Concentrations Of Ropivacaine Research Articles

A randomized double-blinded study assessing the effect of different doses of transnasal dexmedetomidine on the median effective concentration of ropivacaine for a caudal block.

Perineural administration of dexmedetomidine (PN-DEX) can enhance the efficacy of local anesthetics used in regional nerve blocks while decreasing the median effective concentration (EC50) of these anesthetics. Intranasal administration of dexmedetomidine (IN-DEX) is more accessible for sedation during regional anesthesia because of its non-invasive systemic administration and demonstrates synergism with local anesthetic. However, it remains unclear whether IN-DEX affects the EC50 of local anesthetics used in caudal blocks. This study was a prospective, single-center, double-blind, randomized controlled trial. Patients scheduled to undergo elective hemorrhoidectomy were included and divided into three groups. Furthermore, 0.01 mL/kg of normal saline and 1 μg/kg and 2 μg/kg of dexmedetomidine were dripped into both nostrils of the patients in groups IN-NS, IN-DEX1, and IN-DEX2, respectively. These were administered 15 min before the caudal block. The initial concentration of ropivacaine was set at 0.4%, which was then varied by 0.025% using the up-and-down sequential allocation method. Vital signs, instances of hypotension and bradycardia with treatment, and other adverse reactions were recorded and compared. The EC50 values of ropivacaine were 0.275% (95% confidence interval (CI), 0.254-0.296%) in group IN-NS, 0.257% (95% CI, 0.238-0.276%) in group IN-DEX1, and 0.216% (95% CI, 0.195-0.236%) in group IN-DEX2. The EC95 values of ropivacaine were 0.315% (95% CI, 0.295-0.370%) in group IN-NS, 0.297% (95% CI, 0.278-0.351%) in group IN-DEX1, and 0.256% (95% CI, 0.236-0.310%) in group IN-DEX2. Compared to group IN-NS, the EC50 value of ropivacaine in IN-DEX2 was significantly decreased by 21.4% (p = 0.001), while there was no significant difference between group IN-NS and IN-DEX1 (p = 0.125). There were no differences in hypotension and bradycardia with treatment among the different groups. IN-DEX decreased the EC50 of ropivacaine for the caudal block, and there was a specific dose-dependent effect for IN-DEX. The side effects were similar across all groups.

Study on the Analgesic Efficacy of Femoral Nerve Block for Post-Hip Arthroscopy Pain.

Postoperative pain management is challenging for hip arthroscopy, and the effectiveness and specific protocols of femoral nerve block (FNB) in hip surgeries remain insufficient. Therefore, we designed this study to investigate the analgesic efficacy and optimal drug concentrations of FNB after hip arthroscopy. A total of 148 patients undergoing hip arthroscopy were included and randomly divided into three groups: 0.3% ropivacaine FNB group, 0.4% ropivacaine FNB group, and 0.4% ropivacaine intra-articular injection (IAI) group (positive control). The main outcomes included dynamic and static visual analog scale (VAS) scores at various time points postoperatively, total intraoperative remifentanil consumption, and cumulative consumption of morphine within 24h postoperatively. Secondary outcomes included total intraoperative dexmedetomidine consumption, RASMAY sedation scores, and patients' satisfaction scores postoperatively. Both FNB and IAI anesthesia were shown to be safe for post-hip arthroscopy analgesia. Compared with IAI anesthesia, FNB showed no significant differences in analgesic effect within 12h postoperatively but had a better analgesic effect after 24h and lower remifentanil consumption intraoperatively. Group 0.4% ropivacaine showed lower dynamic VAS scores within the first 12h compared with 0.3% ropivacaine for FNB, however, there were no significant differences in patient satisfaction and sedation, and postoperative ambulation was delayed, indicating that the higher concentration of ropivacaine correlated with a longer time to ambulation. The IAI group had greater intraoperative opioid consumption and more side effects. Compared with IAI anesthesia, FNB can better alleviate post-hip arthroscopy pain and reduce opioid consumption. However, it requires specialized equipment and technical support and carries a certain risk of puncture. Chinese Clinical Trials Registry (ChiCTR2400091579).

Effects of varying concentrations of ropivacaine on pain relief in ultrasound-guided brachial plexus block surgery in the intercostal space

Effects of varying concentrations of ropivacaine on pain relief in ultrasound-guided brachial plexus block surgery in the intercostal space

Effect of ropivacaine concentrations in combined spinalepidural anesthesia on efficacy and sedation levels in lower abdominal obesity patients

Effect of ropivacaine concentrations in combined spinalepidural anesthesia on efficacy and sedation levels in lower abdominal obesity patients

The median effective concentration of ropivacaine for ultrasound-guided anterior iliopsoas muscle space block in the elderly undergoing hip surgery: a dose-finding study.

In order to improve perioperative pain and reduce the adverse outcome of severe pain in elderly hip fractures, anterior iliopsoas muscle space block (AIMSB) can be used clinically to reduce pain. The aim of the study is to investigate the 50% effective concentration (EC50) of ropivacaine for ultrasound-guided anterior iliopsoas space block in elderly with hip fracture. A total of 27 patients were enrolled with aged ≥65 years, American society of Anesthesiologists (ASA) physical status classification II-III and undergoing Total Hip Arthroplasty (THA). We measured the EC50 using Dixon's up-and-down method. Ultrasound-guided AIMSB was performed preoperatively with an initial concentration of 0.2% in the first patient. After a successful or unsuccessful postoperative analgesia, the concentration of local anesthetic was decreased or increased 0.05%, respectively in the next patient. The successful block effect was defined as no sensation to pinprick in the area with femoral nerve, obturator nerve, and lateral femoral cutaneous nerve in 30 min. Meanwhile, the EC50 of ropivacaine was determined by using linear model, linear-logarithmic model, probit regression model, and centered isotonic regression. A total of 12 patients (48%) had a successful block. All patients with a successful block had a postoperative visual analog scale score of <4 in the 12 h. The estimated EC50 values in linear model, linear-logarithmic model, probit regression model, and centered isotonic regression (a nonparametric method) were 0.268%, 0.259%, 0.277%, and 0.289%. The residual standard error of linear model was the smallest (0.1245). The EC50 of ropivacaine in anterior iliopsoas space block under ultrasound guidance is 0.259-0.289%.

The median effective concentration of epidural ropivacaine with different doses of dexmedetomidine for motor blockade: an up-down sequential allocation study.

Recent studies have shown that dexmedetomidine can be safely used in peripheral nerve blocks and spinal anesthesia. Epidural administration of dexmedetomidine produces analgesia and sedation, prolongs motor and sensory block time, extends postoperative analgesia, and reduces the need for rescue analgesia. This investigation seeks to identify the median effective concentration (EC50) of ropivacaine for epidural motor blockade, and assess how incorporating varying doses of dexmedetomidine impacts this EC50 value. Prospective, double-blind, up-down sequential allocation study. Operating room, post-anesthesia care unit, and general ward. One hundred and fifty patients were allocated into five groups in a randomized, double-blinded manner as follows: NR (normal saline combined with ropivacaine) group, RD0.25 (0.25 μg/kg dexmedetomidine combined with ropivacaine) group, RD0.5 (0.5 μg/kg dexmedetomidine combined with ropivacaine) group, RD0.75 (0.75 μg/kg dexmedetomidine combined with ropivacaine) group, RD1.0 (1.0 μg/kg dexmedetomidine combined with ropivacaine) group. The concentration of epidural ropivacaine for the first patient in each group was 0.5%. Following administration, the patients were immediately placed in a supine position for observation, and the lower limb motor block was assessed every 5 min using the modified Bromage score within 30 min after drug administration. According to the sequential method, the concentration of ropivacaine in the next patient was adjusted according to the reaction of the previous patient: effective motor block was defined as the modified Bromage score > 0 within 30 min after epidural administration. If the modified Bromage score of the previous patient was >0 within 30 min after drug administration, the concentration of ropivacaine in the next patient was decreased by 1 gradient. Conversely, if the score did not exceed 0, the concentration of ropivacaine in the next patient was increased by 1 gradient. The up-down sequential allocation method and probit regression were used to calculate the EC50 of epidural ropivacaine. Adverse events, hemodynamic changes, demographic data and clinical characteristics. The EC50 of epidural ropivacaine required to achieve motor block was 0.677% (95% CI, 0.622-0.743%) in the NR group, 0.624% (95% CI, 0.550-0.728%) in the RD0.25 group, 0.549% (95% CI, 0.456-0.660%) in the RD0.5 group, 0.463% (95% CI, 0.408-0.527%) in the RD0.75 group, and 0.435% (95% CI, 0.390-0.447%) in the RD1.0 group. The EC50 of the NR group and the RD0.25 group were significantly higher than that of the RD0.75 and the RD1.0 groups, and the EC50 of the RD0.5 group was significantly higher than that of the RD1.0 group. The EC50 of epidural ropivacaine required to achieve motor block was 0.677% in the NR group, 0.624% in the RD0.25 group, 0.549% in the RD0.5 group, 0.463% in the RD0.75 group, and 0.435% in the RD1.0 group. Dexmedetomidine as an adjuvant for ropivacaine dose-dependently reduce the EC50 of epidural ropivacaine for motor block and shorten the onset time of epidural ropivacaine block. The optimal dose of dexmedetomidine combined with ropivacaine for epidural anesthesia was 0.5 μg/kg.

Comparison of different concentrations of ropivacaine in epidural anesthesia for percutaneous transforaminal endoscopic discectomy: a randomized controlled trial

BackgroundThis study investigated the optimal concentration of ropivacaine epidural anesthesia for clinical use in percutaneous transforaminal endoscopic discectomy (PTED) by comparing the effects of different concentrations.MethodsSeventy patients scheduled for their first PTED procedure were enrolled in this randomized controlled trial. Patients were randomized to receive ropivacaine at varying concentrations (0.3% or 0.4%). Primary outcome measures included the numeric rating scale (NRS) and hip extension level (HEL). Secondary outcome measures included intraoperative fentanyl dosage and postoperative complications.ResultsOne patient withdrew due to severe postoperative complications. The remaining 69 patients were allocated to the 0.3% (n = 34) and 0.4% (n = 35) groups, respectively. Baseline characteristics showed no significant differences between the two groups (P > 0.05). The NRS score was significantly lower in the 0.4% group than in the 0.3% group (P < 0.01), whereas the HEL score was significantly higher (P < 0.001). The average fentanyl dose in the 0.4% group was significantly lower than that in the 0.3% group (P < 0.01). Postoperative complications occurred in five and two patients in the 0.3% and 0.4% groups, respectively.ConclusionAlthough 0.4% ropivacaine (20 mL) impacts muscle strength, it does not impede PTED surgery. Given its effective analgesic properties and few postoperative complications, 0.4% ropivacaine can be considered a preferred dose for PTED.Trial registrationThis study was registered with the Chinese Clinical Trials Registry (Registration number: ChiCTR2200060364; Registration Date: 29/5/2022) and on chictr.org.cn (https://www.chictr.org.cn/showproj.html?proj=171002).

Programmed Intermittent Epidural Boluses of 0.1% Ropivacaine Versus 0.2% Ropivacaine for the Maintenance of Epidural Analgesia in Labor.

Objective The gold standard for pain management during labor is epidural analgesia, which can be administered in two different ways to the parturients, either bybolus doses or continuous infusions of local anesthetic solutions with opioids. Recently, programmed intermittent epidural boluses (PIEBs) via a pump are gaining popularity as a very effective method with minimal side effects. The aim of this study was to evaluate the optimum ropivacaine concentration between two different regimens (0.1% or 0.2% both with fentanyl 2 μg/ml) that can provide satisfactory analgesia with the minimum degree of motor blockade, using PIEBs. Methods A prospective randomized controlled study was performed from March 2020 to March 2022. Two different concentrations of ropivacaine 0.1% and 0.2% via PIEBs were equally allocated to two groups of parturients with an additional patient control epidural rescue bolus if needed. Our primary endpoint was motor blockade, as assessed by the modified Bromage scale (MBS). We also recorded visual analog scale (VAS) scores, heart rate, blood pressure, total local anesthetic consumption, labor duration and method of delivery, and APGAR score of the newborns. Results All patients presented Bromage scores equal to 6, and the total consumption of the anesthetic solution was comparable between the two groups. Women in the 0.2% group showed higher pain relief and satisfaction compared to the 0.1% group. Concerning the 0,2% group, diastolic blood pressure and APGAR scores were lower alongside with a lower satisfactory extrusion stage observed bythe obstetrician. Conclusion Both ropivacaine regimens provide satisfactory labor epidural analgesia for the expectant mother without any motor blockade.

To Compare the Effects of 0.2% Ropivacaine Continuous Infusion versus Programmed Intermittent Bolus on Postoperative Analgesia with Adductor Canal Block, in Patients Undergoing Unilateral Knee Arthroplasty: A Randomized Controlled Trial

Background: Multimodal regimens are the mainstay of postoperative analgesia. Analgesic effectiveness of programmed intermittent bolus (PIB) versus continuous infusion (CI) in ultrasound-guided adductor canal block (ACB) for unilateral knee arthroplasty, were compared. Materials and Methods: Following Ethical and Clinical Trials Registry approval, eligible patients were administered pericapsular infiltration, intraoperatively and ACB with catheter, postoperatively. As per randomization, the PIB group received 10 ml 0.2% ropivacaine every 3 hourly while the CI group received 6mL/h. In addition, both groups received patient controlled boluses of 5mL with lockout interval of 30 minutes. The numerical rating score (NRS) score, plasma concentration of ropivacaine, use of rescue analgesics, quadricep strength by Straight Leg Rising Test (SLRT), Medical Research Council (MRC) scale for motor power, were monitored at 0, 1, 4, 24, 48 h, and Likert Scale for patient satisfaction, was measured at 72 h. To be clinically meaningful, sample size calculation, was according to a difference in NRS, for a power of 0.80, and σ‐standard deviation of two points, thus requiring at least 17 patients in each group. Results: In PIB group, patients experienced better analgesia in the first 24 h (rest - 95% CI - 0.089–0.669, P = 0.010 and movement - 95% CI - 0.82–0.884, P = 0.018) and motor power, in the first (P = 0.051) and 4th h (P = 0.034), after recovery, along with improved patient satisfaction (P = 0.001). Ropivacaine plasma concentration, at regular intervals, was independent of the pain scores with rest and movement. Rescue analgesia was inconclusive in both groups. Conclusion: The PIB option provided better analgesia in the postoperative period.

Determining the Maximum Tolerable Concentration of Ropivacaine to Maintain Sensation of the Nerve Root in Percutaneous Endoscopic Transforaminal Lumbar Discectomy: Can Epidural Anaesthesia Achieve Pain-Tactile Separation Block to Avoid Nerve Injury?

Nerve injury is a serious complication of percutaneous endoscopic transforaminal lumbar discectomy due to nerve root contact. The maximum tolerable concentration (MTC) of ropivacaine concentration for epidural anaesthesia, is defined as the concentration that minimises pain while preserving the sensation of the nerve roots. This distinct advantage allows the patient to provide feedback to the surgeon when the nerve roots are contacted. We used a biased-coin design to determine the MTC, which was estimated by the 10% effective concentration (EC10), ie, the concentration at which 10% of patients lost sensation in the nerve roots. The determinant for positive response was lack of sensory feedback upon contact with the nerve root, and the feedback from occurrence of sensations in the innervation area upon contact with the nerve root was defined as a negative response. Primary outcome was the response from contact nerve root. Secondary outcomes were the type and number of statements of negative response and each patient's pain score during surgery. Fifty-four patients were included in this study. The EC10 was 0.434% (95% CI: 0.410%, 0.440%) using isotonic regression in comparison with 0.431% (95% CI: 0.399%, 0.444%) using probit regression. Three type statements of negative response were reported including "tactile sensation", radiculalgia, and numbness. The MTC of ropivacaine used for epidural anaesthesia was 0.434% to avoid nerve injury in percutaneous endoscopic transforaminal lumbar discectomy.

The 90% minimum effective concentration of ropivacaine for ultrasound‐guided interscalene brachial plexus block in children aged 1–10 years: A biased coin design up‐and‐down sequential allocation trial

AbstractRopivacaine is a commonly used local anesthetic for brachial plexus blocks in children, but the minimum effective dose of ropivacaine for interscalene brachial plexus blocks has not been reported. The aim of this study was to determine the 90% minimum effective concentration (MEC90) of ropivacaine for an ultrasound‐guided interscalene brachial plexus block (ISB). A total of 155 patients, aged from 1 to 10 years, underwent unilateral surgical procedures on areas of the upper extremity not innervated by the ulnar nerve. The biased coin design up‐and‐down sequential method (BCD‐UMD) was used to determine the MEC90 of ropivacaine for ultrasound‐guided ISB. In our study, the initial concentration of ropivacaine was 0.07% in the toddler group and 0.09% in the preschool and school‐age groups. During the trial, the concentration of ropivacaine for each subsequent patient was determined by the blocking effect of the previous patient. In case of failure, the concentration for the next patient was increased by 0.01%. Otherwise, the concentration was either decreased by 0.01%, with a probability of 0.11, or kept the same, with a probability of 0.89. Overall, the MEC90 of ropivacaine was 0.104% (95% confidence interval (CI), 0.070%–0.106%) in the toddler group, 0.114% (95% CI, 0.090%–0.117%) in the preschool group, and 0.133% (95% CI, 0.099%–0.136%) in the school‐age group. No adverse events occurred. Our study showed that lower concentrations of ropivacaine could provide effective nerve blocks and reduce the risk of local anesthetics.

SAFETY AND EFFICACY OF INTRAOSSEOUS ROPIVACAINE IN LOWER EXTREMITY (SORE) STUDY

IntroductionDay stay surgery for anterior cruciate ligament (ACL) reconstructions is an increasingly common practice and has driven clinicians to come up with postoperative pain regimes that allow same day mobilisation 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.MethodsThis patient blinded, pilot study randomised 15 patients undergoing ACL reconstruction to receive either IO ropivacaine 1.5 or 2.0 mg/kg; or 300 mg of ropivacaine as local infiltration (standard of care). Toxic plasma levels of ropivacaine have been defined in the literature and therefore the primary outcome for this study was arterial plasma concentration of ropivacaine as a means to determine its safety profile. Samples were taken via an arterial line at prespecified times after tourniquet deflation. Secondary outcomes that we were interested in included immediate postoperative pain scores using the visual analogue scale (VAS) and perioperative opioid equivalent consumption.ResultsParticipants had a mean age of 27.8 (SD 9.2) years and 87% (13/15) were male. 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 1.5 mg/kg dose of ropivacaine reaching 3.59 mg/ml. This would equate to 0.22 µg/ml of free plasma ropivacaine. There were no differences across the three groups regarding pain scores or perioperative opioid consumption.ConclusionsThis study demonstrates that IO administration of 0.2% 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 utilise other analgesics via the IO regional route to improve perioperative pain relief.

Comparative Study of 0.5% Bupivacaine, 0.5% Ropivacaine, and 0.75% Ropivacaine With Fentanyl as a Continuous Intraoperative Epidural Infusion on Post-operative Analgesia.

Introduction Persistent postoperative pain leads to impaired patient recovery and delays in discharge of patients. The aim was to compare the efficacy of 0.5% bupivacaine to two varying concentrations of ropivacaine, specifically 0.5% and 0.75%, along with fentanyl as a continuous epidural infusion in providing adequate pain relief for patients subjected to infraumbilical surgeries. Materials and methods A prospective randomized comparative study was carried out on 150 patients and was divided into three groups, namely group B, group R, and group RP. Group B indicates (0.5% bupivacaine), group R means (0.5% ropivacaine),and finally, group RP means (0.75% ropivacaine); the three groups had 50 patients each. Group B was administered an epidural infusion of bupivacaine at a concentration of 0.5%, group R was given 0.5% ropivacaine, and group RP was treated with 0.75% ropivacaine; all three groups included 40 mcg fentanyl. The duration of the motor and sensory blockade and the time needed for the first rescue analgesia after the stoppage of epidural infusion were assessed in all three groups.The data were statistically analyzed using the ANOVA, "post hoc Tukey," and chi-square tests. Results Comparison of the duration of motor and sensory blockade among all three groups showed that group RP (0.75% ropivacaine with 2 mcg/cc fentanyl)had the longest duration of 328.8 and 406 minutes, and the difference was statistically significant (p < 0.001). Comparison of the time of stoppage of epidural infusion to the requirement of first rescue analgesia showed that the group that received 0.75% ropivacaine with 40 mcg fentanyl had the highest value of 258.6 minutes and was statistically significant (p < 0.001). Conclusion Epidural intraoperative infusion of 0.75% ropivacaine with fentanyl offers better postoperative pain relief as compared to both 0.5% bupivacaine and 0.5% ropivacaine with fentanyl.

Comparison of three concentrations of ropivacaine in posterior quadratus lumborum block: A randomized clinical trial

BackgroundA conclusive evidence regarding the optimal concentration and volume of local anesthetic for quadratus lumborum block is lacking. MethodsIn this single-center, prospective, randomized, controlled study, 60 patients scheduled for laparoscopic colorectal surgery were randomly assigned to 3 different combinations of volume and concentration of ropivacaine (3 mg/kg) - Group 0.25%, Group 0.375% and Group 0.5%. All subjects received ultrasound-guided posterior quadratus lumborum block prior to the induction. The primary outcome was the complete sensory block rate of surgical site measured at 30 min after quadratus lumborum block, after extubation, at 12, 24, and 48 h after operation. Secondary outcomes were the changes in hemodynamic parameters before and after incision (ΔSBP, ΔDBP and ΔHR), postoperative pain score, the sufentanil consumption after surgery, length of stay and adverse reactions. ResultsThe sensory block rate of surgical site at 5 time points differed significantly among the three groups (P < 0.001). Both Group 0.375% (P < 0.001) and Group 0.5% (P < 0.001) had a higher sensory block rate than Group 0.25%, but no significant difference was observed between the former two. Group 0.375% and Group 0.5% had lower postoperative pain scores, lower sufentanil consumption after surgery and shorter length of stay. No statistical difference was observed in ΔSBP, ΔDBP, ΔHR and the incidence of adverse reactions. Conclusions0.375% and 0.5% ropivacaine in posterior quadratus lumborum block provide better sensory block of surgical site when compared to 0.25% in laparoscopic colorectal surgery. Trial registration numberChinese Clinical Trials Registry (ChiCTR2100043949).

Comparison of efficacy and safety of three different concentrations of ropivacaine for labor pain management using patient-controlled epidural analgesia (PCEA): A double-blind, randomized controlled trial.

Labor pain is consistently ranked high on the various pain rating scales, when compared to other painful life experiences, and the experience of labor during the process of childbirth is both complex and subjective. Though patient-controlled epidural analgesia (PCEA) using dilute concentrations of local anesthetics (LAs) has been a popular method to control labor pain, yet the optimal dose and regimen for PCEA remain ambiguous. So, the present study was undertaken to evaluate the safety and efficacy of three different concentrations of ropivacaine for labor analgesia using PCEA. Seventy-five healthy nulliparous women who gave voluntary consent for labor analgesia using PCEA were randomly assigned to three groups to receive three different ropivacaine concentrations (0.0625%, 0.1%, and 0.125%) with adjuvant fentanyl 2 μg/ml, after double-blinding. Analgesic efficacy, neuraxial blockade, vital parameters, neonatal outcomes, maternal satisfaction, and side effects were assessed. Primary outcome was total dose of ropivacaine consumed in milligrams. Number of pain breakthroughs (Visual Analog Score >4) and PCEA demand and rescue boluses were found to be statistically more in group 0.0625% (P < 0.01), followed by group 0.1% and were the least in 0.125%. Still, total drug consumed in milligrams was significantly less in 0.0625% group. Maternal satisfaction was comparable among the three groups (P = 0.33). There was no significant difference in maternal side effects and neonatal APGAR scores among the three groups. When three different concentrations of ropivacaine, that is, 0.0625%, 0.1%, and 0.125%, are used for labor analgesia, the use of 0.125% ropivacaine leads to higher total amount of ropivacaine consumed. Despite the lower efficacy in terms of breakthrough pain episodes observed with a 0.0625% ropivacaine concentration for labor analgesia, maternal satisfaction remained consistent across all three doses of ropivacaine. PCEA demand and rescue boluses for the lowest concentration, that is, 0.0625%; and did not affect maternal satisfaction with the management of labor pain.

Efficacy of transversus abdominis plane block on postoperative nausea and vomiting: a meta-analysis of randomized controlled trial

BackgroundPostoperative nausea and vomiting (PONV) is a common postoperative complication, and Transversus abdominis plane (TAP) block can provide effective analgesia for surgical operation. However, but there is not enough evidence to prove its advantage for nausea and vomiting. The objective of this meta-analysis was to evaluate the efficacy of TAP block on PONV.MethodsTwo independent researchers conducted searches for randomized controlled trials (RCTs) in PubMed, Embase, and Cochrane Central Register of Controlled Trials. We used Review Manager software for meta-analysis.ResultsIn this meta-analysis, twenty-six trials with 1981 patients were examined. The results showed that TAP block reduced postoperative nausea (Risk Difference (RD) = -0.10, 95% confidence interval (CI): -0.15 to -0.05) compared with no TAP block. TAP block reduced the dose of fentanyl (Standardized Mean Difference (SMD) = -1.17, 95% CI: -2.07 to -0.26) and morphine (SMD = -1.12, 95% CI: -2.10 to -0.13) compared with no TAP block, when the timing of administration was before surgery (RD = -0.13, 95% CI: -0.19 to -0.07). TAP block reduced postoperative nausea when the ropivacaine dosage is ≤ 100 mg (RD = -0.13, 95% CI: -0.21 to -0.06), bupivacaine dosage ≥ 100 mg ( RD = -0.08, 95% CI: -0.13 to -0.03), and when the ropivacaine concentration was ≤ 0.375% (RD = -0.11, 95% CI: -0.18 to -0.04). TAP block significantly reduced the incidence of nausea when the types of opioid drugs in PCA is tramadol (RD = -0.13, 95% CI: -0.24 to -0.03). TAP block could reduce the VAS (SMD= -0.99, 95% CI: -1.29 to -0.70) and reduce the time of extubation (SMD = -0.71, 95% CI: -1.34 to -0.08).ConclusionThe meta-analysis conducted in this study revealed that TAP block could reduce the incidence of PONV, and the efficacy of TAP block may be influenced by factors such as administration time, local anesthetic dosage and concentration, types of opioid drugs in PCA.

A prospective randomized double-blind study comparing the dose-response curves of epidural ropivacaine for labor analgesia initiation between parturients with and without obesity.

Background: Previous studies have explored the median effective concentration (EC50) of ropivacaine for labor epidural analgesia in parturients with obesity. However, the clinical relevance of the 90% effective concentration (EC90) remains unclear. This study aimed to determine and compare the dose-response curve of epidural ropivacaine for labor analgesia between parturients with and without obesity. Methods: Parturients were divided into two groups based on body mass index (BMI): group N, consisting of parturients with BMI <30kg/m2, and group O, consisting of parturients with BMI >30kg/m2. Within each group, the patients were randomized to receive one of five concentrations (0.0375%, 0.075%, 0.1125%, 0.15%, or 0.1875%) of epidural ropivacaine for labor analgesia. Analgesia was induced with a loading dose of 15mL of the assigned concentration. Visual analogue scale (VAS) scores were recorded at baseline and 30min post-dose to calculate the response (%) using the formula [(baseline VAS pain score-VAS pain score at 30min)/baseline VAS pain score] ×100%. The EC50 and EC90 values were determined via nonlinear regression analysis. Results: The EC50 and EC90 values of ropivacaine were 0.061% (95% confidence interval [CI], 0.056%-0.066%) and 0.177% (95% CI, 0.152%-0.206%) in group N and 0.056% (95% CI, 0.051%-0.061%) and 0.161% (95% CI, 0.138%-0.187%) in group O, respectively. No significant differences were observed in the EC50 and EC90 values between the two groups (p-values = 0.121 and 0.351, respectively. Conclusion: In conclusion, within the parameters of this study, our findings suggest that obesity, characterized by a mean BMI value of 30.9, does not significantly influence the EC50 and EC90 values of epidural ropivacaine for labor analgesia. Further investigations are warranted to elucidate the dose-response relationship between ropivacaine and obesity with higher BMI values. Clinical trial registration: https://www.chictr.org.cn/showproj.html?proj=190747, Identifier ChiCTR2300073273.

Clinical effect of different concentrations of ropivacaine in the labor analgesia of dural puncture epidural technique for obese puerperae

BackgroundThis study was performed to analyze the clinical effect of different concentrations of ropivacaine in the labor analgesia of the dural puncture epidural (DPE) technique for obese puerperae.MethodsOne hundred and fifty first-term obese women who received vaginal delivery and required labor analgesia in our hospital were selected prospectively for this study, and divided into groups A, B, and C. The three groups of puerpera were given epidurals with different concentrations of ropivacaine (0.075%, 0.10%, and 0.125%) with sufentanil (0.5 μg/ml) for the labor analgesia regimen. The visual analog scale (VAS), Ramsay scale, and Bromage scale of puerperae before analgesia and at different time points after anesthesia, and analgesic onset time, analgesia time, first PCEA time, PCEA pressing time, ropivacaine consumption, labor time, maternal blood pressure and heart rate, maternal adverse reactions, blood gas analysis in the neonatal umbilical artery, and Apgar score were observed.ResultsThe analgesia onset time, PCEA pressing time, and ropivacaine consumption in group C were lower and the analgesia time and the first PCEA time were longer than those in groups A and B. At T1-T3 and T5, VAS scores of group A were higher than those in groups B and C, Ramsay score of group A was lower than that of groups B and C at T2–T3, and Bromage score of group C at any time point was higher than other two groups. The time of the second stage of labor in groups B and C was longer than that in group A, which in group C was longer than that in group B. Compared with groups A and C, the blood pressure and heart rate of puerperae in group B were closer to normal values. Three different concentrations of ropivacaine had no significant effect on the umbilical artery blood gas analysis indices and Apgar scores at 1st minute and 5th minute in neonates. The incidence of maternal adverse reactions in group C was lower than those in groups A and B.Conclusion0.1% ropivacaine combined with 0.5 μg/ml sufentanil through DPE technique has good analgesic efficacy and few adverse effects in obese puerperae.

Physicochemical Stability and Compatibility of Mixtures of Ropivacaine with Dexamethasone or Betamethasone for Epidural Steroid Injections: An In Vitro Study

BACKGROUND: Epidural steroid injections are widely used to treat spinal and radiating pain. However, crystal formation has recently been reported in mixtures of ropivacaine and nonparticulate steroids, commonly used in epidural steroid injections. OBJECTIVES: Our study assessed the physicochemical stability of mixtures of different nonparticulate steroids and ropivacaine and aimed to propose a safe regimen for epidural steroid injections. STUDY DESIGN: An in vitro protocol was used to examine the physicochemical stability of epidural steroid injection mixtures most commonly used at our institution. SETTING: In vitro laboratory study. METHODS: Twelve solutions were prepared by mixing 0.75% or 0.2% ropivacaine with dexamethasone or betamethasone at volume ratios of 1:1, 2:1, and 3:1 in propylene syringes at 24°C. The physical properties of the mixtures were observed with the naked eye and under a microscope, and their pH was measured. The concentration of each drug in the mixture was evaluated using high-performance liquid chromatography. RESULTS: None of the ropivacaine and dexamethasone mixtures showed macroscopic or microscopic crystal formation after 2 hours, and there were no significant changes in pH. The concentrations of the 2 drugs remained stable for up to 2 hours. In contrast, at least 10 mu-m crystals were observed microscopically and macroscopically in all mixtures of ropivacaine and betamethasone; the ropivacaine concentration was reduced by &gt; 10% after one hour. LIMITATIONS: Confirming the stability of drugs in vitro does not ensure that their pharmacokinetics and pharmacodynamics remain unaltered in vivo. CONCLUSION: The combination of ropivacaine and betamethasone should be avoided because of their physicochemical instability. Combinations of ropivacaine and dexamethasone should be administered cautiously because they are more physicochemically stable than combinations of ropivacaine and betamethasone. KEY WORDS: Betamethasone, crystal formation, dexamethasone, drug stability, epidural injection, high-performance liquid chromatography, pH, physicochemical stability, spinal pain

Association of free maternal and fetal ropivacaine after epidural analgesia for intrapartum caesarean delivery: a prospective observational trial

BackgroundRopivacaine is present in plasma in both protein-bound and free forms. The free form is responsible for the occurrence of toxic side effects. During obstetric epidural analgesia, free ropivacaine enters the fetal circulation depending on various factors. The aim of this study was to analyse a potential association between ropivacaine concentrations in maternal and fetal plasma and hence the extent of fetal exposure to ropivacaine. MethodsIn this prospective monocentre study, parturients who met the following criteria were included in the study: 1. epidural administration as part of obstetric anaesthesia, and 2. subsequent intrapartum caesarean delivery, which 3. was performed after an epidural bolus administration of ropivacaine within the existing epidural analgesia. Total and free ropivacaine concentrations were analysed in maternal blood at baseline, prior to epidural bolus administration for caesarean delivery, and in maternal and fetal (umbilical venous, oxygenated) blood at delivery. The results are presented as mean ± SD or median (25/75th percentile). ResultsWe screened 128 parturients who went into labour at term and requested epidural analgesia, of whom 39 were ultimately included in the study. An intrapartum caesarean delivery was performed after the epidural application of 207 (166/276) mg ropivacaine during an epidural treatment period of 577 (360/1010) min. Total and free ropivacaine concentrations were 1402 ± 357 ng/ml and 53 ± 46 ng/ml, respectively, in maternal venous blood and 457 ± 243 ng/ml and 43 ± 27 ng/ml, respectively, in fetal blood. The maternal total and free ropivacaine concentrations were significantly correlated (r = 0.873; P < 0.0001). ConclusionThe results of the present study suggest that determining the concentration of free ropivacaine in maternal blood may be a feasible option for estimating neonatal exposure to ropivacaine.