Benefit-Risk Assessment of Ropivacaine in the Management of Postoperative Pain

CPL-01, an investigational long-acting ropivacaine, demonstrates safety and efficacy in open inguinal hernia repair

BACKGROUND

There is an unmet medical need for effective nonopioid analgesics that can decrease pain while reducing systemic opioid use. CPL-01, an extended-release injectable formulation of ropivacaine, is designed to safely provide analgesia and reduce or eliminate opioid use in the postoperative period.

METHODS

Subjects undergoing open inguinal hernia with mesh were prospectively randomized to 1 of 3 doses of CPL-01 (10, 20, or 30 ml of 2% CPL-01, n = 14, 12, and 14, respectively), Naropin (150 mg, n = 40), or saline placebo (n = 13) infiltrated into the surgical site prior to closure. Pain and rescue medication usage was assessed, and Numeric Rating Scale (NRS) pain scores were adjusted for opioid usage using windowed worst observation carried forward (wWOCF) imputation. The primary efficacy endpoint was the mean area under the curve (AUC) of the NRS pain intensity scores with activity.

RESULTS

Ninety-three subjects were treated, and 91 subjects completed 72 h of post-operative monitoring. Subjects who received the highest dose of CPL-01 in Cohort 3 showed a clinically meaningful reduction in postoperative pain intensity scores, which was the lowest value for any treatment in all cohorts, showing a trend towards statistical significance as compared to the pooled placebo group (p = 0.08), and numerically better than the 40 subjects who received Naropin. Opioid use through 72 h in subjects who received CPL-01 in Cohort 3 was approximately half of that shown in the placebo and Naropin groups; approximately 2/3 of the CPL-01 subjects (9/14) required no opioids at all through the first 72 h after the operation. More CPL-01 subjects avoided severe pain and were ready for discharge earlier than other groups. CPL-01 was safe and well-tolerated, with no clinically meaningful safety signals, and showed predictable and consistent extended-release pharmacokinetics.

CONCLUSION

Results suggest that CPL-01 may be the first long-acting ropivacaine to address postoperative pain while reducing the need for opioids.

Peripheral Nerve Block and Peri-operative Neurocognitive Disorders in Older Patients With Hip Fractures: A Systematic Review With Meta-analysis

Background

Poor pain control and opioid use are risk factors for perioperative neurocognitive disorders (PND). The peripheral nerve block (PNB) can reduce pain and opioid consumption. This systematic review aimed to investigate the effects of PNB on PND in older patients with hip fractures.

Methods

The PubMed, Cochrane Central Registers of Controlled Trial, Embase and ClinicalTrials.gov databases were searched from inception until November 19, 2021 for all randomized controlled trials (RCTs) comparing PNB with analgesics. The quality of the selected studies was assessed according to Version 2 of the Cochrane tool for assessing the risk of bias in RCTs. The primary outcome was the incidence of PND. Secondary outcomes included pain intensity and the incidence of postoperative nausea and vomiting. Subgroup analyses were based on population characteristics, type and infusion method of local anesthetics, and type of PNB.

Results

Eight RCTs comprising 1015 older patients with hip fractures were included. Compared with analgesics, PNB did not reduce the incidence of PND in the elderly hip fracture population comprising patients with intact cognition and those with pre-existing dementia or cognitive impairment (risk ratio [RR] = .67; 95% confidence interval [CI] = .42 to 1.08; P = .10; I2 = 64%). However, PNB reduced the incidence of PND in older patients with intact cognition (RR = .61; 95% CI = .41 to .91; P = .02; I2 = 0%). Fascia iliaca compartment block, bupivacaine, and continuous infusion of local anesthetics were found to reduce the incidence of PND.

Conclusions

PNB effectively reduced PND in older patients with hip fractures and intact cognition. When the study population included patients with intact cognition and those with pre-existing dementia or cognitive impairment, PNB showed no reduction in the incidence of PND. These conclusions should be confirmed with larger, higher-quality RCTs.

"The use of bilateral continuous erector spinae plane blocks for postoperative analgesia after right-sided living donor hepatectomy: A feasibility study"

BACKGROUND

Postoperative pain after living donor hepatectomy is significant. Postoperative coagulopathy may limit the use of epidural analgesia, the gold standard for pain control in abdominal surgery. The erector spinae plane block (ESPB) is a novel regional anesthesia technique that has been shown to provide effective analgesia in abdominal surgery. In this study, we examined the effect of continuous ESPB, administered via catheters, on perioperative opioid requirements after right living donor hepatectomies for liver transplantation.

METHODS

We performed a retrospective cohort study in patients undergoing right living donor hepatectomy. Twenty-four patients who received preoperative ESPB were compared to 51 historical controls who did not receive regional anesthesia. The primary endpoint was the total amount of oral morphine equivalents (OMEs) required on the day of surgery and postoperative day (POD) 1.

RESULTS

Patients in the ESPB group required a lower total amount of OMEs on the day of surgery and POD 1 [141 (107-188) mg] compared the control group [293 (220-380) mg; P < .001].

CONCLUSIONS

The use of continuous ESPB significantly reduced opioid consumption following right living donor hepatectomy.

Wound infiltration with ropivacaine as an adjuvant to patient controlled analgesia for transforaminal lumbar interbody fusion: a retrospective study

Background

Surgical procedure usually causes serious postoperative pain and poor postoperative pain management negatively affects quality of life, function and recovery time. We aimed to investigate the role of wound infiltration with ropivacaine as an adjuvant to patient controlled analgesia (PCA) in postoperative pain control for patients undergoing transforaminal lumbar interbody fusion.

Methods

One hundred twelve patients undergoing lumbar fusion were retrospectively reviewed and divided into two groups (ropivacaine and control groups) according to whether received wound infiltration with ropivacaine or not. Visual Analogue Scale (VAS) score, analgesics consumption, number of patients requiring rescue analgesic, hospital duration and incidence of complications were recorded. Surgical trauma was assessed using operation time, intraoperative blood loss and incision length.

Results

The amount of sufentanil consumption in ropivacaine group at 4 h postoperatively was lower than that of control group (24.5 ± 6.0 μg vs 32.1 ± 7.0 μg, P < 0.001) and similar results were observed at 8, 12, 24, 48 and 72 h postoperatively(P < 0.001). Fewer patients required rescue analgesia within 4 to 8 h postoperatively in ropivacaine group (10/60 vs 19/52, P = 0.017). Length of postoperative hospital durations were shorter in patients receiving ropivacaine infiltration compared to control cohorts (6.9 ± 0.9 days vs 7.4 ± 0.9 days, P = 0.015). The incidence of PONV in ropivacaine group was lower than that in control group (40.4% vs 18.3%, P = 0.01). However, VAS scores were similar in two groups at each follow-up points postoperatively, and no difference was observed(P > 0.05).

Conclusion

Wound infiltration with ropivacaine effectively reduces postoperative opioid consumption and PONV and may be a useful adjuvant to PCA to improve recovery for patients undergoing lumbar spine surgery.

Efficacy of Local Anesthetic Wound Infiltration in Temporomandibular Joint Ankylosis Surgery for Control of Postoperative Pain: A Prospective, Randomized Controlled, and Double-Blinded Trial

PURPOSE

This study aimed to compare the analgesic efficacy of wound infiltration with ropivacaine alone or with adjuvants clonidine or dexamethasone for postoperative pain in temporomandibular joint ankylosis (TMJA) surgery.

MATERIALS AND METHODS

The investigators implemented a randomized controlled trial with 3 parallel groups, among the patients of bilateral TMJA visiting the maxillofacial surgery unit between March 12, 2015 and February 5, 2017. At the completion of surgery, wound infiltration was done with 0.25% of ropivacaine (R group), 0.25% of ropivacaine with 0.5 mcg/kg of clonidine (RC group), 0.25% of ropivacaine with 0.1 mg/kg of dexamethasone (RD group), and 0.2 mL/kg of drug volume on each side. The primary outcome variables were total opioid consumption (fentanyl in micrograms/kilogram) and visual analog scale for pain at rest and movement for 24 hours after surgery. The secondary outcome variables were time (minutes) to first rescue analgesic requirement and patient satisfaction scores. The patients, surgeons, and anesthesiologists collecting the data were blinded to the group allocation. Continuous and qualitative data were summarized using mean (standard deviation) and frequency distribution, respectively.

RESULTS

About 45 patients were randomized into 3 equal groups. Mean age of the sample was 17.6 ± 8.04 years (males = 24 [53%]; females = 21 [47%]). Surgery for TMJA included gap arthroplasty (n = 17), interpositional arthroplasty (n = 24), and total TMJ replacement (n = 4). Total fentanyl (micrograms) consumption during 24 hours was comparable between all the 3 groups and statistically not significant (P = .40). The pain scores (visual analog scale at rest and movement) were comparable at all time points. No significant difference was noted for time to first rescue analgesic requirement (P = .31). Patient satisfaction was higher in RC group as compared with R group (P = .009). No adverse effects were noted in any group.

CONCLUSIONS

Within the confines of the sample size and the absence of power calculation, the study implies that wound infiltration with ropivacaine was as efficacious as when mixed with adjuvants, either clonidine or dexamethasone, for control of postoperative pain for 24 hours.

The benefit of bilateral inferior alveolar nerve block in managing postoperative nausea and vomiting (PONV) after mandibular osteotomy

INTRODUCTION

The purpose of our study was to evaluate the benefit of bilateral inferior alveolar nerve block (BIANB) in managing postoperative pain, nausea and vomiting and opioid and antiemetic consumption in mandibular osteotomy.

MATERIAL AND METHODS

51 patients operated for bilateral sagittal split osteotomy (BSSO) were included in this prospective randomized controlled, double-blind, superiority trial. In the first group (n = 25), standard protocol was applied (general anesthesia and postoperative multimodal analgesia). The second group (n = 26) received bilateral inferior alveolar nerve block anesthesia at the start of surgery in addition to routine protocol. Postoperative monitoring was conducted every 4 h over the first 24 h and targeted the following criteria: postoperative nausea and vomiting (PONV), the visual analog scale (VAS) for pain, consumption of morphine (cumulative dose) and antiemetic agents, need for removal of guiding elastics.

RESULTS

PONV was significantly lower in the BIANB group (15.4 % VS 40 %, p = 0.049), as were mean VAS scores for pain (1 VS 1.57, p = 0.045) and medians of morphine bolus (8 [6-16] VS 5.5 [1-8], p = 0.033). We found no significant difference in incidence of guiding elastic removal, and antiemetic consumption.

DISCUSSION

The use of BIANB in BSSO improved postoperative patient comfort in terms of PONV and pain. Furthermore, it led to a decrease in opioid consumption. In conclusion, it is an additional therapeutic means of improving patients' postoperative comfort.

The Comparative Study of Epidural Anesthesia between Isobaric Ropivacaine 0.5% and Isobaric Bupivacaine 0.5% for Lower Abdominal Surgery

Aim:

The aim of the study was to compare the effectiveness of ropivacaine (0.5%) and bupivacaine (0.5%) in epidural neuraxial blockade for elective lower abdominal surgeries.

Methods:

The present study was conducted in sixty patients undergoing elective lower abdominal surgeries under epidural anesthesia who were included after satisfying the eligibility criteria. The patients were randomly divided into two groups. An epidural catheter was inserted in cephalad direction using Tuohy epidural needle at L₂–L₃ or L₃–L₄ with the help of loss of resistance to air technique. Twenty milliliter of the study drug was given, sensory blockade was tested using the pinprick method, and quality of motor blockade was assessed by the modified Bromage scale.

Results:

In our study, demographic data comparing age and sex show no statistically significant difference among both the groups. In our study, the mean time for the onset of sensory block consider at T₁₀ in Group B was 10.05 ± 2.1 min and in Group R was 9.8 ± 1.8 min. Moreover, the mean time duration of sensory block in Group B was 5.56 ± 0.059 h and in Group R was 5.34 ± 0.073 h. The onset of motor block in Group B was 4.98 ± 1.07 min and in Group R was 5.28 ± 1.2 min, but the duration of motor block for Group B was 4.63 ± 0.39 h and for Group R was 3.53 ± 0.23 h, which is clinically and statistically significant. The maximum level of sensory blockade for Group B was T₄ and for Group R was T₅. The range of block in Group B was T₁₀–T₄ and in Group R was T₁₀–T₃₅.

Conclusion:

The onset of sensory block was comparable in both the group, but the duration of sensory block is shorter with ropivacaine compared to bupivacaine. The onset of motor blockade was comparable in both the groups, but the duration of motor blockade was also shorter and the degree of motor block was less intense with ropivacaine compared to bupivacaine.

Ropivacaine 0.25% is as Effective as Bupivacaine 0.25% in Providing Surgical Anaesthesia for Lumbar Plexus and Sciatic Nerve Block in High-Risk Patients: Preliminary Report

Ropivacaine is potentially less cardiotoxic and neurotoxic than bupivacaine. The aim of this study was to compare the effectiveness of ropivacaine 0.25% and bupivacaine 0.25% for surgical anaesthesia and postoperative analgesia during lumbar plexus and sciatic nerve block in high-risk patients. We performed combined lumbar plexus and sciatic nerve blockade on 62 consecutive ASA III or IV patients undergoing unilateral hip or femur surgery. The first 30 patients received bupivacaine (Group 1) and the remaining 32 patients received ropivacaine (Group 2). Perioperative management was otherwise similar. The groups were compared for the time of onset of the block, additional analgesics and sedatives required, time from end of surgery to the first analgesic requirement and the need for rescue analgesia. Ninety percent (29/32) of the patients in the ropivacaine group and 86% (26/30) of the patients in the bupivacaine group reached surgical anaesthesia. The time from the end of the surgery to the first analgesic requirement was similar between the two groups (10.3±5.2 hours for ropivacaine, 11.2±4.6 hours for bupivacaine). There was no statistically significant difference between the two groups in any of the measured variables (P>0.05). The results of this preliminary study suggest that ropivacaine 0.25% is as effective as bupivacaine 0.25% when used for blocking lumbar plexus and sciatic nerve in high-risk patients undergoing hip or femur surgery.

Preoperative flap-site injection with ropivacaine and epinephrine in BABA robotic and endoscopic thyroidectomy safely reduces postoperative pain: A CONSORT-compliant double-blinded randomized controlled study (PAIN-BREKOR trial)

BACKGROUND

Clinical trials on bilateral axillo-breast approach (BABA) thyroidectomy show that levobupivacaine and ropivacaine significantly reduce postoperative pain, but they focused on BABA robotic thyroidectomy only and did not identify specific sites of significant pain relief. Our objective was to assess the pain reduction at various sites and safety of ropivacaine-epinephrine flap injection in BABA thyroidectomy.

METHODS

This prospective double-blinded randomized controlled trial was conducted in compliance with the revised CONSORT statement (ClinicalTrials.gov registration no. NCT02112370). Patients were randomized into the ropivacaine-epinephrine arm or control (normal saline) arm.

RESULTS

From January 2014 to May 2016, 148 patients participated. The primary endpoint was site-specific pain, as measured by numeric rating scale 12 hours after surgery. The ropivacaine-epinephrine group exhibited significantly less swallowing difficulty (P = .008), anterior neck pain (P = .016), and right (P = .019) and left (P = .035) chest pain. Secondary endpoints were systolic (P = .402), diastolic (P = .827) blood pressure, and pulse rate (P = .397) after injection before incision and during surgery. The vital signs of the groups just after injection did not differ. During surgery, the ropivacaine-epinephrine patients had higher pulse rates (99 ± 13.3 vs 88 ± 16.1, P < .001) but within normal range. There were no adverse events such as postoperative nausea and vomiting. There was no significant difference in pain scores in either patient group between patients who underwent robotic or endoscopic interventions.

CONCLUSION

BABA flap-site injection with ropivacaine and epinephrine mix before incision effectively and safely reduced postoperative pain. Future studies should focus on tailoring ropivacaine and epinephrine dosage for individuals.

A prospective, randomised, double-masked comparison of local anaesthetic agents for vitrectomy

Purpose

To compare the intraoperative and postoperative clinical properties of 1% ropivacaine, 0.75% bupivacaine, 2% lidocaine and a mixture of 0.75% bupivacaine and 2% lidocaine (bupi+lido) administered for peribulbar anaesthesia during vitrectomy.

Methods

A total of 140 patients were randomly allocated to four groups. The time of onset of analgesia and akinesia was measured. The efficacy of anaesthesia, degree of postoperative pain and intraoperative and postoperative complications were recorded.

Results

The mean times of onset (±SD) of analgesia for the ropivacaine, bupivacaine, lidocaine and lido+bupi groups were 90.46±30.08, 94.83±40.72, 78.31±12.56 and 101.51±56.94 s, respectively (p=0.087). The mean times of onset (±SD) of akinesia for the ropivacaine, bupivacaine, lidocaine and lido+bupi groups were 138.89±62.65, 151.86±84.78, 122.66±49.35 and 141.54±62.69 s, respectively (p=0.323). No significant difference was observed in the number of patients who attained grade-5 anaesthesia in the four groups (p=0.966). The outcome of ordered logit analysis showed that the 1% ropivacaine resulted in a significantly lower degree of postoperative pain compared with the other three groups (p=0.017, p=0.001 and p=0.001, respectively). The incidence of postoperative subconjunctival haemorrhage was decreased in the ropivacaine group compared with the other three groups (p<0.001).

Conclusions

For peribulbar anaesthesia in vitrectomy, 1% ropivacaine alone provides an adequate intraoperative anaesthesia similar to that provided by the bupivacaine, lidocaine and lido+bupi solutions, as well as provides a better quality of postoperative analgesia and decreases postoperative subconjunctival haemorrhage.

Trial registration number

ChiCTR-IPR-16007876; Results.

Incidence of cardiovascular complications in knee arthroplasty patients before and after implementation of a ropivacaine local infiltration analgesia protocol: A retrospective study

BACKGROUND

Local infiltration analgesia (LIA) during total knee arthroplasty has been shown to give statistically significant reduction in post-operative pain. The effects of using high volumes of ropivacaine combined with adrenaline as LIA on cardiovascular parameters in knee replacement have not been described before. The objective of this study was to investigate the cardiovascular safety of ropivacaine as part of high volume local infiltration analgesia (LIA) in total knee replacement surgery.

METHODS

This is a retrospective observational comparative cohort study conducted in two independent cohorts, one treated without and one treated with a local infiltration analgesia protocol, containing a total of 744 patients with a mean age of 68years (42 to 89) and 68years (21 to 88) respectively with a follow-up of 12months.

RESULTS

No statistical difference in bradycardia during surgery, post-operative cardiovascular complications, and mortality was found after use of LIA. A statistically significant lower incidence of hypotension was found in the LIA group (P<0.01). This result has to be interpreted with care, due to the use of adrenaline in the LIA mixture, which could mask possible hypotension. No statistical difference was found in the occurrence of hypertension or tachycardia, despite the addition of adrenaline to the LIA mixture. No difference in mortality was found between the two groups (P=0.11).

CONCLUSION

These results show safe use of high volume ropivacaine with adrenaline as local infiltration analgesia during total knee replacement surgery.

Pain management via local anesthetics and responsive hydrogels

Acute and chronic pain control is a significant clinical challenge that has been largely unmet. Local anesthetics are widely used for the control of post-operative pain and in the therapy of acute and chronic pain. While a variety of approaches are currently used to prolong the duration of action of local anesthetics, an optimal strategy to achieve neural blockage for several hours to days with minimal toxicity has yet to be identified. Several drug delivery systems such as liposomes, microparticles and nanoparticles have been investigated as local anesthetic delivery vehicles to achieve prolonged anesthesia. Recently, injectable responsive hydrogels raise significant interest for the localized delivery of anesthetic molecules. This paper discusses the potential of injectable hydrogels to prolong the action of local anesthetics.

Comparison of ropivacaine and bupivacaine with fentanyl for caudal epidural in pediatric surgery

CONTEXT

Ropivacaine, s-enantiomer of amide local anaesthetic produces differential neural blockade with less motor blockade, cardiovascular and neurological toxicity makes it suitable for day case surgery in children.

AIMS

To compare the effectiveness of Inj. Ropivacaine (0.2 or 0.25%) or Inj. Bupivacaine (0.25%) with fentanyl in caudal block for intra and postoperative analgesia.

SETTINGS AND DESIGN

Double blind retrospective randomized study.

MATERIALS AND METHODS

All the patients (n=112) varying from age group 3.02 ± 3.29 years belonging to ASA I-IV were randomly allocated to receive caudal analgesia Group BF inj. Bupivacaine (0.25%, 2 mg/kg) + Inj. Fentany1 μg/kg (n=70) and group RF: Inj. Ropivacaine (0.25% or 0.2%, 2 mg/kg) + inj. Fentanyl 1 μg/kg (n=42). We monitored vitals and requirement of inhalational gases inraoperatively and also observed pain by pain score (Visual Analogue Score in verbal group and Objective Pain Scale in nonverbal group) and vitals postoperatively. We used rescue analgesics (inj. Paracetamol 5 mg/kg iv) when VAS score ≥4.

STATISTICAL ANALYSIS

Student's t-test.

RESULTS

Duration of analgesia was prolonged in both group RF and BF. Time for first rescue analgesic for group RF (6.1 ± 1.1 hr) compared to group BF (5.6 ± 0.9 hr). Haemodynamic stability and less requirement of inhalation agent intraoperatively with group RF than others.

CONCLUSIONS

Ropivacaine with Fentanyl found to be better combination for pediatric surgeries for below umbilical surgeries as an adjuvant to general anaesthesia or sole technique with chances of less complication with high success rate.

Local anesthetic cytotoxicity on human mesenchymal stem cells during chondrogenic differentiation

PURPOSE

This study was to investigate the cytotoxic potency of local anesthetics on human mesenchymal stem cells during chondrogenesis.

METHODS

Aggregates were created from density-gradient centrifugation-separated bone marrow-derived mesenchymal stem cells. After 7, 14, and 21 days, aggregates were analyzed histologically and immunohistochemically and exposed to equipotent concentrations of bupivacaine, ropivacaine, and mepivacaine for 1 h. 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.

RESULTS

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 1 day after treatment at 7 and 14 days. Four days after exposure, death rates were 13-15 % at 7 and 11-17 % at 14 days. Mesenchymal stem cell viability in aggregates at 21 days 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 4 days after treatment. Local anesthetic exposure on day 7 reduced Collagen II, but not DNA contents in aggregates at 21 days. Bupivacaine, ropivacaine, and mepivacaine did not differ in mesenchymal stem cell cytotoxicity in aggregates.

CONCLUSION

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.

Prospective, randomized controlled trial on use of ropivacaine after robotic thyroid surgery: Effects on postoperative pain

BACKGROUND

We evaluated the effects of ropivacaine for pain relief after robotic thyroid surgery.

METHODS

One hundred eight patients scheduled for robotic thyroid surgery were randomized into ropivacaine (n = 54) or control (n = 54) groups. After surgery, 40 mL of 0.25% ropivacaine or 0.9% saline (control) was instilled into the skin flap. Postoperative pain intensity (visual analog scale [VAS]), analgesic requirements (fentanyl), and adverse events were assessed at 1, 2, 4, 8, 16, and 24 hours postoperatively.

RESULTS

One hundred three patients completed the study protocol. VAS scores were lower in the ropivacaine group than the control group (p = .010); however, VAS scores were not significantly different after 8 hours postoperatively. Total analgesic consumption was higher in controls than ropivacaine-treated patients (p = .01). Adverse events did not differ between the 2 groups.

CONCLUSION

Ropivacaine instillation after robotic thyroid surgery reduces acute postoperative pain and analgesic requirements without adverse events. © 2015 Wiley Periodicals, Inc. Head Neck 38: E-E, 2016.

Lysine-based surfactants as chemical permeation enhancers for dermal delivery of local anesthetics

The aim of this study is to investigate the efficacy of new, biocompatible, lysine-based surfactants as chemical permeation enhancers for two different local anesthetics, tetracaine and ropivacaine hydrochloride, topically administered. Results show that this class of surfactants strongly influences permeation, especially in the case of the hydrophilic and ionized drug, ropivacaine hydrochloride, that is not easily administered through the stratum corneum. It is also seen that the selected permeation enhancers do not have significant deleterious effects on the skin structure. A cytotoxicity profile for each compound was established from cytotoxicity studies. Molecular dynamics simulation results provided a rationale for the experimental observations, introducing a mechanistic view of the action of the surfactants molecules upon lipid membranes.

Effect of systematic local infiltration analgesia on postoperative pain in vaginal hysterectomy: a randomized, placebo-controlled trial

OBJECTIVE

To assess the effect of systematic local infiltration analgesia on postoperative pain in vaginal hysterectomy, and describe the technique in detail.

DESIGN

A randomized, double-blind, placebo-controlled study following the CONSORT criteria.

SETTING

A university hospital.

PATIENTS

Thirty-seven patients undergoing vaginal hysterectomy.

METHODS

Patients received high-volume (50 mL) ropivacaine 0.50% (n = 20) or saline (n = 17) infiltration using a systematic technique ensuring uniform delivery to all tissues incised, handled or instrumented during the procedure.

MAIN OUTCOME MEASURES

Pain, nausea, vomiting and opioid requirements were assessed for 32 h as well as time spent in the post-anesthesia care unit and time to first mobilization.

RESULTS

Pain at rest was significantly reduced after one, four and eight hours in the ropivacaine group (p ≤ 0.001-0.01). Pain during coughing was significantly reduced after one and four hours (p ≤ 0.001 and p ≤ 0.003), and pain during movement was significantly reduced after four hours (p ≤ 0.02). Opioid requirements and time spent in the post-anesthesia care unit were significantly reduced in the ropivacaine group (p < 0.001 and p < 0.001, respectively), as well as the time to first mobilization (p < 0.001).

CONCLUSION

Intra-operative systematic local infiltration analgesia reduces postoperative pain in patients undergoing vaginal hysterectomy, facilities mobilization and improves early recovery.

Cytotoxicity of local anesthetics on human mesenchymal stem cells in vitro

PURPOSE

The purpose of this study was to investigate the cytotoxic potency of local anesthetics on human mesenchymal stem cells (MSCs) before and after chondrogenic differentiation.

METHODS

MSCs were exposed to equal and equipotent concentrations of bupivacaine, ropivacaine, and mepivacaine for 1 hour. Cell viability, apoptosis, and necrosis were determined using flow cytometry and live/dead staining. After chondrogenic differentiation, MSC viability was determined in aggregates exposed to equipotent concentrations of the named agents, applying fluorescence microscopy.

RESULTS

All local anesthetics showed detrimental cytotoxic effects on MSC monolayer cultures in a concentration- and time-specific manner. Minimum viability rates were found 96 hours after a 1-hour exposure. Bupivacaine 0.5% caused a reduction of vital MSCs to 5% ± 1%. Sixteen percent ± 2% viable cells were detected after treatment with 0.75% ropivacaine. Exposure to 2% mepivacaine decreased vitality rates to 1% ± 0%. Ropivacaine was significantly less cytotoxic than were bupivacaine and mepivacaine. Immediate cell death was mainly caused by necrosis followed by apoptosis afterward. Viability rates of MSCs embedded in cartilaginous tissue after chondrogenic differentiation were not reduced by local anesthetic treatment.

CONCLUSIONS

Local anesthetics are cytotoxic to MSCs in a concentration-, time-, and agent-dependent manner in monolayer cultures but not in whole-tissue probes.

CLINICAL RELEVANCE

MSCs are applied for treatment of cartilage defects. Intra-articular application of local anesthesia is a common procedure in pain management and has shown chondrotoxic effects. Therefore, it is crucial to evaluate the impact of local anesthetics on human MSCs and regenerative cartilage tissue engineering.

The cytotoxicity of bupivacaine, ropivacaine, and mepivacaine on human chondrocytes and cartilage

BACKGROUND

Intraarticular injections of local anesthetics are frequently used as part of multimodal pain regimens. However, recent data suggest that local anesthetics affect chondrocyte viability. In this study, we assessed the chondrotoxic effects of mepivacaine, ropivacaine, and bupivacaine. We hypothesized that specific cytotoxic potencies directly correlate with analgesic potencies, and that cytotoxic effects in intact cartilage are different than in osteoarthritic tissue.

METHODS

Human articular chondrocytes were exposed to equal and equipotent concentrations of bupivacaine, ropivacaine, and mepivacaine for 1 hour. Cell viability, apoptosis, and necrosis were determined at predefined time points using flow cytometry, live-dead staining, and caspase detection. Intact and osteoarthritic human cartilage explants were treated with equipotent concentrations of named drugs to determine cell viability applying fluorescence microscopy.

RESULTS

Chondrotoxic effects increased from ropivacaine to mepivacaine to bupivacaine in a time-dependent and concentration-dependent manner. Compared with control, bupivacaine 0.5% decreased chondrocyte viability to 78% ± 9% (P = 0.0183) 1 hour and 16% ± 10% (P < 0.0001) 24 hours later, as determined by live-dead staining in monolayer cultures. Viability rates were reduced to 80% ± 7% (P = 0.0475) 1 hour and 80% ± 10% (P = 0.0095) 24 hours after treatment with ropivacaine 0.75%. After exposure to mepivacaine 2%, viable cells were scored 36% ± 6% (P < 0.0001) after 1 hour and 30% ± 11% (P < 0.0001) after 24 hours. Ropivacaine treatment was less chondrotoxic than bupivacaine (P = 0.0006) and mepivacaine exposure (P = 0.0059). Exposure to concentrations up to 0.25% of bupivacaine, 0.5% of ropivacaine, and 0.5% of mepivacaine did not reveal significant chondrotoxicity in flow cytometry. However, chondrotoxicity did not correlate with potency of local anesthetics. Immediate cell death was mainly due to necrosis followed by apoptosis. Cellular death rates were clearly higher in osteoarthritic compared with intact cartilage after bupivacaine, mepivacaine, and ropivacaine treatment in a decreasing order.

CONCLUSION

Bupivacaine, ropivacaine, and mepivacaine are chondrotoxic in a time-dependent, concentration-dependent, and drug-dependent manner. Chondrotoxic and analgesic potencies do not directly correlate. Cellular death rates were higher in osteoarthritic compared with intact cartilage after local anesthetic treatment.

Rotator cuff healing after continuous subacromial bupivacaine infusion: an in vivo rabbit study

BACKGROUND

The objective of this study was to evaluate the effects of continuous subacromial bupivacaine infusion on supraspinatus muscle and rotator cuff tendon healing using gross, biomechanical, and histologic analyses.

MATERIALS AND METHODS

Thirty-three New Zealand White rabbits underwent unilateral supraspinatus transection and rotator cuff repair (RCR). Rabbits were assigned to 1 of 3 groups: (1) RCR only, (2) RCR with continuous saline infusion for 48 hours, or (3) RCR with continuous 0.25% bupivacaine with epinephrine (1:200,000) infusion for 48 hours. Rabbits were euthanized postoperatively at 2 weeks (for histologic assessment) or 8 weeks (for biomechanical and histologic assessment).

RESULTS

Tensile testing showed a significantly higher load to failure in intact tendons compared with repaired tendons (P < .01); however, no statistical differences were detected among RCR only, RCR saline, and RCR bupivacaine groups. Histologically, the enthesis of repaired tendons showed increased cellularity and disorganized collagen fibers compared with intact tendons, with no differences between treatment groups. Muscle histology demonstrated scattered degenerative muscle fibers at 2 weeks in RCR saline and RCR bupivacaine groups, but no degeneration was noted at 8 weeks.

CONCLUSIONS

The healing supraspinatus tendons exposed to bupivacaine infusion showed similar histologic and biomechanical characteristics compared with untreated and saline-infused RCR groups. Muscle histology showed fiber damage at 2 weeks for the saline and bupivacaine-treated groups, with no apparent disruption at 8 weeks, suggesting a recovery process. Therefore, subacromial bupivacaine infusion in this rabbit rotator cuff model does not appear to impair muscle or tendon after acute injury and repair.

Early postoperative analgesic effects of a single epidural injection of ropivacaine administered preoperatively in posterior lumbar interbody spinal arthrodesis: a pilot randomized controlled trial

BACKGROUND

Despite the suitable characteristics of ropivacaine as an epidural analgesic agent, such as better preservation of motor function and less neurotoxicity, we are aware of no data on its clinical application in pain management following lumbar spine surgery. The purpose of the present study was to evaluate the preemptive analgesic effects and safety of a single epidural injection of ropivacaine during lumbar arthrodesis.

METHODS

We performed a randomized, double-blinded, intention-to-treat study. Patients with planned one-level posterior lumbar interbody arthrodesis were randomly assigned to either the injection group (n = 32) or the control group (n = 34). The injection group received a 10-mL epidural injection of 0.1% ropivacaine twenty minutes before the skin incision at the planned vertebral level, and the control group received an epidural injection of 10 mL of 0.9% saline solution. A numeric rating scale (from 0 to 10) was measured at seven time points after surgery (at two, four, eight, twelve, twenty-four, and forty-eight hours and at the time of discharge), and the frequency of pushed-button patient-controlled analgesia and total fentanyl consumption were assessed at similar time points (up to two, up to four, up to eight, up to twelve, up to twenty-four, and up to forty-eight hours after surgery). Postoperative nausea and vomiting, the duration of the hospital stay, and the Likert satisfaction score at the time of discharge were evaluated.

RESULTS

There were no significant differences between the two groups preoperatively. The numeric rating scale score was higher until twelve hours (p < 0.05) and the frequency of button pushes was higher at every time point except eight to twelve hours (p < 0.05) in the control group as compared with the injection group. Fentanyl consumption until eight to twelve hours (p < 0.05) and total consumption (p < 0.001) at discharge were higher in the control group. There were no differences between the two groups in terms of postoperative nausea and vomiting, the duration of hospital stay, or the mean satisfaction score, and no transient motor weakness was seen in relation to epidural injection of ropivacaine.

CONCLUSIONS

A single-dose epidural injection of 0.1% ropivacaine before lumbar spine surgery is effective for reducing early postoperative pain without related complications such as transient motor weakness.

The efficacy of intra-articular injections for pain control following the closed reduction and percutaneous pinning of pediatric supracondylar humeral fractures: a randomized controlled trial

BACKGROUND

The purpose of this single-blinded, randomized, controlled trial was to compare the analgesic efficacy of intra-articular injections of bupivacaine or ropivacaine with that of no injection for postoperative pain control after the operative treatment of supracondylar humeral fractures in a pediatric population.

METHODS

Subjects (n=124) were randomized to treatment with 0.25% bupivacaine (Group B) (n=42), 0.20% ropivacaine (Group R) (n=39), or no injection (Group C) (n=43). The opioid doses and the times of administration as well as child-reported pain severity (Faces Pain Scale-Revised) and parent-reported pain severity (Total Quality Pain Management survey) were recorded.

RESULTS

The proportion of subjects who required morphine and/or fentanyl injections was significantly (p=0.004) lower in Group B (10%) as compared with Group R (36%) and Group C (44%). On the basis of the log-rank test, the opioid-free survival rates were significantly greater in Group B as compared to Groups C and R. Total opioid consumption (morphine equivalent mg/kg) in the first seventy-two hours postoperatively was significantly less in Group B as compared with Group C (mean difference, 0.225; [95% confidence interval (CI), 0.0152 to 0.435]; p=0.036). Parent-reported pain scores were also significantly lower in Group B as compared with both Group C (mean difference, 1.81 [95% CI, 0.38 to 3.25]; p=0.014) and Group R (mean difference, 1.66; 95% CI, 0.20 to 3.12; p=0.027). There were no significant differences across the three groups in terms of self-reported pain. Differences between Groups R and C were not significant for any of the outcome variables.

CONCLUSIONS

The intra-articular injection of 0.25% bupivacaine significantly improves postoperative pain control following the closed reduction and percutaneous pinning of supracondylar humeral fractures in pediatric patients.

Intrapleural analgesia using ropivacaine for postoperative pain relief after minimally invasive thoracoscopic surgery

PURPOSE

to evaluate the efficacy and safety of intrapleural analgesia (IPA) using ropivacaine after thoracoscopic surgery, compared with thoracic epidural analgesia (TEA) using ropivacaine.

METHODS

forty patients undergoing thoracoscopic bullectomy for spontaneous pneumothorax were randomly assigned to one of two groups. IPA group (n = 20) received intermittent bolus injection of 0.375% ropivacaine into intrapleural space two times; at the end of operation and one more time as the pain increased. TEA group (n = 20) received continuous epidural analgesia with 0.375% ropivacaine. Transrectal diclofenac was administered as an additional analgesic. Pain was assessed on the basis of additional analgesics requirements and by using a visual analog scale (VAS).

RESULTS

the time courses of VAS scores along the postoperative time course were not significantly different (p = 0.175). Consumption of transrectal diclofenac was significantly smaller in IPA group (p = 0.025). No major complications appeared in both groups, and incidence of adverse symptoms was not different.

CONCLUSIONS

in IPA group, pain was managed with less consumption of additional analgesics. IPA could be one of the good choices after thoracoscopic surgery for its efficacy, safety, and benefit of easy placement of the catheter.

Antinociceptive effects of low dose lumbosacral epidural ropivacaine in healthy ponies

The objective of this study was to evaluate the safety and efficacy of low dose lumbosacral epidural ropivacaine in ponies. Antinociceptive effects of epidural ropivacaine were evaluated by means of mechanical nociceptive thresholds (MNTs) at several spinal levels in conscious ponies. The effects of ropivacaine on nociceptive afferent transmission to the spinal cord were also assessed by measuring spinal cord somatosensory evoked potentials (SSEPs) in anaesthetised ponies. Ataxia scores were determined in conscious ponies to assess the effects on motor function. A randomised, placebo controlled, double blind cross-over design was used. Low dose lumbosacral epidural ropivacaine led to increases in MNTs at various anatomical locations with a maximum effect at the lumbosacral and sacrococcygeal regions, both with respect to increase in threshold and duration of effect. Analysis of SSEPs showed that epidural ropivacaine influenced both Aβ- and Aδ-mediated afferent transmission to the spinal cord at the level of the lumbosacral junction. Ponies showed mild ataxia after low dose lumbosacral epidural ropivacaine, but all ponies remained standing. Application of low dose lumbosacral epidural ropivacaine provided safe and efficacious antinociceptive effects in conscious and anaesthetised ponies, and could therefore be a valuable addition to multimodal analgesic protocols in Equidae.

Intrathecally administered ropivacaine is less neurotoxic than procaine, bupivacaine, and levobupivacaine in a rat spinal model

PURPOSE

The aim of this study was to compare the neurotoxicity of intrathecal procaine, bupivacaine, levobupivacaine, and ropivacaine in an animal model.

METHODS

The study comprised two experiments. In the concentration experiment, rats (n = 78) were administered 0.12 μL·g(-1) body weight (BW) of 2% or 20% procaine, 0.5% or 5% bupivacaine, 0.5% or 5% levobupivacaine, or 0.5% or 5% ropivacaine. Based on the findings, the doses were increased by volume in the subsequent volume experiment using 0.12, 0.24, or 0.48 μL·g(-1) BW of 6% procaine, 6% levobupivacaine, or 6% ropivacaine (n = 79). Walking behaviour and sensory threshold were analyzed, and a histological examination of the spinal cord, posterior and anterior roots, and cauda equina was performed.

RESULTS

The concentration experiment showed abnormalities only in the 5% bupivacaine group, and these abnormal findings were in the posterior root (PR) and posterior column (PC). The volume experiment revealed that procaine 0.24 μL·g(-1) was neurotoxic, mainly affecting the PR. At 0.48 μL·g(-1), severe injury was observed in the PR and PC in all six procaine rats and four of six levobupivacaine rats, while milder injury was limited to the PR in one of six ropivacaine rats, which differed significantly from the former two groups (P = 0.006 and P = 0.014, respectively). Electron microscopy showed axonal degeneration.

CONCLUSION

All four local anesthetics seemed to cause identical neurotoxic lesions commencing in the PR and extending to the PC by axonal degeneration. Bupivacaine appeared to be the most neurotoxic of the four drugs, and the neurotoxicity at higher doses increased by volume with procaine > levobupivacaine > ropivacaine.

Local infiltration analgesia in urogenital prolapse surgery: a prospective randomized, double-blind, placebo-controlled study

OBJECTIVE

To evaluate the analgesic effect of high-volume infiltration analgesia in urogenital prolapse surgery and provide a detailed description of the infiltration technique.

DESIGN

A randomized, double-blind, placebo-controlled study following the CONSORT criteria.

SETTING

A university hospital.

PATIENTS

48 patients undergoing posterior wall repair and perineorraphy.

METHODS

Patients received high-volume (26 ml) ropivacaine 1% with epinephrine (n=23) or saline (n=22) infiltration using a systematic technique ensuring uniform delivery to all tissues incised, handled or instrumented during the procedure.

MAIN OUTCOME MEASURES

Pain and opioid requirements were assessed for 24 hours as well as time spent in the post-anesthesia care unit and time to first mobilization.

RESULTS

Pain at rest, during coughing and movement was significantly reduced for the first four hours with the high-volume local anesthetic infiltration technique (p<0.001-0.006). Opioid requirements and time spent in the post-anesthesia care unit were significantly reduced in the ropivacaine group (p<0.001 and p<0.001, respectively) as well as the time to first mobilization (p<0.014).

CONCLUSION

Systematic high-volume infiltration analgesia is an effective analgesic technique in patients undergoing posterior wall repair and perineorraphy, and improves early recovery.

Continuous local analgesic therapy reduces pain after radical inguinal/iliacal lymph node dissection

BACKGROUND

To optimize postoperative pain therapy after a radical inguinal/iliacal lymph node dissection (RILND), we investigated the influence of a continuous application of a local anaesthetic via a subfascial wound catheter in the abdominal wall in addition to a standardized systemic analgesia.

MATERIALS AND METHODS

Between July 2007 and December 2009, 50 patients with stage III/IV of melanoma disease received, in an observational study, a systemic analgesic therapy. Of these patients, 30 were additionally treated with a subfascial catheter. Main outcome criterion was the pain under mobilisation at the first postoperative morning registered via a visual analogue score. Minor criteria were the analgesic requirement, the specific (surgical) complications and the day of discharge.

RESULTS

Patients treated with the subfascial catheter had significant less pain at the first postoperative morning in rest (p = 0.02) and after mobilisation (p = 0.03) without increased morbidity (p = 0.45). Less patients of the treatment group needed a supplementary analgesic medication (p = 0.01) and were able to leave hospital earlier than patients of the control group (p = 0.01).

CONCLUSIONS

A subfascially placed pain catheter enhances postoperative pain therapy after RILND.

Postoperative analgesic effect of preoperative intravenous flurbiprofen in arthroscopic rotator cuff repair

PURPOSE

This study was carried out to evaluate the postoperative analgesic effects of preoperative intravenous flurbiprofen in patients undergoing arthroscopic rotator cuff repair under general anesthesia.

METHODS

We studied 44 patients who underwent an elective arthroscopic rotator cuff repair in a prospective, randomized, and double-blind fashion. The patients were divided into two groups. Group A (n = 22) received lipid emulsion 0.1 ml kg(-1) as a placebo, and group B (n = 22) received flurbiprofen 1 mg kg(-1) before the surgery. Intralipid or flurbiprofen was given intravenously 5 min before the surgery. General anesthesia was maintained with sevoflurane and nitrous oxide, and 10 ml of 0.75% ropivacaine was administered intraarticularly at the end of the surgery. Postoperative analgesia was supplied with intravenous 0.1 mg buprenorphine according to the patient's demand. The effectiveness of flurbiprofen's analgesic effect was measured by a visual analog scale (VAS) and by the amount of buprenorphine consumption at 0.5, 1, 2, 4, 6, 12, and 24 h after the surgery. Time to the first analgesic was also recorded.

RESULTS

VAS in group B was significantly (P < 0.01) lower than that in group A during the first 6 h postoperatively. The amount of buprenorphine consumption in group B was also significantly (P < 0.01) less than that in group A within the first 2 h postoperatively. The time to first analgesic request in group B was significantly (P < 0.01) longer than that in group A.

CONCLUSION

These results show that preoperative intravenous flurbiprofen facilitates the analgesic effect in the early postoperative period after arthroscopic rotator cuff repair.

Perineural dexmedetomidine added to ropivacaine causes a dose-dependent increase in the duration of thermal antinociception in sciatic nerve block in rat

BACKGROUND

The current study was designed to test the hypothesis that dexmedetomidine added to ropivacaine would increase the duration of antinociception to a thermal stimulus in a dose-dependent fashion in a rat model of sciatic nerve blockade.

METHODS

Fifty adult Sprague-Dawley rats (10 rats/group) received unilateral sciatic nerve blocks with 0.2 ml ropivacaine (0.5%) or 0.2 ml ropivacaine (0.5%) plus dexmedetomidine (2.7 microm [0.5 microg/kg], 11.7 microm [2 microg/kg], 34.1 microm [6 microg/kg], or 120.6 microm [20 microg/kg]) in a randomized, blinded fashion. Time to paw withdrawal latency to a thermal stimulus for both paws and an assessment of motor function were measured every 30 min after the nerve block until a return to baseline.

RESULTS

Dexmedetomidine added to ropivacaine increased the duration of dense sensory blockade and time for return to normal sensory function in a dose-dependent fashion (P < 0.005). There was a significant time (P < 0.005), dose (P < 0.005), and time-by-dose effect (P < 0.005) on paw withdrawal latencies of the operative paws. There were no significant differences in paw withdrawal latencies of the control paws, indicating little systemic effect of the dexmedetomidine. The duration of motor blockade was also increased with dexmedetomidine. High-dose dexmedetomidine (120.6 mum) was not neurotoxic.

CONCLUSION

This is the first study showing that dexmedetomidine added to ropivacaine increases the duration of sensory blockade in a dose-dependent fashion in rats. The findings are an essential first step encouraging future efficacy studies in humans.

Lipid emulsion improves recovery from bupivacaine-induced cardiac arrest, but not from ropivacaine- or mepivacaine-induced cardiac arrest

BACKGROUND

Cardiac toxicity significantly correlates with the lipophilicity of local anesthetics (LAs). Recently, the infusion of lipid emulsions has been shown to be a promising approach to treat LA-induced cardiac arrest. As the postulated mechanism of action, the so-called "lipid sink" effect may depend on the lipophilicity of LAs. In this study, we investigated whether lipid effects differ with regard to the administered LAs.

METHODS

In the isolated rat heart, cardiac arrest was induced by administration of equipotent doses of bupivacaine, ropivacaine, and mepivacaine, respectively, followed by cardiac perfusion with or without lipid emulsion (0.25 mL x kg(-1) x min(-1)). Subsequently, the times from the start of perfusion to return of first heart activity and to recovery of heart rate and rate-pressure product (to 90% of baseline values) were assessed.

RESULTS

In all groups, lipid infusion had no effects on the time to the return of any cardiac activity. However, recovery times of heart rate and rate-pressure product (to 90% of baseline values) were significantly shorter with the administration of lipids in bupivacaine-induced cardiac toxicity, but not in ropivacaine- or mepivacaine-induced cardiac toxicity.

CONCLUSIONS

These data show that the effects of lipid infusion on LA-induced cardiac arrest are strongly dependent on the administered LAs itself. We conclude that lipophilicity of LAs has a marked impact on the efficacy of lipid infusions to treat cardiac arrest induced by these drugs.

Pharmacologic management of acute pediatric pain

The accurate assessment and effective treatment of acute pain in children in the hospital setting is a high priority. During the past 2 to 3 decades, pediatric pain management has gained tremendous knowledge with respect to the understanding of developmental neurobiology, developmental pharmacology the use of analgesics in children, the use of regional techniques in children, and of the psychological needs of children in pain. A wide range of medications is available to treat a variety of pain types. This article provides an overview of the most common analgesic medications and techniques used to treat acute pain in children.

Effects of preoperative local ropivacaine infiltration on postoperative pain scores in infants and small children undergoing elective cleft palate repair

Previous data have shown that preoperative analgesia may reduce postoperative analgesic demands. The aim of the current study was to determine if preincisional ropivacaine infiltration may reduce postoperative oral pain in infants and small children undergoing elective cleft palate patients.Twenty nonsyndromic cleft palate patients were randomly divided into 2 groups. Injection with ropivacaine hydrochloride, at dose of 0.2 mg/kg, was performed by submucous infiltration of the proposed incisional site groups of patients. In control group, no medication was given before cleft palate repair under general anesthesia. Postoperative pain scores were measured according to Children and Infants Postoperative Pain Scale. Heart rate recordings and noninvasive blood pressure measurements were also done in all the patients.Measurements of Children and Infants Postoperative Pain Scale scores at all the observational postoperative periods showed significantly favorable values in ropivacaine group than in control group (P < 0.05). Six patients in the control group required rescue analgesia, whereas 2 patients required analgesic therapy in the treatment group.Preemptive analgesia using ropivacaine may enhance early postoperative comfort by reducing early postoperative pain in primary cleft repair.

The toxicity of local anesthetics: the place of ropivacaine and levobupivacaine

PURPOSE OF REVIEW

Ropivacaine and levobupivacaine were developed after evidence of bupivacaine-related severe toxicity. Despite a comparable analgesic profile, quantitative differences become evident with regard to their specific rate of systemic toxicity. The present article provides a concise review of the toxic potencies of levobupivacaine and ropivacaine.

RECENT FINDINGS

As lipophilicity is known to be a major determinant in local anesthetic toxicity, the clinical safety profile of ropivacaine seems to be more favorable than that of levobupivacaine. Experimental studies and case reports confirm this hypothesis, showing that ropivacaine is characterized by fewer (cardio) toxic effects and, most probably, a greater margin of safety. Both agents also may dose dependently damage neurons and skeletal muscle tissue at the injection site. Although their specific rate of neurotoxicity appears to be rather low, levobupivacaine is characterized by an outstanding myotoxic potential.

SUMMARY

Compared with bupivacaine, both agents may be considered as 'more well tolerated' but not as 'totally well tolerated', as they are still capable of inducing systemic and local toxicity. However, ropivacaine seems to have the greatest margin of safety of all long-acting local anesthetics at present.

A Comparison of Three Different Concentrations of Ropivacaine with Fentanyl for Patient-Controlled Epidural Analgesia

BACKGROUND

The optimal concentration of ropivacaine in combination with fentanyl for patient-controlled epidural analgesia focusing on preservation of bowel function, analgesia, and motor function remains unclear.

METHODS

Three hundred-twelve women scheduled to undergo gynecologic lower abdominal surgery, were randomly allocated to receive ropivacaine 0.05, 0.075, or 0.1% in combination with fentanyl 4 mug/mL and droperidol 25 microg/mL. The settings of patient-controlled epidural analgesia were as follows: initial loading volume 5 mL, background infusion 2 mL/h during night-time, no background infusion during daytime, bolus volume 2 mL, and lockout interval 10 min. Bowel function was evaluated by the first passage of flatus and feces. Pain was assessed with a visual analog scale, and motor function was examined by modified Bromage scale. Data were collected in the evening on the day of surgery, in the morning and in the evening on the first postoperative day, and in the morning on the second postoperative day.

RESULTS

Gastrointestinal motility was not different among the three groups. All three solutions produced equivalent analgesia and no motor blockade.

CONCLUSION

We conclude that ropivacaine 0.05% is sufficient to preserve gastrointestinal motility, and provides excellent postoperative pain relief without motor blockade.

Epidural ropivacaine -- where are the benefits? A prospective, randomized, double-blind trial in patients with retropubic prostatectomy

BACKGROUND

In comparison with bupivacaine, ropivacaine exhibits comparable anaesthetic effects but with less motor impairment and systemic toxicity. However, the analgesic potency may differ. For example, ropivacaine during obstetric epidural analgesia provides an approximately 40% lower analgesic potency than bupivacaine. Equal visual analogue pain scores require significantly higher dosages of ropivacaine, and general statements about a favourable benefit-risk profile relative to that of bupivacaine may therefore have limited clinical impact. We addressed this topic in a male pain model by evaluating the analgesic efficacy of epidural ropivacaine 0.2% vs. bupivacaine 0.125% after retropubic prostatectomy.

METHODS

Forty patients scheduled for retropubic prostatectomy were randomly assigned to two groups (20 patients per group). In a double-blind prospective design, patient-controlled lumbar epidural analgesia was provided by ropivacaine 0.2% in the ropivacaine group and by bupivacaine 0.125% in the bupivacaine group. The primary endpoint was the total amount of local anaesthetic consumption. The secondary endpoints were the numeric rating scale scores for rest and dynamic pain and the degree of motor impairment.

RESULTS

Ropivacaine consumption was 60% higher (mean +/- standard deviation, 1372.5 +/- 108.3 mg) than that of bupivacaine (852 +/- 75.2 mg) (P < 0.001). There were no significant differences in the numeric rating scale scores and motor impairment.

CONCLUSIONS

In male patients, lumbar epidural administration of ropivacaine 0.2% after retropubic prostatectomy does not appear to provide benefits over bupivacaine 0.125%. Moreover, in view of the significantly higher drug requirements, general statements focusing on the favourable therapeutic index of ropivacaine may require critical analysis, at least during epidural administration.

New local anesthetics for pediatric anesthesia

PURPOSE OF REVIEW

To evaluate the relevance of new local anesthetics in pediatric regional anesthesia.

RECENT FINDINGS

Several studies evaluate the pharmacokinetics of new local anesthetics, like ropivacaine and levobupivacaine, and compare their safety and efficacy with the old but widely used bupivacaine.

SUMMARY

The goal of anesthetists using regional anesthesia is to use local anesthestics that are as safe and effective as possible, with a rapid onset and a long duration. Even though adequate dose guidelines are available, several toxic effects are reported with the use of bupivacaine in children due to inadvertent intravenous injection, long-term infusion (> 48 h) or administration in newborn babies and infants with reduced metabolism. Ropivacaine and levobupivacaine are new local anesthetics with a wider safety margin that have similar characteristics: both of them are pure S-(-)-enantiomers whose main pharmacological features are less cardio- and neuro-affinity and -toxicity in comparison with the racemic formulae and R-isomers, and a differential neural blockade with less motor than sensory block. Several clinical studies in children compare ropivacaine and levobupivacaine with bupivacaine.

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

Ropivacaine (Naropin) is the pure S(-)-enantiomer of propivacaine, and is a long-acting amide local anaesthetic agent, eliciting nerve block via reversible inhibition of sodium ion influx in nerve fibres. Ropivacaine is a well tolerated regional anaesthetic effective for surgical anaesthesia as well as the relief of postoperative and labour pain. The efficacy of ropivacaine is similar to that of bupivacaine and levobupivacaine for peripheral nerve blocks and, although it may be slightly less potent than bupivacaine when administered epidurally or intrathecally, equi-effective doses have been established. Clinically adequate doses of ropivacaine appear to be associated with a lower incidence or grade of motor block than bupivacaine. Thus ropivacaine, with its efficacy, lower propensity for motor block and reduced potential for CNS toxicity and cardiotoxicity, appears to be an important option for regional anaesthesia and for the management of postoperative and labour pain.