Ropivacaine: a review of its use in regional anaesthesia and acute pain management

Ropivacaine effect on hemostasis and pain level in patients undergoing orthognathic surgery: a triple-blinded, randomized, clinical trial

OBJECTIVE

This triple-blind, controlled clinical trial aimed to assess the effects of ropivacaine and lidocaine on hemodynamic factors, blood loss, opioid consumption, and postoperative pain in patients undergoing orthognathic surgery.

METHODS

Thirty-two patients with Class III malocclusion scheduled for orthognathic surgery were included. The participants were randomly assigned to receive 0.5% ropivacaine or 2% lidocaine with 1:80,000 epinephrine for local anesthesia (n = 16). Hemodynamic parameters were recorded at various time intervals, which included heart rate (HR), systolic blood pressure, diastolic blood pressure, mean arterial pressure, oxygen saturation (SpO2), intraoperative bleeding, opioid consumption, and postoperative pain intensity.

RESULTS

The participants' mean age was 23.67 ± 4.56 years, and 75% were female. The groups were comparable in most measured outcomes. HR was significantly higher in the ropivacaine group at 30 and 60 min post-injection (P < 0.05). SpO2 percentages were comparable between the groups, except at 15 min post-anesthesia, where the lidocaine group demonstrated a significantly higher SpO2 (P = 0.029). Blood pressure, postoperative opioid consumption, intraoperative bleeding, and postoperative pain levels showed no statistically significant differences between the two groups.

CONCLUSION

Within the limitations of this study, both 0.5% ropivacaine and lidocaine with epinephrine demonstrated comparable effects on hemodynamic stability, intraoperative blood loss, postoperative pain levels, and opioid consumption in patients undergoing orthognathic surgery. These findings suggest that ropivacaine may serve as a safe and effective alternative to lidocaine for local anesthesia in orthognathic procedures.

The application of Bayesian forecasting to explore the effects of sex and high-fat diet on the pharmacokinetics of ropivacaine in the rat

Bayesian forecasting is commonly applied as part of therapeutic drug monitoring to obtain individual estimates of pharmacokinetic parameters in patients. Here its utility was explored in a preclinical study involving ropivacaine, in which sparse blood sampling data was available in the rat. Initially sample-population estimates of parameters were obtained by injecting male cannulated male Sprague-Dawley rats subcutaneously with ropivacaine HCl. Blood samples were serially drawn from each rat for 12 h after the dose (rich sampling); the concentrations were used with compartmental analysis to optimize model selection and obtain mean and variances of pharmacokinetic parameters. Two additional single doses, spaced by 5 days, were injected, each followed by 1 to 3 sparse blood draws. Other sparsely sampled age-matched groups of male and female rats given standard diet, and a group of males given high-fat diet, were dosed. Bayesian forecasting was conducted for each of these sparsely sampled rats to estimate pharmacokinetic parameters. Plasma was assayed using liquid-chromatographic method using mass spectrometry. For validation, the Bayesian parameter forecasts were compared to those using nonlinear mixed-effects modelling (NLMEM). Ropivacaine had a high clearance compared to hepatic blood flow, and a large volume of distribution. Excellent correlations were present between observed and estimated plasma concentrations using Bayesian forecasting, as was the relationship between those estimates and those obtained from NLMEM. The male rats given high-fat diet had a significant decrease in the weight-normalized clearance of ropivacaine, and female rats had a slower absorption rate. The effects were also identified using NLMEM. Bayesian forecasting has applicability in estimating pharmacokinetic properties of drugs in preclinical studies.

Safety, tolerability, pharmacokinetic, and pharmacodynamic of CZ1S injection for unilateral brachial plexus blockade in healthy Chinese adults: Double-blind, randomized, positive-controlled Phase I study

CZ1S injection is a novel, extended-release local anaesthetic formulation of ropivacaine, classified as a type 2.2 new drug, with potential for post-operative analgesia by subcutaneous infiltration and peripheral nerve blockade. This study aimed to validate the superior properties of CZ1S over ropivacaine hydrochloride injection and to evaluate the safety, tolerability, pharmacokinetic (PK) and pharmacodynamic (PD) profiles of a single dose of brachial plexus block with CZ1S in healthy Chinese adults. The tolerability and PK profile of CZ1S were investigated following a unilateral brachial plexus injection in 24 healthy adults. Safety assessments were performed throughout the study and the PD effects of CZ1S injection for unilateral brachial plexus block were also evaluated. The results showed that CZ1S was slowly absorbed after a single injection in healthy subjects, with PK parameters of ropivacaine (including Cmax, AUCt and AUC∞) increasing with the CZ1S doses. CZ1S demonstrated a prolonged and non-constant release profile compared to a single 75 mg injection of ropivacaine hydrochloride, resulting in a smooth and sustained blood concentration. CZ1S significantly prolonged the duration of sensory and motor blockade, and further analysis revealed a correlation between PK and sensory nerve block. The PK profile of CZ1S was enhanced compared to that of ropivacaine injection, and it was deemed safe and well tolerated in healthy Chinese adults, suggesting its potential application in postoperative analgesia. CLINICAL TRIAL REGISTRATION: Chinadrugtrials.org.cn: CTR20231295 (registration date: 26 April 2023).

LC-MS/MS assisted pharmacokinetic and tissue distribution study of ropivacaine and 3-OH-ropivacaine on rats after plane block anesthesia

Knowledge of drug pharmacokinetics and tissue distribution is precious for ensuring patient safety and optimizing treatments. The varied use of local anesthetics, as well as the fact that anesthetics can sometimes have low therapeutic indices and numerous adverse drug reactions, makes any novel pharmacokinetics information valuable. The present manuscript describes a pharmacokinetic study of ropivacaine carried out after plane block anesthesia on an animal model, using high sensitivity, accurate, and precise LC-MS/MS bioanalysis. Both plasmatic concentrations and tissue distribution of ropivacaine and its primary active metabolite were determined. The results showed a tissue affinity of the anesthetics, a clearance of ropivacaine mainly by hepatic metabolism, and the final, mainly renal excretion of the hydroxylated metabolite. While the results cannot simply and directly be transposed to human pharmacokinetics, they offer a valuable basis for future studies and can contribute to a better understanding of the bioavailability and toxicology of the widely used modern anesthetic.

The Study of Ropivacaine Pharmacokinetics in a Clinical Setting: A Critical Scoping Review from the Perspective of Analytical Methodologies

Ropivacaine, a widely used regional anesthetic also used for pain management, has been increasingly used in recent years due to its increased efficacy and improved safety compared to similar anesthetics. Biomonitoring of ropivacaine and its metabolites during and after anesthesia is an essential process for ensuring therapeutic efficacy and safe usage for patients. The most useful biomonitoring tool in recent years has been liquid chromatography coupled with mass spectrometry (LC-MS/MS), which offers selectivity, sensitivity, as well as accuracy of measurements. The current manuscript summarizes and discusses the existing liquid chromatographic methods described in the literature, as well as the personal experience with developing bioanalytical and analytical methods for the quantification of ropivacaine in biological samples for clinical applications. It is focused on methodological aspects, recent advancements, challenges, and future perspectives, highlighting the importance of LC-MS/MS techniques in ropivacaine analysis.

Pectoral Nerve Blocks Under Direct Vision During Endoscopic-Assisted Transaxillary Breast Augmentation: A Novel, Effective Regional Blocking Approach

BACKGROUND

Endoscopic-assisted transaxillary breast augmentation allows performing Pecs block under direct visualization. This study aimed to describe this new technique and demonstrat its short-term efficacy and safety with a preliminary clinical study.

METHODS

Patients enrolled for transaxillary endoscopic-assisted prosthetic breast augmentation between February 2022 and March 2023 in two medical centers were included in the pectoral nerve block group. Postoperative VAS scores at 1, 4, 12, 24, 48, and 72 h, surgery duration, and the occurrence of nausea and vomiting were compared with a historical cohort of patients collected between February 2021 and January 2022 with the same inclusion criteria.

RESULTS

229 patients were included in the Pecs group and 116 patients were identified in the control group. No statistical difference was observed in patient characteristics. VAS score at postoperative 1 h and 72 h was similar between the two groups, whereas VAS score at postoperative 4 h, 12 h, 24 h and 48 h in Pecs group was significantly lower than control group. The occurrence of PONV in the Pecs group is significantly lower than in the control group. The duration of surgery is similar between the two groups. No block-related complication was observed in the Pecs group.

CONCLUSION

A novel approach by combining pectoral nerve blocks with transaxillary endoscopic-assisted breast augmentation to perform blocks under direct vision was proposed and its short-term efficacy and safety was determined by this study.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The effect of pericapsular nerve group (PENG) block on postoperative analgesia in elderly patients who underwent proximal femoral nail anti-rotation surgery: a prospective, randomized-controlled trial

BACKGROUND

As a fascial plane block technique, further exploration is needed to determine the safety and efficacy of a peri-capsular nerve group (PENG) block in elderly patients with intertrochanteric femur fractures. We aimed to evaluate whether opioid consumption during a PENG block is better than a conventional opioid-based program for postoperative pain management after proximal femoral nail anti-rotation (PFNA).

METHODS

We conducted a prospective, randomized, controlled trial comparing the efficacy of the PENG block with the control group for elderly patients undergoing primary PFNA under general anesthesia. The primary outcome was the cumulative administration of sufentanil during the first 48 h after surgery.

RESULTS

110 participants (55 in each group) were included in the analysis. Cumulative Sufentanil consumption between the PENG group and the control group at 48 h was 132.6 ± 12.3 vs. 141.0 ± 15.3, with a difference of -8.4; 95% CI, -13.6 to -3.1, P = 0.002. Sufentanil consumption at 24 h was 78.3 ± 6.1 vs. 94.0 ± 10.2, with a difference of -15.7; 95% CI, -18.9 to -12.5, P < 0.001. There were statistical differences in the visual analogue scale score trajectories between the two groups at 48 h postoperatively (P < 0.001). The median time to first remedial analgesia was lower in the PENG block group than in the control group (P < 0.001). However, there was no difference in the time to first standing.

CONCLUSION

Incorporating the PENG block into a multimodal analgesia regimen can decrease opioid consumption among elderly patients undergoing PFNA under general anesthesia.

TRIAL REGISTRATION

The study was registered in the Chinese Clinical Trial Registry (ChiCTR2100054290, principal investigator: Xiao-dan, Wu, 13/12/2021).

Association between plain ropivacaine dose and spinal hypotension for cesarean delivery: a retrospective study

Background

Data on the association between the plain ropivacaine dose and maternal hypotension during cesarean delivery are limited. Thus, this study aimed to explore this association.

Methods

This retrospective study included patients undergoing cesarean sections under spinal or combined spinal-epidural anesthesia with plain ropivacaine at The First Hospital of Fuyang, Hangzhou, China, between 2018 and 2022. Data were obtained from the anesthesia information management system. Liner trend tests were used to distinguish the linear relationship between spinal hypotension and the plain ropivacaine dose, and receiver operating characteristic curves were used to calculate the dose threshold. Logistic regression was used to adjust for confounders. Sensitivity analyses were performed to evaluate the stability of the results. The secondary outcome was vasopressor use (metaraminol and ephedrine).

Results

In total, 1,219 women were included. The incidence of hypotension linearly correlated with the plain ropivacaine dose (adjusted P-value for trend, P < 0.001). Thus, we used a dose threshold of 17.5 mg to compare the dose as a binary variable (≥17.5 mg vs. < 17.5 mg). Plain ropivacaine doses of ≥17.5 mg were associated with a higher incidence of spinal hypotension (adjusted odds ratio: 2.71; 95% confidence interval [1.85-3.95]; P < 0.001). The sensitivity analyses yielded similar results. The plain ropivacaine dose also correlated with metaraminol use but not ephedrine use.

Conclusions

The incidence of spinal-induced hypotension in women undergoing cesarean section linearly correlated with the plain ropivacaine dose. The dose threshold for hypotension risk was 17.5 mg.

Minimum Local Anesthetic Dose of Ropivacaine in Cesarean Section for Real-Time Ultrasound-Guided Spinal Anesthesia Using 24-Gauge versus 26-Gauge Needles Based on Fluid Simulation Technology: A Randomized Controlled Trial

Purpose

Previous research has demonstrated that real-time ultrasound-guided (UG) spinal anesthesia requires a higher minimum local anesthetic dose (MLAD) compared to traditional methods. However, the precise MLAD of ropivacaine for UG cesarean sections remains undetermined. In this study, we ascertained the MLAD of ropivacaine for cesarean section. We also investigated the mechanism underlying the diffusion of ropivacaine within the spinal canal using fluid simulation technology.

Patients and Methods

We randomly placed 60 healthy parturients undergoing elective cesarean section with real-time UG spinal anesthesia into Groups I (26-gauge spinal needle) and II (24-gauge spinal needle). For the first parturient in both groups, 15 mg of ropivacaine was administered intrathecally. Based on the effective or ineffective response of the previous parturient, the dose for the subsequent parturient was increased or decreased by 1 mg. Spinal anesthesia characteristics and side effects were recorded. A computer-generated spinal canal model was developed. Leveraging fluid dynamics simulation technology, we documented the diffusion of ropivacaine in the spinal canal using 26-and 24-gauge spinal needles.

Results

The MLADs in Groups I and II were 12.728 mg (12.339-13.130 mg) and 9.795 mg (9.491-10.110 mg), respectively. No significant difference was observed in the onset times and durations of sensory or motor blocks, incidence of complications, or neonatal Apgar scores between both groups. Fluid simulation modeling indicated that the 26-gauge spinal needle achieved a higher distribution level more quickly; however, its peak drug concentration was lower compared to the 24-gauge spinal needle.

Conclusion

For cesarean section anesthetization, the required MLAD of ropivacaine when using a real-time UG 26-gauge spinal needle is significantly greater than that with a 24-gauge needle. The spinal needle diameter influences ropivacaine's MLAD by markedly affecting its diffusion rate within the spinal canal.

Ropivacaine suppresses the progression of renal cell carcinoma through regulating the lncRNA RMRP/EZH2/CCDC65 axis

BACKGROUND

Renal cell carcinoma (RCC) is a common malignancy. Local anesthetics were displayed powerful effects against various cancers. This study aims to probe the functions and molecular mechanism of ropivacaine in RCC.

METHODS

Different concentrations of ropivacaine were performed to administrate RCC cells including 786-O and Caki-1 cells. Cell viability and cell apoptosis were examined using CCK-8 and flow cytometry, respectively. Cell migration and invasion were determined by transwell assay. RMRP and CCDC65 expression was firstly predicted using TCGA dataset and further validated in RCC cells using qRT-PCR and western blot. The interactions among RMRP, EZH2 and CCDC65 were verified by RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assays.

RESULTS

Ropivacaine effectively suppressed RCC cell viability, migration and invasion and enhanced cell apoptosis rate. Aberrantly elevated RMRP expression in RCC tissues was predicted by TCGA database. Interestingly, overexpressed RMRP observed in RCC cells could be also blocked upon the administration of ropivacaine. Likewise, RMRP knockdown further strengthened ropivacaine-mediated tumor suppressive effects on RCC cells. In terms of mechanism, RMRP directly interacted with EZH2, thereby modulating the histone methylation of CCDC65 to silence its expression. Moreover, ropivacaine inhibited tumor growth in mice bearing RCC tumor through regulating RMRP/EZH2/CCDC65 axis.

CONCLUSION

In sum up, our work revealed that ropivacaine suppressed capacities of RCC cell viability, migration and invasion through modulating the RMRP/EZH2/CCDC65 axis, which laid the experimental foundation of ropivacaine for clinical application in the future.

Ultrasound‑guided erector spinae plane block in posterior lumbar surgery (Review)

The erector spinae plane block (ESPB) is a novel fascial planar block technique, which is used to reduce postoperative pain in several surgical procedures, including breast, thoracic, spine and hip surgery. Due to its recognizable anatomy and low complication rate, the application of ESPB has been significantly increased. However, it is rarely used in clinical practice for postoperative analgesia after posterior lumbar spine surgery, while the choice of adjuvant drugs, block levels and drug doses remain controversial. Based on the current literature review, ropivacaine and dexmedetomidine could be considered as the best available drug combination. The present review aimed to analyze the currently available clinical evidence and summarize the benefits and challenges of ESPB in spinal surgery, thus providing novel insights into the application of ESPB in the postoperative management of posterior lumbar surgery.

Ultrasound-guided stellate ganglion block benefits the postoperative recovery of patients undergoing laparoscopic colorectal surgery: a single-center, double-blinded, randomized controlled clinical trial

BACKGROUND

With the increasing prevalence of colorectal cancer (CRC), optimizing perioperative management is of paramount importance. This study investigates the potential of stellate ganglion block (SGB), known for its stress response-mediating effects, in improving postoperative recovery. We postulate that preoperative SGB may enhance the postoperative recovery of patients undergoing laparoscopic CRC surgery.

METHODS

We conducted a randomized controlled trial of 57 patients undergoing laparoscopic colorectal cancer surgery at a single center. Patients, aged 18-70 years, were randomly assigned to receive either preoperative SGB or standard care. SGB group patients received 10 mL of 0.2% ropivacaine under ultrasound guidance prior to surgery. Primary outcome was time to flatus, with secondary outcomes encompassing time to defecation, lying in bed time, visual analog scale (VAS) pain score, hospital stays, patient costs, intraoperative and postoperative complications, and 3-year mortality. A per-protocol analysis was used.

RESULTS

Twenty-nine patients in the SGB group and 28 patients in the control group were analyzed. The SGB group exhibited a significantly shorter time to flatus (mean [SD] hour, 20.52 [9.18] vs. 27.93 [11.69]; p = 0.012), accompanied by decreased plasma cortisol levels (mean [SD], postoperatively, 4.01 [3.42] vs 7.75 [3.13], p = 0.02). Notably, postoperative pain was effectively managed, evident by lower VAS scores at 6 h post-surgery in SGB-treated patients (mean [SD], 4.70 [0.91] vs 5.35 [1.32]; p = 0.040). Furthermore, patients in the SGB group experienced reduced hospital stay length (mean [SD], day, 6.61 [1.57] vs 8.72 [5.13], p = 0.042).

CONCLUSIONS

Preoperative SGB emerges as a promising approach to enhance the postoperative recovery of patients undergoing laparoscopic CRC surgery.

CLINICAL TRIAL REGISTRATION

ChiCTR1900028404, Principal investigator: Xia Feng, Date of registration: 12/20/2019.

Dexmedetomidine adjunct to ropivacaine for ultrasound-guided transversus abdominis plane block for open inguinal hernia repair in the older adults: A randomised clinical trial

OBJECTIVE

The aim of this study was to evaluate the effect of adding dexmedetomidine to ropivacaine on pain relief and quality of recovery in older patients undergoing open inguinal hernia repair surgeries.

METHODS

This was a prospective and randomised clinical trial of 102 patients aged over 65 years who received an ultrasound-guided transversus open mesh herniorrhaphy abdominis plane (TAP) block with either 0.375% ropivacaine 20 ml (Group R, n = 47) or 0.375% ropivacaine combined with 1 μg/kg dexmedetomidine 20 ml (Group RD, n = 45) in the pre-anaesthesia care unit before elective open inguinal hernia surgeries. The primary outcome measure was Visual Analogue Scale (VAS) pain scores at rest and on movement at 2, 4, 8, 12 and 24 h and at 1 and 3 months' postoperatively. The secondary outcome measures were the incidence of post-operative delirium (POD), nausea and vomiting and the occurrence of side effects or complications on post-operative day 1.

RESULTS

Group RD had lower VAS scores at rest and on movement at 8 and 12 h postoperatively and a lower incidence of POD on the post-operative day 1 than Group R. Transient bradycardia was more frequent in Group RD than in Group R, and side effects or post-operative complications were reported in either group.

CONCLUSION

The addition of dexmedetomidine to ropivacaine in a TAP block enhances postoperative analgesia during hospitalisation and improves the quality of recovery without affecting chronic pain in older patients undergoing open inguinal hernia repair surgery.

Preoperative versus postoperative ultrasound-guided rectus sheath block for acute postoperative pain relief after laparoscopy: A retrospective cohort study

Although rectus sheath block (RSB) is routinely used in laparoscopic surgeries to reduce mid-abdominal pain, whether RSB should be performed before or after surgery remains unclear. Herein, the optimal timing for RSB in patients undergoing laparoscopic surgery was investigated. This retrospective cohort study analyzed the data of patients who underwent RSB during laparoscopic procedures at our hospital between January 2013 and December 2018. The primary outcome was the time to rescue analgesia within 24 hours postanesthesia. The patients were divided into preoperative (pre-) and postoperative (post-) RSB groups. A multivariable Cox proportional hazards regression model was used to analyze the time to rescue analgesia in the unmatched and propensity score (PS)-matched patient populations. In total, 609/14,284 patients were included (pre-RSB group, 227 patients; post-RSB group, 382 patients). After PS matching, 97 patients were assigned to both groups. Although the time from extubation to the first analgesic request was not significantly different between the 2 groups (322 vs 294 minutes, P = .57), the patients in the pre-RSB group showed a lower risk of postoperative first analgesic administration after PS matching (adjusted hazard ratio, 0.71; 95% confidence interval, 0.53-0.95; P = .023). Among patients undergoing laparoscopic surgery, those in the pre-RSB group tended to have a longer time to the first analgesic request and had a lower risk of analgesic administration within the first 24 hours than those in the post-RSB group. Thus, performing RSB preoperatively may be preferable.

The Efficacy and Safety of Spinal Anesthesia With Hyperbaric Ropivacaine 0.75% and Bupivacaine 0.5% in Patients Undergoing Infra-Umbilical Surgeries: A Randomized, Double-Blind Study

BACKGROUND

Spinal anesthesia utilizing hyperbaric 0.75% ropivacaine has been gaining clinical acceptance recently. It is a pure S-enantiomer of bupivacaine, which is expected to have a better clinical profile, but the studies for the same are yet limited. We aimed to compare the efficacy and safety of these two drugs.

METHODS

Sixty patients, aged 18 to 60 years of either sex, classified as American Society of Anesthesiologists class I and II, who were undergoing elective infra-umbilical surgery, were randomly assigned to receive either 3 mL of 0.5% bupivacaine heavy or 3 mL of 0.75% ropivacaine heavy intrathecally. Efficacy parameters, including the onset and duration of sensory and motor block, time to rescue analgesia, hemodynamics, and safety in terms of complications, were recorded. We compared the data for statistical significance, considering a p-value of less than 0.05 as significant.

RESULTS

Ropivacaine exhibited a slower onset for both sensory (153.90 ± 6.53 versus 92.46 ± 12.16 seconds; p < 0.001) and motor blockades (301 ± 6.62 versus 239.96 ± 6.27 seconds; p < 0.001). Two-segment sensory and motor blockade regression were faster with ropivacaine compared to bupivacaine (p < 0.001). However, the mean duration of sensory blockade for ropivacaine compared to that for bupivacaine (219.29 ± 15.14 versus 227.31 ± 17.20 minutes) and the requirement for rescue analgesia were not statistically different (p > 0.05). Ropivacaine also caused fewer side effects on a percentage scale.

CONCLUSION

In patients undergoing infra-umbilical surgery, hyperbaric ropivacaine at an equipotent dose (0.75%) proved to be a comparable and safer alternative to hyperbaric bupivacaine (0.5%). Furthermore, it had better motor-recovery profiles.

Differential blockade, comparative study of different ropivacaine concentrations (0.75%; 0.2%; 0.12%) for ultrasound guided sciatic and femoral nerve blocks in calves: Prospective cross-over study

Pharmacodynamic understanding of the different local anesthetic concentrations allows adapting their use to diverse clinical/surgical procedures, such as intraoperative and/or postoperative analgesia. A crossover study was performed, where 6 calves (5 male and 1 female), weighing 120 ± 28 Kg, were subjected to combined sciatic and femoral nerve block using three ropivacaine concentrations. The treatments were: R0.75, using 0.75% ropivacaine; R0.2, 0.2% ropivacaine; and R0.12%, 0.12% ropivacaine. All treatments were performed with ultrasound and neurostimulation assistance, and a volume of 0.1 mL/kg of the respective local anesthetic solution was administered in each block point. The sites of mechanical nociceptive threshold (MNT) evaluation were based on the calf pelvic limb dermatomes. The proportion between desensitized areas, MNT elevation time and level of ataxia were registered. Elevation of MNT occurred in 100% of the tested areas in the R0.75 and R0.2 treatments, and in 82% of the R0.12 treatment. Mean MNT elevation times were 9.5 ± 0.7 h for R0.75, 6 ± 0.8 for R.02, and 2.4 ± 2.3 for R0.12, differing significantly between all treatments. No difference was observed between MNT elevation time and ataxia duration time, in each treatment. It is concluded that the duration of sensory-motor effects is dose-dependent, but there was not possible to detect block selectivity as the concentrations was reduced. More desensitized areas and extension were obtained with the use of higher concentrations.

Femoral nerve block using lower concentration ropivacaine preserves quadriceps strength while providing similar analgesic effects after knee arthroscopy

PURPOSE

Femoral nerve block (FNB) is widely used in patients undergoing knee arthroscopy. However, the most commonly used concentration of ropivacaine (0.2% or above) may cause an unexpected decrease in the muscle strength of the quadriceps. Therefore, a lower concentration of ropivacaine (0.1%) for FNB was administered to investigate the effect on quadriceps strength and postoperative pain after knee arthroscopy.

METHODS

This was a double-blind, randomized, controlled trial (ChiCTR2000041404). A total of 83 patients scheduled for elective knee arthroscopy were randomized to receive 0.1% or 0.2% ropivacaine for FNB under ultrasound guidance. The primary outcomes were quadriceps strength and numerical rating scale (NRS) pain score. Quadriceps strength was measured before surgery and 6 h and 24 h after surgery, while NRS score was recorded before surgery, at the postanaesthesia care unit (PACU), and 6 h and 24 h after surgery. Multiple linear regression tests were used to compare the differences in quadriceps strength and NRS score between the two groups. Two-factor analysis of variance, using the factors group and time of measurement, was used for repeated NRS scores. Secondary outcomes included knee mobility, side effects, patient satisfaction, and length of hospital stay.

RESULTS

The mean (SD) quadriceps strength at 6 h after surgery was 7.5 (5.7) kg for the 0.1% ropivacaine group and 3.0 (4.4) kg for the 0.2% ropivacaine group. The mean difference adjusted for baseline characteristics was - 5.2 (95% CI - 7.2 to - 3.1) kg (P < 0.001). There was no significant difference between the two groups in quadriceps strength at 24 h after surgery. The mean differences in the average NRS score and maximum NRS score in the PACU were - 0.6 (P = 0.008) and - 1.0 (P < 0.001), respectively. There was no significant difference in NRS score at 6 h or 24 h after surgery. Two-factor analysis of variance showed no significant difference in the interaction factors of time and group for average NRS score and maximum NRS score.

CONCLUSIONS

Compared with 0.2% ropivacaine, 0.1% ropivacaine for FNB preserved quadriceps strength at 6 h after knee arthroscopy while providing similar analgesic effects.

LEVEL OF EVIDENCE

I.

Nanocrystals Slow-Releasing Ropivacaine and Doxorubicin to Synergistically Suppress Tumor Recurrence and Relieve Postoperative Pain

Although surgical resection provides a straightforward and effective treatment for most malignant solid tumors, tumor recurrence and acute postoperative pain continue to be two big problems associated with this treatment. To resolve these problems, a nanocrystal composite slow-releasing ropivacaine and doxorubicin was fabricated in this study. Briefly, a self-assembling peptide was used to form nanoparticle complexes with the two drugs, based on which homogeneous nanocrystals were obtained by adjusting the pH. In cultured human melanoma cells, the nanocrystals exhibited improved antitumor activity due to a synergistic effect and enhanced cellular uptake of the two drugs. On the other hand, the nanocrystals could slowly release ropivacaine in vitro and in vivo, generating long-acting analgesia on the rat sciatic nerve block model and incisional pain model. On a nude mouse tumor resection model, the nanocrystals simultaneously suppressed the recurrence of solid tumor and relieved postoperative pain, indicating a potential postoperative treatment for tumor resection patients. This nanocrystal system also suggested a promising and facile strategy for developing multifunctional formulations combining different drugs, which could achieve better therapeutic outcomes in a synergistic and sustained manner.

LC-MS/MS assisted biomonitoring of ropivacaine and 3-OH-ropivacaine after plane block anesthesia for cardiac device implantation

Introduction: Ropivacaine is a popular local anesthetic used for regional anesthesia or for pain management. Although designed as an enantiomerically pure drug, an aspect that reduces the adverse effects, its toxicological effects are still a risk. As such, biomonitoring to assure appropriate dosage and bioavailability are essential to avoid complications during or post-surgery. Methods: The study focused on developing a sensitive, selective, and accurate liquid chromatography-mass spectrometry (LCMS/MS) method which facilitates the biomonitoring of ropivacaine and its main metabolite in plasma after regional anesthesia using ropivacaine. Results and Discussion: The method was validated with regards to all relevant parameters, such as sensitivity, selectivity, accuracy, precision, and the effect of sample matrix. The method was successfully used in a pilot study, which included one patient undergoing plane block anesthesia for cardiac device implantation. The results showed the method is appropriate for its intended purpose and could even be used in other, similar applications.

Evaluation of efficacy of peribulbar block with the combination of 2% lidocaine and 0.5% bupivacaine in comparison with 2% lidocaine and 0.75% ropivacaine in cataract surgery

Introduction

Cataract surgery is performed under peribulbar or retrobulbar block. Majority of the patients posted for cataract have some form of medical diseases like diabetes, hypertension, angina, ischaemic heart disease etc. Lidocaine and bupivacaine are the most commonly used local anesthetic for the block procedure. Here we compare the efficacy of peribulbar block in cataract surgery using the combination of 1:1 mixture of 2% lidocaine with 0.5% bupivacaine and 1:1 mixture of 2% lidocaine with 0.75% ropivacaine.

Materials and Methods

It is a prospective, randomized, double blinded study including 60 patients were devided into two groups of 30 each, Group-R received 8 ml of 1:1 mixture of 4 ml of 2% lidocaine, 4 ml of 0.75% ropivacaine and 15 IU/ml of hyaluronidase and group-B received 8 ml of 1:1 mixture of 4 ml of 2% lidocaine, 4 ml of 0. 5% bubivacaineand 15 IU/ml of hyaluronidase. Peribulbar block was performed as per Bloomberg's modification of the Davis and Mandel technique where 5 ml of local anesthetic was injected in the infero temporal region and 3 ml of drug was injected in the superi nasal area. Patients were assessed for sensory block, eyelid and occular movements at an interval of 2 minutes. Systolic, diastolic and mean arterial pressures, heart rate, oxygen saturation, ECG were monitored non invasively at 1,3,5,8,10,15 and then every 10 minutes till the end of the surgery.

Observation and Discussion

Mean time for the onset of sensory blockade was 2.70 ± 6.5 minutes in Group B and 2.63 ± 0.57 minutes in group R with P-value 0.671, showing no significant difference in the onset of sensory blockade. Onset of motor blockade was 6.53 ± 1.81 minutes in group B, and 7.57 ± 1.46 minutes in the group R, the P-value being 0.018 was statistically significant. Regarding the duration of analgesia, our study showed mean time for analgesia lasted for 295 ± 54.63 minutes in group B and 414.67 ± 99.47 in group R with P value 0.001 showing statistically significant prolongation of duration of analgesia with group R. We observed a significant increase of mean IOP in bupivacaine group from 13.333 ± 1.582 mm Hg to 21.966 ± 2.697 mm Hg, whereas in ropivacaine group it increased from 12.766 ± 1.222 mm Hg to 13.0 ± 1.341 mm Hg after peribulbar anaesthesia.

Study on MEV90 of 0.5% ropivacaine for US-guided caudal epidural block in anorectal surgery

Background

Choosing the appropriate concentration and volume of anesthetics is critical for a successful nerve block. The current study aimed to determine the minimum effective volume (MEV) of 0.5% ropivacaine for US-guided CEB in 90% of patients (MEV90) undergoing anorectal surgery. The aims were to reduce the occurrence of complications associated with a sacral blockade in anorectal surgery, broaden the indications for surgical procedures and treatment, and improve patient satisfaction. This study presents the groundwork for the development of individualized anesthetic programs. We believe that the study would serve as a reference for the use of caudal epidural block (CEB) in lower abdominal surgery for intraoperative and postoperative analgesia.

Methods

This study used a biased coin design (BCD) up-and-down method (UDM). We divided the participants into two groups based on gender, and each group independently performed the biased coin design up-and-down method. We used 0.5% ropivacaine for the first patient in each group; however, the volume was 10 ml for men and 8 ml for women. Therefore, the dose of anesthetics given to each patient was determined by the response of the previous patient. If the block of the previous patient failed, the volume was increased by 2 ml in the following patient. Otherwise, the next subject had an 11% chance of receiving a volume of 2 ml less or an 89% chance of receiving no volume change. We defined a successful block as painless surgery with anal sphincter relaxation 15 min after the drug injection. Enrollment was completed after 45 successful caudal blocks for each group.

Results

Caudal epidural block was successfully performed on 50 men and 49 women. The MEV90 of ropivacaine for CEB was calculated to be 12.88 ml (95% CI: 10.8-14 ml) for men and 10.73 ml (95% CI: 9.67-12 ml) for women. Men had a MEV99 of 13.88 ml (95% CI: 12.97-14 ml), and women had a MEV99 of 11.87 ml (95% CI: 11.72-12 ml).

Conclusion

With operability and general applicability, it is possible to increase the success rate of CEB for anorectal surgery to 99% as well as decrease the incidence of anesthesia-related complications. CEB can meet the needs of patients for rapid postoperative rehabilitation, improve patient satisfaction, and lay a solid foundation for postoperative analgesia.

Engineering 2D Silicene-Based Mesoporous Nanomedicine for In Vivo Near-Infrared-Triggered Analgesia

The utilization of local anesthetics for postoperative analgesia represents an effective approach, but generally suffers from short half-lives and brachychronic local neurotoxicity. A desirable anesthetic with controllable and sustainable drug-releasing performance for adequate analgesia effect is highly required. In this work, the core/shell-structured two-dimenional (2D) silicene nanosheets coated with mesoporous silica layer (abbreviated as Silicene@MSNs) have been rationally constructed as localized drug-delivery system in sciatic nerve block to achieve on-demand release of loaded ropivacaine (RP) in mesoporous silica layer for local analgesia. Based on the specific photothermal performance of 2D silicene core, this local anesthesia system can be triggered by near-infrared laser to release the loaded RP, resulting in on-demand and long-lasting regional anesthesia. The analgesia effect is assessed by pain behavior tests, which demonstrates that the RP-loaded Silicene@MSNs core/shell nanosystem behaves almost five times longer analgesia effect than free RP. Furthermore, the activation of pain-related neurons in nerve conduction pathways is tested to explore the underlying analgesia mechanism, revealing that the designed nanosystem can improve the pain threshold, reduce the activation of neurons in dorsal root ganglion and excitability in spinal substantia gelatinosa neurons. This designed anesthetic nanomedicine provides a facile but effective methodology for long-lasting regional anesthesia.

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.

Pharmacodynamics, toxicology and toxicokinetics of ropivacaine oil delivery depot

BACKGROUND

Ropivacaine oil delivery depot (RODD) can be used to treat postoperative incision pain. The aim was to study pharmacodynamics, toxicity and toxicokinetics of RODD.

METHODS

The base research of RODD were conducted. Thirty rabbits were randomly divided into saline, solvent, ropivacaine aqueous injection (RAI) 0.9 mg, RODD 0.9 mg and RODD 3 mg groups. The sciatic nerve of rabbits were isolated, dripped with RODD and the effect of nerve block were observed. In toxicity study, the rats were divided into saline, solvent and RODD 75, 150 and 300 mg/kg groups, 30 rats per group. In toxicokinetics, rats were divided into RODD 75, 150 and 300 mg/kg groups, 18 rats per group. The rats were subcutaneously injected drugs.

RESULTS

The analgesic duration of RODD 3 mg and RAI 0.9 mg blocking ischiadic nerve lasted about 20 h and 2 h, respectively, and their blocking intensity was similar. The rats in RODD 75 mg/kg did not show any toxicity. Compared with saline group, in RODD 150 mg/kg group neutrophils and mononuclear cells increased, lymphocytes decreased and albumin decreased(P < 0.05), and pathological examination showed some abnormals. In RODD 300 mg/kg group, 10 rats died and showed some abnormalities in central nerve system, hematologic indexes, part of biochemical indexes, and the weights of spleen, liver, and thymus. However, these abnormal was largely recovered on 14 days after the dosing. The results of toxicokinetics of RODD 75 mg/kg group showed that the Cmax was 1.24 ± 0.59 µg/mL and the AUC(0-24 h) was 11.65 ± 1.58 h·µg/mL.

CONCLUSIONS

Subcutaneous injection RODD releases ropivacaine slowly, and shows a stable and longer analgesic effect with a large safety range.

The Assessment of Prolonged Inferior Alveolar Nerve Blockade for Postoperative Analgesia in Mandibular Third Molar Surgery by a Perineural Addition of Dexamethasone to 0.5% Ropivacaine: A Randomized Comparison Study

Background: Perineurally adding dexamethasone to local anesthetics could enable postoperative analgesia. Our aim was to investigate the efficacy of 4 mg dexamethasone and 0.5% ropivacaine on the prolonged duration of mandibular anesthesia for postoperative analgesia during third molar surgery. Materials and method: The patients of both sexes, and in the age range of 17 to 50 yrs of age, received the Gow-Gates anesthesia. Group I received 4 mL of plain 0.5% ropivacaine, with perineurally added 1 mL/4 mg of dexamethasone; group II received 4 mL of plain 0.5% ropivacaine with perineurally added 1 mL of 0.9% saline; group III received 4 mL of plain 0.5 bupivacaine with perineurally added 1 mL of 0.9% saline. The prime anesthesia outcome was the duration of conduction anesthesia (DCA); the secondary outcome was the duration of analgesia (DAN) and analgesia before analgesic intake. Results: In 45 randomly selected subjects (mean age 27.06 ± 8.20), DCA was statistically longest in group I (n = 15) (592.50 ± 161.75 min, p = 0.001), collated with groups II (n = 15) and III (n = 15) (307.40 ± 84.71 and 367.07 ± 170.52 min, respectively). DAN was significantly the longest in group I (mean: 654.9 ± 198.4 min, p = 0.001), compared with group II (345.4 ± 88.0 min) and group III (413.7 ± 152.3 min), with insignificant adverse reactions. One-third of the operated patients absented from the use of analgesics. Conclusion: A amount 0.5% ropivacaine with dexamethasone usefully served as an analgesic with a success rate of 93.4% of the given anesthesia.

Intraoperatively local infiltration anesthesia in hemiarthroplasty patients reduces the needs of opioids: a randomized, double-blind, placebo-controlled trial with 96 patients in a fast-track hip fracture setting

Background and purpose - Local infiltration analgesia (LIA) is commonly used as a component in multimodal analgesia. Pain management directed towards hip fracture patients operated on with hemiarthroplasty is often based on knowledge regarding pain treatment following elective surgery. In this elderly patient population, it is of value to clarify whether adding local infiltration analgesia (LIA) to the postoperative analgesic regimen might reduce postoperative pain or have an opioid-reducing effect. Patients and methods - 96 hip fracture patients undergoing hemiarthroplasty in spinal anesthesia were included. All patients received a multimodal pain regimen and were randomized to receive either ropivacaine or placebo. All patients received morphine depot-opioid and morphine as rescue medication postoperatively. The primary endpoint was pain during mobilization in the recovery unit on the day of surgery. Secondary endpoints were pain during mobilization the day after surgery and postoperative opioid requirements on the first postoperative day. Results - The levels of pain (NRS) during mobilization both in the recovery unit and on the day after surgery were similar in the 2 groups, with median 4 and 0.5 in the placebo group and median 3.5 and 1 in the ropivacaine group respectively. Total consumption of opioids on day 0 and day 1 were 4.6 mg lower in the ropivacaine group (p = 0.04). Pain during mobilization was registered for only 44 of 96 patients for several reasons, including lack of mobilization. Interpretation - There were similar pain scores in both the local infiltration and placebo group postoperatively. However, substantially reduced opioid consumption was found in patients receiving LIA.

The Comparison of Fluoroscopy-Guided Epidural Anesthesia with Conscious Sedation and General Anesthesia for Endoscopic Lumbar Decompression Surgery: A Retrospective Analysis

BACKGROUND

With advances and refinements in endoscopic lumbar spine surgery showing effective and satisfactory results, the need for simple yet effective anesthetic techniques for minimally invasive endoscopic spine surgery has increased. The aim of this study was to compare feasibility and postoperative outcomes of fluoroscopy-guided epidural anesthesia with general anesthesia in patients undergoing endoscopic lumbar decompression surgery (≤3 levels).

METHODS

Patients who underwent 1-3 levels of endoscopic lumbar decompression surgery under either fluoroscopy-guided epidural or general anesthesia between January 2019 and October 2020 were retrospectively reviewed. Postoperative pain intensity and use of rescue analgesics for up to 48 hours were compared between the epidural and general anesthesia groups. Intraoperative anesthetic data and postoperative recovery profiles were also analyzed.

RESULTS

Postoperative pain scores were significantly lower in the epidural anesthesia group compared with the general anesthesia group at 10 minutes after recovery room admission (2.1 ± 1.8 vs. 5.7 ± 1.9, P < 0.001), 24 hours postoperatively (3.3 ± 1.0 vs. 5.4 ± 1.8, P < 0.001), and 48 hours postoperatively (3.2 ± 0.6 vs. 4.4 ± 1.4, P < 0.001). The proportion of patients requiring rescue analgesics in the recovery room was significantly lower in the epidural anesthesia group (1.9% vs. 20.5%, P = 0.027). The median 15-item Quality of Recovery score on postoperative day 1 was significantly higher in the epidural anesthesia group (118.0 [113.5-123.0] vs. 82.0 [73.5-111.5], P < 0.001). Occurrence of nausea, vomiting, and voiding difficulty up to 48 hours postoperatively did not differ between groups.

CONCLUSIONS

Compared with general anesthesia, epidural anesthesia provided better analgesia and recovery characteristics during the early postoperative period in endoscopic lumbar decompression surgery.

Preoperative Paravertebral Block and Chronic Pain after Breast Cancer Surgery: A Double-blind Randomized Trial

BACKGROUND

The effectiveness of paravertebral block in preventing chronic pain after breast surgery remains controversial. The primary hypothesis of this study was that paravertebral block reduces the incidence of chronic pain 3 months after breast cancer surgery.

METHODS

In this prospective, multicenter, randomized, double-blind, parallel-group, placebo-controlled study, 380 women undergoing partial or complete mastectomy with or without lymph node dissection were randomized to receive preoperative paravertebral block with either 0.35 ml/kg 0.75% ropivacaine (paravertebral group) or saline (control group). Systemic multimodal analgesia was administered in both groups. The primary endpoint was the incidence of chronic pain with a visual analogue scale (VAS) score greater than or equal to 3 out of 10, 3 months after surgery. The secondary outcomes were acute pain, analgesic consumption, nausea and vomiting, chronic pain at 6 and 12 months, neuropathic pain, pain interference, anxiety, and depression.

RESULTS

Overall, 178 patients received ropivacaine, and 174 received saline. At 3 months, chronic pain was reported in 93 of 178 (52.2%) and 83 of 174 (47.7%) patients in the paravertebral and control groups, respectively (odds ratio, 1.20 [95% CI, 0.79 to 1.82], P = 0.394). At 6 and 12 months, chronic pain occurred in 104 of 178 (58.4%) versus 79 of 174 (45.4%) and 105 of 178 (59.0%) versus 93 of 174 (53.4%) patients in the paravertebral and control groups, respectively. Greater acute postoperative pain was observed in the control group 0 to 2 h (area under the receiver operating characteristics curve at rest, 4.3 ± 2.8 vs. 2.9 ± 2.8 VAS score units × hours, P < 0.001) and when maximal in this interval (3.8 ± 2.1 vs. 2.5 ± 2.5, P < 0.001) but not during any other interval. Postoperative morphine use was 73% less in the paravertebral group (odds ratio, 0.272 [95% CI, 0.171 to 0.429]; P < 0.001).

CONCLUSIONS

Paravertebral block did not reduce the incidence of chronic pain after breast surgery. Paravertebral block did result in less immediate postoperative pain, but there were no other significant differences in postoperative outcomes.

EDITOR’S PERSPECTIVE

Novel local anaesthesia technique 'NATURE' (Nerves And Transversalis-fascia Using RopivacainE) to improve outcomes during endo-laparoscopic inguinal hernia repair

BACKGROUND

The use of local anaesthesia infiltration techniques may attenuate pain following endo-laparoscopic inguinal hernia surgery. We aim to reduce post-operative pain and the subsequent need for analgesia using a novel technique of local anaesthesia infiltration 'NATURE' (Nerves And Transversalis-fascia Using RopivacainE).

METHODS

This is a retrospective study of patients who underwent endo-laparoscopic inguinal hernia repair in two institutions in Singapore. Patients who received the local anaesthesia according to the new technique (intervention group) were compared to patients who received local anaesthesia only over their surgical incisions (control group).

RESULTS

Data on 97 patients were analysed. There were 50 (51.5%) patients in the intervention group and 47 (48.5%) patients in the control group. No significant differences were observed in the two patient population's baseline characteristics, operative time and cumulative need for medications. The intervention group reported lower pain levels immediately after surgery (1.4 ± 1.7 versus 2.4 ± 1.9, p<0.01) and at 4 hours post-surgery (0.9 ± 1.1 versus 1.4 ± 1.2, p = 0.02). They also had lower levels of post-operative complications (4% versus 21.3%, p = 0.03).

CONCLUSION

Infiltration of local anaesthesia at specific anatomical locations during endo-laparoscopic inguinal hernia surgery can be effective in minimising post-operative pain. Prospective randomised controlled trials are needed to further substantiate this technique.

The minimum effective concentration (MEC90) of ropivacaine for ultrasound-guided caudal block in anorectal surgery. A dose finding study

Background

Caudal epidural block (CEB) provides reliable anesthesia for adults undergoing anorectal surgery. Despite the widely utilization, the minimum effective concentration for 90% patients (MEC₉₀) of ropivacaine for CEB remains unknown.

Objective

To estimate MEC of ropivacaine for CEB in anorectal surgery.

Design

A prospective dose-finding study using biased coin design up-and-down sequential method.

Setting

Operating room and postoperative recovery area of Chengdu Shangjin Nanfu Hospital, from October 2019 to January 2020.

Patients

50 males and 51 females scheduled for anorectal surgery.

Interventions

We conducted two independent biased coin design up-and down trials by genders. The concentration of ropivacaine administered to the first patient of male and female were 0.25% with fixed volume of 14ml for male and 12ml for female patients based on our previous study. In case of failure, the concentration was increased by 0.05% in the next subject. Otherwise, the next subject was randomized to a concentration 0.05% less with a probability of 0.11, or the same concentration with a probability of 0.89. Success was defined as complete sensory blockade of perineal area 15 min after the block evidenced by the presence of a lax anal sphincter and pain-free surgery.

Main outcome measures

The MEC of ropivacaine to achieve a successful CEB in 90%(MEC₉₀) of the patients.

Results

The MEC₉₀ of ropivacaine for CEB were estimated to be 0.35% (95% CI 0.29 to 0.4%) for male and 0.353% (95%CI 0.22 to 0.4%) for female. By extrapolation to MEC in 99% of subjects (MEC99) and pooled adjacent violators algorithm (PAVA) adjusted responses, it would be optimal to choose 0.4% ropivacaine with a volume of 14ml for male and 12ml for female.

Conclusions

A concentration of 0.35% ropivacaine with a volume of 14ml provided a successful CEB in 90% of the male patients, while 0.353% ropivacaine with a volume of 12ml provided a successful CEB in 90% of the female patients. A concentration of 0.4% and a volume of 14ml for male and 12 ml for female would be successful in 99% of the patients.

Trial registration

Chictr.org.cn identifier: No. ChiCTR 1900024315.

Analgesic effect of intercostal nerve block given preventively or at the end of operation in video-assisted thoracic surgery: a randomized clinical trial

OBJECTIVE

To compare the analgesic effect of intercostal nerve block (INB) with ropivacaine when given preventively or at the end of the operation in patients undergoing video-assisted thoracic surgery (VATS).

METHODS

A total of 50 patients undergoing VATS were randomly divided into two groups. The patients in the preventive analgesia group (PR group) were given INB with ropivacaine before the intrathoracic manipulation combined with patient-controlled analgesia (PCA). The patients in the post-procedural block group (PO group) were administered INB with ropivacaine at the end of the operation combined with PCA. To evaluate the analgesic effect, postoperative pain was assessed with the visual analogue scale (VAS) at rest and Prince Henry Pain Scale (PHPS) scale at 6, 12, 24, 48, and 72 hours after surgery.

RESULTS

At 6 h and 12 h post-surgery, the VAS at rest and PHPS scores in the PR group were significantly lower than those in the PO group. There were no significant differences in pain scores between two groups at 24, 48, and 72 hours post-surgery.

CONCLUSION

In patients undergoing VATS, preventive INB with ropivacaine provided a significantly better analgesic effect in the early postoperative period (at least through 12 h post-surgery) than did INB given at the end of surgery.

Spinal Anesthesia Using Ropivacaine Leads to Earlier Ambulation After Total Hip Arthroplasty

Spinal anesthesia has grown in popularity for total hip arthroplasty (THA) due to its documented low complications. However, the use of a local anesthetic agent dictates the recovery of neuraxial blockade. Bupivacaine has emerged as the most popular choice, but its relatively long-acting effect limits its use with rapid recovery. Although not well studied, ropivacaine may offer a viable alternative with shorter-acting properties. Primary unilateral THA patients who received either ropivacaine or bupivacaine spinal anesthesia were retrospectively reviewed. These groups were compared for common demographics, such as age, sex, and body mass index. The primary outcomes included postoperative ambulation time and distance, post-anesthesia care unit transition time, and selective complications. Five hundred three patients were included. Of these, 227 received ropivacaine and 276 received bupivacaine. The ropivacaine group showed superior ambulation time and distance, quicker post-anesthesia care unit transition, and equivalent complications compared with the bupivacaine group. Ropivacaine shows a clear advantage over bupivacaine for spinal anesthesia during THA when considering rapid recovery. Its use should be strongly considered, especially in the ambulatory setting. [Orthopedics. 2021;44(3):e343-e346.].

Predicting outcomes in patients undergoing intra-articular corticosteroid hip injections

OBJECTIVE

To investigate the associations between clinical, procedural, and radiographic factors and outcomes of steroid hip injections, including long-term and immediate pain reduction, time to arthroplasty, time to reinjection, and the total number of injections.

MATERIALS AND METHODS

All intra-articular anesthetic and steroid injections of the hip under fluoroscopic guidance between January 2014 and March 2016 were retrospectively reviewed. Hip radiographs were scored using the Kellgren-Lawrence (KL) and Osteoarthritis Research Society International (OARSI) scores. Immediate pain relief and response were evaluated using a change in visual analog scale and OMERACT-OARSI criteria respectively. Long-term pain relief was evaluated at 2‑7 months after injection by reviewing the medical records. Correlation between patient characteristics, procedural variations, and radiographic factors with injection outcomes was analyzed by using linear and logistic regression models.

RESULTS

Of 361 injections, 79.8% showed an immediate pain response and 32.7% had subjective long-term pain relief (> 2 months). There was no significant correlation between immediate pain relief and response with long-term pain relief and other outcomes. Older age and higher KL score, OARSI-central joint space narrowing (JSN), and inferior acetabular osteophyte were correlated with long-term pain relief (p = 0.01‑0.03). Higher KL and OARSI grades, particularly JSN, were significantly correlated with increased immediate pain relief and total number of injections but decreased time to arthroplasty. Baseline pain positively correlated with immediate pain response (p < 0.001).

CONCLUSIONS

Older patients with higher grades of radiographic OA and high baseline pain were good candidates for steroid injections, particularly for those patients awaiting hip arthroplasty.

Ropivacaine: A Novel Local Anaesthetic Drug to Use in Otorhinolaryngology Practice

Ropivacaine is a long-acting amide local anaesthetic agent which has a significant vasoconstrictive property, long duration of action, least central nervous system and cardiac complications due to the pure (S)-enantiomer property by reversible inhibition of sodium ion influx in nerve fibres. By using additives the duration of analgesia may be prolonged. Ropivacaine has been used routinely in our otorhinolaryngology procedures since 2010 (10 years). The present article details the clinical applications of ropivacaine and its current place as a local anaesthetic in otorhinolaryngology practice.

Simultaneous Determination of Ropivacaine and 3-Hydroxy Ropivacaine in Cerebrospinal Fluid by UPLC-MS/MS

In this paper, a UPLC-MS/MS method was developed for the determination of ropivacaine and its metabolite 3-hydroxy ropivacaine in cerebrospinal fluid. The cerebrospinal fluid was processed by ethyl acetate liquid-liquid extraction. The multiple reaction monitoring (MRM) mode was used for quantitative analysis by monitoring the transitions of m/z 275.3 → 126.2 for ropivacaine, m/z 291.0 → 126.0 for 3-hydroxy ropivacaine, and m/z 290.2 → 198.2 for the internal standard. Standard curves for ropivacaine and 3-hydroxy ropivacaine in cerebrospinal fluid were conducted over the concentration range of 0.2–2000 ng/mL, demonstrating excellent linearity, and the lower limit of quantification was 0.2 ng/mL. The intraday precision of ropivacaine and 3-hydroxy ropivacaine was less than 11%, while the interday precision was less than 7%. The accuracy ranged between 87% and 107%, the average extraction efficiency was higher than 79%, and the matrix effect was between 89% and 98%. The developed method was then applied to a case of suspected poisoning of ropivacaine.

Efficacy and safety of different doses of ropivacaine for laparoscopy-assisted infiltration analgesia in patients undergoing laparoscopic cholecystectomy: A prospective randomized control trial

BACKGROUND

Wound infiltration analgesia provides effective postoperative pain control in patients undergoing laparoscopic cholecystectomy (LC). However, the efficacy and safety of wound infiltration with different doses of ropivacaine is not well defined. This study investigated the analgesic effects and pharmacokinetic profile of varying concentrations of ropivacaine at port sites under laparoscopy assistance.

METHODS

In this randomized, double-blinded study, 132 patients were assigned to 4 groups: Group H: in which patients were infiltrated with 0.75% ropivacaine; Group M: 0.5% ropivacaine; Group L: 0.2% ropivacaine; and Group C: 0.9% normal saline only. The primary outcome was pain intensity estimated using numeric rating scale (NRS) at discharging from PACU and at 4 hours, 6 hours, 8 hours, and 24 hours after infiltration. Secondary outcomes included plasma concentrations of ropivacaine at 30 minutes after wound infiltration, rescue analgesia requirements after surgery, perioperative vital signs changes, and side effects.

RESULTS

The NRS in Group C was significantly higher at rest, and when coughing upon leaving PACU and at 4 hours, 6 hours, 8 hours, and 24 hours after infiltration (P < .05) and rescue analgesic consumption was significantly higher. Notably, these parameters were not significantly different between Groups H, Group M and Group L (P > .05). Intra-operative consumption of sevoflurane and remifentanil, HR at skin incision and MAP at skin incision, as well as 5 minutes after skin incision were significantly higher in Group C than in the other 3 groups (P < .01). In contrast, these parameters were not significantly different between Groups H, Group M and Group L (P > .05). The concentration of ropivacaine at 30 minutes after infiltration in Group H was significantly higher than that of Group L and Group M (P < .05). No significant differences were observed in the occurrence of side effects among the 4 groups (P > .05).

CONCLUSIONS

Laparoscopy-assisted wound infiltration with ropivacaine successfully decreases pain intensity in patients undergoing LC regardless of the doses used. Infiltration with higher doses results in higher plasma concentrations, but below the systematic toxicity threshold.

The analgesic efficacy of a single injection of ultrasound-guided retrolaminar paravertebral block for breast surgery: a prospective, randomized, double-blinded study

BACKGROUND

The thoracic paravertebral block is an effective analgesic technique for postoperative pain management after breast surgery. The ultrasound-guided retrolaminar block (RLB) is a safer alternative to conventional paravertebral block. Thus, we assessed the analgesic efficacy of ultrasound-guided RLB for postoperative pain management after breast surgery.

METHODS

Patients requiring breast surgery were randomly allocated to group C (retrolaminar injection with saline) and group R (RLB with local anesthetic mixture). The RLB was performed at the level of T3 with local anesthetic mixture (0.75% ropivacaine 20 mL + 2% lidocaine 10 mL) under general anesthesia before the skin incision. The primary outcome was cumulative morphine consumption using intravenous patient-controlled analgesia (IV-PCA) at 24 hour postoperatively. The secondary outcomes were the visual analogue scale (VAS) scores at 1, 6, 24, and 48 hour postoperatively and the occurrence of adverse events and patient satisfaction after the surgery.

RESULTS

Forty-six patients were included, 24 in group C and 22 in group R. The cumulative morphine consumption using IV-PCA did not differ between the two groups (P = 0.631). The intraoperative use of remifentanil was higher in group C than in group R (P = 0.025). The resting and coughing VAS scores at 1 hour postoperatively were higher in group R than in group C (P = 0.011, P = 0.004). The incidence of adverse events and patient satisfaction was not significantly different between the two groups.

CONCLUSIONS

A single injection of ultrasound-guided RLB did not reduce postoperative analgesic requirements following breast surgery.

Effect of ropivacaine on peripheral neuropathy in streptozocin diabetes-induced rats through TRPV1-CGRP pathway

Objective To determine the effect of ropivacaine on peripheral neuropathy in diabetic rats and its possible mechanism.

Methods Forty-eight Sprague–Dawley rats were randomly divided into six groups: nondiabetic control group, nondiabetic group A (0.25% ropivacaine), nondiabetic group B (0.75% ropivacaine), diabetic control group (diabetic peripheral neuropathy (DPN) +artificial cerebrospinal fluid), diabetic group A (DPN+0.25% ropivacaine), and diabetic group B (DPN + 0.75% ropivacaine), with eight rats in each group. Within an hour of the last administration, the sciatic motor nerve conduction velocity (MNCV) of each group was measured, and the morphological changes of rat sciatic nerve were observed by HE, Weil’s staining and electron microscopy. The expression of transient receptor potential vanilloid (TRPV1) in the spinal cord dorsal horn of rats was analyzed by immunohistochemistry, and the expression of Calcitonin gene-related peptide (CGRP) protein in the spinal cord was analyzed by Western blot.

Results Compared with the nondiabetic control group, elevated blood glucose, decreased weight and reduced average mechanical withdrawal threshold (MWT), additionally, the sciatic nerves showed significantly slowed conduction velocity (both P<0.001) and damaged pathological structure, the expression of TRPV1 and CGRP were decreased (both P<0.001) in the diabetic groups. Compared with the diabetic control group, down-regulation of TRPV1 and CGRP in spinal cord was significant for the diabetic groups A and B treated with 0.25 and 0.75% ropivacaine, the higher concentration of ropivacaine correlated with a greater change.

Conclusion Ropivacaine can significantly block sciatic nerve conduction velocity in DPN rats in a concentration-dependent manner, which may be related to the expression of the TRPV1-CGRP pathway.

Validation according to European and American regulatory agencies guidelines of an LC-MS/MS method for the quantification of free and total ropivacaine in human plasma

Background

Ropivacaine is a widely used local anaesthetic drug, highly bound to plasma proteins with a free plasma fraction of about 5%. Therefore, the monitoring of free drug concentration is most relevant to perform pharmacokinetic studies and to understand the drug pharmacokinetic/pharmacodynamic (PK/PD) relationship.

Methods

A high-sensitivity liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using reverse-phase LC and electrospray ionisation mass spectrometry with multiple reaction monitoring (MRM) is described for the quantitation of both free and total ropivacaine in human plasma. Ropivacaine-d7 was used as an internal standard (IS).

Results

The method was validated in the range 0.5–3000 ng/mL, with five levels of QC samples and according to the European Medicine Agency and Food and Drug Administration guidelines. The performance of the method was excellent with a precision in the range 6.2%–14.7%, an accuracy between 93.6% and 113.7% and a coefficient of variation (CV) of the IS-normalised matrix factor below 15%. This suitability of the method for the quantification of free and total ropivacaine in clinical samples was demonstrated with the analysis of samples from patients undergoing knee arthroplasty and receiving a local ropivacaine infiltration.

Conclusions

A method was developed and validated for the quantification of free and total ropivacaine in human plasma and was shown suitable for the analysis of clinical samples.

Ultrasound-guided psoas compartment and sciatic nerve blocks for pain management of hind limb procedures in the alpaca (Vicugna pacos)

Background:

Loco-regional anesthetic techniques are considered important in the multimodal approach to analgesia in both human and veterinary medicine. No such techniques are described in the alpaca, bar the use of epidural. This is in part due to the lack of anatomical description for this species. While this limitation exists, the use of ultrasound guidance makes peripheral nerve blocks a viable possibility in the alpaca.

Case description:

A 12-month-old alpaca was referred for the treatment of a septic left tarso-crural joint. Due to a poor prognosis, amputation of the limb under general anesthesia was performed. Sciatic and psoas compartment blocks were attempted with the ultrasound-guided injection of ropivacaine prior to the start of the procedure. While the femoral nerve was possible to visualize, no obturator nerve was identified. A 5-year old alpaca was also referred for a left hind lateral claw removal, due to a squamous cell carcinoma. The sciatic nerve block was performed prior to the claw amputation under general anesthesia. No changes in heart and respiratory rate, or blood pressure suggestive of nociception, were observed in either of these cases. At the end of both the procedures, the patients experienced uneventful recoveries characterized by the ability to maintain the standing position, interest in food, and normal behavior.

Conclusion:

This report identifies the ease of performance and the challenges encountered using the ultrasound-guided psoas compartment and sciatic nerve blocks in the alpaca. It is our hope that this report encourages the use of ultrasound-guided loco-regional techniques in this species.

Effects of regional anesthesia techniques on local anesthetic plasma levels and complications in carotid surgery: a randomized controlled pilot trial

BACKGROUND

The ultrasound guided intermediate cervical plexus block with perivascular infiltration of the internal carotid artery (PVB) is a new technique for regional anesthesia in carotid endarterectomy (CEA). We conducted a pilot study investigating the effects of deep cervical block (DCB), intermediate cervical block alone (ICB) and PVB on perioperative complications in patients undergoing elective CEA. We hypothesized, that the ropivacaine plasma concentration is higher in patients receiving DCB compared to PVB and ICB.

METHODS

In a randomized controlled pilot study thirty patients scheduled for elective CEA were randomly assigned into three groups: DCB receiving 20 mL ropivacaine 0.5% (n = 10), ICB receiving 20 mL ropivacaine 0.5% (n = 10) and PVB receiving 20 mL ropivacaine 0.5% and 10 mL ropivacaine 0,3% (n = 10). As primary outcome, plasma levels of ropivacaine were measured with high performance liquid chromatography before, 5, 10, 20, 60, and 180 min after the injection of ropivacaine. Secondary outcomes were vascular and neurological complications as well as patients' and surgeons' satisfaction. All analyses were performed on an intention-to-treat basis. Statistical significance was accepted at p < 0.05.

RESULTS

No conversion to general anesthesia was necessary and we observed no signs of local anesthetic intoxication or accidental vascular puncture. Plasma concentration of ropivacaine was significantly higher in the DCB group compared to PVB and ICB (p < 0.001) and in the PVB group compared to ICB (p = 0.008). Surgeons' satisfaction was higher in the PVB group compared to ICB (p = 0.003) and patients' satisfaction was higher in the PVB group compared to ICB (p = 0.010) and DCB group (p = 0.029). Phrenic nerve paralysis was observed frequently in the DCB group (p < 0.05). None of these patients with hemi-diaphragmatic paralysis showed signs of respiratory distress.

CONCLUSION

The ultrasound guided PVB is a safe and effective technique for CEA which is associated with lower plasma levels of local anesthetic than the standard DCB. Considering the low rate of complications in all types of regional anesthesia for CEA, larger randomized controlled trials are warranted to assess potential side effects among the blocks.

TRIAL REGISTRATION

The trial was registered at German Clinical Trials Register (DRKS) on 04/05/2019 (DRKS00016705, retrospectively registered).

Dexamethasone added to local anesthetics in ultrasound-guided transversus abdominis plain (TAP) block for analgesia after abdominal surgery: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the analgesic efficacy of dexamethasone added to local anesthetics in ultrasound-guided transversus abdominis plane (TAP) block for the patients after abdominal surgery.

METHODS

PubMed, CENTRAL, EMBASE, Web of science were searched to identify eligible randomized controlled trials (RCTs) that compared dexamethasone added to local anesthetics in ultrasound-guided TAP block with control for postoperative analgesia in adult patients undergoing abdominal surgery. Primary outcomes included postoperative pain intensity, the time to the first request for additional analgesics, and opioid consumption over 24 h after surgery. Secondary outcome was the incidence of postoperative nausea and vomiting. Analysis was performed by RevMan 5.3 software and the quality of evidence was rated using GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach.

RESULTS

Nine RCTs involving 575 patients were included. Compared to the control, dexamethasone added to local anesthetics in ultrasound-guided TAP block significantly decreased visual analogue scale (VAS) scores at rest at 4h (mean difference [MD] = -1.01; 95% confidence intervals [CI], -1.29 to -0.73; P<0.00001; moderate quality of evidence), 6h (MD = -1.21; 95% CI, -1.74 to -0.69; P<0.00001; low quality of evidence), and 12h after surgery (MD = -0.79; 95% CI, -0.97 to -0.60; P<0.00001; moderate quality of evidence). No difference was found at 2h (MD = -0.64; 95% CI, -1.35 to 0.08; P = 0.08; low quality of evidence) and 24 h (MD = -0.41; 95% CI, -0.91 to 0.09; P = 0.11; moderate quality of evidence) in VAS scores. The time to the first request for additional analgesics was prolonged in the dexamethasone group (MD = 3.08; 95% CI, 2.37 to 3.78; P<0.00001; moderate quality of evidence). Opioid consumption over 24 h after surgery was also reduced (MD = -5.42; 95% CI, -8.20 to -2.63; P = 0.0001; low quality of evidence). Meanwhile, the incidence of postoperative nausea and vomiting was significantly decreased in the dexamethasone group (risk ratios [RR] = 0.40; 95% CI, 0.28 to 0.58; P<0.00001; high quality of evidence). No complications were reported in all the included studies.

CONCLUSIONS

Dexamethasone added to local anesthetics in ultrasound-guided TAP block was a safe and effective strategy for postoperative analgesia in adult patients undergoing abdominal surgery.

Efficacy of preemptive analgesia on acute postoperative pain in children undergoing major orthopedic surgery of the lower extremities

Background

Children undergoing major orthopedic surgery of the lower extremities can experience severe postoperative pain; yet, the ideal postoperative pain management strategy is unknown. Thus, in this patient population, we investigated the effect of intraoperative epidural infusion of local anesthetic on acute postoperative pain and analgesic consumption.

Patients and methods

Patients (N=50, 3-12 years) randomly received either ropivacaine 0.15% (preemptive group) or normal saline (control group) as an initial bolus of 0.2 mL/kg, followed by continuous infusion of 0.15 mL/kg/h throughout surgery. Following surgery, patient-controlled epidural analgesia with ropivacaine 0.1% was provided. The main study outcomes were the revised Face, Legs, Activity, Cry, and Consolability pain scores, epidural ropivacaine consumption, and additional analgesic requirements during the first 48 hours postoperatively.

Results

Forty-seven patients completed the study, 23 in the preemptive group and 24 in the control group, respectively. The revised Face, Legs, Activity, Cry, and Consolability pain scores were significantly lower in the preemptive group only at 30 minutes after postanesthesia care unit arrival and 6 hours after surgery (median difference -1.0, 95% CI -2.0 to -1.0, P=0.001 and median difference -2.0, 95% CI -3.0 to -1.0, P=0.005, respectively). However, they were not significantly different between the groups at 12, 24, and 48 hours postoperatively. Epidural ropivacaine consumption and additional analgesic requirements throughout 48 hours postoperatively were not significantly different between the groups.

Conclusion

Intraoperative epidural infusion of ropivacaine did not demonstrate preemptive analgesic efficacy within 48 hours postoperatively in children undergoing extensive lower limb orthopedic surgery.

Injectable nanocomposite analgesic delivery system for musculoskeletal pain management

Musculoskeletal pain is a major health issue which results from surgical procedures (i.e. total knee and/or hip replacements and rotator cuff repairs), as well as from non-surgical conditions (i.e. sympathetically-mediated pain syndrome and occipital neuralgia). Local anesthetics, opioids or corticosteroids are currently used for the pain management of musculoskeletal conditions. Even though local anesthetics are highly preferred, the need for multiple administration presents significant disadvantages. Development of unique delivery systems that can deliver local anesthetics at the injection site for prolonged time could significantly enhance the therapeutic efficacy and patient comfort. The goal of the present study is to evaluate the efficacy of an injectable local anesthetic nanocomposite carrier to provide sustained analgesic effect. The nanocomposite carrier was developed by encapsulating ropivacaine, a local anesthetic, in lipid nanocapsules (LNC-Rop), and incorporating the nanocapsules in enzymatically crosslinked glycol chitosan (0.3GC) hydrogels. Cryo Scanning Electron Microscopic (Cryo SEM) images showed the ability to distribute the LNCs within the hydrogel without adversely affecting their morphology. The study demonstrated the feasibility to achieve sustained release of lipophilic molecules from the nanocomposite carrier in vitro and in vivo. A rat chronic constriction injury (CCI) pain model was used to evaluate the efficacy of the nanocomposite carrier using thermal paw withdrawal latency (TWL). The nanocomposite carriers loaded with ropivacaine and dexamethasone showed significant improvement in pain response compared to the control groups for at least 7 days. The study demonstrated the clinical potential of these nanocomposite carriers for post-operative and neuropathic pain.

STATEMENT OF SIGNIFICANCE

Acute or chronic pain associated with musculoskeletal conditions is considered a major health issue, with healthcare costs totaling several billion dollars. The opioid crisis presents a pressing clinical need to develop alternative and effective approaches to treat musculoskeletal pain. The goal of this study was to develop a long-acting injectable anesthetic formulation which can sustain a local anesthetic effect for a prolonged time. This in turn could increase the quality of life and rehabilitation outcome of patients, and decrease opioid consumption. The developed injectable nanocomposite demonstrated the feasibility to achieve prolonged pain relief in a rat chronic constriction injury (CCI) model.