popliteal Sciatic Nerve Block for Pain Management Following Total Knee Arthroplasty: A Retrospective Analysis

Introduction Total knee arthroplasty (TKA) is associated with severe acute postoperative pain. The use of tourniquets and drains (T/D) is common in TKA but may have an influence on postoperative pain and muscular strength. The infiltration of local anesthetic between the popliteal artery and capsule of the knee (iPACK block) is a motor-sparing block that provides analgesia to the posterior aspect of the knee. However, evidence regarding its efficacy is scarce. This study aims to assess the effectiveness of iPACK block and the impact of T/D use on pain and muscular strength after TKA. Material and methods A retrospective study was carried out including patients who underwent TKA from January 2020 to April 2023. Patients were allocated into groups according to the peripheral nerve block performed and T/D use. Results We included 415 patients in this study. No differences were found in pain at rest or the need for rescue analgesia between patients who received an iPACK block or sciatic nerve block (SNB) with T/D applied. Patients who received a SNB reported lower pain scores on movement (p = 0.019), but with a higher prevalence of motor block (p < 0.001). Patients who underwent surgery without using T/D reported lower pain scores on movement (p = 0.021) and reduced need for rescue analgesia (p = 0.041). Conclusion These findings indicate that iPACK block can facilitate early mobilization after TKA without significant impact on postoperative muscle strength. Furthermore, the use of a T/D may be a source of postoperative pain that could compromise early rehabilitation.

Caudal Neuraxial Blocks for Pain Relief From Pelvic Neuropathy Caused by Extensive Diffuse Large B-cell Lymphoma

Central neuraxial blocks can be a vital therapeutic tool for neuropathic pain, but they are infrequently implemented for pain management in cancer patients. Upon a literature review, further data on the role or efficacy of central nerve blocks for neuropathic cancer pain would be beneficial. Additionally, evidence-based guidelines and practices are lacking regarding additional interventions for neuropathic pain relief, a common manifestation of cancer burden. Here, we report the case of a 29-year-old male patient who presented in the ED with intractable neuropathic pain from extensive diffuse large B-cell lymphoma. The patient demonstrated left lower extremity pain, fevers, chills, and tenderness with erythema over the site of his port-a-catheter on his chest. The patient was also hypotensive, despite IV fluid resuscitation. Recent imaging showed a hypermetabolic soft tissue mass in the left upper quadrant of the abdomen. There was also extensive cancer spread in the peripheral pelvis, presacral region, and within multiple sacral foramina, with a secondary perineural spread of the tumor. The patient previously positively responded to a caudal nerve block at an outpatient pain clinic. The patient was admitted to the ICU for three days, and following the resolution of sepsis, the patient received caudal and sciatic nerve blocks on admission day 8. Upon further imaging showing metastasis to the brain, the patient was discharged to inpatient hospice on hospitalization day 10 following a palliative conversation with the patient and family.

Preoperative Femoral Nerve Block and Postoperative Sciatic Nerve Block at the Subgluteal Space After Total Knee Arthroplasty: A Retrospective Cohort Study

Background A preoperative sciatic nerve block (SNB) before total knee arthroplasty (TKA) frequently causes postoperative drop foot; however, this can also occur as an unintended result of surgical invasion. This study assessed the benefits of a postoperative SNB at the subgluteal space for patients who underwent TKA. Methodology This was a single-center, retrospective cohort study. Patients who underwent TKA under general anesthesia between May 2018 and June 2019 at the Teikyo University School of Medicine were screened for inclusion. They received either a preoperative femoral nerve block alone (control group; n = 87) or a preoperative femoral nerve block and postoperative SNB at the subgluteal space (post-SNB group; n = 40). The primary outcome was the pain-related Numerical Rating Scale (NRS) scores. The secondary outcomes were postoperative nausea and vomiting (PONV), intravenous patient-controlled analgesia (iv-PCA) suspension, and postoperative complications. Results No significant differences were observed in the characteristics, NRS scores, time to first drug use for pain, and iv-PCA suspension between groups. However, the incidence of PONV was significantly lower in the post-SNB group (p = 0.03). Logistic regression analysis revealed that droperidol doses of iv-PCA and the presence of postoperative SNB were independently associated with PONV occurrence [A1] {(p = 0.008, 95% confidence intervals (CI) [0.46, 0.89] and (p = 0.02, 95% CI [0.25, 0.88])}. Conclusions A postoperative SNB at the subgluteal space following TKA does not improve postoperative pain control; however, it may have contributed to reduced PONV.

Quantitative assessment of ultrasound-guided sciatic nerve block - A comparison of a single-point versus two-point injection technique: A randomised controlled, double-blinded trial

Background and Aims

Sciatic nerve block at the popliteal level for lower limb procedures provides unpredictable success rates even with ultrasonographic (USG) guidance. This study aimed to compare USG-guided single-point versus two-point injection techniques.

Methods

Sixty patients posted for foot surgeries under USG-guided sciatic nerve block were randomised into Group Single Point, receiving a single injection of 20 mL of 1.5% lignocaine with adrenaline just proximal to the sciatic nerve bifurcation, and Group Double Point, receiving two injections of 10 mL of 1.5% lignocaine with adrenaline, one at the point similar to the first group and a second injection 6 cm above the first point. Sensory blockade onset, time to complete sensory blockade, time to complete motor blockade, length of the nerve exposed and analgesia duration were evaluated. Statistical analysis was performed with Statistical Package for the Social Sciences (SPSS) statistics version 20 software.

Results

Double-point injection technique showed a significantly faster time to complete motor blockade [14.46 (9.93) min], increased length of nerve exposed to local anaesthetic [23.23 (7.209) cm] and extended duration of analgesia [420.40 (99.34) min] compared to the single-point injection technique [20.89 (12.62) min, 18.78 (5.95) cm and 344.28 (125.97) min, respectively]. The onset of sensory blockade and the time to complete sensory blockade were comparable between the two groups.

Conclusion

USG-guided popliteal sciatic nerve block with a double-point injection technique does not significantly shorten the time to complete the sensory block. However, the time to complete motor nerve block and duration of analgesia are prolonged significantly, which may be clinically beneficial for postoperative analgesia.

Ultrasound-Guided Block of the Sciatic and the Femoral Nerves in Rabbits-A Descriptive Anatomical Study

The rabbit is a popular animal model for human biomechanical research involving surgery on the hind limb. Mortality is higher in rabbits when undergoing general anesthesia compared to dogs and cats. Moreover, due to their nature as prey animals, rabbits have a tendency to hide signs of pain, making it challenging to detect discomfort at an early stage. Incorporating regional anesthesia into an anesthetic protocol can greatly reduce the requirements for systemic anesthetic and analgesic drugs, thereby minimizing associated side effects. In other species, a block of the sciatic (ScN) and the femoral nerves (FN) is usually applied in patients undergoing hind limb surgery. In phase 1 of this study, the ScN and the FN have been localized and an appropriate approach has been evaluated under sonographic guidance. In phase 2, a mixture of new methylene blue and lidocaine have been administered to the ScN and the FN in 10 cadavers (20 hind limbs). Staining of the nerves was evaluated by dissection. Ultrasonographically, the ScN appeared as a binocular structure surrounded by a hyperechoic rim. The FN appeared as a hypoechoic structure in the dorsal part of the iliopsoas muscle (IPM), becoming hyperechoic/honey-comb-like in the ventral part. Both nerves could be successfully stained in all animals over a median length of 2.3 cm which was considered effective. This technique allows feasible and accurate access to block the ScN and the FN and may lead to successful analgesia in rabbits undergoing hind limb surgery.

Improvement in "Jumping Stump" Syndrome Following Diagnostic Sciatic Nerve Block and Home Exercise Program in a Transtibial Amputee

"Jumping Stump" syndrome is a rare postoperative complication seen in the residual limb of amputees, with only a few cases documented in the literature. It has been defined as a peripherally induced movement disorder leading to either dystonia, myoclonus, tremors, or choreiform movements in the amputated residual limb. It is often associated with significant discomfort and an inability to ambulate with a prosthetic limb. Treatment options remain inconclusive at this time. We present a case of "Jumping Stump" syndrome in a young female transtibial amputee following revision transtibial amputation (TTA) with myodesis and targeted muscle reinnervation. About six weeks after revision surgery, the patient started experiencing significant myoclonus of the right residual limb when extending the knee. She was trialed on various oral pharmacologic agents over six months and had multiple prosthetic adjustments without any symptomatic relief. Moreover, the patient was also prescribed a daily knee range of motion (ROM) and stretching program. Six months after symptom onset, she underwent a diagnostic right sciatic nerve block and right biceps femoris point block with immediate and significant improvement in symptoms. She had a greater ROM in the affected limb without myoclonus and was able to ambulate once again with her prosthetic limb. Our patient's response to a diagnostic nerve and motor point block, as well as her marked improvement of symptoms with a consistent home exercise (stretching) program, suggests that desensitization of a muscle-tendon stretch response likely accounted for the improvement of symptoms. It is hypothesized that chemodenervation via botulinum toxin, in addition to the consistent home stretching program, would have accelerated the improvement of symptoms and should be further explored as a potential treatment modality for "Jumping Stump" syndrome.

Evaluation of a New Method of Sciatic Nerve Block: A Prospective Pilot Study

Purpose

The location of the sciatic nerve deep within the thigh tissue makes it challenging to locate while the patient is in a supine position. The posterior intermuscular septum of the thigh, which encircles the posterior surface of the adductor magnus muscle (AMM), is where the sciatic nerve is located. Our hypothesis was that administering local anesthetic injections into this area could block the sciatic nerve. Therefore, our aim was to evaluate the effectiveness of sciatic nerve block achieved by injecting local anesthetic into the posterior intermuscular septum of the thigh, named the AMM approach.

Methods

Twenty-six patients undergoing total knee arthroplasty were included in the study. We performed an ultrasound-guided sciatic nerve block by injecting 20 mL of 0.25% ropivacaine into the posterior surface of the adductor magnus muscle, using the AMM approach. Additionally, we administered a femoral nerve block with 20 mL of 0.4% ropivacaine. We assessed the sensory and motor effects of the blockade in the operated lower limb and recorded postoperative pain scores at 0, 4, 8, 12, 24, and 48 hours after the operation.

Results

The AMM approach successfully block the sciatic nerve in all 26 patients. The onset of the sensory and motor blockades was achieved within 5.4 ± 1.9 min and 8.7 ± 3.5 min, respectively. We achieved a satisfactory position with the first puncture in 19 of 26 patients (73.1%). The muscle strength of the tibialis anterior immediately after surgery was 4 (ranging from 2 to 5). Additional rescue analgesics were required in 5 of the 26 patients (19.2%) during the first 24 hours postoperatively.

Conclusion

The AMM approach is an innovative and effective method for sciatic nerve block. When combined with simultaneous femoral nerve block in patients undergoing total knee arthroplasty, it provides a useful analgesic treatment option.

Ultrasound-guided femoral and sciatic nerve block as an option for below-knee amputation in an elderly patient: A case report

Peripheral nerve blocks can be a very safe option in elderlypatients with multiple comorbidities where spinal or general anesthesia may be associated with increased risks. We present a 67 years male taking antiplatelet drugs with deranged coagulation profile with bilateral pneumonia with diabetic foot with wet gangrene planned for emergency below knee amputation under ultrasound guided femoral and sciatic nerve block.

Effect of Intramuscular Tramadol on the Duration of Clinically Relevant Sciatic Nerve Blockade in Patients Undergoing Calcaneal Fracture Fixation: A Randomized Controlled Trial

BACKGROUND

Calcaneal fracture fixation can generate severe postoperative pain and analgesia can be supported by a sciatic nerve block. However, following resolution of the sensory blockade, rebound pain may ensue. The aim of this study was to assess whether an incidental finding of two patients with an extension of the sciatic nerve block beyond 24 h following 100 mg of intramuscular tramadol administration could be confirmed.

METHODS

Thirty-seven patients scheduled for a calcaneal intramedullary fixation (Calcanail^®) were randomly divided into two groups. The tramadol group (n = 19) received a sciatic nerve block with 20 mL of 0.25% bupivacaine and a concomitant dose of 100 mg of intramuscular tramadol, while the control group (n = 18) received an identical sciatic nerve block with concomitant injection of normal saline (placebo). All patients had a spinal anesthesia with light sedation for the procedure. The time to first analgesic request defined as appearance of any pain (NRS > 0) was assessed as the primary endpoint with a clinically relevant expected result of at least 50% elongation in sensory blockade.

RESULTS

The median time to first analgesic request from time of blockade in the tramadol group was 670 min compared with 578 min in the control group. The result was clinically not relevant and statistically not significant (p = 0.17). No statistical difference could be demonstrated in the time to first opioid request, although a trend for opioid sparing in the tramadol group could be seen. Total morphine consumption in the first 24 h was also statistically insignificant (the tramadol group 0.066 mg kg^-1 compared with 0.125 mg kg^-1 in the control group). In conclusion, intramuscular tramadol does not extend the duration of analgesia of a sciatic nerve block following a calcaneal fracture fixation beyond 2 h and an opioid sparing effect could not be demonstrated in this trial.

Preparation of Ropivacaine Encapsulated by Zeolite Imidazole Framework Microspheres as Sustained-Release System and Efficacy Evaluation

The management of persistent postoperative pain still remains a clinical challenge currently. Although ropivacaine (RVC) is widely used for postoperative analgesia as a local anesthetic, the short half-life makes it difficult to achieve the desired duration of analgesia. Herein, a RVC sustained-release microspheres encapsulated by zeolite imidazole framework-8 (RVC@ZIF-8) was synthesized for the first time, which prolonged the sustained-release of RVC and decreased the resulting drug toxicity. RVC can continuously release in vitro for at least 96 h with high drug loading of 30.6 % and RVC@ZIF-8 had excellent biocompatibility and low cytotoxicity. In sciatic nerve block model, the sensory block time of RVC@ZIF-8 was significantly prolonged compared with RVC, achieving more than 72 h post injection and no inflammation or lesion were found. Based on high drug loading, ideal sustained-release and superior biological safety, RVC@ZIF-8 will be a novel delivery material for local anesthetic with potential application.

Sciatic Nerve Block Combined with Flurbiprofen Inhibits Spinal Cord Inflammation and Improves Postoperative Pain in Rats with Plantar Incision

Background and Purpose

Peripheral nerve block is often used to relieve postoperative pain. But the effect of nerve block on inflammatory response is not fully understood. Spinal cord is the primary center of pain processing. This study is to investigate the effect of single sciatic nerve block on the inflammatory response of the spinal cord in rats with plantar incision and the combined effect with flurbiprofen.

Methods

The plantar incision was used to establish a postoperative pain model. Single sciatic nerve block, intravenous flurbiprofen or the combination of both were used for intervention. The sensory and motor functions after nerve block and incision were evaluated. The changes of IL-1β, IL-6, TNF-α, microglia and astrocytes in the spinal cord were examined by qPCR and immunofluorescence respectively.

Results

Sciatic nerve block with 0.5% ropivacaine in rats induced sensory block for 2h and motor block for 1.5h. In the rats with plantar incision, the single sciatic nerve block did not alleviate postoperative pain or inhibit the activation of spinal microglia and astrocytes, but the levels of IL-1β and IL-6 in spinal cord were decreased when the nerve block wore off. The combined effect of a single sciatic nerve block and intravenous flurbiprofen not only decreased the levels of IL-1β, IL-6, and TNF-α, but also relieved the pain and alleviated the activation of microglia and astrocytes.

Conclusion

The single sciatic nerve block cannot improve postoperative pain or inhibit the activation of spinal cord glial cells, but can reduce the expression of spinal inflammatory factors. Nerve block combined with flurbiprofen can inhibit spinal cord inflammation and improve postoperative pain. This study provides a reference for rational clinical application of nerve block.

PLGA-based microspheres containing ropivacaine and betamethasone for sciatic nerve block in mice

The aim of the present study was to develop Poly (lactic-co-glycolic acid) (PLGA)-based microspheres containing ropivacaine and betamethasone (RPC/BTM PLGA MS) by emulsion-solvent evaporation method. RPC/BTM PLGA MS were characterized by physical properties, such as morphology and particle size, and in vitro drug release. In addition, in vivo pharmacokinetics and pharmacodynamics of RPC/BTM PLGA MS were also investigated. The prepared RPC/BTM PLGA MS was suitable for local injection with a well-dispersed spherical shape, high stability, and high encapsulation efficiency. The mean diameter was 14.8 ± 1.2 µm and the polydispersity index (PDI) was 0.32 ± 0.04. In an in vitro study of drug release, it can be concluded that the RPC/BTM PLGA MS exhibited sustained and long-term release properties for 16 days. Furthermore, the result of an in vivo study indicated that the RPC/BTM PLGA MS had sustained release effect and the pharmacodynamics result showed that preparing RPC/BTM PLGA MS as microsphere preparation could not only extend the drug effect time but also prolong the duration of local anesthetics compared with the common RPC PLGA MS.

Development and internal validation of a multivariable risk prediction model for severe rebound pain after foot and ankle surgery involving single-shot popliteal sciatic nerve block

BACKGROUND

Rebound pain occurs after up to 50% of ambulatory surgeries involving regional anaesthesia. To assist with risk stratification, we developed a model to predict severe rebound pain after foot and ankle surgery involving single-shot popliteal sciatic nerve block.

METHODS

After ethics approval, we performed a single-centre retrospective cohort study. Patients undergoing lower limb surgery with popliteal sciatic nerve block from January 2016 to November 2019 were included. Exclusion criteria were uncontrolled pain in the PACU, use of a perineural catheter, or loss to follow-up. We developed and internally validated a multivariable logistic regression model for severe rebound pain, defined as transition from well-controlled pain in the PACU (numerical rating scale [NRS] 3 or less) to severe pain (NRS ≥7) within 48 h. A priori predictors were age, sex, surgery type, planned admission, local anaesthetic type, dexamethasone use, and intraoperative anaesthesia type. Model performance was evaluated using area under the receiver operating characteristic curve (AUROC), Nagelkerke's R², scaled Brier score, and calibration slope.

RESULTS

The cohort included 1365 patients (mean [standard deviation] age: 50 [16] yr). The primary outcome was abstracted in 1311 (96%) patients, with severe rebound pain in 652 (50%). Internal validation revealed poor model performance, with AUROC 0.632 (95% confidence interval [CI]: 0.602-0.661; bootstrap optimisation 0.021), Nagelkerke's R² 0.063, and scaled Brier score 0.047. Calibration slope was 0.832 (95% CI: 0.623-1.041).

CONCLUSIONS

We show that a multivariable risk prediction model developed using routinely collected clinical data had poor predictive performance for severe rebound pain after foot and ankle surgery. Prospective studies involving other patient-related predictors are needed.

CLINICAL TRIAL REGISTRATION

NCT05018104.

Levobupivacaine Consumption in Automated Intermittent Bolus in Ultrasound Guided Subparaneural Sciatic Nerve Catheters: A Prospective Double-Blind Randomized Trial

Purpose

Continuous sciatic nerve blocks have proven benefits for postoperative analgesia after foot surgery. However, the optimal mode of administration remains a point of debate. Ultrasound guided subparaneural injection accelerates onset time and increases duration after a single shot sciatic nerve block. This double blind prospective randomized trial compares the 48-hour local anesthetic (LA) dose consumption of an automated intermittent bolus technique to a continuous infusion regimen in a subparaneural sciatic nerve catheter after hallux valgus surgery.

Patients and Methods

Patients scheduled for hallux valgus surgery were randomized to receive either a continuous infusion of levobupivacaine 0.125% at 5mL/h (group A) or an intermittent automated bolus of 9.8 mL every 2 hours with a background of 0.1 mL/h (group B), both with a PCA bolus of 6 mL and lockout of 30 minutes. The 48 hour LA consumption, PCA boluses, Numeric Rating Scale (NRS), satisfaction and return of normal sensation were recorded.

Results

Sixteen patients were excluded because of protocol violation or technical problems and 42 patients remained for analysis. The 48 hour ropivacaine consumption was higher in group A (293 ±60 mL) than group B (257±33 mL). The median and highest NRS scores and patient satisfaction were not statistically different between groups. Normal sensation returned after 75 ± 22 hours (group A) and 70 ± 17 hours (group B).

Conclusion

Programmed bolus administration in subparaneural sciatic nerve catheters reduces LA consumption 48 hours after surgery with equal analgesia and patient satisfaction. Return of sensation is variable and can last more than 75 hours.

Ultrasound-Guided Anterior Approach to a Sciatic Nerve Block: Influence of Lower Limb Positioning on the Visibility and Depth of the Sciatic Nerve

OBJECTIVES

We aimed to identify the optimal lower limb position for an ultrasound (US)-guided anterior approach to a sciatic nerve block.

METHODS

We included 45 patients who met the following criteria: American Society of Anesthesiologists physical status of 1 to 3, age between 18 and 80 years, and scheduled to undergo knee surgery that required a sciatic nerve block. The lower limbs of each patient were placed in the following 4 positions: N, neutral; ER, external rotation of the hip (angle, 45°); ER/F15, ER (angle, 45°) and flexion (angle, 15°) of the hip; and ER/F45, ER (angle, 45°) and F (angle, 45°) of the hip. An investigator acquired US scans of the sciatic nerve in each position, and the visibility score and depth of the sciatic nerve from the skin were analyzed.

RESULTS

The visibility scores were significantly higher in positions ER/F15 and ER/F45 than in positions ER and N (P < .0001). However, there was no difference between the visibility scores in positions ER/F15 and ER/F45 (P = .0959). The depth of the sciatic nerve from the skin decreased with ER and an increase in the F angle of the hip (overall P < .0001).

CONCLUSIONS

Based on the visibility score and depth from the skin, ER of the hip to 45° with a greater F angle (45° versus 15°) of the hip appears to be the optimal position for an US-guided anterior approach to a sciatic nerve block.

Ultrasound-guided sciatic nerve block at the midthigh level in a porcine model: A descriptive study

BACKGROUND AND OBJECTIVE

There are a growing number of porcine models being used for orthopaedic experiments for human beings. Therefore, pain management of those research pigs using ultrasound (US)-guided nerve block can be usefully performed. The aim of this study is to determine optimal US approaches for accessing and localizing the sciatic nerve at the midthigh level, a relevant block site for hindlimb surgery in female Yorkshire pigs.

METHODS

As a first step, we dissected the intubated, blood-washed out pigs (n = 3) and confirmed the anatomical position of the sciatic nerve at midthigh level. After dissection, we found the sciatic nerve, connected with nerve stimulator, and checked the dorsiflexion or plantar flexion of the hindlimb. We matched the sciatic nerve location with the US image. After the pigs were euthanized, the neural structures of the sciatic nerve were confirmed by histological examination with H&E staining. In second step, a main US-guided sciatic nerve block study was done in the intubated, live pigs (n = 8) based on the above study.

RESULTS

In lateral position, the effective US-guided nerve block site was about 6 cm from the patella crease level; immediately proximal to the bifurcation of the sciatic nerve into the tibial nerve and common peroneal nerve. The distal femur was selected as the landmark. There were no vessels or other nerves surrounding the sciatic nerve. The needle-tip was positioned less than 1 cm lateral from the distal femur and about 2 cm deep to skin. 'Donut sign' in US images was confirmed in all 16 nerves.

CONCLUSIONS

Midthigh level sciatic nerve is located superficially, which enables nerve block to be easily performed using US. This is the first study to describe midthigh sciatic nerve block in the lateral position under US guidance in a porcine model from a clinical perspective.

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.

Peripheral nerve block versus systemic analgesia in dogs undergoing tibial plateau levelling osteotomy: Analgesic efficacy and pharmacoeconomics comparison

OBJECTIVE

To compare the perioperative effects and pharmacoeconomics of peripheral nerve blocks (PNBs) versus fentanyl target-controlled infusion (fTCI) in dogs undergoing tibial plateau levelling osteotomy (TPLO).

STUDY DESIGN

Randomized clinical study.

ANIMALS

A total of 39 dogs undergoing unilateral TPLO.

METHODS

After acepromazine and methadone, anaesthesia was induced with propofol and maintained with isoflurane. Dogs were allocated to group fTCI [target plasma concentration (TPC) 1 ng mL^-1] or group PNB (nerve stimulator-guided femoral-sciatic block using 0.2 and 0.1 mL kg^-1 of levobupivacaine 0.5%, respectively). If nociceptive response occurred, isoflurane was increased by 0.1%, and TPC was increased by 0.5 ng mL^-1 in group fTCI; a fentanyl bolus (1 μg kg^-1) was administered in group PNB. During the first 24 postoperative hours, methadone (0.2 mg kg^-1) was administered intramuscularly according to the Short Form Glasgow Composite Pain Scale, or if pain was equal to 5/24 or 4/20 for two consecutive assessments, or if the dog was non-weight bearing. The area under the curve (AUC) of pain scores, cumulative postoperative methadone requirement, food intake and pharmacoeconomic implications were calculated.

RESULTS

Incidence of bradycardia (p = 0.025), nociceptive response to surgery (p = 0.041) and AUC of pain scores (p < 0.0001) were greater in group fTCI. Postoperatively, 16/19 (84.2%) and eight/20 (40%) dogs in groups fTCI and PNB, respectively, were given at least one dose of methadone (p = 0.0079). Food intake was greater in group PNB (p = 0.049). Although total cost was not different (p = 0.083), PNB was more cost-effective in dogs weighing >15 kg.

CONCLUSIONS AND CLINICAL RELEVANCE

Compared with group fTCI, incidence of bradycardia, nociceptive response to surgery, postoperative pain scores, cumulative methadone requirement were lower, and food intake was greater in group PNB, with an economic advantage in dogs weighing >15 kg.

Combined Sciatic and Lumbar Plexus Nerve Blocks for the Analgesic Management of Hip Arthroscopy Procedures: A Retrospective Review

Hip arthroscopy is a minimally invasive alternative to open hip surgery. Despite its minimally invasive nature, there can still be significant reported pain following these procedures. The impact of combined sciatic and lumbar plexus nerve blocks on postoperative pain scores and opioid consumption in patients undergoing hip arthroscopy was investigated. A retrospective analysis of 176 patients revealed that compared with patients with no preoperative peripheral nerve block, significant reductions in pain scores to 24 hours were reported and decreased opioid consumption during the post anesthesia care unit (PACU) stay was recorded; no significant differences in opioid consumption out to 24 hours were discovered. A subgroup analysis comparing two approaches to the sciatic nerve block in patients receiving the additional lumbar plexus nerve block failed to reveal a significant difference for this patient population. We conclude that peripheral nerve blockade can be a useful analgesic modality for patients undergoing hip arthroscopy.

Comparison of local infiltration analgesia and sciatic nerve block as an adjunct to femoral nerve block for pain control after total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

To perform a meta-analysis to assess the efficiency and safety between local infiltration analgesia (LIA) and sciatic nerve block (SNB) when combined with femoral nerve block (FNB) for pain control following total knee arthroplasty (TKA).

METHODS

We systemically searched the following electronic databases for potentially relevant articles: Embase (1980-2017.01), Medline (1966-2017.01), PubMed (1966-2017.01), ScienceDirect (1985-2017.01), web of science (1950-2017.01) and the Cochrane Library. Only studies published in English that were accessible online were considered. Furthermore, we only considered studies that were published from 1966 to 2017. Only studies that met the following inclusion criteria were considered: (a) patients were adult human subjects who were set to undergo TKA; (b) the intervention was either SNB combined with FNB or LIA combined with FNB; (c) the outcomes of the studies, such as visual analog scale (VAS) scores, morphine consumption, length of stay and postoperative adverse effects, including the risk of nausea, vomiting and falls, were reported; (d) studies were either RCTs or non-RCT. Meta-analysis was performed using Stata 11.0 software. Modified Jadad score (7-points scale) which was based on Cochrane Handbook for Systematic Reviews of Interventions is used for assessment of RCTs. The Methodological Index for Nonrandomized Studies (MINORS) scale was used to assess non-RCTs with scores ranging 0 to 24. The synthesis of the outcomes for all studies was calculated as the weighted average rate by using a fixed or random effect model which depends on statistical heterogeneity. Systematic review registration number is CRD42017110661.

RESULTS

Three randomized controlled trials (RCTs) and 2 nonrandomized controlled trials (Non-RCTs), including 240 patients met the inclusion criteria. The present meta-analysis indicated that there were significant differences between groups in terms of visual analog scale (VAS) score at 12 hours (SMD = -0.337, 95% CI: -0.593 to -0.081, P =.010), VAS score at 24 hours (SMD = -0.337, 95% CI: -0.612 to -0.061, P =.017), morphine equivalent consumption at 24 hours (SMD = -0.371, 95% CI: -0.627 to -0.114, P = .005) and incidence of nausea (RD = 0.215, 95% CI: 0.078 to 0.353, P = .002) and vomiting (RD = 0.143, 95% CI: 0.026 to 0.260, P = .017).

CONCLUSION

FNB combined with SNB provided decreased VAS scores and less morphine consumption at 12 and 24 hours compared with FNB combined with LIA in total knee arthroplasty. In addition, it was associated with lower risks of nausea and vomiting. We assessed the quality of the evidence as low to very low; therefore, our confidence in the effect estimate is limited, and the true effect may be substantially different from our estimates. Further studies should focus on surgeries that are known to be associated with significant postoperative pain, particularly surgeries where improved pain control may deliver significant clinical benefits through reduced morbidity, or cost-effectiveness benefits through faster rehabilitation and discharge. The present meta-analysis has the following limitations: (1) only 5 studies were included in the meta-analysis. Although all of them are recently published studies, the sample sizes are relatively small; (2) Functional outcome is an important parameter; however, owing to the insufficiency of relevant data, we failed to perform a meta-analysis on functional outcome; (3) The doses of anesthetics and the concomitant pain management regimes varied between the studies, which may have influenced the results; (4) The duration of follow-up was relatively short, which might have led to an underestimating of complications; and (5) publication bias present in the meta-analysis may have influenced the results.

Arthroscopic medial meniscus trimming or repair under nerve blocks: Which nerves should be blocked?

Background:

This study aimed to determine the role of the sciatic and obturator nerve blocks (in addition to femoral block) in providing painless arthroscopic medial meniscus trimming/repair.

Materials and Methods:

One hundred and twenty patients with medial meniscus tear, who had been scheduled to knee arthroscopy, were planned to be included in this controlled prospective double-blind study. The patients were randomly allocated into three equal groups; FSO, FS, and FO. The femoral, sciatic, and obturator nerves were blocked in FSO groups. The femoral and sciatic nerves were blocked in FS group, while the femoral and obturator nerves were blocked in FO group. Intraoperative pain and its causative surgical maneuver were recorded.

Results:

All the patients (n = 7, 100%) in FO group had intraoperative pain. The research was terminated in this group but completed in FS and FSO groups (40 patients each). During valgus positioning of the knee for surgical management of the medial meniscus tear, the patients in FS group experienced pain more frequently than those in FSO group (P = 0.005).

Conclusion:

Adding a sciatic nerve block to the femoral nerve block is important for painless knee arthroscopy. Further adding of an obturator nerve block may be needed when a valgus knee position is required to manage the medial meniscus tear.

Long-term effect of ropivacaine nanoparticles for sciatic nerve block on postoperative pain in rats

Purpose

The analgesic effect of ropivacaine (Rop) for nerve block lasts only ~3–6 hours for single use. The aim of this study was to develop long-acting regional anesthetic Rop nanoparticles and investigate the effects of sciatic nerve block on postoperative pain in rats.

Materials and methods

Rop nanoparticles were developed using polyethylene glycol-co-polylactic acid (PELA). One hundred and twenty adult male Wistar rats were randomly divided into four groups (n=30, each): Con (control group; 0.9% saline, 200 µL), PELA (PELA group; 10 mg), Rop (Rop group; 0.5%, 200 µL), and Rop-PELA (Rop-PELA group; 10%, 10 mg). Another 12 rats were used for the detection of Rop concentration in plasma. The mechanical withdrawal threshold and thermal withdrawal latency were measured at 2 hours, 4 hours, 8 hours, 1 day, 2 days, 3 days, 5 days, and 7 days after incision. The expression of c-FOS was determined by immunohistochemistry at 2 hours, 8 hours, 48 hours, and 7 days. Nerve and organ toxicities were also evaluated at 7 days.

Results

The duration of Rop absorption in the plasma of the Rop-PELA group was longer (>8 hours) than that of the Rop group (4 hours). Mechanical withdrawal threshold and thermal withdrawal latency in the Rop-PELA group were higher than that in other groups (4 hours–3 days). c-FOS expression in the Rop-PELA group was lower than that in the control group at 2 hours, 8 hours, and 48 hours and lower than that in the Rop group at 8 hours and 48 hours after paw incision. Slight foreign body reactions were observed surrounding the sciatic nerve at 7 days. No obvious pathophysiological change was found in the major organs after Rop-PELA administration at 7 days.

Conclusion

Rop-PELA provides an effective analgesia for nerve block over 3 days after single administration, and the analgesic mechanism might be mediated by the regulation of spinal c-FOS expression. However, its potential long-term tissue toxicity needs to be further investigated.

Postoperative sciatic and femoral or saphenous nerve blockade for lower extremity surgery in anesthetized adults

Background:

Guidelines warn of increased risks of injury when placing regional nerve blocks in the anesthetized adult but complications occurred in patients that received neither sedation nor local anesthetic. This restriction of nerve block administration places vulnerable categories of patients at risk of severe opioid induced side effects. Patient and operative technical factors can preclude use of preoperative regional anesthesia. The purpose of this study was to assess complications following sciatic popliteal and femoral or saphenous nerve blockade administered to anesthetized adult patients following foot and ankle surgery.

Materials and Methods:

Postoperative patients administered general anesthesia received popliteal sciatic nerve blockade and either femoral or saphenous nerve blockade if operative procedures included medial incisions. Nerve blocks were placed with nerve stimulator or ultrasound guidance. A continuous nerve catheter was inserted if hospital admission was over 24 hours. Opioid analgesic supplementation was administered for inadequate pain relief. Postoperative pain scores and total analgesic requirements for 24 hours were recorded. Nerve block related complications were monitored for during the hospital admission and at follow up surgical clinic evaluation.

Results:

190 anesthetized adult patients were administered 357 nerve blocks. No major nerve injury or deficit was reported. One patient had numbness in the toes not ascribed to a specific nerve of the lower extremity. Perioperative opioid dose differences were noted between male and female and between opioid naïve and tolerant patients.

Cold bupivacaine versus magnesium sulfate added to room temperature bupivacaine in sonar-guided femoral and sciatic nerve block in arthroscopic anterior cruciate ligament reconstruction surgery

BACKGROUND

Cooling of local anesthetic potentiates its action and increases its duration. Magnesium sulfate (MgSo₄) added to local anesthetic prolongs the duration of anesthesia and postoperative analgesia with minimal side effects.

AIM

The aim of this prospective, randomized, double-blind study was to compare the effect of cold to 4°C bupivacaine 0.5% and Mg added to normal temperature (20-25°C) bupivacaine 0.5% during sonar-guided combined femoral and sciatic nerve blocks on the onset of sensory and motor block, intraoperative anesthesia, duration of sensory and motor block, and postoperative analgesia in arthroscopic anterior cruciate ligament (ACL) reconstruction surgery.

PATIENTS AND METHODS

A total of 90 American Society of Anesthesiologists classes I and II patients who were scheduled to undergo elective ACL reconstruction were enrolled in the study. The patients were randomly allocated to 3 equal groups to receive sonar-guided femoral and sciatic nerve blocks. In Group I, 17 ml of room temperature (20-25°C) 0.5% bupivacaine and 3 ml of room temperature saline were injected for each nerve block whereas in Group II, 17 ml of cold (4°C) 0.5% bupivacaine and 3 ml of cold saline were injected for each nerve block. In Group III, 17 ml of room temperature 0.5% bupivacaine and 3 ml of MgSo₄ 5% were injected for each nerve block. The onset of sensory and motor block was evaluated every 3 min for 30 min. Surgery was started after complete sensory and motor block were achieved. Intraoperatively, the patients were evaluated for heart rate and mean arterial pressure, rescue analgesic and sedative requirements plus patient and surgeon satisfaction. Postoperatively, hemodynamics, duration of analgesia, resolution of motor block, time to first analgesic, total analgesic consumption, and the incidence of side effects were recorded.

RESULTS

There was no statistically significant difference in demographic data, mean arterial pressure, heart rate, and duration of surgery. Onset of both sensory and motor block was significantly shorter in both Groups II and III compared to Group I. Intraoperative anesthetic quality was comparable between groups with good patient and surgeon satisfaction. The time to first analgesia was significantly longer in Groups II and III compared to Group I with nonsignificant difference between each other. Moreover, the total opioid consumption was significantly lower in Groups II and III and duration of analgesia and motor block were significantly longer in Groups II and III compared to Group I. There was no difference in the incidence of side effects.

CONCLUSIONS

The use of cold 0.5% bupivacaine or the addition of Mg to normal temperature 0.5% bupivacaine prolongs the sensory and motor block duration without increasing side effects and enhances the quality of intra- and post-operative analgesia with better patient satisfaction in sonar-guided femoral and sciatic nerve block for arthroscopic ACL reconstruction surgery.

Readmission and Complications for Catheter and Injection Femoral Nerve Block Administration After Total Knee Arthroplasty in the Medicare Population

There is general agreement that femoral nerve blocks (FNB) provide adequate immediate postoperative analgesia after total knee arthroplasty (TKA), although the effect of this technique on hospital readmission and other complications has not been quantified in a large sample. The Medicare 5% sample was used to identify TKA patients who were grouped according to postoperative FNB administration: FNB via injection; FNB via pain pump; and no FNB. Multivariate Cox regressions were used to evaluate risk factors for the postoperative outcomes. Both FNB groups were associated with a lower risk of readmission (30, 90 and 365 days, P<0.001). Future clinical studies may help elucidate whether the lower hospital readmissions may be associated with more effective pain control with the use of FNB.

Adding dexmedetomidine to ropivacaine for lumbar plexus and sciatic nerve block for amputation of lower limb in high-risk patient-a case report

The ischemia necrosis of limb frequently requires surgery of amputation. Lumbar plexus and sciatic nerve block is an ideal intra-operative anesthetic and post-operative antalgic technique for patients of amputation, especially for high-risk patients who have severe cardio-cerebrovascular diseases. However, the duration of analgesia of peripheral nerve block is hardly sufficient to avoid the postoperative pain and the usage of opioids. In this case, a 79-year-old man, with multiple cerebral infarcts, congestive heart failure, atrial flutter and syncope, was treated with an above knee amputation because of ischemia necrosis of his left lower limb. Dexmedetomidine 1 μg/kg was added to 0.33% ropivacaine for lumbar plexus and sciatic nerve block in this case for intra-operative anesthesia and post-operative analgesia. The sensory function was blocked fully for surgery and the duration of analgesia maintained 26 hours with haemodynamic stability and moderate sedation. The patient did not complain pain and require any supplementary analgesics after surgery. This case showed that adding 1 μg/kg dexmedetomidine to ropivacaine for lumbar plexus and sciatic nerve block may be a feasible and safe technique for high-risk patients for lower limb surgery of amputation.

Comparison of local infiltration of analgesia and sciatic nerve block in addition to femoral nerve block for total knee arthroplasty

We conducted a prospective randomized controlled trial to test the null hypothesis that there is no difference between sciatic nerve block (SNB) and local infiltration of analgesia (LIA) regarding postoperative analgesia after total knee arthroplasty (TKA), when administrated in addition to femoral nerve block (FNB). Forty-six patients scheduled for TKA were randomized into two groups: concomitant administration of FNB and SNB or FNB and LIA. Average pain scores during the first 21days after surgery were similar in the two groups and remained at low level. There was no significant difference in the need for adjuvant analgesics, patient satisfaction level, the time to achieve rehabilitation goals, and length of hospital stay. The LIA offers a potentially safer alternative to SNB as an adjunct to FNB.

A randomized clinical trial comparing the effectiveness of ultrasound guidance versus nerve stimulation for lateral popliteal-sciatic nerve blocks in obese patients

OBJECTIVES

Ultrasound guidance may decrease the procedural time for many peripheral nerve blocks compared to nerve stimulation, but these studies have generally excluded obese patients. This single-blinded randomized clinical trial was designed to compare procedural times and related outcomes for ultrasound- versus nerve stimulation-guided lateral popliteal-sciatic nerve blockade specifically in obese patients.

METHODS

With Institutional Review Board approval and informed consent, patients with a body mass index greater than 30 kg/m(2) who were scheduled for foot/ankle surgery and desiring a peripheral nerve block were offered enrollment. Study patients were randomly assigned to receive a lateral popliteal-sciatic nerve block under either ultrasound or nerve stimulation guidance. The patient and assessor were blinded to group assignment. The primary outcome was procedural time in seconds. Secondary outcomes included number of needle redirections, procedure-related pain, patient satisfaction with the block, success rate, sensory and motor onset times, block duration, and complication rates.

RESULTS

Twenty-four patients were enrolled and completed the study. All patients had successful nerve blocks. The mean procedural times (SD) were 577 (57) seconds under nerve stimulation and 206 (40) seconds with ultrasound guidance (P< .001; 95% confidence interval for difference, 329-412 seconds). Patients in the ultrasound group had fewer needle redirections and less procedure-related pain, required less opioids, and were more satisfied with their block procedures. There were no statistically significant differences in other outcomes.

CONCLUSIONS

The results of this study show that, for obese patients undergoing lateral popliteal-sciatic nerve blocks, ultrasound guidance reduces the procedural time and procedure-related pain and increases patient satisfaction compared to nerve stimulation while providing similar block characteristics.

Comparing the effects of single shot sciatic nerve block versus posterior capsule local anesthetic infiltration on analgesia and functional outcome after total knee arthroplasty: a prospective, randomized, double-blinded, controlled trial

Peripheral nerve blocks appear to provide effective analgesia for patients undergoing total knee arthroplasty. Although the literature supports the use of femoral nerve block, addition of sciatic nerve block is controversial. In this study we investigated the value of sciatic nerve block and an alternative technique of posterior capsule local anesthetic infiltration analgesia. 100 patients were prospectively randomized into three groups. Group 1: sciatic nerve block; Group 2: posterior local anesthetic infiltration; Group 3: control. All patients received a femoral nerve block and spinal anesthesia. There were no differences in pain scores between groups. Sciatic nerve block provided a brief clinically insignificant opioid sparing effect. We conclude that sciatic nerve block and posterior local anesthetic infiltration do not provide significant analgesic benefits.

The effects of dexketoprofen on duration of analgesia to a thermal stimulus when compared with a systemic control in a rat sciatic nerve block with levobupivacaine

This study was designed to investigate whether dexketoprofen added to perineuraly or subcutaneously alters the effects of levobupivacaine in a rat model of sciatic nerve blockade. Thirty-six rats received unilateral sciatic nerve blocks along with a subcutaneous injection by a blinded investigator assigned at random. Combinations were as follows: Group 1 (sham) perineural and subcutaneous saline; Group 2, perineural levobupivacaine alone and subcutaneous saline; Group 3, perineural levobupivacaine plus dexketoprofen and subcutaneous saline; Group 4, perineural levobupivacaine and subcutaneous dexketoprofen; Group 5, perineural dexketoprofen and subcutaneous saline; and Group 6, perineural saline and subcutaneous dexketoprofen. The levobupivacaine concentration was fixed at 0.05%, and the dose of dexketoprofen was 1 mg kg(-1) . Sensory analgesia was assessed by paw withdrawal latency to a thermal stimulus every 30 min. The unblocked paw served as the control for the assessment of systemic, centrally mediated analgesia. Perineural and subcutaneous dexketoprofen coadministered with perineural levobupivacaine did not enhance the duration of sensory blockade when compared with levobupivacaine alone. There were significant differences between the operative and control paws for time points 30-90 min in the perineural levobupivacaine alone, levobupivacaine + dexketoprofen and subcutaneous dexketoprofen added levobupivacaine group. Significant differences were not determined between the levobupivacaine alone group and dexketoprofen added groups in operative paw. The effects of dexketoprofen are unknown for perineural administration. There is no significant difference between the analgesic effects of peripheral nerve blocks using levobupivacaine alone and plus subcutaneous or perineural dexketoprofen.

Ultrasound guided obturator versus sciatic nerve block in addition to continuous femoral nerve block for analgesia after total knee arthroplasty

Both obturator and sciatic nerve block in combination with femoral nerve block (FNB) have been suggested to be useful in relieving pain after total knee arthroplasty (TKA), compared with FNB alone. We compared their efficacy in this retrospective study. For six consecutive months, patients undergoing unilateral TKA under general anesthesia with continuous FNB plus obturator nerve block (n = 8) or continuous FNB plus sciatic nerve block (n = 8) were investigated. Knee pain was assessed using visual analogue scale (VAS) on the day of surgery and on postoperative days one to three. In addition, we also investigated intraoperative and postoperative morphine consumption. VAS scores and total morphine consumption were not different between the two groups, although patients in the FNB plus sciatic nerve block group were administered less morphine during surgery. Sciatic nerve block with continuous FNB may be superior to obturator nerve block with continuous FNB for analgesia during surgery for TKA.

A comparison of epidural anesthesia and lumbar plexus-sciatic nerve blocks for knee surgery

OBJECTIVES

The efficacy of combined lumbar plexus-sciatic nerve blocks was compared to epidural anesthesia in patients undergoing total knee surgery.

PATIENTS AND METHODS

The study included 80 American Society of Anesthesiologists (ASA) Physical Status I-III patients (age range 18 to 65) undergoing knee surgery. The patients were randomly divided into one of two groups. Epidural anesthesia was performed in the epidural anesthesia (EA) group (n=40), and the lumbar plexus and sciatic nerves were blockedin the lumbar plexus-sciatic nerve blocks (LPSB) group (n=40). For each patient, onset of sensory and motor block, degree of motor block, sign of sensory block in the contralateral lower limb for the lumbar plexus-sciatic nerve blocks group, success in providing adequate anesthesia, hemodynamic changes, time of first analgesic request, and patient and surgeon satisfaction with the anesthetic technique were recorded.

RESULTS

One patient in the epidural anesthesia group and three patients in the lumbar plexus-sciatic nerve blocks group required general anesthesia due to failed block. There were no significant differences between the two groups regarding the success of providing adequate anesthesia. Eight patients in the lumbar plexus-sciatic nerve blocks group developed contralateral spread. The onset of sensory-motor block and the time of the first analgesic request were significantly later in the lumbar plexus-sciatic nerve blocks group than in the epidural anesthesia group. Although there were no significant differences regarding patient satisfaction with the anesthetic technique between the two groups, surgeon satisfaction was significantly higher in the lumbar plexus-sciatic nerve blocks group than in the epidural anesthesia group.

CONCLUSION

The lumbar plexus -sciatic nerve blocks provide effective unilateral anesthesia and may offer a beneficial alternative to epidural anesthesia in patients undergoing total knee surgery.