Cortical modulations before lower limb motor blocks are associated with freezing of gait in Parkinson's disease: an EEG source localization study.

BACKGROUND: Freezing of gait (FOG) is a debilitating symptom of Parkinson's disease (PD) characterized by paroxysmal episodes in which patients are unable to step forward. A research priority is identifying cortical changes before freezing in PD-FOG. METHODS: We tested 19 patients with PD who had been assessed for FOG (n=14 with FOG and 5 without FOG). While seated, patients stepped bilaterally on pedals to progress forward through a virtual hallway while 64-channel EEG was recorded. We assessed cortical activities before and during lower limb motor blocks (LLMB), defined as a break in rhythmic pedaling, and stops, defined as movement cessation following an auditory stop cue. This task was selected because LLMB correlates with FOG severity in PD and allows recording of high-quality EEG. Patients were tested after overnight withdrawal from dopaminergic medications ("off" state) and in the "on" medications state. EEG source activities were evaluated using individual MRI and standardized low resolution brain electromagnetic tomography (sLORETA). Functional connectivity was evaluated by phase lag index between seeds and pre-defined cortical regions of interest. RESULTS: EEG source activities for LLMB vs. cued stops localized to right posterior parietal area (Brodmann area 39), lateral premotor area (Brodmann area 6), and inferior frontal gyrus (Brodmann area 47). In these areas, PD-FOG (n=14) increased alpha rhythms (8-12 Hz) before LLMB vs. typical stepping, whereas PD without FOG (n=5) decreased alpha power. Alpha rhythms were linearly correlated with LLMB severity, and the relationship became an inverted U-shape when assessing alpha rhythms as a function of percent time in LLMB in the "off" medication state. Right inferior frontal gyrus and supplementary motor area connectivity was observed before LLMB in the beta band (13-30 Hz). This same pattern of connectivity was seen before stops. Dopaminergic medication improved FOG and led to less alpha synchronization and increased functional connections between frontal and parietal areas. CONCLUSIONS: Right inferior parietofrontal structures are implicated in PD-FOG. The predominant changes were in the alpha rhythm, which increased before LLMB and with LLMB severity. Similar connectivity was observed for LLMB and stops between the right inferior frontal gyrus and supplementary motor area, suggesting that FOG may be a form of "unintended stopping." These findings may inform approaches to neurorehabilitation of PD-FOG.

Programmed intermittent epidural bolus regimen vs continuous epidural infusion: a retrospective study of motor block and obstetric outcomes using the Robson's Ten Group Classification System.

BACKGROUND: Use of a programmed intermittent epidural bolus (PIEB) regimen during labour is associated with several benefits over a continuous epidural infusion (CEI), including reduced local anaesthetic consumption and reduced risk of motor block. We hypothesise that the benefits of a PIEB regimen may vary according to the Robson Ten Group Classification System (TGCS). The aim of this study was to determine if introduction of a PIEB regimen was associated with reduced incidence of motor block. We also wished to examine changes in obstetric outcomes following PIEB introduction across the Robson TGCS. METHODS: This was a single-centre retrospective cohort study. Data were collected over two three-month periods before and after PIEB introduction. The primary outcome was the incidence of motor block. Maternal and obstetric outcomes across Robson Groups 1-4 were analysed. RESULTS: Introduction of PIEB was associated with reduced incidence of motor block (28.4% (95% CI 25.7% to 31.3%) vs 22.4%, (95% CI 19.9% to 25.2%), difference 5.9% (95% CI 1.0% to 21.1%), P=0.003), with no association with changes in rates of caesarean section, operative vaginal delivery or other obstetric outcomes. Use of a PIEB regimen was associated with reduced incidence of motor block in Robson Group 4a (20.3% (16.0%, 28.0%) vs 12.0%, (7.6%, 16.4%), difference 9.9% (95% CI -17.4% to -2.4%) P=0.009). There were no significant changes in other outcomes assessed across Robson TGCS. CONCLUSION: Introduction of PIEB for maintenance of labour analgesia was associated with reduced incidence of motor block in our institution compared with CEI. Presenting results according to Robson's TGCS in future studies may allow better elucidation of the impact of neuraxial analgesia on maternal and obstetric outcomes.

The Effects of Premedication With Three Different Doses of Intravenous Dexmedetomidine on Spinal Anesthesia: A Randomized Comparative Study.

BACKGROUND: Intravenous dexmedetomidine is one of the commonly preferred techniques for sedation during any regional procedure. However, only a very few studies compared the impact of different bolus doses during spinal anesthesia, and none for our geographical area. MATERIALS AND METHODS: A total of 60 patients were allocated into either of the three groups (group I, II, III) to receive intravenous dexmedetomidine 0.5, 0.75, and 1 mcg/kg, respectively. The primary outcome was to compare the duration of sensory and motor blockade and the secondary outcomes were the level of sedation, hemodynamic stability, duration of analgesia, and the side effects, if any. RESULTS: Two-dermatome regression time and the duration of motor block were significantly higher in groups II and III when compared to group I. However, the difference in duration of analgesia, Ramsay sedation scores, bradycardia, and hypotension was statistically insignificant between the groups. CONCLUSION: Intravenous dexmedetomidine in doses of 0.75 and 1 mcg/kg significantly prolongs the two-dermatome regression time and duration of the motor block when compared to 0.5 mcg/kg dose. Hence, it is better to titrate the dose between 0.75 and 1 mcg/kg, as the administration of bolus intravenous Dex in doses ranging between 0.75 and 1 mcg/kg appears to provide adequate intraoperative block characteristics while maintaining hemodynamic stability without any significant respiratory depression or other adverse effects.

Adding intrathecal midazolam to local anesthetics improves sensory and motor block and reduces pain score without increasing side effects in lower limb surgeries: A meta-analysis and systematic review.

This meta-analysis was done to investigate the role of intrathecal midazolam in lower limb surgeries regarding prolongation of spinal block, postoperative pain control and associated side effects. The included studies reported onset and duration of sensory and motor block, time to first request analgesia, 24h opioid consumption, postoperative pain control, and associated side effects following use of intrathecal midazolam for lower limb surgeries. This review was performed following the PRISMA guidelines and using the online databases, Medline, Science Direct, Google scholar and Cochrane library. We registered this review with the PROSPERO database (ID-CRD42022346361) in August 2022. A total of 10 randomised controlled trials were included in this meta-analysis. Our results showed patients receiving 1mg intrathecal midazolam showed significantly faster onset of sensory block [P=.001 (CI: -0.98, -0.31)]. Duration of sensory and motor block were also significantly prolonged in intrathecal midazolam group [P<.00001 (CI: 18.08, 39.12), P=.002 (CI: 0.45, 2). Intrathecal midazolam also increased the time to first request analgesia [P=.0003, (CI: 1.22, 4.14)]. Pain scores at 4 and 12h postoperatively were significantly lower in patients receiving intrathecal midazolam [P=.00001 (CI: -1.20, -0.47) and P=.05 (CI: -0.52, -0.01) respectively]. In conclusion, the addition of intrathecal midazolam to local anesthetics in lower limb surgeries results in early onset of sensory and motor block. It also increases the duration of sensory and motor block. The time to first request analgesia is increased. VAS pain scores at 4 and 12h postoperatively were also lower without any increased side effects.

Effects of combined spinal-epidural anesthesia on anxiety, labor analgesia and motor blocks in women during natural delivery.

BACKGROUND: The background of this study was analgesia in natural delivery. The combined spinal-epidural anesthesia has obvious analgesic effect on the parturients in natural labor, and combined spinal-epidural anesthesia has been widely used in anesthesia for various diseases. AIM: To study the effects of combined spinal-epidural anesthesia on anxiety, labor analgesia, and motor blocks in parturients during natural delivery. METHODS: A total of 120 women who gave birth at Changning District Maternal and Child Health Hospital between December 2021 to December 2022 were included; a random number table approach was employed to divide the women into a control group and a joint group, with each group consisting of 60 women. The control group was given epidural anesthesia, while the joint group was given combined spinal-epidural anesthesia. The visual analog scale (VAS) was used to evaluate the degree of maternal pain. Comparisons were made between the two groups' conditions of childbirth and the duration of labor. Apgar scores were used to evaluate the status of the newborns at birth; Self-rating Anxiety Scale (SAS) and General Self-Efficacy Scale (GSES) scores, umbilical artery blood gas analysis indices and stress indices were compared between the two groups; and the frequencies of motor block and postpartum complications were analyzed. RESULTS: In comparison to the control group, in the joint group, the VAS scores for the first, second, and third stages of labor were lower (P < 0.05). The rates of conversion to cesarean section and postpartum blood loss in the joint group were lower than those in the control group (P < 0.05). No significant differences were observed in the Apgar score, the duration of the first stage of labor, or the total duration of labor between the two groups (P > 0.05). The second and third stages of labor in the joint group were shorter than those in the control group (P < 0.05). When compared to the control group, the postpartum SAS score of the joint group was lower, while the GSES score was greater (P < 0.05). Between the control group and the joint group, the differences observed in pH, arterial carbon dioxide partial pressure, arterial oxygen partial pressure, or arterial hydrogen ion concentration were not significant (P > 0.05). Nitric oxide, cortisol, and adrenaline levels were lower in the joint group than in the control group (P < 0.05). There were no substantial differences in Bromage grade or rate of complications between the two groups (P > 0.05). CONCLUSION: For parturients during natural delivery, combined spinal-epidural anesthesia can reduce anxiety, provide labor analgesia, shorten labor time, and reduce postoperative stress levels but did not result in a motor block.

High-volume patient-controlled epidural vs. programmed intermittent epidural bolus for labour analgesia: a randomised controlled study.

The aim of neuraxial analgesia is to achieve excellent pain relief with the fewest adverse effects. The most recently introduced technique for epidural analgesia maintenance is the programmed intermittent epidural bolus. In a recent study, we compared this with patient-controlled epidural analgesia without a background infusion and found that a programmed intermittent epidural bolus was associated with less breakthrough pain, lower pain scores, higher local anaesthetic consumption and comparable motor block. However, we had compared 10 ml programmed intermittent epidural boluses with 5 ml patient-controlled epidural analgesia boluses. To overcome this potential limitation, we designed a randomised, multicentre non-inferiority trial using 10 ml boluses in each group. The primary outcome was the incidence of breakthrough pain and total analgesic intake. Secondary outcomes included motor block; pain scores; patient satisfaction; and obstetric and neonatal outcomes. The trial was considered positive if two endpoints were met: non-inferiority of patient-controlled epidural analgesia with respect to breakthrough pain; and superiority of patient-controlled epidural analgesia with respect to local anaesthetic consumption. A total of 360 nulliparous women were allocated randomly to patient-controlled epidural analgesia-only or programmed intermittent epidural bolus groups. The patient-controlled group received 10 ml boluses of ropivacaine 0.12% with sufentanil 0.75 µg.ml-1 ; the programmed intermittent group received 10 ml boluses supplemented by 5 ml patient-controlled boluses. The lockout period was 30 min in each group and the maximum allowed hourly local anaesthetic/opioid consumption was identical between the groups. Breakthrough pain was similar between groups (11.2% patient controlled vs. 10.8% programmed intermittent, p = 0.003 for non-inferiority). Total ropivacaine consumption was lower in the PCEA-group (mean difference 15.3 mg, p < 0.001). Motor block, patient satisfaction scores and maternal and neonatal outcomes were similar across both groups. In conclusion, patient-controlled epidural analgesia is non-inferior to programmed intermittent epidural bolus if equal volumes of patient-controlled epidural analgesia are used to maintain labour analgesia and superior with respect to local anaesthetic consumption.

Evaluation of the Effect of Intravenous Dexamethasone on the Duration of Spinal Anaesthesia in Parturients Undergoing Lower Segment Caesarean Section.

Introduction Dexamethasone is shown to prolong the duration of nerve blocks when administered perineurally as well as intravenously. The effect of intravenous dexamethasone on the duration of hyperbaric bupivacaine spinal anesthesia is lesser known. We conducted a randomized control trial to determine the effect of intravenous dexamethasone on the duration of spinal anesthesia in parturients undergoing lower-segment cesarean section (LSCS). Methods Eighty parturients planned for LSCS under spinal anesthesia were randomly allocated to two groups. Patients in group A were administered dexamethasone intravenously, and group B received normal saline intravenously before spinal anesthesia. The primary objective was to determine the effect of intravenous dexamethasone on the duration of sensory and motor block after spinal anesthesia. The secondary objective was to determine the duration of analgesia and complications in both groups. Result The total duration of the sensory and motor blocks in group A was 118.38 ± 19.88 minutes and 95.63 ± 19.91 minutes, respectively. The entire sensory and motor blockade duration in group B was 116.88 ± 13.48 minutes and 97.63 ± 15.15 minutes, respectively. The difference between the groups was found to be statistically insignificant. Conclusion Intravenous 8 mg dexamethasone in patients planned for LSCS under hyperbaric spinal anesthesia does not prolong the sensory or motor block duration compared to placebo.

Comparison of Intravenous Granisetron and Ondansetron on Hemodynamics and Sensory Motor Block After Spinal Anaesthesia With Hyperbaric Bupivacaine in Patients Undergoing Elective Surgery: A Randomized Double-Blind Study.

BACKGROUND: Bezold Jarisch reflex (BJR) is mediated by peripheral serotonin receptor 5-HT3 type. BJR and sympathetic blockade are important causes of hypotension and bradycardia after spinal anaesthesia. Premedication with serotonin receptor antagonists has a role in the attenuation of hemodynamic disturbances. AIM: To compare the effect of intravenous granisetron and ondansetron on the hemodynamic and sensory-motor block after spinal anaesthesia with hyperbaric bupivacaine in patients undergoing elective surgery. METHODOLOGY: Ninety patients posted for elective surgery under spinal anaesthesia were randomly divided into three groups of 30 each. Group A patients received ondansetron 4mg, group B received granisetron 1mg, and group C received normal saline intravenously. Hemodynamic variables such as heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and peripheral oxygen saturation, were recorded at baseline and then 2 minutes intervals for 20 minutes and thereafter every 5 minutes till the end of the surgery. The onset and duration of sensory and motor block were recorded at baseline and then every 2 minutes till the complete block was achieved. RESULT: No patient was excluded from our study. During the intergroup comparison, heart rate and mean arterial pressure remained stable in group A compared to groups B and C. Time to reach peak sensory block level T4 was faster in group A compared to group B and group C. The rate of sensory block regression to two segments (T4 to T6) and thereafter up to T10, T12, and S1 was faster in group B compared to groups A and C. The attainment of complete motor block, Modified Bromage Score (MBS)=4 was faster in group A compared to group B and group C. The rate of motor block regression to MBS=3 and MBS=0 was faster in group B compared to group A and group C. CONCLUSION: Premedication with ondansetron 4mg and granisetron 1mg intravenously significantly reduces ephedrine use. Ondansetron provides better hemodynamic stability, earlier onset of the sensory and motor blocks as well as prolonged duration of sensory and motor blocks, and duration of analgesia compared to granisetron.

Isobaric forms of ropivacaine vs. bupivacaine in lower abdominal surgeries: a hospital-based, prospective, comparative study.

We aimed to assess whether ropivacaine (0.75%; 22.5 mg) can replace bupivacaine (0.5%; 15 mg) as a better intrathecal anesthetic in lower abdominal surgery. In this hospital-based, single-blind, randomized, prospective, comparative study, 100 patients of either sex, aged between 18 and 70 years, weighing 40-80 kg, with American Society of Anesthesiologists physical status 1 and 2, and undergoing lower abdominal surgery were randomly allocated into two groups to receive intrathecal isobaric bupivacaine 0.5% 3 mL (15 mg) or ropivacaine 0.75% 3 mL (22.5 mg). In the intraoperative period, the onset, efficacy, duration, and regression of sensory and motor blockade and the quality of anesthesia and hemodynamic effects were observed at regular intervals. The ropivacaine and bupivacaine groups were comparable for demographic parameters. The duration of onset of sensory and motor blocks was significantly shorter in the bupivacaine group (P < 0.01). In the ropivacaine group, a faster recovery from sensory block (P = 0.02) and higher segmental height [thoracic (T)10 and T8] were achieved (P < 0.01). Bradycardia and hypotension were insignificant in the ropivacaine group (P > 0.05). Isobaric ropivacaine is a better spinal anesthetic in lower abdominal surgeries as it provides faster recovery from sensory block and a higher level of segmental sensory block with fewer side-effects.

Effectiveness Of Intrathecal Dexmedetomidine In Combination With Hyperbaric Bupivacaine For Lower Abdominal Surgeries And Its Postoperative Analgesic Characteristic.

Background: Intra-thecal anaesthesia is the commonly preferred, block for surgeries of lower abdomen, perineal and lower limb. It is easy to administer and very economical but needs skills. Intrathecal use of local anaesthetics possesses a short duration of action and needs early use of rescue analgesia postoperatively. Objective was to assess the efficacy of Dexmedetomidine in adjuvant with bupivacaine for neuraxial anaesthesia and postoperative analgesic characteristics. It was a prospective comparative study, conducted at Anaesthesia Department, Liaquat National Hospital, Karachi from January to July 2020. Methods: Overall 100 patients conveniently recruited who underwent lower abdominal procedures were allocated into two groups by randomization, i.e., 50 in each group and were labelled as Group N and Group D10. Group N consist of 0.5% bupivacaine 10 mg (2 ml) + diluted with 0.5ml normal saline dilution and group D10 consist of 10 µg Dexmedetomidine + 0.5% bupivacaine 10 mg (2 ml) with 0.5 ml normal saline dilution, total 2.5 ml dose in each group. The duration of block and regression was evaluated. . Results: The study showed significant differences in sensory and motor block to reach T10 and Bromage 3 respectively. Patients who were assigned in Group D reported short onset of sensory to reach T10 (5.4±1.17) and motor to reach Bromage 3 (10.4±1.03) as compared to Group N (9.9±2.12 and 17±22) respectively. Participants of Group D required rescue analgesia in less amount throughout intervals as compare to group N. Conclusion: The usage of 10ug Dexmedetomidine adjuvant with 0.5% bupivacaine significantly reduced the onset on sensory T10 and motor Bromage 3 and also prolong duration of sensory and motor regression, moreover minimal adverse effects and less use of rescue analgesic drugs were observed.

Comparison of Oral versus Intramuscular Clonidine for the Prolongation of Bupivacaine Spinal Anesthesia in Patients Undergoing Lower Abdominal and Lower Limb Surgeries.

Background: Spinal subarachnoid block (SAB) is the first choice anesthesia in lower abdominal and lower limb surgeries. It produces a varying degree of sensory analgesia, motor blockade, and sympathetic blockade depending on the dose, concentration, and volume of the local anesthetic given. This study was undertaken to assess the degree of sensory and motor block with 150 µg of oral versus intramuscular clonidine as an adjuvant to bupivacaine for spinal anesthesia. Aims and Objective: To compare the efficacy of oral versus intramuscular clonidine as an adjuvant to bupivacaine for the prolongation of sensory and motor block in patients undergoing lower abdominal and lower limb surgeries under SAB. Materials and Methods: After institutional ethical clearance, 90 patients were randomized into three groups scheduled for lower abdominal and lower limb surgeries under spinal anesthesia. • Group O: Bupivacaine 0.5% (heavy) 3.0 mL and oral clonidine 150 µg 1 h before spinal anesthesia. • Group I: Bupivacaine 0.5% (heavy) 3.0 mL and intramuscular clonidine 150 µg 1 h before spinal anesthesia. • Group C: Control group - 3 mL bupivacaine 0.5% (heavy) alone. Result: The onset of sensory block in Group O was 4.9 ± 0.52 min, whereas in Group I, it was 4.6 ± 0.42 min than Group C (5.1 ± 0.60). Onset of motor block was also significantly lower in Group O and Group I (3.9 ± 0.53 and 3.7 ± 0.42 min) than in Group C (4.4 ± 0.6 min) which was a control group. There was also a significant difference in the duration of the sensory block between Group O (206.4 ± 9.2 min), Group I (219 ± 8.6 min), and Group C (184.3 ± 9.1 min). The duration of motor block was significantly higher in Group O (183.6 ± 8.2 min) and Group I (197.8 ± 9.6 min) when compared to Group C (162.8 ± 8.9 min). The timing of rescue analgesia in Group O was 222.4 ± 11.7 min, whereas in Group I, it was 243.46 ± 10.9. Conclusion: On the basis of finding of our study, we conclude that the use of clonidine as a premedication at a dose of 150 µg significantly increased the duration of sensory block, motor block, and duration of analgesia and shortened the time of onset of sensory and motor blockade.

Comparison between 10 and 12 mg doses of intrathecal hyperbaric (0.5%) bupivacaine on sensory block level after first spinal failure in cesarean section: A double-blind, randomized clinical trial.

Background: Reducing adverse effects during cesarean delivery and improving the quality of sensory blocks with appropriate doses of intrathecal hyperbaric bupivacaine can play an important role in the safe management of cesarean delivery. The aim of this study was to compare the doses of 10 and 12 mg of intrathecal hyperbaric bupivacaine 0.5% on sensory block level after first spinal failure in cesarean section (CS). Methods: In this double-blind, randomized clinical trial, 40 candidates of CS after first spinal failure with class I-II based on American Society of Anesthesiologists (ASA) were randomly assigned into two equal groups (n = 20). Group A and B received the spinal anesthesia with 10 mg and 12 mg of hyperbaric bupivacaine (0.5%), respectively. Maximum levels of sensory block, motor block quality, and vital signs were measured in two groups by 60 min after SPA. Incidence of SPA complications during surgery were also recorded. Data were analyzed by SPSS ver.21 software using repeated measures analysis of variance at 95% confidence interval (CI) level. Results: Excellent quality of sensory blocks and complete quality of motor blocks were achieved in all participants (100%). However, the mean time to onset of anesthesia (4.47 ± 0.69 vs. 3.38 ± 0.47, P < 0.001) and time to reach T10 level (60.73 ± 11.92 vs. 79.00 ± 19.21, P < 0.001) in the Group A, were significantly shorter than in the patients of Group B. The incidence of hypotension (P = 0.001), nausea/vomiting (P = 0.007) and bradycardia (P = 0.012) as well as administration of ephedrine and atropine were significantly higher in Group B compared to Group A. Conclusion: Spinal anesthesia can be safely repeated with a 10 mg of hyperbaric bupivacaine 0.5% in a caesarean section after the initial spinal failure. Clinical trial registration: [https://en.irct.ir/trial/40714], identifier [IRCT20120915010841N20].

Transmuscular Quadratus Lumborum Block versus Infrainguinal Fascia Iliaca Nerve Block for Patients Undergoing Elective Hip Replacement: A Double-blinded, Pilot, Randomized Controlled Trial.

Purpose: Transmuscular quadratus lumborum (TQL) block has been described as an effective option for postoperative analgesia in patients undergoing hip replacement with single injection described as providing analgesia for up to 24 h. We hypothesize that a TQL block, when compared to fascia iliaca block (FIB), will provide better analgesia and less motor block in the initial 24-h postoperative period. Patients and Methods: Fifty patients undergoing elective hip replacement surgery, ASA I-III, were included in the study. Patients were randomized into two groups. Patients in group A received spinal anesthesia followed by FIB. Patients in group B received spinal anesthesia followed by TQLB. Postoperative pain scores and motor block were assessed at 6 and 24 hours. The primary outcome measure was 24 h total morphine consumption. Secondary outcome measures included pain score (VNS) and motor block (modified Bromage scale) at 6 and 24 h postoperatively. Results: There was no statistical difference in morphine consumption between the two groups (p-value 0.699). There was no difference in pain scores at 6 h (p-value 0.540) or 24 h (p-value 0.383). There was no difference in motor block at 6 h (p-value 0.497) or at 24 h (p-value 0.773). Conclusion: Transmuscular quadratus lumborum block along with spinal anesthesia for patients undergoing elective hip replacement surgery does not reduce opioid consumption or motor weakness when compared to fascia iliaca block. The results and conclusion apply to a dose of 20 mL of 0.25% bupivacaine used in each group.

Median Effective Concentration of Ropivacaine for Femoral Nerve Block Maintaining Motor Function During Knee Arthroscopy in Two Age Groups.

Background: Femoral nerve block combined with general anesthesia is commonly used for patients undergoing knee arthroscopy in ambulatory care centers. An ideal analgesic agent would selectively (differentially) block sensory fibers, with little or no effect on motor nerves. Ropivacaine is considered to cause less motor block than others. This study investigated the median effective concentration (EC50) of ropivacaine for differential femoral nerve block in adults either younger or older than 60 years. Methods: Patients with American Society of Anesthesiologists physical status I-III and scheduled for knee arthroscopy were categorized as 18- to 60-years-old (Group 1), or older than 60 years (Group 2). Surgeries were performed under general anesthesia combined with femoral nerve block via 22 mL ropivacaine. The EC50 of ropivacaine for differential femoral nerve block was determined using the up-and-down method and probit regression. The primary outcome was the EC50 (95% confidence interval [CI]) of the 2 groups. Data on the sensory block, analgesic effect, complications, and hemodynamics during surgery were also recorded. Results: The EC50 of 22 mL ropivacaine for differential femoral nerve block of Group 1 (0.124%, 95% CI 0.097-0.143%) was significantly higher than that of Group 2 (0.088%, 95% CI 0.076-0.103%). The sensory block and hemodynamic data of the 2 groups were comparable. None of the patients experienced neurological complications. Conclusion: The EC50 of ropivacaine administered for differential femoral nerve block during knee arthroscopy was lower in patients older than 60 years, relative to younger adults.

Evaluation Effect of Aspiration of 0.2 ml of Cerebrospinal Fluid After Completion of Injection 0.5% Bupivacaine and Reinjection Into Subarachnoid Space on Sensory and Motor Block in Cesarean Section: A Randomized Clinical Trial.

Background: Spinal anesthesia (SPA) is the most common type of anesthesia administered for cesarean section. The main aim of this study was to evaluate the effect of aspiration of CSF (0.2 mL) immediately after SPA with hyperbaric 0.5% bupivacaine on the extent of sensory and motor block. Methods: In this clinical trial, 60 women at ≥37 weeks of gestation and aged between 18 and 46 years, candidate for cesarean delivery under spinal anesthesia were randomly allocated into two equal groups (n = 30). Group A (CSF-aspiration group) received the spinal anesthesia with 10 mg of hyperbaric 0.5% bupivacaine with aspiration of 0.2 ml of CSF. Group B (no-CSF-aspiration group) received only 10 mg of 0.5% hyperbaric bupivacaine. Pin-prick analgesia and motor block were tested during the induction. Results: The mean maximum level of analgesia was T6 in each group. Although the mean time to reach the maximum level of anesthesia (4.43 ± 5.14 vs. 2.76 ± 2.04, P = 0.107) and to reach T10 level (50.56 ± 11.51 vs. 49.10 ± 13.68, P = 0.665) in the CSF-aspiration group is longer than the non-CSF-aspiration group, but this differences were not significant. There were no significant between-group differences regarding sensory and motor block quality (P = 0.389) or failed SPA (four cases in CSF-aspiration group vs. two cases in no-CSF-aspiration group, P = 0.389). The incidence of bradycardia, hypotension, headache, vomiting and nausea were similar in both groups (P > 0.05). In addition, the difference in hemodynamic parameters between the two groups over times was not statistically significant. Conclusion: Our finding indicated that the aspiration of 0.2 ml of CSF after injection of spinal anesthesia with hyperbaric 0.5% bupivacaine does not seem to affect the extent of sensory and motor block, success rate, or outcome after SPA in cesarean section. Clinical Trial Registration: [https://www.irct.ir/search/result?query=IRCT20120915010841N25], identifier [IRCT20120915010841N25].

Alcohol Motor Blocks: Case Series and a Narrative Review.

Alcohol neurolysis and intramuscular blocks are interventions for spasticity management. Here, we illustrate two clinical cases with spasticity impeding ease of care and pain which required selective alcohol intramuscular blocks with alcohol neurolysis. Post-interventions, both cases demonstrated improvement in pain and joint range of motion which facilitated better positioning and reduced caregiver burden. Pertinent learning points from alcohol neurolysis with intramuscular blocks are discussed concerning therapeutic effectiveness and intervention safety.

Effect of combined versus sequential injection of 2% lidocaine and 0.5% bupivacaine on the onset and duration of supraclavicular brachial plexus block: A double blinded randomised controlled trial.

OBJECTIVE: To assess whether sequential (one after the other with a delay of 120 s) or combined (freshly prepared mixture) administration of 2% lidocaine and 0.5% bupivacaine in supraclavicular brachial plexus block (SCBPB) provides faster onset and prolonged duration of block. DESIGN: Randomised controlled double blinded study. SETTING: Single centre study in an operating theatre of a tertiary care facility between November 2018 and May 2020. PATIENTS: Ninety-seven patients of either sex, aged between 18 and 65 years, belonging to ASA I to III and undergoing surgery suitable to be performed under SCBPB were enrolled. INTERVENTION: Ultrasound guided SCBPB was performed with 20 mL of freshly prepared mixture of 2% lidocaine and 0.5% bupivacaine (10 mL each) in group C (combined) and 10 mL 2% lidocaine followed 120 s later by 10 mL 0.5% bupivacaine in group S (sequential). MAIN OUTCOME MEASURES: Time to onset of complete sensory block was the primary outcome while time to onset of first sensory block and complete motor block, duration of sensory and motor block, duration of analgesia, use of intraoperative supplement, rescue analgesic consumption, and pain scores at rest and with movement were secondary outcomes. MAIN RESULTS: There was no significant difference between group C and group S in time to onset of complete sensory block [median (IQR) 16 (11, 20.5) and 15.5 (13, 21.75) minutes respectively] (p-value 0.58). The time to onset of first sensory block and motor block, duration of sensory and motor block, duration of analgesia, use of intraoperative supplement, postoperative pain scores and rescue analgesic requirement were also similar (p-value >0.05). CONCLUSION: There was no advantage of sequential administration of 2% lidocaine and 0.5% bupivacaine over the administration of combination of both LAs in terms of onset and duration of block.

Effects of adding dexmedetomidine, fentanyl, and verapamil to 0.5% ropivacaine on onset and duration of sensory and motor block in forearm surgeries: a randomized controlled trial.

This study was aimed to compare the onset and duration of axillary block with ropivacaine 0.5% plus either dexmedetomidine, fentanyl, or verapamil in forearm surgeries. This double-blind clinical trial enrolled three equal-sized block-randomized groups of patients (n = 105) scheduled for hand and forearm surgery at Arak, Iran in 2019, who received: (i) ropivacaine (40 mL/0.5%) + dexmedetomidine (1 µg/kg), (ii) ropivacaine (40 mL/0.5%) + fentanyl (1 µg/kg), and (iii) ropivacaine (40 mL/0.5%) + verapamil (2.5 mg), respectively. We recorded some vital signs such as mean arterial pressure, heart rate and oxygen saturation, onset of complete sensory and motor block, duration of the block, opioid use, as well as pain score at recovery and certain time points (2, 4, 6, 12, and 24 hours post-operation). Adding dexmedetomidine to ropivacaine (40 mL/0.5%) prolonged the duration of sensory (P = 0.001) and motor block (P = 0.001) in compared to adding fentanyl and verapamil and it also shortens the time to onset of sensory (P = 0.001) and motor block (P = 0.001). There is a significant difference between three groups in terms of visual analog scale mean and the lowest pain score was obtained in the dexmedetomidine group (P = 0.001), significant time trend (P = 0.001), as well as the time and groups interaction (P = 0.001). Dexmedetomidine was concluded to be associated with alleviated pain; reduced opioid use; short onset of sensory block; and prolonged duration of sensory and motor block. It hence is recommended to lengthen the duration of axillary block and to help relieve postoperative pain and ultimately to move to cut down the postoperative opioid use in forearm surgery. The study was approved by the Ethical Committee of Arak University of Medical Sciences (approval No. IR.ARAKMU.REC.1397.266), and registered on Iranian Registry of Clinical Trials (registration No. IRCT20141209020258N111) on May 9, 2019.

Cervical erector spinae plane block as a perioperative analgesia method for shoulder arthroscopy: a case series.

Shoulder arthroscopy, a common intervention for severe rotator cuff injuries, is associated with severe postoperative pain. Upon performing cervical erector spinae plane (ESP) blocks at the C7 TP (tip or posterior tip) or the posterior tip of the C6 TP posterior tubercle in six patients undergoing shoulder arthroscopy, sensory block was detectable in congruent cervico-thoracic dermatomes. Effective intraoperative and postoperative analgesia were consistently obtained for all six patients. This preliminary study illustrated that the cervical ESP block can be considered a potential simple regional anesthesia method for providing analgesia during shoulder arthroscopy with low risks of diaphragmatic paresis, upper extremity motor paresis, nerve injury and persistent hypotension.

Motor blocks during bilateral stepping in Parkinson's disease and effects of dopaminergic medication.

INTRODUCTION: Freezing of gait (FOG) is a complex symptom in Parkinson's disease (PD) that manifests during walking as limited forward progression despite the intention to walk. It is unclear if lower limb motor blocks (LLMB) that occur independently from FOG are related to overground FOG and the effects of dopaminergic medications. METHODS: Nineteen patients with PD were tested on two separate days in the dopaminergic medication "on" and "off" states. The patients completed a series of freezing-provoking tasks while videotaped. Raters assessed videos for FOG presence using Movement Disorders Society Unified Parkinson's Disease Rating Scale item 3.11 score greater than or equal to 1 and FOG severity using the standardized FOG score. Whilst seated in a virtual environment, patients and 20 healthy controls stepped in right-left sequence on foot pedals. Frequency and percent time in LLMB were assessed for accurate classification of FOG presence and correlation to the FOG score. RESULTS: Frequency and percent time spent in LLMB predicted the presence of FOG in both medication states. Percent time spent in LLMB correlated with FOG severity in both medication states. LLMB frequency predicted FOG severity in the "off" state only. CONCLUSIONS: LLMB during bilateral stepping in a virtual environment predicted the presence and severity of FOG in PD in both "on" and "off" medication states. These findings support the use of this non-walking paradigm to detect and assess FOG in PD patients unable or unsafe to walk.