Lumbar Plexus-sciatic Nerve Block Research Articles

Combined lumbar plexus sciatic nerve block for hip fracture: a case series with 442 patients

Introduction: Hip fractures are a global health problem in the elderly population. The mortality and morbidity after anesthesia are high in the elderly population with hip fractures due to numerous comorbidities. In recent years, the combined lumbar sciatic block (CLSB) method is safely applied in high-risk hip fracture surgeries. This study aims to examine 442 cases of hip fracture surgery in our clinic. Method: 442 high-risk patients operated in Istanbul University Cerrahpasa, Cerrahpasa Faculty of Medicine, Department of Orthopedics and Traumatology between 2004 and 2016 are included in this retrospective study. Neurostimulation technique combined with lumbar plexus and sciatic nerve block applied in all cases. The Lumber plexus block consists of bupivacaine 15 cc 0.5 % and prilocaine 15 cc 2%. Sciatic nerve block consists of bupivacaine 10 cc 0.5 % and prilocaine 10 cc 2%. Cases are evaluated for anesthesia quality and complication rate. Results: There was no need for any sedation or analgesia in 199 cases. Sedation was required in 147 cases. In 82 cases, the need for sedation combined with analgesia occurred. The conversion to general anesthesia was required in 14 cases. Complication wise, the epidural spread was observed in 5 cases and 3 cases got convulsions. Conclusion: It is concluded that CLSB is a safe alternative technique to use in high-risk hip fracture surgery.

Effects of dexmedetomidine combined with ropivacaine on the treatment of lumbar plexus sciatic nerve block in elderly patients with lower limb fractures

To further explore the effects of dexmedetomidine combined with ropivacaine in the treatment of lumbar plexus sciatic nerve block in elderly patients with lower limb fractures. 98 patients with lower limb fractures enrolled from January 2020 to January 2022 were randomly divided into the study and control groups, with 49 cases in each group. The study group received dexmedetomidine combined with ropivacaine for nerve block; while the control group received ropivacaine for nerve block. The anesthesia effect (duration time of onset and duration time of sensory block and motor block), heart rate, blood pressure, pain score, and adverse effects were compared between the study and control groups. Patients in the study group given dexmedetomidine combined with ropivacaine for lumbar plexus sciatic nerve block had a longer duration time of sensory block and motor block than the control group, showing a better anesthetic effect. The levels of mean arterial blood pressure (MAP) and heart rate (HR) in the study group at T1, T2, T3, T4, and T5 were significantly lower than that in the control group. The pain scores of the study group was lower than that of the control group, indicating the effects of dexmedetomidine combined with ropivacaine on reducing pain. Besides, the study group showed an adverse reaction incidence of 4.08%, which was slightly higher than that of the control group, with an index of 2.04%, without statistically significant difference. Dexmedetomidine combined with ropivacaine can enhance the effect of ropivacaine block, improve the heart rate index, and reduce patients’ pain, which is one of the reliable schemes in clinical practice for lumbar plexus sciatic nerve block.

Effects of Different Concentrations of Ropivacaine Lumbar Plexus-Sciatic Nerve Block on Recovery from Anesthesia, Postoperative Pain and Cognitive Function in Elderly Patients with Femoral Neck Fracture.

To investigate the effects of lumbar plexus-sciatic nerve block with different concentrations of ropivacaine on recovery from anesthesia, postoperative pain, and cognitive function in elderly patients with femoral neck fracture. A total of 110 elderly patients with femoral neck fractures who were treated in our hospital from January 2020 to January 2022 were selected as the research objects. According to the concentration of ropivacaine, they were divided into low-, medium-, and high-concentration groups (concentrations of ropivacaine were 0.15%, 0.25%, and 0.40%, respectively), with 36, 37, and 37 cases, respectively. Extubation time, anesthesia recovery time, and hospitalization time were recorded. Cognitive symptoms were assessed by the spatial cognitive ability, working memory ability, simple computing ability, and picture recognition ability test. The pain degree of patients was assessed by visual analogue scale (VAS). The occurrence of adverse reactions in patients was recorded. There was no significant difference in extubation time, anesthesia recovery time, and hospitalization time among the three groups (P > 0.05). The PCA time of the patients in the high-concentration group was significantly longer than that in the low- and medium-concentration groups. The dosage of sufentanil within 24 hours and total sufentanil in the high-concentration group were significantly lower than those in the low- and medium-concentration groups, and the dosage of sufentanil within 24 hours and total sufentanil in the medium-concentration group was significantly less than that in the low-concentration group (P < 0.05). The cognitive function score for each entry of the three groups 1 d after surgery was lower than that before surgery (P < 0.05); On the 1 day after operation, the cognitive function score for each entry of the patients in the low-concentration group was significantly higher than that in the middle- and high-concentration groups, and the cognitive function score for each entry in the middle-concentration group was significantly higher than that in the high-concentration group (P < 0.05). There was no significant difference in VAS scores between the three groups at 2 h and 8 h after surgery (P > 0.05); 16 h and 24 h after operation, the VAS score of patients in the high-concentration group was significantly lower than that in the low- and medium-concentration groups, and the VAS score in the medium-concentration group was significantly lower than that in the low-concentration ropivacaine group (P < 0.05). The incidence of adverse reactions in the high-concentration ropivacaine group was significantly higher than that in the low- and medium-concentration groups (P < 0.05). The middle concentration of ropivacaine has good analgesic and nerve block effects and has less influence on cognitive function and less adverse reactions in elderly patients.

Reduced Concentrations of NSE, S100β, Aβ, and Proinflammatory Cytokines in Elderly Patients Receiving Ultrasound-Guided Combined Lumbar Plexus-Sciatic Nerve Block during Hip Replacement.

Objective The increase of hip fractures is related to the aging of the population, which has caused a huge medical burden in many countries. Hip replacement has been approved as a highly successful surgical intervention for the patients with hip fractures. Different anesthesia choices in the surgical intervention are associated with the prognosis of patients. This study focused on investigating the application of ultrasound-guided combined lumbar plexus-sciatic nerve block in elderly patients with hip fractures. Methods In this retrospective study, 62 elderly patients received combined spinal-epidural anesthesia and 58 elderly patients underwent ultrasound-guided combined lumbar plexus-sciatic nerve block during the surgery. Hemodynamic monitoring including pulse oxygen saturation (SpO2), heart rate and blood pressure, the assessment of pain intensity using Visual Analogue Scale (VAS), cognitive function assessment through Montreal Cognitive Assessment (MoCA) and biomarkers consisting of serum levels of neuron specific-enolase (NSE), S100 beta protein (S100-β), and amyloid beta protein (Aβ), as well as immune function by interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and high sensitivity C-reactive protein (hs-CRP) were detected in this study. Furthermore, length of hospital stay (LOS) and adverse reactions including hematoma, hypotension, nausea, and vomit were analyzed. Results The findings indicated that comparing with the patients receiving combined spinal-epidural anesthesia, those undergoing ultrasound-guided combined lumbar plexus-sciatic nerve block showed significantly lower level of heart rate, higher level of SpO2, and lower level of diastolic pressure and systolic pressure at 5 minutes and 30 minutes after anesthesia and after surgery (P < 0.05), indicated obviously lower VAS score at 12, 24, and 48 hours after surgery (P < 0.05), and revealed higher MoCA score at 12 days after surgery (P < 0.05). A significantly higher level of NSE, S100β, Aβ, IL-6, IL-1β, TNF-α, and hs-CRP was revealed in the two groups receiving different anesthesia methods at 10 days after surgery compared with that before surgery (P < 0.05). However, the patients receiving ultrasound-guided combined lumbar plexus-sciatic nerve block had obviously lower expression of NSE, S100β, Aβ, IL-6, IL-1β, TNF-α, and hs-CRP compared with the group accepting combined spinal-epidural anesthesia (P < 0.05). The two groups indicated no significant difference in incidence of hypotension and vomit, etc. (P < 0.05), but showed remarkable difference referring to total incidence of adverse reactions and LOS (P < 0.05). Conclusion The application of ultrasound-guided combined lumbar plexus-sciatic nerve block in hip replacement contributes to the stability of hemodynamics and alleviation of postoperative pain intensity. It can reduce cognitive and immune impairment of the elderly patients with hip fractures.

Combined lumbar plexus-sciatic nerve block in the emergency surgery for pertrochanteric fracture: an alternative technique in patients at high risk of anaesthetic complications

Introductionl’anesthésie pour la chirurgie urgente de la fracture pertrochantérienne (FPT) chez les patients à haut risque anesthésique représente souvent un véritable challenge pour les praticiens en vue du risque periopératoire majeur. Nous rapportons notre expérience avec le bibloc ou bloc combiné lombaire et sciatique plexique (BCLS) comme technique anesthésique alternative face à ce type de situation.Méthodesune étude transversale, descriptive, monocentrique, a été menée sur une période de 3 ans, incluant les patients à haut risque anesthésique présentant une FPT récente. Les deux blocs nerveux étaient réalisés au niveau plexique selon la technique classique de neurostimulation. Un mélange de 20ml de lidocaine 2% et de bupivacaine 0,5% (50/50) a été injecté au niveau de chaque bloc. Le critère d’évaluation principal était l’efficacité du BCLS apprécié par l’incidence d’échecs de la technique anesthésique, définie par la nécessité de convertir en anesthésie générale (AG). Les critères d’évaluation secondaires étaient: 1) les données techniques de la procédure anesthésique, 2) les retentissements hémodynamiques, respiratoires et neurologiques periopératoires, et 3) les résultats et les complications éventuelles en postopératoire.Résultatstrente patients ont été colligés. L’âge moyen était de 74 ± 10 ans. Le délai moyen d’admission aux urgences-intervention était de 12(5-36) heures. La durée moyenne pour la réalisation de la procédure était de 15,20 ± 3,45 minutes. Aucune conversion en AG n’a été nécessaire. Il n’y avait pas de différences statistiquement significatives entre les différentes valeurs enregistrées des paramètres hémodynamiques et respiratoires periopératoires (PAM, FC, SpO2) (p > 0,05). La durée de l’intervention était de 46 ± 5 minutes. La satisfaction des chirurgiens était de 9,7 ± 0,1. La première demande en antalgiques postopératoires était après 8(1-24) heures. Tous les patients avaient une récupération sensitivomotrice complète.Conclusionle BCLS est une alternative anesthésique pour les interventions urgentes de FPT chez les patients à haut risque anesthésique: délais opératoires réduits, efficacité anesthésique, stabilité hémodynamique et respiratoire periopératoire, absence de complications inhérentes aux autres techniques anesthésiques, passage rapide en salle de surveillance post-interventionnelle (SSPI), et analgésie postopératoire de qualité.

Effects of lumbar plexus-sciatic nerve block on postoperative outcome in elderly patients after total hip arthroplasty

Objective To investigate the effects of lumbar plexus-sciatic nerve block combined with general anesthesia on postoperative outcome in elderly patients after total hip arthroplasty. Methods Seventy elderly patients who were scheduled for total hip arthroplasty were randomly divided into two groups: group LPSN (n=35) and group GA (n=35), lumbar plexus-sciatic nerve block combined with general anesthesia were performed in patients of group LPSN, patients in group GA were performed with general anesthesia. saturation of pulse oximetry (SpO2), Visual analogue scale (VAS) before anesthesia (T0), at 3 h (T1), 24 h (T2), 48 h (T3) after anesthesia, operation time, the remifentanil consumption, time to remove the tracheal tube, the incidence of respiratory events and the length of stay were recorded. Results As compared with group GA, the VAS of group LPSN was reduced at T1, T2[(2.5±1.4) vs. (3.2±1.4), (1.9±1.2) vs. (2.7±1.2), P 0.05]. Conclusion lumbar plexus-sciatic nerve block combined with general anesthesia could decrease the use of remifentanil in elderly patients after total hip arthroplasty, have a fewer incidence of respiratory events, and it is beneficial to the early postoperative rehabilitation. Key words: Nerve block; Elderly patient; Arthroplasty; Postoperative outcome

Application value of ultrasound guided lumbar plexus sciatic nerve block anesthesia in elderly patients with hip replacement

Objective To investigate the effect of ultrasound guided lumbar plexus sciatic nerve block anesthesia in elderly patients undergoing hip replacement. Methods From June 2015 to June 2016, 84 elderly patients in Taizhou Bone Injury Hospital received hip replacement were randomly divided into 2 groups according to the digital table, with 42 patients in each group.The control group received epidural anesthesia, the observation group received ultrasound guided lumbar plexus sciatic nerve block anesthesia.The occurrence of adverse reaction, hemodynamic changes and the effect of anesthesia were observed in the two groups. Results In the control group, the SBP, DBP levels at T2, T3, T4, T5 were lower than those at T0 (t=3.998, 4.042, 3.768, 3.974, 4.505, 4.276, 4.022, 4.076, all P 0.05). The SBP, DBP levels at T2, T3, T4, T5 in the observation group were higher than those in the control group (t=3.667, 3.839, 3.997, 3.654, 3.330, 3.675, 3.759, 3.885, all P<0.05). The excellent and good rate of anesthesia effect in the observation group was 95.24%, which was significantly higher than 78.57% in the control group, and the difference was statistically significant (χ2=12.209, P<0.05). Conclusion Ultrasound guided lumbar plexus sciatic nerve block anesthesia for elderly patients underwent hip replacement has good effect, and has no obvious influence on hemodynamics, and with less adverse reactions. Key words: Arthroplasty, replacement, hip; Anesthesia; Sciatic nerve; Nerve block; Ultrasonography, interventional; Aged

General laryngeal mask airway anesthesia with lumbar plexus and sciatic block provides better outcomes than general anesthesia and endotracheal intubation in elderly patients undergoing hip surgery

ObjectiveTo compare the perioperative outcomes and hemodynamic effects at induction of general laryngeal mask airway (LMA) anesthesia with lumbar plexus-sciatic nerve block (LPSB) and general anesthesia with endotracheal intubation (ET) in elderly patients undergoing hip surgery. MethodsA total of 63 patients having open reduction internal fixation of an intertrochanteric fracture were randomly assigned to receive LMA anesthesia with LPSB or general anesthesia with ET. Perioperative and postoperative outcomes were compared between the 2 groups. ResultsCompared with the LMA/block group, there were significant reductions in systolic blood pressure, diastolic blood pressure, and mean arterial pressure at induction in the general endotracheal group (all, P < 0.001). In the general ET group, 84% of the patients experienced at least one episode of significant hypotension, whereas no patient in the LMA/block group had significant hypotension (P < 0.001). There were no changes in cardiac output, cardiac index, stroke volume, and stroke volume index of the LMA/block group, whereas significant changes were noted in the general anesthesia ET group. Significantly fewer complications were noted in the LMA/block group, and LMA block was associated with shorter weaning time, fewer returns to the intensive care unit, and less postoperative pain. ConclusionsGeneral LMA anesthesia with LPSB provides better outcomes that general ET anesthesia in elderly patients undergoing hip surgery.

Impact of local administration of various doses of dexmedetomidine on ropivacaine-induced lumbar plexus-sciatic nerve block.

The present study aimed to investigate the impact of various doses of dexmedetomidine (DEX) on ropivacaine (ROP)-induced lumbar plexus-sciatic nerve block (LSB). A total of 80 patients who underwent ankle surgery under LSB were divided into group R (applied with 30 ml 5% ROP), Dex1 (30 ml 0.5% ROP + 1 µg/kg DEX), Dex2 (30 ml 0.5% ROP + 1.5 µg/kg DEX) and Dex3 (30 ml 0.5% ROP + 2 µg/kg DEX), with 20 cases in each group. The onset time and duration of sensory and motor block, mean arterial pressure (MAP), heart rate (HR), oxygen saturation, Ramsay score, serum vascular endothelial growth factor (VEGF) level and adverse reactions in the four groups were observed. Results demonstrated that the durations of sensory and motor block in group R were shorter than those in groups Dex1-3 (P<0.01), followed by the sequence of group Dex1<Dex2<Dex3 (P<0.05). MAP and HR in groups Dex1-3 at T2-T5 were significantly lower than those in group R (P<0.01), and HR in group Dex3 at T3 and T4 was significantly lower than that in groups Dex1 and Dex2 (P<0.05). Ramsay scores in groups Dex1-3 at T2-T4 were significantly higher than those in group R (P<0.05). Serum VEGF levels in groups Dex2 and Dex3 at T2-T5 were significantly higher than those in group R (P<0.01). The incidences of over-sedation, bradycardia and dry mouth in group Dex3 were notably higher than those in the other groups. In conclusion, 1.5 µg/kg DEX exhibits a superior effect in improving ROP-induced LSB.

Comparison of combined spinal-epidural anesthesia versus lumbar plexus-sciatic nerve block in elderly patients undergoing internal fixation of hip fractures

Objective To compare combined spinal-epidural anesthesia(CSEA)versus lumbar plexus-sciatic nerve block(LPSB)in elderly patients undergoing internal fixation of hip fractures. Methods Sixty American Society of Anesthesiologists physical status Ⅱ or Ⅲ elderly patients, aged 66-94 yr, with body mass index of 15.2-28.0 kg/m2, scheduled for internal fixation of hip fractures, were randomly assigned into CSEA group and LPSB group using SPSS 18.0 software, with 30 patients in each group.In CSEA group, intrathecal catheter was successfully placed at L3, 4 interspace, 0.5% hyperbaric bupivacaine 8-10 mg was injected into the subarachnoid space and then an epidural catheter was placed.In LPSB group, posterior lumbar plexus block was performed with 0.4% ropivacaine 25-30 ml and parasacral sciatic nerve block with 0.4% ropivacaine 15-20 ml.Dexmedetomidine 0.4-0.6 μg·kg-1·h-1 was infused during the procedure to maintain the Observer′s Assessment of Alertness/Sedation Scale score of 3 or 4 in two groups.Patient-controlled intravenous analgesia was performed with sufentanil and lasted for 48 h. The anesthesia time, volume of intraoperative fluid infused, blood loss, consumption of dexmedetomidine, requirement for vasoactive agents, cardiovascular events, consumption of sufentanil within 24 and 48 h after surgery, rescue analgesia and postoperative adverse reactions were recorded. Results Compared with CSEA group, the anesthesia time was significantly prolonged, the volume of intraoperative fluid infused and consumption of ephedrine were reduced, the consumption of dexmedetomidine was increased, the incidence of bradycardia was decreased, the postoperative consumption of sufentanil was reduced, the rescue analgesia rate was decreased, and no significant change was found in the incidence of postoperative adverse events in LPSB group(P>0.05). Conclusion LPSB can maintain hemodynamics stable and provide postoperative analgesic effect, with better anesthetic efficacy than CSEA when used for internal fixation of hip fractures in elderly patients. Key words: Anesthesia, spinal; Anesthesia, epidural; Nerve block; Hip fracture; Aged

Effects of lumbar plexus-sciatic nerve block combined with sevoflurane on cognitive function in elderly patients after hip arthroplasty: study protocol for a prospective, single-center, open-label, randomized, controlled clinical trial

Background: Elderly patients often suffer from postoperative cognitive dysfunction after total hip arthroplasty, but the precise mechanism remains unclear. Sevoflurane regulates the concentration of basic fibroblast growth factor in the brain, but it is not known whether sevoflurane can decrease cognitive dysfunction after hip arthroplasty. We hypothesized that lumbar plexus-sciatic nerve block combined with sevoflurane could reduce the incidence of cognitive dysfunction in elderly patients after hip arthroplasty. Methods/Design: We conducted a prospective, single-center, open-label, randomized, controlled clinical trial at the Affiliated Hospital, Qinghai University, China. Seventy elderly patients undergoing unilateral total hip arthroplasty were randomized into two groups. All patients underwent endotracheal intubation and mechanical ventilation. In the experimental group, a lumbar plexus-sciatic nerve block was performed and general anesthesia was maintained with sevoflurane. In the control group, general anesthesia was maintained with intravenous propofol. Outcomes were measured preoperatively and on the first and third postoperative days. The primary outcome measure was the Mini-Mental State Examination, and the secondary outcomes were the Montreal Cognitive Assessment, serum basic fibroblast growth factor concentration, intraoperative blood loss, and operation time. The other outcome was the incidence of intraoperative and postoperative adverse events. Discussion: This trial examined whether lumbar plexus-sciatic nerve block combined with sevoflurane reduced the incidence of cognitive dysfunction in elderly patients after hip arthroplasty, documented the changes in serum basic fibroblast growth factor concentration, and further explored the therapeutic mechanism of sevoflurane. Trial registration: ClinicalTrials.gov identifier: NCT03162861. Ethics: The study protocol has been approved by the Ethics Committee of Affiliated Hospital of Qinghai University of China. All protocols will be in accordance with Declaration of Helsinki, formulated by the World Medical Association. Informed consent: Written informed consent was provided by participants prior to enrollment in the trial.

Effects of age factors on pharmacokinetics of ropivacaine during combined lumbar plexus-sciatic nerve block

Objective To evaluate the effects of age factors on the pharmacokinetics of ropivacaine during combined lumbar plexus-sciatic nerve block in patients. Methods Twenty patients of both sexes, aged ≥18 yr, weighing 50-75 kg, of American Society of Anesthesiology physical status Ⅰ or Ⅱ, scheduled for elective lower extremity surgery, were divided into 2 groups (n=10 each) according to age: young and middle-aged group (18-59 yr) and elderly group (≥ 60 yr). Combined lumbar plexus-sciatic never block was performed using an ultrasonic instrument and a nerve stimulator.Lumbar plexus block was performed with 0.5% ropivacaine 30 ml.Sciatic never block was performed with 2% lidocaine 10 ml plus 0.75% ropivacaine 10 ml.Before administration and at 5, 10, 15, 20, 30, 45, 60, 120, 180 and 360 min after administration, blood samples were collected from the radial artery for determination of the blood concentration of ropivacaine by high-performance liquid chromatography.The area under the concentration-time curve, maximum concentration (Cmax), time to Cmax, terminal elimination half-life and clearance were calculated. Results Compared with young and middle-aged group, the blood concentration of ropivacaine was significantly decreased at 5-45 min after administration, the Cmax was significantly decreased, terminal elimination half-life was significantly prolonged (P 0.05). Conclusion Age factors can affect the pharmacokinetics of ropivacaine during combined lumbar plexus-sciatic nerve block, and both absorption and metabolism of ropivacaine are slower in elderly patients than in young and middle-aged patients. Key words: Age factor; Amides; Pharmacokinetics; Lumbosacral plexus; Sciatic nerve; Neuromuscular blockade

The Effects of Lidocaine Used in Sciatic Nerve on the Pharmacodynamics and Pharmacokinetics of Ropivacaine in Sciatic Nerve Combined with Lumbar Plexus Blockade: A Double‐Blind, Randomized Study

In this controlled, randomized, double-blind study, we compared the pharmacodynamics and pharmacokinetics of ropivacaine and staged injection of lidocaine and ropivacaine in a combined lumbar plexus-sciatic nerve block. The experiment was performed in two parts: pharmacodynamics study (Group r, n = 20; Group lr, n = 20) and pharmacokinetics study (Group R, n = 10; Group LR, n = 10). The sciatic nerve blockade was performed using either (1) 10 mL of 2% lidocaine and then 10 mL of 0.75% ropivacaine (Group lr and Group LR) or (2) 10 mL of normal saline (N.S.) and then 10 mL of 0.75% ropivacaine (Group r and Group R). Two kinds of solutions were 'staged' injection. The sensory onset time and sensory recovery time were assessed in the pharmacodynamics study. Arterial blood samples were collected for the pharmacokinetics study. Sciatic sensory block onset times were reduced, and the sensory recovery times were decreased in Group lr. C(max) of ropivacaine in Group LR was significantly higher than that in Group R. A significant increase in AUC((0-t)) and AUC((0-∞)) was observed in Group LR compared with Group R. When 2% lidocaine and 0.75% ropivacaine are used for a combined sciatic nerve-lumbar plexus block by 'staged' injection, lidocaine induced faster onset times, decreased the block duration and increased the AUC and C(max) of ropivacaine.

Comparison of effects of sevoflurane versus propofol on tourniquet-induced lower extremity ischemia-reperfusion injury in patients undergoing orthopedic operation

Objective To compare the effects of sevoflurane versus propofol on a tourniquet-induced lower extremity ischemia-reperfusion (I/R) injury in patients undergoing orthopedic operation.Methods Fifty-four ASA Ⅰ or Ⅱ patients,aged 18-64 yr,weighing 44-85 kg,scheduled for elective orthopedic operation,were randomly assigned into 3 groups (n =18 each)∶ control group (group C),propofol group (group P) and sevoflurane group (group S).After lumbar plexus-sciatic nerve block,the laryngeal mask airway insertion was facilitated with propofol 2-4 mg/kg and anesthesia was maintained with infusion of propofol at 2-4 mg· kg-1 · h-1 during operation in group P.In group S,8 ％ sevoflurane was inhaled,the laryngeal mask airway was inserted and anesthesia was maintained with inhalation of 2％ sevoflurane during operation.A tourniquet was applied and inflated (300 mm Hg)during 15-20 min after administration of propofol or sevoflurane in groups P and S,and a tourniquet was also applied at the same time point in group C.The tourniquet was released at the end of operation.Postoperative analgesia was performed with oral meloxicam or intramuscular pethidine and VAS score was maintained ＜ 3.Blood samples were taken after admission to the operating room (T1) and 30 min after tourniquet release (T2) to determine the plasma concentrations of MDA and TNF-α.The changing rate of MDA and TNF-α concentrations was calculated.The tourniquet-related adverse events and amount of analgesics consumed within 24 h after operation were recorded.Results No tourniquet-related adverse events occurred in all the patients.Compared with group C,the plasma concentrations of MDA and TNF-α and changing rate were significantly decreased at T2 in groups P and S (P ＜ 0.05).There were no significant differences in the plasma concentrations of MDA and TNF-α and changing rate between group S and group P (P ＞ 0.05).Compared with the baseline value at T1,no significant change was found in the plasma concentrations of MDA and TNF-α at T2 in groups P and S (P ＞ 0.05),and the plasma concentrations of MDA and TNF-α were significantly increased at T2 in group C (P ＜ 0.05).There was no significant difference in the amount of analgesics consumed within 24 h after operation between the three groups (P ＞ 0.05).Conclusion Both sevoflurane and propofol can reduce a tourniquet-induced lower extremity I/R injury in patients undergoing orthopedic operation and the efficacy is comparable. Key words: Anesthetics, inhalation ; Propofol ; Tourniquets ; Reperfusion injury ; Lower extremity

Time course of action and pharmacokinetics of ropivacaine in adult and elderly patients following combined lumbar plexus-sciatic nerve block

Large doses of local anesthetics are needed in combined lumbar plexus-sciatic nerve block. The safety of local anesthetics is important among elderly patients. This study investigates the pharmacokinetics of ropivacaine in elderly patients with combined lumbar plexus-sciatic nerve block. Ropivacaine pharmacokinetics and the time of onset, duration of sensory and motor block were studied in adult patients (18 - 60 y) and elderly patients (>= 60 y). Combined lumbar plexus-sciatic nerve block was performed using a nerve stimulator. 0.375% ropivacaine was injected in patients. Plasma concentration of ropivacaine was determined by high performance liquid chromatography. There was no significant difference in onset time and time to peak (tmax1, tmax2) between elderly patients and adult patients. Half-life time (t1/2alpha, t1/2beta) and the duration of sensory and motor block were longer in elderly patients (p < 0.05). While the peak plasma concentrations of (double peaks, Cmax1, Cmax2) wer lower in elderly patients than that in adult patients. Age does not affect the onset time of ropivacaine after combined lumbar plexus-sciatic nerve block but can influence the motor and sensory recovery. Local absorption of ropivacaine is slower in elderly patients compared to adults.

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.