Concentrations Of Ropivacaine Research Articles

LC-MS/MS quantification of ropivacaine and local analgesic and adverse effects of Long-acting Ropivacaine Injection based on pharmacokinetic-pharmacodynamic modelling in Bama minipigs

The local analgesic efficacy and adverse effects of a new Long-acting Ropivacaine formulation were examined based on pharmacokinetic-pharmacodynamic (PK-PD) modelling in Bama minipigs. 24 Bama minipigs, 12 males and 12 females, were randomly and equally divided into the following treatment groups: normal saline injection, drug vehicle injection, Long-acting Ropivacaine Injection and Ropivacaine Hydrochloride Injection. After routine disinfection, a skin incision about 3 cm long and 3 cm deep was produced in the leg of each pig, and mechanical withdrawal threshold (MWT) measured at various times pre- and post-injection as an index of analgesia against incision pain. Plasma ropivacaine concentrations were also measured at the same times using a novel liquid chromatography-tandem mass spectroscopy (LC-MS/MS) method. Minipigs were sacrificed 24 h post-injection and hearts collected for drug concentration measurements by LC-MS/MS. The LC-MS/MS method demonstrated high sensitivity, linearity and precision. The Long-acting Ropivacaine formulation produced a longer analgesic effect (∼12 h) at a lower plasma concentration than Ropivacaine Hydrochloride (∼4h), suggesting a better side-effects profile. A PK-PD model revealed a direct relationship between plasma ropivacaine concentration and MWT, with peak analgesia at about 1000 ng/mL and behaved good prediction ability. Long-acting Ropivacaine Injection is a superior local anaesthetic-analgesic treatment due to longer-lasting efficacy at lower concentrations compared to Ropivacaine Hydrochloride, which will reduce the risk of side effects such as cardiotoxicity.

The Minimum Effective Concentration (MEC95) of different volumes of ropivacaine for ultrasound-guided caudal epidural block: a dose-finding study

BackgroundCaudal epidural block (CEB) may be beneficial in anorectal surgery because its use may extend postoperative analgesia. This dose-finding study aimed to estimate the minimum effective anesthetic concentrations for 95% patients(MEC95) of 20 ml or 25 ml of ropivacaine in with CEB.Patients and methodsIn this double-blind, prospective study, the concentration of ropivacaine administered in 20 ml and 25 ml for ultrasound-guided CEB were determined using the sample up-and-down sequential allocation study design of binary response variables. The first participant was given 0.5% ropivacaine. Depending on whether a block was successful or unsuccessful, the concentration of local anesthesia was decreased or increased by 0.025% in the next patient. Every five minutes for 30 min, the sensory blockade using a pin-prick sensation at S3 dermatome compared to at T6 dermatome were evaluated every 5 min within 30 min. An effective CEB was defined as a a reduction of sensation at S3 dermatome and the existence of flaccid anal sphincter. Anesthesia was considered successful if the surgeon could perform the surgery without additional anesthesia. We determined the MEC50 using the Dixon and Massey up-and-down method and estimated the MEC95 using probit regression.ResultsThe concentration of ropivacaine administered in 20 ml for CEB ranged from 0.2% to 0.5%. Probit regression with a bias-corrected Morris 95% CI derived by bootstrapping showed an MEC50 and MEC 50 of ropivacaine for anorectal surgical anesthesia were 0.27% (95% CI, 0.24 to 0.31) and 0.36%(95% CI, 0.32 to 0.61). The concentration of ropivacaine administered in 25 ml for CEB ranged from 0.175 to 0.5. Probit regression with a bias-corrected Morris 95% CI derived by bootstrapping showed an MEC50 and MEC95 for CEB were 0.24% (95% CI, 0.19 to 0.27) and 0.32% (95% CI, 0.28 to 0.54).ConclusionWith ultrasound-guided CEB, the MEC95 of 0.36% ropivacaine at 20 ml and 0.32% ropivacaine at 25 ml provide adequate surgical anesthesia/analgesia 95% of patients undergoing anorectoal surgery.Trial registrationClinicaltrails.gov: Retrospectively registered (ChiCTR2100042954; Registration date:1/2, 2021).

Ropivacaine pharmacokinetics in the arterial and venous pools after ultrasound-guided continuous thoracic paravertebral nerve block.

Although thoracic paravertebral blockade (TPVB) is employed in thoracic surgery to ensure satisfactory postoperative analgesia, large doses of anesthetics are required and manifestations of local anesthetic systemic toxicity (LAST) may appear. Currently, there are limited data on the pharmacokinetics of ropivacaine after continuous TPVB. The aim of this prospective study was to investigate ropivacaine kinetics, in the arterial and venous pools, after continuous TPVB and assess the risk of LAST. Immediately after induction of general anesthesia, an ultrasound-guided continuous TPVB at T5 or T6 or T7 thoracic level was performed in 18 adult patients subjected to open thoracotomy. A 25-ml single bolus injection of ropivacaine 0.5% was administered through thoracic paravertebral catheter, followed by a 14 ml/h continuous infusion of ropivacaine 0.2% starting at the end of surgery. Quantification of total ropivacaine concentrations was performed using a validated high-performance liquid chromatography method. Population pharmacokinetic models were developed separately for arterial and venous ropivacaine data. The best model was one-compartment disposition with an additional pre-absorption compartment corresponding to thoracic paravertebral space. Gender had a significant effect on clearance, with females displaying lower elimination than males. Some patients had ropivacaine concentrations above the toxic threshold, but none displayed evidence of LAST. Continuous thoracic paravertebral nerve blocks provided adequate postoperative analgesia. Ropivacaine doses at the upper end of clinical use (800 mg/d) did not inflict the manifestations of LAST and provided adequate postoperative pain control. Pharmacokinetic models were developed, and the effect of gender was identified.

Serum concentrations of local anesthetics after unilateral interpectoral-pectoserratus plane block in breast cancer surgery: a pharmacokinetic study

IntroductionThe ultrasound-guided interpectoral-pectoserratus plane block is a fascial plane block for superficial surgery of the anterolateral chest wall. This technique involves injecting a relatively large volume of local anesthetics (typically...

Assessment of cardiotoxicity and plasma ropivacaine concentrations after serratus intercostal fascial plane block in an experimental model

Serratus intercostal fascial plane block (SIFPB) has emerged as an alternative to paravertebral block in breast surgery. It involves the administration of high volumes and doses of local anesthetics (LA) that can potentially reach toxic levels. Ropivacaine is widely used in thoraco-fascial blocks; however, there is no information on the plasma concentrations attained after SIPFB and whether they are associated with cardiotoxicity. Plasma concentrations of ropivacaine and its electrophysiological effects were evaluated in eight pigs after bilateral SIFPB with ropivacaine in doses of 3 mg/kg. Plasma concentrations, electrophysiological and hemodynamic parameters were measured sequentially for the following 180 min until the end of the study. The area under the curve, the maximum plasma concentration (Cmax) and the time to reach Cmax (tmax) were calculated. The median arterial ropivacaine concentration Cmax was, 2.34 [1.40 to 3.74] µg/ml. The time to reach the highest concentration was 15 [10 to 20] min. Twenty-five percent of the animals had arterial concentrations above the lower limit concentration of ropivacaine for LA systemic toxicity (3.4 µg/ml). No alterations were observed in the electrophysiological or electrocardiographic parameters except for a prolongation of the QTc interval, from 489 ± 30 to 544 ± 44 ms (Δ11.38 ± 6%), P = 0.01. Hemodynamic parameters remained in the physiological range throughout the study. SIFPB with ropivacaine in doses of 3 mg/kg has reached potentially toxic levels, however, it has not been associated with adverse electrophysiological or hemodynamic effects.

Comparison of Analgesic Effect of Clonidine as an Adjuvant with Different Concentration of Ropivacaine (0.35% and 0.2%) in Thoracic Paravertebral Block among Modified Radical Mastectomy Patients: A Randomised Double Blinded Clinical Study

Introduction: Thoracic Paravertebral Block (TPVB) appears promising for reduction of postoperative pain in Modified Radical Mastectomy (MRM). Various combinations of local anaesthetics and adjuvants have been tried in TPVB but search for an ideal combination is still on. Aim: To evaluate analgesic efficacy of clonidine (1 µg/kg) as adjuvant with different concentrations of ropivacaine (0.35%, 0.2%) for TPVB in MRM surgery. Materials and Methods: This randomised double blind comparative clinical study was carried out in a tertiary care centre in Southern Rajasthan from January 2019 to March 2020, clinical study, 120 American Society of Anaesthesiologists (ASA) grade I, II patients aged 18-60 years female patients undergoing MRM surgery were randomised into three groupsRP, RC and LDRC to receive 0.35% Ropivacaine 19 mL, 0.35% Ropivacaine 19 ml+Clonidine (1 µg/kg) and 0.2% Ropivacaine 19 ml+Clonidine(1 µg/kg) diluted upto total 20 ml with normal saline, respectively. TPVB was performed at T4 level as single injection followed by administration of general endotracheal anaesthesia. The primary outcome measured was duration of analgesia. Secondary outcomes measured included consumption of rescue analgesic, Visual analog scale and perioperative haemodynamic parameters. Quantitative and qualitative data were analysed using Analysis of Variance (ANOVA) and Chi-square test respectively. p<0.05 was considered statistically significant. Results: Mean duration of analgesia was prolonged in clonidine groups RC and LDRC (811.5±110.99 and 753±119.76 min, respectively) as compared to group RP (400.125±108.13 min), although no statistically significant difference was noted between group RC and LDRC. Similar observations were noted when total dose of rescue analgesic in group RC (82.50±7.21 mg) and LDRC (99.38±35.57 mg) was compared to group RP (142.50±53.169 mg) as well as when total number of rescue analgesic doses in group RC (1.10±0.496) and group LDRC (1.32±0.474) were compared to group RP (1.92±0.694). Visual Analogue Scale (VAS) was noted at rest, cough, movement at 0, 4, 8, 12, 24 hours and showed a statistically significant difference between ropivacaine group RP and ropivacaine clonidine groups. Conclusion: Addition of clonidine to ropivacaine in TPVB during breast cancer surgery results in lower pain scores, prolong duration of analgesia and reduce postoperative requirement of rescue analgesics. Both lower (0.2%) and higher (0.35%) concentrations of ropivacaine provide equally effective postoperative analgesia.

不同浓度罗哌卡因前锯肌平面阻滞于机器人辅助胸腔镜下肺切除术患者的镇痛效果

不同浓度罗哌卡因前锯肌平面阻滞于机器人辅助胸腔镜下肺切除术患者的镇痛效果

Investigation of the Median Effective Concentration of Ropivacaine Combined with Nalbuphine as Epidural Analgesia

Investigation of the Median Effective Concentration of Ropivacaine Combined with Nalbuphine as Epidural Analgesia

Safety and efficacy of intraosseous ropivacaine in lower extremity (SORE) study.

Day stay surgery for anterior cruciate ligament (ACL) reconstructions is an increasingly common practice and has driven clinicians to develop postoperative pain regimes that allow same day mobilization and a safe and timely discharge. There is a paucity of literature surrounding the use of intraosseous (IO) ropivacaine used as a Bier's block to provide both intraoperative and postoperative analgesia in lower limb surgery. This patient blinded, pilot study randomized 15 patients undergoing ACL reconstruction to receive either IO ropivacaine 1.5 or 2.0mg/kg; or 300 mg of ropivacaine as local infiltration. The primary outcome for this study was arterial plasma concentration of ropivacaine. Samples were taken via an arterial line at prespecified times after tourniquet deflation. Secondary outcomes included immediate postoperative pain scores using the visual analogue scale and perioperative opioid equivalent consumption. All patients in the intervention group receiving IO ropivacaine had plasma concentrations well below the threshold for central nervous system (CNS) toxicity (0.60 μg/mL). The highest plasma concentration was achieved in the intervention group receiving 1.5mg/kg dose of ropivacaine reaching 2.93 mg/mL. This would equate to 0.18 μg/mL of free plasma ropivacaine. There were no differences across the three groups regarding pain scores or perioperative opioid consumption. This study demonstrates that IO ropivacaine is both safe and effective in reducing perioperative pain in patients undergoing ACL reconstruction. There may be scope to increase the IO dose further or utilize other analgesics via the IO regional route to improve perioperative pain relief.

The minimum effective concentration (MEC90) of ropivacaine for ultrasound-guided quadratus lumborum block for analgesia after cesarean delivery: a dose finding study

BackgroundQuadratus lumborum block was recently proposed as an alternative technique for post-cesarean delivery analgesia. However, there is not a definite optimum concentration of local anesthetics. A biased coin design up-and-down method was used to explore the minimum effective concentration of ropivacaine in quadratus lumborum block for satisfactory analgesia after cesarean delivery.MethodsFifty-six patients weighing 60–80 kg after cesarean section and with ages between 18 and 40 years were recruited. For the posterior quadratus lumborum block, a volume of 25 ml of the assigned concentration of ropivacaine was injected bilaterally.The concentration administered to each patient depended on the response to the previous dose. The first patient received 0.25%. If a successful block was observed, the next patient was randomized to receive the same ropivacaine concentration (with a probability of 0.89) or 0.025% less (with a probability of 0.11). After any block failure, the concentration was always increased by 0.025% for the next. The study ended when 45 successful blocks were obtained.We defined effective quadratus lumborum block as a resting visual analog score ≤ 3 and the absence of a need for rescue anesthetics.ResultsThe 90% minimum effective concentration of ropivacaine was 0.335% (95% CI 0.306 to 0.375%), and the 99% minimum effective concentration was 0.371% (95% CI 0.355 to 0.375%). The sufentanil consumption was 11 (11,13) and 24 (22,27) μg at 12 and 24 hours after quadratus lumborum block, respectively.ConclusionsThe optimum dosage of ropivacaine is a 25 ml volume of 0.335% for quadratus lumborum block after cesarean delivery.Trial registrationThe study was registered in the Chinese Clinical Trial Registry (No. ChiCTR2000040415).

Comparison Features of Methods of Epidural Analgesia as a Part of Combined Anesthesia in Laparoscopic Surgery

The objective: choosing the optimal method of epidural analgesia combined with general anesthesia for typical laparoscopic colorectal surgeries by comparing three different options for its implementation. Subjects and Methods. 90 patients aged 60 to 85 years were examined, they all underwent planned laparoscopic interventions for colorectal cancer under combined anesthesia (general + epidural anesthesia). Depending on the method of administration of ropivacaine to achieve an epidural block, they were randomized into three groups. In Group 1, it was administered at a concentration of 0.25% in the form of a continuous infusion at a rate of 8 m l/h during the first hour, then 6 ml/ h until the end of the operation. In Group 2, its concentration was increased to 0.375%, the rate of continuous infusion was 8 ml/ h in the first hour, then 6 m l/h . Patients of Group 3 first received ropivacaine as a bolus before the induction of general anesthesia (0.375% – 8 ml over 5 min), then continued administration continuously but at a concentration of 0.25% at a rate of 6 m l/h . Endpoints for hemodynamic assessment: upon admission to the operating room, after induction of anesthesia, after application of carboxyperitoneum, after 1 hour of laparoscopic stage, after elimination of carboxyperitoneum, after extubation, and 1 hour after transfer to the ICU . The total dose of fentanyl was recorded. The assessment of the sensory block was performed using a cold test, the severity of the pain syndrome ‒ on a visua l-a nalog scale (10 points), the density of the block ‒ on an ordinal scale, its upper and lower levels were noted. The motor block was evaluated using a modified Bromage scale. Results. The doses of fentanyl, rocuronium and the consumption of desflurane during general anesthesia, the values of the BIS index and the time of awakening of patients in all groups did not differ. The average doses of ropivacaine in the groups were different. The total volume of ropivacaine solution was the largest in Group 3, there were no significant differences in the volume of the injected local anesthetic between Group 1 and Group 2. The number of patients who needed vasopressor support with norepinephrine during anesthesia in Group 1 was less versus Groups 2 and 3. The maximum intraoperative dose of norepinephrine and duration of its use were also lower in Group 1. When applying carboxyperitoneum, the most pronounced decrease in hemodynamic parameters was revealed in patients of Group 3. At the 4th stage of the study, after 1 hour of the laparoscopic stage, hemodynamic parameters were higher in patients of Group 1. There were no significant differences in pain intensity between the groups after surgery. At the same time, the level of motor block was significantly higher in patients of Group 2, while in Groups 1 and 3, motor block did not develop in most of the patients. Conclusion: The optimal method of epidural analgesia in typical laparoscopic colorectal operations is the use of 0.25% ropivacaine concentration as a continuous infusion only due to ensuring an acceptable level of analgesia, adequate distribution of the sensory block, the minimum degree of motor block, as well as the least negative effect on hemodynamic parameters which reduces the volume of infusion therapy and doses of vasopressors.

Continuous Ropivacaine Peroneal Nerve Infiltration for Fibula Free Flap in Cervicofacial Cancer Surgery: A Randomized Controlled Study.

Introduction: Pain after cervicofacial cancer surgery with free flap reconstruction is both underestimated and undertreated. There is a rational for regional anesthesia at the flap harvest site, but few studies describe it. We assessed the influence of common peroneal nerve infiltration on pain and opioid consumption in patients having oropharyngeal cancer surgery with fibular free flap mandibular reconstruction. Methods: After institutional review board (IRB) approval and written informed consent, fifty-six patients were randomly allocated to perineural catheter with ropivacaine infiltration (ROPI) or systemic analgesia (CONTROL). In the ROPI group, an epidural catheter was placed by the surgeon before closure, and ropivacaine 0.2% 15 mL, followed by 4 mL/h during 48 h, was administered. The primary outcomes were pain scores and morphine consumption during the 48 h postoperative period. We also measured ropivacaine concentration at the end of infusion. Finally, we retrospectively assessed long-term pain up to 10 years using electronic medical charts. Results: Perineural infiltration of ropivacaine significantly reduced pain scores at the harvest site only at day 1, and did not influence overall postoperative opioid consumption. Ropivacaine assay showed a potentially toxic concentration in 50% of patients. Chronic pain was detected at the harvest site in only one patient (ROPI group), and was located in the cervical area in the case of disease progression. Discussion: Although the catheter was visually positioned by the surgeon, continuous ropivacaine infiltration of the common peroneal nerve did not significantly reduce postoperative pain, but induced a blood concentration close to the toxic threshold at day 2. Further studies considering other infiltration locations or other dosing schemes should be tested in this context, both to improve efficacy and reduce potential toxicity.

Comparison of epidural dexmedetomidine to fentanyl in reducing ropivacaine dose in Programmed Intermittent Epidural Bolus plus Patient Controlled Epidural Analgesia during labor: A randomized, double-blind, controlled study.

Dexmedetomidine has been documented to reduce the dose of both intrathecal local anesthetic during cesarean delivery, and the concentration of ropivacaine needed for inducing analgesia during labor. However, few studies have compared adjuvant dexmedetomidine to fentanyl on how they impact the dose of ropivacaine required during labor. The aim of the current study was to evaluate the efficacy of epidural dexmedetomidine at doses of 0.3, 0.4, or 0.5 and 2 μg/ml of fentanyl (the traditional clinical concentration), when added to epidural 0.125% ropivacaine. This was a randomized, double-blinded study that comprised one hundred eighty-eight patients, allocated into four groups receiving either epidural fentanyl at 2 μg/ml, or dexmedetomidine at 0.3, 0.4, or 0.5 μg/ml for labor analgesia. The primary outcome was the amount of ropivacaine necessary per hour. Secondary outcomes included visual analogue pain scale (VAS), motor block (Bromage Scale), side effects, patient satisfaction, and neonatal outcomes. At the completion of the study, data from 165 participants were analyzed. The mean hourly amount of epidural ropivacaine administered was 16.2 ± 3.3, 14.0 ± 3.1, 13.1 ± 3.7 and 12.1 ± 2.5 ml/h in the 2 μg/ml fentanyl group, and the 0.3, 0.4 and 0.5 μg/ml dexmedetomidine groups, respectively. There was a significant difference among groups in the mean hourly consumption of epidural ropivacaine (P < 0.0001 for 1 way ANOVA). The frequency of PCEA (patient-controlled epidural analgesia) was significantly higher in the fentanyl group than in the three dexmedetomidine groups (P < 0.001), and similar among the dexmedetomidine groups. The mean values of the VAS among all groups were similar over time, P > 0.05. The incidence of pruritus in the fentanyl group was 17.5%, whereas no patient experienced pruritus in any of the dexmedetomidine groups, P < 0.0001. The study demonstrated that epidural dexmedetomidine (0.3 and 0.4 μg/ml) was superior to standard dose epidural fentanyl in reducing the mean hourly amount of ropivacaine administered, and minimizing opioid-related side effects. Further large and multicenter studies would be necessary to confirm the benefits of dexmedetomidine, and potentially serve as an alternative to opioids for routine use in labor analgesia. [http://www.chictr.org.cn/showproj.aspx?proj=62846], identifier [ChiCTR2000039067].

Local Anesthetic Cardiac Toxicity Is Mediated by Cardiomyocyte Calcium Dynamics.

Long-lasting local anesthetic use for perioperative pain control is limited by possible cardiotoxicity (e.g., arrhythmias and contractile depression), potentially leading to cardiac arrest. Off-target cardiac sodium channel blockade is considered the canonical mechanism behind cardiotoxicity; however, it does not fully explain the observed toxicity variability between anesthetics. The authors hypothesize that more cardiotoxic anesthetics (e.g., bupivacaine) differentially perturb other important cardiomyocyte functions (e.g., calcium dynamics), which may be exploited to mitigate drug toxicity. The authors investigated the effects of clinically relevant concentrations of racemic bupivacaine, levobupivacaine, or ropivacaine on human stem cell-derived cardiomyocyte tissue function. Contractility, rhythm, electromechanical coupling, field potential profile, and intracellular calcium dynamics were quantified using multielectrode arrays and optical imaging. Calcium flux differences between bupivacaine and ropivacaine were probed with pharmacologic calcium supplementation or blockade. In vitro findings were correlated in vivo using an anesthetic cardiotoxicity rat model (females; n = 5 per group). Bupivacaine more severely dysregulated calcium dynamics than ropivacaine in vitro (e.g., contraction calcium amplitude to 52 ± 11% and calcium-mediated repolarization duration to 122 ± 7% of ropivacaine effects, model estimate ± standard error). Calcium supplementation improved tissue contractility and restored normal beating rhythm (to 101 ± 6%, and 101 ± 26% of control, respectively) for bupivacaine-treated tissues, but not ropivacaine (e.g., contractility at 80 ± 6% of control). Similarly, calcium pretreatment mitigated anesthetic-induced arrhythmias and cardiac depression in rats, improving animal survival for bupivacaine by 8.3 ± 2.4 min, but exacerbating ropivacaine adverse effects (reduced survival by 13.8 ± 3.4 min and time to first arrhythmia by 12.0 ± 2.9 min). Calcium channel blocker nifedipine coadministration with bupivacaine, but not ropivacaine, exacerbated cardiotoxicity, supporting the role of calcium flux in differentiating toxicity. Our data illustrate differences in calcium dynamics between anesthetics and how calcium may mitigate bupivacaine cardiotoxicity. Moreover, our findings suggest that bupivacaine cardiotoxicity risk may be higher than for ropivacaine in a calcium deficiency context.

Effect of species, concentration and volume of local anesthetics on intervertebral disk degeneration in rats with discoblock.

Discoblock is effective in relieving discogenic low back pain, but it can also cause intervertebral disk degeneration (IDD). The effect of species, concentration and volume of local anesthetics on IDD with discoblock have not been reported. The purpose was to study the effect of species, concentration and volume of local anesthetics on IDD in rats undergoing discoblock. The effects of local anesthetics on nucleus pulposus cell (NPC) viability in vitro were studied. NPCs were exposed to lidocaine, bupivacaine and ropivacaine at different concentrations. NPC viability was measured. The least cytotoxic local anesthetic was used in vivo. The concentration and volume of local anesthetics on IDD in rat with discoblocks were tested in vivo. Detection indicators included X-ray, MRI, water content of the disk and histological changes. The toxicity of local anesthetics to NPCs was dose and time dependent, and the cytotoxicity of different local anesthetics was different. Among the three local anesthetics, ropivacaine was the least toxic to NPCs. The effect of ropivacaine concentration on IDD was not significant, as detected by X-ray, MRI, disk water content and histology (P < 0.05). The volume of ropivacaine has a significant effect on IDD, as supported by X-ray, MRI, disk water content and histology (P < 0.05). Acupuncture itself significantly increased IDD, as detected by MRI, disk water content and histology (P < 0.05). Ropivacaine should be selected for its low cytotoxicity. A lower volume and slow injection speed should be used to reduce IDD during discoblock.

Effects of Unilateral Intermediate Cervical Plexus Block on the Diaphragmatic Function in Patients Undergoing Unilateral Thyroidectomy: A Randomized Controlled Study.

Background and PurposeAlthough unilateral intermediate cervical plexus block (ICPB) can be used for perioperative analgesia in neck surgery, its effect on diaphragm function remains controversial. This prospective study aimed to examine whether unilateral ICPB with different concentrations of ropivacaine resulted in the diaphragmatic dysfunction in unilateral thyroidectomy.MethodsA total of 54 patients scheduled to undergo unilateral thyroidectomy under general anesthesia were randomly allocated to receive either 10 mL of 0.3% (Group L) or 0.5% (Group H) ropivacaine for ICPB. General anesthesia was then administered for surgery. The diaphragm thickness and diaphragmatic excursion were measured at three different times: before the ICPB, at 40 min and 4 h after the block. The primary outcome was the incidence of diaphragmatic dysfunction of the block side at 40 min and 4 h after ICPB. Secondary outcomes included the maximum pain score within 24 h after the surgery, rescue analgesics within 24 h after the surgery, and time to first ambulation.ResultsThe incidence of diaphragmatic dysfunction on the block side of Group H was higher than that of Group L at 40 min after block (58% vs 29%, P = 0.01). However, the incidence of diaphragmatic dysfunction was comparable between Group H and Group L (65% vs 46%) at 4 h after block placement. Within 24 h after the operation, the maximum VAS pain score of Group H was significantly lower than Group L (P = 0.04), and fewer patients in Group H required rescue analgesics (P < 0.01).ConclusionThe ICPB with different concentrations of ropivacaine can induce the ipsilateral diaphragmatic dysfunction. The high concentration of ropivacaine results in higher incidence of diaphragmatic dysfunction at 40 min, but comparable incidence at 4 h after block compared with lower concentration of ropivacaine.Chinese Clinical Trial RegistryChiCTR2000029348.

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.

The median effective analgesic concentration of ropivacaine in ultrasound-guided interscalene brachial plexus block after arthroscopic rotator cuff repair.

Background: The median effective analgesic concentration (MEAC) of ropivacaine in interscalene brachial plexus block (ISBPB) for postoperative analgesia after arthroscopic rotator cuff repair (ARCR) has not been determined. Therefore, this study aimed to evaluate the MEAC after ARCR using 10 ml ropivacaine. Method: This study was conducted on 40 patients with American Society of Anesthesiologists grade I or II who had selective ARCR. The 10 ml ropivacaine was administered for determined, with an initial concentration of 0.3% using up-and-down sequential allocation. After successful or unsuccessful postoperative analgesia, the concentration of ropivacaine was decreased or increased by 0.05% in the next patient. We defined successful postoperative analgesia as a visual analog scale score of <4 at rest within the initial 8 h after ISBPB. The analytic techniques of linear, linear-logarithmic, exponential regressions and centered isotonic regression were used for calculating MEAC. The secondary outcomes was sufentanil consumption, time to 1st rescue analgesic, onset time of sensory block and motor block. Results: The concentration of ropivacaine administered ranged from 0.1% to 0.35%. The MEAC from the four different methods (linear, linear-logarithmic, exponential regressions and centered isotonic regression) were 0.207% (95% CI, 0.168–0.355%), 0.182% (95% CI, 0.165–0.353%), 0.196% (95% CI, 0.154–0.356%), and 0.163%, respectively. Of the four models, exponential regression had the least residual standard error (0.0990). Conclusion: The MEAC derived from the four statistical models for 10 ml ropivacaine in ultrasound-guided ISBPB for postoperative analgesia was distributed within a narrow range of 0.163%–0.207%. The exponential regression model calculated by the goodness-of-fit test at a concentration of 0.196% best fits the study data. Clinical Trial Registration: http://www.chictr.org.cn/showproj.aspx?proj=127449, identifier ChiCTR2100047978

Optimization of programmed intermittent epidural bolus volume for different concentrations of ropivacaine in labor analgesia: a biased coin up-and-down sequential allocation trial

Background and objectivesTo date, programmed intermittent epidural bolus (PIEB) has been widely used in obstetric analgesia, while no optimal PIEB regimen has been proposed. This study aimed to assess effective analgesia in 90% of women (EV90) with different concentrations of ropivacaine (0.075% and 0.1%) combined with 0.5 µg/mL sufentanil, at an interval of 40 min using the biased coin design-up-and-down method (BCD-UDM), and to explore whether there is a difference in EV90 with the increase of ropivacaine concentration.MethodsIn total, 103 primiparous women were assigned to two groups, including group A (n = 52) and group B (n = 51). Parturients in group A were treated with 0.075% ropivacaine and 0.5 µg/mL sufentanil, while those in group B were treated with 0.1% ropivacaine and 0.5 µg/mL sufentanil. Used the biased coin up-and-down sequential allocation method to determine the EV90. The secondary outcomes were sensory block level, motor block, and adverse events (hypotension, urinary retention, and pruritus).ResultsThe results revealed that EV90 was 10 mL (95% confidence interval (CI):8.03–11.54) in group A, and EV90 was 9 mL (95% CI:7.49–10.51) in group B by the isotonic regression method. The highest level of the sensory block was T8, and the lowest was T12. No case of hypotension was recorded,and only 4 parturients complained of motor block.ConclusionWith an interval of 40 min, the optimal PIEB bolus volume of 0.075% ropivacaine and 0.5 µg/mL sufentanil was 10 mL, 0.1% ropivacaine and 0.5 µg/mL sufentanil was 9 mL. Moreover, the PIEB volume decreased along with the higher concentration of ropivacaine.Trial registrationChiCTR registration number: ChiCTR2000040917. Registration date: December 15, 2020.

Ultrasound-guided erector spinae plane block improves analgesia after laparoscopic hepatectomy: a randomised controlled trial

BackgroundLaparoscopic hepatectomy is associated with trauma and severe pain. We examined whether bilateral, ultrasound-guided, single-injection erector spinae plane block (ESPB) could improve on postoperative analgesia compared with patient-controlled intravenous analgesia in patients undergoing laparoscopic hepatectomy. MethodsFifty adults were randomly allocated to receive patient-controlled intravenous analgesia alone or combined with bilateral single-injection ESPB (ropivacaine 0.5%, 15 ml on each side). Primary outcome was resting pain scores at 3 h postoperatively assessed with visual analogue scale (VAS). Secondary outcomes included VAS scores at rest and during movement at 6, 12, 16, 20, 24, 48, and 72 h postoperatively; use of intraoperative opioids; postoperative rescue analgesia; sleep quality; time of first ambulation; ESPB-related complications; and ropivacaine concentration in plasma. ResultsThe ESPB group showed lower resting VAS scores at 3 h postoperatively (mean [standard deviation]), 2.0 (0.5) vs 4.3 (0.7), P<0.001, and significantly lower scores at rest and during movement at 6–24 h postoperatively. The ESPB group showed lower intraoperative opioid use, lower consumption of rescue analgesia within 72 h postoperatively, and better sleep quality. ESPB subjects began to ambulate 10 h earlier than control subjects. None of the ESPB subjects showed ESPB-related complications, and analysis of a subset of subjects showed that ropivacaine concentrations in plasma decreased gradually over time. ConclusionsCompared with patient-controlled intravenous analgesia only, preoperative ultrasound-guided erector spinae plane block can improve postoperative analgesia, reduce opioid demand, and accelerate recovery in patients undergoing laparoscopic hepatectomy. Clinical trial registrationChinese Clinical Trial Registry ChiCTR1900020961.