Concentrations Of Ropivacaine Research Articles

Sparing effects of sufentanil on epidural ropivacaine in elderly patients undergoing transurethral resection of prostate surgery.

PurposeThis study examined the sparing effect of sufentanil on the median effective concentration (EC50) of epidural ropivacaine in elderly patients undergoing elective transurethral resection of prostate (TURP).Materials and MethodsThis was a prospective randomized double-blind dose-response study. Fifty eight elderly patients with American Society of Anesthesiologists physical status I-II who were scheduled for TURP surgery under epidural anesthesia were randomly allocated to a group receiving 15 mL of ropivacaine (group R) or a group receiving ropivacaine plus 5 µg of sufentanil (group RS). The concentration of ropivacaine was determined by a Dixon's up-and-down sequential allocation. The first participant received 0.3% of ropivacaine in both groups and subsequent concentrations were determined by the response of the previous patient in the same group. The EC50 of epidural ropivacaine was analyzed using the Dixon and Massey method.ResultsThe EC50 of ropivacaine during TURP surgery was 0.186% (95% confidence interval, 0.173-0.200%) in group R, and 0.136% (95% confidence interval, 0.127-0.144%) in group RS (p<0.01). No differences in Bromage scale of motor block examination and the onset time of sensory block were observed.ConclusionAdministration of 5 µg of epidural sufentanil caused a 37% reduction in the EC50 of epidural ropivacaine in elderly patients who underwent TURP surgery. Thus, sufentanil addition during surgery of TURP can decrease the dose of ropivacaine anesthesia required.

The effect of high concentration of magnesium with ropivacaine, gentamicin, rocuronium, and their combination on neuromuscular blockade.

BackgroundMagnesium, ropivacaine, gentamicin, and rocuronium block neuromuscular (NM) transmission by different mechanisms. Therefore, concurrent administration of these agents may induce prolonged muscle paralysis via synergistic interaction. This study investigated the efficacy and safety of NM block caused by the administration of high concentrations of magnesium in combination with ropivacaine, gentamicin, and rocuronium.MethodsEighty-three left phrenic nerve-hemidiaphragms from male SD rats (150-250 g) were hung in Krebs solution. Three consecutive single twitch tension (ST, 0.1 Hz) and one tetanic tension (TT, 50 Hz for 1.9 s) were obtained before drug application and at each new drug concentration. The concentration of MgCl2 and MgSO4 in Krebs solution was increased until an 80 to 90% reduction in ST was reached. To test the effects of combinations of NM agents, a Krebs solution was premixed with MgCl2 alone, MgCl2 and ropivacaine, or MgCl2, ropivacaine, and gentamicin. The concentration of ropivacaine, gentamicin, or rocuronium was then progressively increased until an 80 to 90% reduction in ST was reached. The effective concentrations were estimated with a probit model.ResultsThe potency of MgCl2 was greater than that of MgSO4, and pretreatment with MgCl2 increased the potency of gentamicin and rocuronium. Unexpectedly, MgCl2 did not potentiate ropivacaine, and the potency of gentamicin and rocuronium failed to show an increase when premixed with 0.5 µM ropivacaine.ConclusionsThe concomitant administration of high concentrations of magnesium and ropivacaine together with clinically relevant concentrations of gentamicin or rocuronium potentiated NM blockade but not with clinically relevant concentrations of ropivacaine.

Epidural analgesia with amide local anesthetics, bupivacaine, and ropivacaine in combination with fentanyl for labor pain relief: a meta-analysis.

BackgroundThe study compares the effectiveness of bupivacaine and fentanyl (BUPI-FEN) and ropivacaine and fentanyl (ROPI-EFN) in epidural analgesia for labor pain through a meta-analysis of relevant randomized clinical trials.Material/MethodsMultiple electronic databases were searched using appropriate MeSH terms and keywords for original English language research papers published between 1990 and March 2014. Meta-analyses results were based on the mean differences between the groups as well as odds ratios where appropriate. Statistical heterogeneity amongst the included studies was tested by I2 index.ResultsNine studies that met the inclusion criteria were selected for analysis which consisted of 556 parturient patients. The duration of the second stage of labor was significantly shorter in the BUPI-FEN group by a mean of −6.87 (−10.98, −2.77; P<0.002). On the other hand, the ROPI-FEN group had a significantly lower incidence of motor blockade by a mean of 0.31 (0.18, 0.51; P<0.00001). A positive relationship between the amide local anesthetic concentration and the number of women having motor blockade was observed, but a negative relationship between fentanyl concentration and the number of women experiencing a motor block. Moreover, a positive correlation was found between the concentration of ropivacaine and the incidence of instrumental delivery and between the concentration of bupivacaine and the incidence of cesarean delivery.ConclusionsIn combination with fentanyl, bupivacaine and ropivacaine exhibit comparable efficacy and safety. However, BUP-FEN analgesia led to a shortened second-stage labor and ROPI-FEN resulted in a significantly lower incidence of motor block.

Early pharmacokinetic of ropivacaine without epinephrine after injection into the psoas compartment

Large amounts of local anaesthetics (LA) are used during psoas compartment block (PCB), especially if combined with sciatic nerve block. Data regarding early pharmacokinetics of ropivacaine for PCB are lacking, notably when a vasoconstrictive agent has not been added. PCB was established in 11 patients using 150 mg ropivacaine without epinephrine. Free and total arterial plasma concentrations of ropivacaine were measured at nine time points during the following 30 min. Also total protein, albumin, and α1-acid glycoprotein concentrations were analysed. Ropivacaine plasma concentrations were found in all patients within 30 s after injections. Maximum measured plasma concentrations were measured in all but two patients within the first 10 min. One patient experienced partial intravascular injection. Plasma concentrations showed wide inter-individual variability. Ranges of maximum measured plasma concentrations of total and free ropivacaine were 422-3905 and 5-186 ng ml(-1), respectively. The Pearson correlation between total and free concentrations was 0.96. No obvious relationship between concentrations of different plasma proteins (total protein, albumin, α1-acid glycoprotein) and ropivacaine concentrations was found. Maximal 5% of the measured ropivacaine was unbound. All blocks were successful and no signs of toxicity were observed. Maximum measured plasma concentrations of ropivacaine after PCB must be expected within 10 min. Although plasma concentrations stayed below toxic thresholds, our study demonstrates the risk of this regional anaesthesia technique. The clinical study was not registered because enrolment of study patients occurred in 2006.

0.2% ropivacaine with fentanyl in the management of labor analgesia: A case study of 30 parturients.

Background:Epidural infusion of 0.2% ropivacaine is recommended by the manufacturers for labor analgesia.Aims:The aim of this study is to evaluate the analgesic efficacy, degree of motor blockade, obstetric outcome in the form of incidence of normal vaginal, assisted vaginal and lower segment cesarean section.Settings and Design:Pilot study.Materials and Methods:In this pilot study, 30 nulliparous parturients in active labor had epidural analgesia established using 0.2% ropivacaine with 25 mcg fentanyl for initiation when cervical dilatation was 3–4 cm and then analgesia was maintained with 0.2% ropivacaine at 10 ml/h till the delivery of baby.Statistical Analysis:It was done by Wilcoxon sign rank test and paired t-test as applicable.Results:There was a significant difference (P < 0.05) between prebolus, postbolus and postinfusion with respect to visual analog score. There was a significant difference (P > 0.05) between prebolus, postbolus, and postinfusion with respect to Bromage motor score, (Wilcoxon sign rank test). Six out of 30 paturients complained of tingling and heaviness in lower limbs after continuous infusion of 2–2.5 h.Conclusion:We conclude that 0.2% ropivacaine (8 ml) with fentanyl 25 mcg is good for initiation of ambulatory labor analgesia. But for maintenance of labor analgesia lower concentration of ropivacaine may be preferred.

Ropivacaine 0.025% mixed with fentanyl 3.0 μg/ml and epinephrine 0.5 μg/ml is effective for epidural patient-controlled analgesia after cesarean section.

Background and Aims:We aimed to determine the ropivacaine concentration that provided adequate analgesia with early ambulation and minimal urinary retention or other side-effects when used with fentanyl and epinephrine for patient-controlled epidural analgesia (PCEA) after elective cesarean section.Material and Methods:Forty-eight patients were randomized to four groups in a double-blinded fashion. All groups received an initial 10 ml/h of epidural study solution for 24 h. The solution contained: 0.2, 0.1, 0.05, or 0.025% ropivacaine for Groups I-IV, respectively, with fentanyl 3.0 μg/ml and epinephrine 0.5 μg/ml. Patients could administer additional PCEA doses of 4 ml of their study solution with a lock-out time of 10 min. Overall satisfaction, side-effects, motor block, neurologic function, and pain using Visual Analog Scale were assessed.Results:Patients in all groups showed no difference in sedation, pruritus, nausea, vomiting, and uterine cramps. Pain scores at rest were lower for Group IV than Groups I-III (P < 0.001). Twelve, five, one, and zero patients could not ambulate in Groups I-IV, respectively. Nine, nine, two, and zero (III <I and II, P = 0.02; IV P = 0.001) patients reported urinary retention in Groups I-IV, respectively. Overall satisfaction scores were high for all groups. Neonatal behavior score was similar and high in all groups.Conclusion:0.025% ropivacaine PCEA combined with fentanyl and epinephrine provided effective pain relief after cesarean section with early ambulation and without sensory loss, urinary retention, or increase of side-effects.

Chronological Changes in Ropivacaine Concentration and Analgesic Effects Between Transversus Abdominis Plane Block and Rectus Sheath Block

Transversus abdominis plane block (TAPB) and rectus sheath block (RSB) are popular methods of controlling postoperative pain. Chronological changes in blood concentrations of local anesthetics have not been described, although a large amount of local anesthetic is required to block these compartments. We postulated that blood concentrations of anesthetics would peak earlier during TAPB than RSB (primary end point). Secondary end points were elapsed time from block until first postoperative rescue analgesia and affected dermatomes. This prospective, randomized study included 22 patients scheduled for laparoscopic ovarian surgery under general anesthesia. The patients were randomized to receive either a bilateral single-shot TAPB or a bilateral RSB (15 mL of 0.5% ropivacaine per side). Arterial blood was sampled 10, 20, 30, 45, 60, 90, and 120 minutes after ropivacaine administration. This trial was registered at the UMIN-Clinical Trials Registry (UMIN000012133) before patient recruitment. Arterial ropivacaine levels after block peaked earlier in the TAPB than in RSB [Tmax: 35 (12) vs 53 (16) minutes; P = 0.02], whereas peak ropivacaine concentrations did not significantly differ between the groups [Cmax: 1.83 (0.41) vs 1.79 (0.33) μg/mL; P = 0.54]. Peak ropivacaine concentrations exceeded 2.2 μg/mL in 1 and 2 patients in the RSB and TAPB groups, respectively, although symptoms of local anesthetic systemic toxicity were not evident in any of them. The median [interquartile range] duration of analgesia was significantly longer for TAPB than RSB (421 [335-536] vs 196 [168-277] minutes; P = 0.01). Peak ropivacaine concentrations were comparable during TAPB and RSB, but peaked earlier during TAPB. Although 150 mg of ropivacaine remained effective significantly longer during TAPB than RSB during laparoscopic surgery, this dose could cause local anesthetic systemic toxicity. The analgesic effects of blocks with less ropivacaine should be assessed.

Ropivacaine (total and unbound) and AGP concentrations after transversus abdominis plane block for analgesia after abdominal surgery.

The goal of this study was to assess the safety of single bolus dose of ropivacaine (ROP) followed by continuous infusion through transversus abdominis plane block catheter. The aim was to determine ROP absorbed from the infusion site, changes in protein binding after surgery, and clinical determinants of adverse effects. Twelve patients undergoing laparotomy, received bilateral transversus abdominis plane block under ultrasound guidance using a 20-mL bolus of 0.5% ROP followed by 10 mL/h of 0.2% ROP infusion for 48 hours. Serial blood samples were drawn presurgery and to 48 hours postbolus. Plasma concentrations of total and unbound ROP were measured by high performance liquid chromatography with ultraviolet detection. Alpha-1 acid glycoprotein concentrations were measured by enzyme-linked immunosorbent assay. Patients were monitored for any signs or symptoms of central nervous system and chorionic villus sampling toxicity. After the bolus dose, the mean (±SD) peak plasma total (bound plus unbound) ROP concentration (Cmax) was 2.1 (±0.8) mg/L and unbound ROP concentration was 0.04 (±0.02) mg/L. During the infusion phase, total ROP concentration continued to rise to a mean (±) Cmax of 3.3 (±1.6) mg/L, and the peak unbound concentration was 0.06 (±0.0) mg/L. No patients showed symptoms of ROP toxicity or unacceptable QTc intervals. Although the total ROP concentrations approached or exceeded reported neurotoxicity thresholds, no patients had unbound ROP concentrations approaching the unbound toxicity threshold, nor showed any signs or symptoms of toxicity. This result was consistent with changes in protein binding to alpha-1 acid glycoprotein after surgery.

Serum Free Ropivacaine Concentrations Among Patients Receiving Continuous Peripheral Nerve Block Catheters

Serum Free Ropivacaine Concentrations Among Patients Receiving Continuous Peripheral Nerve Block Catheters

Ropivacaine pharmacokinetics after local infiltration analgesia in hip arthroplasty.

In this study, we determined the plasma concentration of ropivacaine by liquid chromatography-mass spectrometry for 30 hours after local infiltration analgesia in 15 patients with elective hip arthroplasty. The 95% upper prediction bound of maximal unbound plasma concentration of ropivacaine was 0.032 mg/L. Side effects sufficient to stop an IV infusion have been reported at arterial concentrations of 0.34 to 0.85 mg/L. Alpha-1-acid glycoprotein did not correlate with the fraction of unbound ropivacaine during the first 24 hours after local infiltration analgesia. No signs or symptoms of systemic local anesthetic toxicity were observed. The Clopper-Pearson 95% upper confidence limit for adverse signs was 0.218.

Online Detection of Ropivacaine in Drip Bags Using Polypyrrole/graphene Oxide Materials

AbstractA novel method of measuring the concentration of the local anesthetic ropivacaine drip bags used in hospi‐ tals was developed using electrochemical impedance technique. Polypyrrole (Ppy)/graphene oxide (GO) composites were prepared by electrochemically polymerization over Au electrodes, which served as working electrodes. The Ppy/GO composite electrodes were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Various concentrations of ropivacaine (0.1–20 ppm) were prepared in a sample drip bag solution of 0.9 % NaCl from hostpital. The composite Ppy/1 % GO electrode exhibited strongest linearity (R2=0.960) than the Ppy electrode (R2=0.928) at a frequency of 100 kHz. The detection limits of ropivacaine on Ppy and Ppy/1 % GO were calculated as 0.11 ppm and 0.08 ppm, respectively. The proposed system yielded response and recovery times under 1 sec detecting 0.1 ppm (100 g/L) of ropivacaine; thus, the proposed online method is promising for measuring ropivacaine concentrations in drip bags. Molecular simulations and equivalent circuits were applied to explain the dynamic behavior of ropivacaine detection system using Ppy and Ppy/GO materials.

Local anesthetic cytotoxicity on human mesenchymal stem cells during chondrogenic differentiation.

This study was to investigate the cytotoxic potency of local anesthetics on human mesenchymal stem cells during chondrogenesis. Aggregates were created from density-gradient centrifugation-separated bone marrow-derived mesenchymal stem cells. After 7, 14, and 21days, aggregates were analyzed histologically and immunohistochemically and exposed to equipotent concentrations of bupivacaine, ropivacaine, and mepivacaine for 1h. Cell viability, apoptosis, and necrosis were determined using live-dead and caspase staining. Additionally, following a 1-h exposure on day 7, aggregates were cultured under chondrogenic conditions until day 21 to assess the effects of local anesthetics on differentiation potency of mesenchymal stem cells. In the course of chondrogenesis, mesenchymal stem cells were embedded in varying amount and structure of cartilage-specific extracellular matrix. Contents of sulfated glycosaminoglycan, type I and II collagen increased from day 7 to day 21. Compared to control, death rates of mesenchymal stem cells were significantly elevated 1day after treatment at 7 and 14days. Four days after exposure, death rates were 13-15% at 7 and 11-17% at 14days. Mesenchymal stem cell viability in aggregates at 21days was unchanged to controls. The width of the superficial aggregate zone containing stem cell necrosis decreased with elongated differentiation time. Apoptosis rates were elevated in the edge regions of aggregates, reaching maximum values 4days after treatment. Local anesthetic exposure on day 7 reduced Collagen II, but not DNA contents in aggregates at 21days. Bupivacaine, ropivacaine, and mepivacaine did not differ in mesenchymal stem cell cytotoxicity in aggregates. Local anesthetic exposure results in cytotoxicity of mesenchymal stem cells undergoing chondrogenesis, especially in superficial layers. Therefore, induced cell damage should be avoided during chondrogenesis of mesenchymal stem cells, particularly early after cartilage repair.

Clinical research on different concentrations of ropivacaine in walking epidural labor analgesia

Objective To compare the different concentrations of ropivacaine combined with fentanyl infusion analgesia labor in walking labor analgesia in maternal BP,HR,SpO2,labor,fetal heart,uterine contractions and oxytocin usage and the visual analogue scale (VAS) and maternal motor nerve block.Methods 180 cases of primipara volunteered for labor analgesia,ropivacaine with different concentration of patient controlled epidural analgesia (PCEA),and compared with parturients without analgesia,were randomly divided into group A,group B and group C with 60 cases in each group,three groups were respectively injected into the epidural 0.075％ ropivacaine and fentanyl 2 μ g/ml (group A,n=60),0.125％ ropivacaine plus fentanyl 2 μ g/ml (group B,n=60),0.20％ ropivacaine and fentanyl 2 μ g/ml (group C,n=60).With the cervix opening to the 2-3 cm,L2-3 epidural cephalad catheter,injection of 0.8％ lidocaine,5 mins to the load of 8-10 resistant analgesic liquid,confirming the analgesic plane,pain significantly reduced with analgesia pump.Continuous infusion of 6-8 ml,a single push volume of 3 ml,interval time of 15 min,wide open withdrawal.Results The results of three groups of maternal analgesia labor walk at each time point after VAS score was significantly lower with significant difference (P ＜ 0.05); feasible implementation of labor analgesia in group A,group B motor nerve block,in class 0,grade 1,2 cases of group C,and the difference was statistically significant (P ＜ 0.05);additional anesthesia compound liquid of three groups had no significant difference (P ＞ 0.05); there was no significant difference between three groups of maternal mode of delivery and use of oxytocin and neonatal Apgar score (P ＞ 0.05).Conclusion 0.125％ ropivacaine + fentanyl was 2 μg/ml continuous infusion for labor analgesia when walk good analgesic effect,motor nerve block light,is worth the clinical promotion. Key words: Ropivacaine; Fentanyl; Patient controlled epidural analgesia; Walking labor analgesia

Tumescent local anesthesia with ropivacaine in different concentrations in bitches undergoing mastectomy: plasma concentration and post-operative analgesia

ObjectiveTo compare two concentrations of ropivacaine administered for tumescent local anesthesia (TLA) in dogs undergoing mastectomy. Study designProspective randomized clinical study. AnimalsSeventeen bitches of various breeds, aged 12 ± 2 years and weighing 10 ± 6.5 kg requiring total unilateral or bilateral mastectomy. MethodsDogs were premedicated with acepromazine (0.04 mg kg−1) and morphine (0.4 mg kg−1) intramuscularly. Anesthesia was induced with propofol (2.5 mg kg−1) and midazolam (0.2 mg kg−1) intravenously, followed by intubation and maintenance with isoflurane and TLA. Dogs were randomly allocated to receive TLA either with 0.1% ropivacaine (group G1) or with 0.05% ropivacaine (group G05). TLA was performed by insertion of a multihole needle under the skin and infusion of ropivacaine and lactated Ringer’s solution at a fixed volume of 15 mL kg−1. Ropivacaine concentrations in arterial blood were measured by high-performance liquid chromatography. Post-operative pain was assessed using two scales (University of Melbourne pain scale and a modified composite measure pain scale) and von Frey filaments, 4 hours after TLA and at 1 hour intervals until sensitivity was regained. A score above 30% of the maximum possible score was considered a positive indicator of pain. ResultsPeak plasma concentrations of ropivacaine were measured 240 minutes after TLA in G1. Low concentrations were measured in G05 for 60 minutes, with subsequent increase. Analgesic rescue and return of sensitivity occurred at 7 ± 2.3 and 7 ± 1.9 hours (mean ± SD) after TLA for G1 and G05, respectively. Conclusions and clinical relevanceTumescent local anesthesia with ropivacaine provided satisfactory post-operative analgesia that lasted for several hours, with no difference in duration between the concentrations. No serious side effects were attributed to TLA. Results indicated that 0.05% ropivacaine provided adequate analgesia for mastectomy, however, more studies are required to support this conclusion.

Symptomatic Local Anesthetic Toxicity and Plasma Ropivacaine Concentrations After Transversus Abdominis Plane Block for Cesarean Section

Symptomatic Local Anesthetic Toxicity and Plasma Ropivacaine Concentrations After Transversus Abdominis Plane Block for Cesarean Section

Optimum concentration and dose of ropivacaine for caudal block in neonates undergoing laparotomy under general anesthesia: evaluation of postoperative outcome

Objective To investigate the optimum concentration and dose of ropivacaine for caudal block in the neonates undergoing laparotomy under general anesthesia.Methods One hundred pediatric patients of both sexes,aged 9-30 days,weighing 2.5-4.5 kg,scheduled for elective pyloromyotomy,were randomly divided into 5 groups (n =20 each) using a random number table:control group (group C),0.10％ ropivacaine 1.0 ml/kg group (group 0.1％ L1),0.15 ％ ropivacaine 1.0 ml/kg group (group 0.15 ％ L1),0.10 ％ ropivacaine 1.2 ml/kg group (group 0.10 ％ L2),and 0.15 ％ ropivacaine 1.2 ml/kg group (group 0.15 ％ L2).Anesthesia was induced with sevoflurane and cisatracurium.The pediatric patients were tracheally intubated and mechanically ventilated.Remifentanil was infused intravenously at 0.2-0.3 μg· kg-1 · min-1 in group C.In 0.10 ％ L1,0.15 ％ L1,0.10 ％ L2 and 0.15％L2 groups,the corresponding concentrations and doses of ropivacaine were injected into the sacral canal under the guidance of ultrasound.The operation was started at 15 min after administration and sevoflurane was inhaled and the end-tidal concentration of sevoflurane was maintained at 0.8-1.0 MAC.Before induction (T1),at pyloric muscle retraction (T2),and at 4,8,12 and 24 h after operation (T3-6),blood samples were collected from the central vein for determination of plasma concentrations of cortisol and interleukin-6 (IL-6).Pain was assessed using CRIES score at T3-6.When CRIES scores ＞ 3,10％ chloral hydrate 0.5 ml/kg was given by retention enema for analgesia,and the requirement for chloral hydrate was recorded.The emergence time,extubation time,duration of stay in post-anesthesia care unit (PACU) and hospital discharge time were recorded.Bradycardia and hypotension during operation,and development of motor block of lower extremities,infection and dehiscence of incision,vomiting,and urinary retention after operation were also recorded.Results Compared with group C,no significant changes were found in the emergence time,extubation time,duration of stay in PACU,hospital discharge time,plasma concentrations of cortisol and IL-6,the requirement for chloral hydrate,and the incidence of bradycardia,hypotension,motor block of lower extremities,and infection and dehiscence of incision in 0.10％ L1 and 0.15 ％ L1 groups,the emergence time,extubation time,duration of stay in PACU,hospital discharge time were significantly shortened,and the plasma concentrations of cortisol and IL-6,requirement for chloral hydrate,and the incidence of hypotension and infection of incision were decreased in 0.10％ L2 and 0.15％ L2 groups,and the incidence of vomiting and urinary retention was increased in 0.15％ L1 and 0.15％ L2 groups.Compared with group 0.10％ L2,the incidence of vomiting and urinary retention was significantly decreased,and no significant changes were found in the other parameters mentioned above in 0.15％ L2 group.Conclusion The optimum concentration and dose of ropivacaine are 0.10％ and 1.2 ml/kg,respectively,for caudal block in the neonates undergoing laparotomy under general anesthesia. Key words: Amides ; Anesthesia, caudal ; Anesthesia, general; Infant, newborn

Plasma ropivacaine concentration following ultrasound-guided subcostal transversus abdominis plane block in adults.

Ultrasound-guided subcostal transversus abdominis plane block (TAPB) is widely used for abdominal surgery; however, arterial plasma concentration of the anesthetic ropivacaine after the blockade is still unclear. We evaluated ropivacaine concentration after subcostal TAPB in adult patients undergoing upper abdominal surgery. Twelve patients with American Society of Anesthesiologists physical status 1-2 were enrolled. They received ultrasound-guided subcostal TAPB with 0.45 % ropivacaine at 3 mg/kg. Arterial plasma samples were collected at 15, 30, 45, 60, 90, and 120 min after the blockade and analyzed for total ropivacaine concentration using liquid chromatography and mass spectrometry. At every time point, the maximum concentrations (C(max)), and time to the C max (T(max)) were recorded. The mean C(max) and T(max) were 1.87 (0.78) µg/ml and 31.3 (16.7) min, respectively. No adverse events or clinical symptoms indicating systemic toxicity were observed during this study. The study demonstrated that administration of ropivacaine at 3 mg/kg during subcostal TAPB led to rapid increases in plasma concentration of the anesthetic during the first 2 h after the blockade. C(max) nearly reached the threshold for systemic toxicity.

Comparing the effectiveness of ropivacaine 0.5% versus ropivacaine 0.2% for transabdominis plane block in providing postoperative analgesia after appendectomy

ObjectiveThe basis for the transversus abdominis plane (TAP) block involves infiltration of a local anesthetic into the neurofascial plane between the internal oblique and the transversus abdominis muscles, causing a regional block that spreads between the L1 and T10 dermatomes. Thus, the TAP block is said to be suitable for lower abdominal surgery. This study was designed to compare the analgesic efficacy of two different concentrations of ropivacaine for TAP block in patients undergoing appendectomy. MethodsFifty-six patients with American Society of Anesthesiologists physical status I or II, aged 18 years and above, undergoing appendectomy were recruited in this prospective, randomized, double-blind study. They were divided into two groups: Group A patients who received 0.5 mL/kg of ropivacaine 0.5% and Group B patients who received 0.5 mL/kg of ropivacaine 0.2% via TAP block under ultrasound guidance. Postoperative pain was assessed using the visual analog scale upon arrival at the recovery room in the operating theatre, just prior to being discharged to the ward, and at 6 hours, 12 hours, 18 hours, and 24 hours postoperatively to compare the effectiveness of analgesia. ResultsIntraoperatively, patients in Group B required a significantly greater amount of additional intravenous fentanyl than those in Group A. There were no significant statistical differences in pain scores at rest and on movement at all assessment times as well as in the dose of 24-hour intravenous morphine consumption given via patient-controlled analgesia postoperatively between the two groups. ConclusionThe effectiveness of two different concentrations of ropivacaine (0.5% versus 0.2%) given via TAP block was comparable in providing postoperative analgesia for patients undergoing appendectomy.

Endothelial Barrier Protection by Local Anesthetics

Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase-Akt-nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability. Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed. Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10 M for ropivacaine; IC50 = 5.864 × 10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10 M for ropivacaine; IC50 = 6.377 × 10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated. Ropivacaine and lidocaine effectively blocked inflammatory TNFα signaling in endothelial cells by attenuating p85 recruitment to TNF-receptor-1. The resultant decrease in Akt, endothelial nitric oxide synthase, and Src phosphorylation reduced neutrophil adhesion and endothelial hyperpermeability. This novel anti-inflammatory "side-effect" of ropivacaine and lidocaine may provide therapeutic benefit in acute inflammatory disease.

Plasma concentration of ropivacaine after abdominal truncal blocks with or without epinephrine

Kitayama, M.; Hashimoto, H.; Yakoshi, C.; Wada, M.; Kudo, T.; Hirota, K. Author Information