Plasma Concentrations Of Ropivacaine Research Articles

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.

Systemic Ropivacaine Concentrations Following Local Infiltration Analgesia and Femoral Nerve Block in Older Patients Undergoing Total Knee Arthroplasty.

The study examined the pharmacokinetic profile of fixed formulation mixtures comprising 225 mg of ropivacaine for local infiltration analgesia with or without epinephrine, and femoral nerve block in older patients presenting for orthopedic surgery and explored potential influences of block type, age, and body weight on this profile. Twenty four patients scheduled for total knee arthroplasty were randomly assigned to three groups: femoral nerve block, local infiltration analgesia with epinephrine and local infiltration analgesia without epinephrine. Blood samples were collected at 10, 30, 60, and 120 min following the block and total plasma concentrations of ropivacaine were quantified by high performance liquid chromatography. The mean individual peak total plasma concentrations of ropivacaine in local infiltration analgesia with and without epinephrine, and femoral nerve block group were 0.334, 0.490 and 0.545 μg mL-1 (p = 0.16). Local infiltration with epinephrine group had significantly lower plasma ropivacaine concentrations at 30, 60 and 120 minutes. The plasma ropivacaine concentrations exceeded 2.2 μg mL-1 in one patient. Age, but not body weight, had a moderate correlation with peak plasma ropivacaine concentration (r = 0.37, p = 0.08). Administration of a fixed 225 mg dose of ropivacaine for local infiltration analgesia with epinephrine and femoral nerve block results in plasma ropivacaine concentrations below the toxicity threshold, indicating their safety. The use of local infiltration analgesia with epinephrine provides a greater safety margin, as local infiltration analgesia without epinephrine may lead to ropivacaine concentrations associated with symptoms of local anesthetic toxicity.

Comparing postoperative analgesia of bilateral serratus anterior plane block and thoracic paravertebral block for children following the Nuss procedure: protocol for a randomised, double-blind, non-inferiority clinical trial

IntroductionThe Nuss procedure, despite being a minimally invasive surgery, is regarded as one of the most painful surgical procedures in children, and postoperative pain control remains a major clinical issue...

Safety and feasibility of ultrasound-guided serratus anterior plane block and intercostal nerve block for management of post-sternotomy pain in pediatric cardiac patients: A prospective, randomized trial

BackgroundPostoperative analgesia in the cardiothoracic ICU has traditionally relied on intravenous opioids. Thoracic nerve blocks are attractive alternatives for analgesia that reduce the requirement for opioids, but their safety and feasibility remain unclear. MethodsSixty children were allocated randomly to three groups: group C received intravenous opioids alone, while group SAPB (deep serratus anterior plane block) and group ICNB (intercostal nerve block) received opioids combined with ultrasound-guided regional nerve blocks (0.2% ropivacaine 2.5 mg.kg−1) after patients were transferred to the ICU. The primary outcome was opioid requirement in the first 24 h after surgery. Other outcomes included the postoperative FLACC scale value, tracheal extubation time, and plasma ropivacaine concentrations after the block. ResultsThe mean [sd] cumulative dose of opioids administered postoperatively within 24 h in the SAPB (168.6 [76.9] μg.kg−1) and ICNB groups (170.0 [86.8] μg.kg−1) were significantly lower by nearly 53% than those in group C (359.3 [125.3] μg.kg−1, p = 0.000). The tracheal extubation time was shorter in the regional block groups than that in the control group, but the difference was not statistically significant (p = 0.177). The FLACC scale values at 0, 1, 3, 6, 12, and 24 h post-extubation were similar in the three groups. The mean peak plasma ropivacaine concentrations in the SAP and ICNB groups were 2.1 [0.8] and 1.8 [0.7] mg.L−1, respectively, 10 min post-block and then slowly decreased. No noticeable complications associated with regional anesthesia were observed. ConclusionsUltrasound-guided SAPB and ICNB provided safe and satisfactory early postoperative analgesia while reducing opioid consumption following sternotomy in pediatric patients. Clinical trial registrationChinese Clinical Trial Registry ChiChiCTR2100046754.

Comparison of postoperative analgesic effects of erector spinae plane block and quadratus lumborum block in laparoscopic liver resection: study protocol for a randomized controlled trial

BackgroundCompared with open surgery, laparoscopic liver resection is a minimally invasive surgical technique. However, a number of patients experience moderate-to-severe postoperative pain after laparoscopic liver resection. This study aims to compare the postoperative analgesic effects of erector spinae plane block (ESPB) and quadratus lumborum block (QLB) in patients undergoing laparoscopic liver resection.MethodsOne hundred and fourteen patients undergoing laparoscopic liver resection will be randomly allocated to three groups (control, ESPB, or QLB) in a 1:1:1 ratio. In the control group, participants will receive systemic analgesia consisting of regular NSAIDs and fentanyl-based patient-controlled analgesia (PCA) according to the institutional postoperative analgesia protocol. In the two experimental groups (ESPB or QLB group), the participants will receive preoperative bilateral ESPB or bilateral QLB in addition to systemic analgesia according to the institutional protocol. ESPB will be performed at the 8th thoracic vertebra level with ultrasound guidance before surgery. QLB will be performed in the supine position on the posterior plane of the quadratus lumborum with ultrasound guidance before surgery. The primary outcome is cumulative opioid consumption 24 h after surgery. Secondary outcomes are cumulative opioid consumption, pain severity, opioid-related adverse events, and block-related adverse events at predetermined time points (24, 48, and 72 h after surgery). Differences in plasma ropivacaine concentrations in the ESPB and QLB groups would be investigated, and the quality of postoperative recovery among the groups will be compared.DiscussionThis study will reveal the usefulness of ESPB and QLB in terms of postoperative analgesic efficacy and safety in patients undergoing laparoscopic liver resection. Additionally, the study results will provide information on the analgesic superiority of ESPB versus QLB in the same population.Trial registrationProspectively registered with the Clinical Research Information Service on August 3, 2022; KCT0007599.

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

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

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

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

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

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

Comparison of postoperative analgesic effects of posterior quadratus lumborum block and intrathecal morphine in laparoscopic donor hepatectomy: a prospective randomized non-inferiority clinical trial

BackgroundPosterior quadratus lumborum block (QLB) and intrathecal morphine are accepted analgesic strategies in laparoscopic liver resection, but their effects have not been compared after laparoscopic donor hepatectomy. This study was...

Comparison of Analgesic Efficacy of Erector Spinae Plane Block and Posterior Quadratus Lumborum Block in Laparoscopic Liver Resection: A Randomized Controlled Trial.

PurposeUltrasound-guided fascial plane blocks, including the erector spinae plane (ESP) and quadratus lumborum (QL) blocks, provide effective postoperative abdominal analgesia. However, there is limited evidence on the analgesic efficacy of ESP and QL blocks after liver surgery. Therefore, we aimed to compare the cumulative opioid consumption between the ESP and QL blocks in patients with hepatocellular carcinoma undergoing laparoscopic liver resection.Patients and MethodsEighty-eight patients scheduled to undergo laparoscopic liver resection were randomized to receive bilateral single injection of ESP block at T8 (ESP group) or bilateral single injection of posterior QL block (QL group; 20 mL of 0.375% ropivacaine for each side, ie, total 150 mg of ropivacaine), in addition to intravenous (IV) fentanyl patient-controlled analgesia and multimodal analgesia. The primary outcome was cumulative opioid consumption over the first 24 h, expressed as IV morphine equivalents. Secondary outcomes included serial plasma ropivacaine concentrations, pain scores, time to first flatus, and Quality of Recovery-15 scores.ResultsEighty-five patients were analyzed (ESP group, n = 42; QL group, n = 43). Cumulative 24-h opioid consumption was similar between the ESP and QL groups (41.4 ± 22.6 mg vs 44.2 ± 20.0 mg, mean difference (QL-ESP), 2.8 mg, 95% confidence interval, −6.4 to 12 mg, p > 0.99). There were no significant differences in resting pain scores at 24, 48 and 72 h postoperatively or recovery outcomes. The peak plasma ropivacaine concentration 30 min after injection was significantly higher in the ESP group (1.5 ± 0.3 µg/mL) than in the QL group (1.3 ± 0.5 µg/mL, p = 0.035); however, both were lower than the arterial threshold value of systemic toxicity (4.3 µg/mL).ConclusionESP and QL blocks provided similar postoperative analgesia in patients undergoing laparoscopic liver resection.

Preperitoneal ropivacaine infusion versus epidural ropivacaine–morphine for postoperative analgesia in dogs undergoing ovariohysterectomy: a randomized clinical trial

ObjectiveTo assess the effect of continuous wound infusion (CWI) with preperitoneal ropivacaine on postoperative analgesia and compare it with the epidural administration of ropivacaine and morphine in bitches undergoing ovariohysterectomy. Study designA parallel, randomized, clinical, prospective and nonblinded study. AnimalsA group of 38 Greyhound bitches. MethodsIn the catheter group (CathG), CWI with ropivacaine 1% (1 mg kg–1 + 0.8 mg kg–1 hour–1) was applied to the preperitoneal space over the surgical incision. In the epidural group (EpiG), ropivacaine 0.5% (1.3 mg kg–1) and morphine (0.1 mg kg–1) were epidurally administered. Occipital-coccygeal length was used to calculate the volume for the epidural. Pain was scored using a dynamic interactive visual analogue scale (DIVAS) and Glasgow composite measure pain scale–short form (CMPS-SF) before anaesthesia and at 2, 4, 6, 18, 21 and 24 hours after extubation. Incisional sensitivity using a dynamometer (MWTs-incision) was evaluated simultaneously. Plasma ropivacaine and cortisol concentrations, degree of sedation, motor blockade and response to interdigital clamping were measured or assessed. A two-way mixed analysis of variance and a Mann–Whitney U test were used to analyse data; p < 0.05. ResultsNo differences were detected in the DIVAS (p = 0.301), CMPS-SF (p = 0.600) scores, MWTs-incision measurements (p = 0.257) and cortisol values (p = 0.878) between the groups. Rescue analgesia was required in two dogs, one in each group, at 2 hours. Sedation, motor blockade and negative response to interdigital clamping were detected in EpiG at 2, 4 and 6 hours. Mean plasma ropivacaine values were higher in CathG (0.475 ± 0.164 ng mL–1) than in EpiG (0.184 ± 0.213 ng mL–1; p = 0.001). Conclusion and clinical relevanceCompared with epidural ropivacaine and morphine, CWI with preperitoneal ropivacaine is an effective analgesic technique for postoperative pain management in bitches undergoing ovariohysterectomy without motor blockade.

Population pharmacokinetic analysis of ropivacaine extended-release from a temperature-responsive hydrogel in rats.

Therapeutic agents with a short half-life need to be administered frequently to achieve sustained and effective concentrations. This could be accomplished using sustained drug delivery technology. PF-72 (TGel Bio, Inc., Seoul, Korea) is a drug delivery system based on a powder obtained from lyophilisation of a reverse thermal hydrogel, which could assist in achieving prolonged pain relief if mixed with an anaesthetic and injected into the incision site following surgery. The pharmacokinetic parameters related to the absorption of the local anaesthetic ropivacaine delivered using this hydrogel were quantified. Ten rats were divided into two groups (n=5 each), and equal doses (4mg/kg) of different formulations were subcutaneously injected into the abdomen. The experimental group received PF-72 mixed with 0.75% ropivacaine, and the control group received 0.75% ropivacaine. Blood was collected at specific times to measure the plasma concentration of ropivacaine. Population pharmacokinetic analysis was performed using NONMEM VII level 4 (ICON Development Solutions, Dublin, Ireland). The one-compartment absorption model, which combines zero-order absorption and first-order absorption, was used to describe the change in ropivacaine plasma concentration over time. The type of formulation was a significant covariate for zero-order absorption duration (experimental group, 92.9min; control group, 60.5min). The addition of PF-72 to 0.75% ropivacaine increased the duration of absorption into the blood, suggesting a longer lasting effect of the analgesic injected into the surgical wound.

Population pharmacokinetics of ropivacaine used for local infiltration anaesthesia during primary total unilateral and simultaneous bilateral knee arthroplasty

BackgroundRopivacaine is commonly used in local infiltration anaesthesia (LIA) as pain management after total knee arthroplasty (TKA). Although considered safe, no studies evaluated the pharmacokinetics of high-dose ropivacaine infiltration in simultaneous bilateral TKA. MethodsWe studied 13 patients undergoing unilateral and 15 undergoing bilateral TKA. Standard LIA technique was used with ropivacaine 0.2%, 200 ml (400 mg) injected peri-articularly in each knee. Free and total plasma concentrations of ropivacaine were measured within 24 h using liquid chromatography–mass spectrometry. A population pharmacokinetic model was built using non-linear mixed-effects models. ResultsPeak free ropivacaine concentration was 0.030 (0.017–0.071) μg ml−1 (mean [99% confidence interval]) vs 0.095 (0.047–0.208) μg ml−1, and peak total ropivacaine concentration was 0.756 (0.065–1.222) μg ml−1vs 1.695 (0.077–3.005) μg ml−1 for unilateral and bilateral TKA, respectively. The pharmacokinetics was ascribed a one-compartment model with first-order absorption. The main identified covariates were protein binding, allometrically scaled body weight on clearance and volume, and unilateral or bilateral surgery on volume. ConclusionsThis is the first study to investigate the pharmacokinetics of free and total ropivacaine after unilateral and bilateral TKA. A population model was successfully built and peak free ropivacaine concentration stayed below previously proposed toxic thresholds in patients undergoing unilateral and bilateral TKA receiving LIA with high-dose ropivacaine. Clinical trial registrationClinicalTrials.gov Identifier: NCT04702282

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 Safety and Efficacy of Ultrasound-Guided Bilateral Dual Transversus Abdominis Plane (BD-TAP) Block in ERAS Program of Laparoscopic Hepatectomy: A Prospective, Randomized, Controlled, Blinded, Clinical Study.

PurposePostoperative pain management for patients undergoing hepatic resection is still a challenge due to the risk of perioperative liver dysfunction. The transversus abdominis plane (TAP) block is a promising regional analgesic technique. However, the correct guidelines regarding the dose and regimen of local anesthetics in patients undergoing hepatic resection have yet to be established completely. This study aimed to evaluate the safety and efficacy of ultrasound-guided BD-TAP block with a large dose of ropivacaine in laparoscopic hepatectomy.Patients and MethodsThis prospective, blinded, randomized, controlled study was conducted with 50 patients who were scheduled for selective laparoscopic hepatectomy. Patients who received a BD-TAP block (3 mg/kg of ropivacaine diluted to 60 mL) with general anesthesia were categorized into the BD-TAP block group (n = 25), and those who received general anesthesia were categorized into the control group (n = 25). The primary outcomes were consumption of sufentanil within 48 hours post-operation and plasma ropivacaine concentration. The secondary outcomes were the severity of pain (at rest and upon coughing), nausea and/or vomiting, and quality of recovery.ResultsCompared with the control group, the patients in BD-TAP block group had a significant reduction of postoperative sufentanil consumption at 2 hours (P = 0.019), 24 hours (P = 0.001), and 48 hours (P = 0.001), and the visual analog scale (VAS) scores on coughing were significantly lower at postoperative 2 hours (P = 0.004). There were no statistically significant differences in postoperative nausea and/or vomiting, flatus, catheter removal, off-bed activity, liver function, or postoperative hospital stay. The mean peak total ropivacaine concentration was 1,067.85 ng/mL, which occurred 1 hour after administering the block, and mean free ropivacaine concentration was 52.32 ng/mL. The highest individual peak plasma concentration was 2,360.90 ng/mL at 45 min postinjection, and the free ropivacaine concentration was 139.29 ng/mL.ConclusionUltrasound-guided BD-TAP block provides effective postoperative analgesia after laparoscopic hepatectomy. This study also confirms that ultrasound-guided BD-TAP blocks with 3 mg/kg ropivacaine during laparoscopic hepatectomy almost never results in the plasma ropivacaine concentrations associated with neurotoxicity.

Comparing post-operative analgesic effects of varying doses of dexmedetomidine as an adjuvant to ropivacaine for ultrasound-guided dual transversus abdominis plane block following laparotomy for gynecologic malignancies.

The aim of the present study was to determine the analgesic effects of ropivacaine combined with different doses of dexmedetomidine for ultrasound-guided transversus abdominis plane (TAP) block immediately following laparotomy in patients with gynecologic malignancies. A further aim was to determine the appropriate clinical dose of dexmedetomidine as an adjuvant for ropivacaine. Patients with gynecologic malignancies scheduled for laparotomy were randomly assigned to group R (TAP block with 0.3% ropivacaine), group RD1 (TAP block with ropivacaine and 0.5 µg/kg dexmedetomidine), group RD2 (TAP block with ropivacaine and 1 µg/kg dexmedetomidine) and group RD3 (TAP block with ropivacaine and 2 µg/kg dexmedetomidine). TAP blocks were performed post-operatively. The four groups all received patient-controlled intravenous analgesia (PCIA) after the operation. The numerical rating scale (NRS) as well as the Ramsay sedation scale (RSS) scores, the first request time for PCIA bolus, oxycodone hydrochloride consumption, the plasma concentration of ropivacaine, the incidence of post-operative complications and adverse events, and patient satisfaction were recorded. Post-operative NRS scores at rest exhibited significant differences between the R group and all the RD groups at 24 h after surgery (P<0.05). Compared with the other groups, the NRS score in the RD3 group was decreased (P<0.05). The RSS scores were higher in all of the RD groups compared with those in the R group at 2 h (P<0.05) and were highest in the RD3 group compared with those in all other groups at 4 h (P<0.05). The first request time for PCIA was significantly longer in the RD3 group compared with that in the RD2, RD1 and R groups (510.47±102.67, 595.47±100.11, 682.43±104.46 and 776.42±143.91 min, respectively; P<0.05). Cumulative opioid consumption based on the number of PCIA bolus requested at 24 and 48 h post-operatively indicated that the total number of PCIA boluses was significantly lower in the RD groups compared with those in the R group at 24 and 48 h (P<0.05). The ropivacaine concentration did not differ among the four groups. There was no significant difference between groups with respect to post-operative nausea and vomiting, bradycardia and hypotension; however, all RD groups had a higher patient satisfaction than group R (P<0.05). Compared with that in the other groups, the duration of post-anesthesia care unit stay in group RD3 was relatively longer due to excessive sedation (P<0.05). In conclusion, TAP blockade using 0.5-2 µg/kg dexmedetomidine combined with 0.3% ropivacaine is a safe and effective treatment for analgesia in laparotomy procedures for gynecologic malignancies. The study was registered in the Chinese Clinical Trial Registry (CHICTR; www.chictr.org.cn) on January 15th, 2019 (registration no. ChiCTR1900020995).

Ropivacaine Plasma Concentrations and Pharmacokinetics Following Erector Spinae Plane Block in the Pediatric Population

Ropivacaine Plasma Concentrations and Pharmacokinetics Following Erector Spinae Plane Block in the Pediatric Population

Single-Injection Ultrasound-Guided Thoracic Paravertebral Block versus Local Anesthetic Infiltration in Peritoneal Dialysis Catheter Surgeries: A Randomized Controlled Trial

Introduction: Ultrasound-guided thoracic paravertebral block (US-TPVB) is generally used for postoperative analgesia. We hypothesized that single-injection US-TPVB could be used as the principal anesthetic technique for a peritoneal dialysis catheter (PDC) procedure (implantation or removal). The anesthetic effect and venous ropivacaine level after a TPVB would be compared with that after local anesthetic infiltration (LAI). Methods: Patients undergoing PDC procedures were randomized into Group LAI or TPVB. In Group LAI, 40 mL of 0.25% ropivacaine were used. In Group TPVB, single-injection of US-TPVB at T10–T11 level was performed with 20 mL of 0.25% ropivacaine. The quality of anesthesia, visual analogue scale of pain, and venous total plasma ropivacaine level were compared between the 2 groups. Results: Seventy-four eligible patients were enrolled and 38 in Group TPVB. Thirty patients in Group TPVB and 26 patients in Group LAI underwent PDC procedures successfully. Higher satisfaction rates by nephrologists and patients (76.3 and 78.9%) were reported in Group TPVB (44.4 and 44.4% in Group LAI, respectively). The peak venous total plasma ropivacaine concentrations were below the reported toxic threshold in the 2 groups. Conclusions: A single-injection US-TPVB with 20 mL of 0.25% ropivacaine at T10–T11 could be the principal anesthetic technique for PDC procedures, which provided a comparable anesthetic effect to that of LAI with 40 mL ropivacaine. Higher satisfaction rates by nephrologists and patients were observed in Group TPVB. The 20 mL dose of 0.25% ropivacaine used for an US-TPVB was safe in end-stage renal diseases patients.

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

BackgroundThe 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.MethodsIn 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.ResultsNo 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.ConclusionThe 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 registrationThe trial was registered at German Clinical Trials Register (DRKS) on 04/05/2019 (DRKS00016705, retrospectively registered).

Pharmacokinetics of ropivacaine in elderly patients receiving fascia iliaca compartment block.

Local anesthetic of ropivacaine was demonstrated to reduce the postoperative pain in elderly patients. This study investigated the pharmacokinetics of ropivacaine at different concentrations in elderly patients subjected to fascia iliaca compartment block. Forty patients with femoral neck fracture at American Society of Anesthesiologists (ASA) I–II status, undergoing fascia iliaca compartment block (FICB) were randomized to two groups receiving 0.7 ml/kg of solution containing 0.375% ropivacaine (group L) or 0.5% ropivacaine (group H). Samples of venous blood were obtained immediately at different time points after FICB, and the total and free plasma concentrations of ropivacaine were measured by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Statistical analysis was carried out using a pharmacokinetic calculation program (DAS 3.0). Visual Analogue Scale (VAS) scores were significantly decreased after FICB in both groups, and VAS score in group H was lower compared with group L. The total maximum plasma concentration (Cmax) and the free Cmax of ropivacaine in group H was higher than that in group L (P<0.05). The decrease of the total and free plasma concentration was operation time-dependent. Neither group showed signs of central nervous system and circulatory system toxicity. On the basis of these results, the concentrations of 0.375 and 0.5% ropivacaine held an efficiently analgesic effect for FICB, suggesting that ropivacaine can be employed in analgesic therapy. However, both concentrations have a potentially theoretical risk of local anesthetics poisoning, suggesting that a lower concentration may be a safer option for a single large volume of FICB.