0.125% Ropivacaine Is Similar to 0.125% Bupivacaine for Labor Analgesia Using Patient-Controlled Epidural Infusion

Comparison of Epidural Analgesia Using 0.2% Bupivacaine and 0.2% Ropivacaine for the Management of Postoperative Pain in Major Orthopedic Surgery

Introduction

Ropivacaine is preferred over racemic bupivacaine for postoperative analgesia as it is less cardiotoxic and has high selectivity for sensory fibers. We aim to compare postoperative epidural analgesia using 0.2% bupivacaine and 0.2% ropivacaine in major lower limb orthopedic surgery.

Materials and Methods

In a prospective, randomized, double-blind study, 100 patients, aged 18-70 years, undergoing elective major lower limb orthopedic surgery under spinal anesthesia, were randomly allocated to receive either 7 ml ropivacaine 0.2% (Group R) or 7 ml bupivacaine 0.2% (Group B) for postoperative analgesia through a lumbar epidural catheter. The onset and duration of epidural analgesia, total epidural dose requirement, mean number of epidural topup, rescue analgesia, incidence of motor blockade, and adverse effects were recorded.

Results

No differences were noted in demographic data and hemodynamic variables in either group. The onset time of epidural analgesia was 10.46 min ± 0.68 (Group B) and 10.52 min ± 0.71 (Group R). The duration of analgesia was 253.10 ± 17.46 min (Group B) and 251.80 ± 15.77 min (Group R). The total analgesic dose requirement was 78.40 mg ± 6.93 in Group B while in Group R, it was 78.96 mg ± 6.79. Epidural topup requirement and the need for rescue analgesia were similar in both the groups. Motor blockade, hypotension, and nausea were noted more in Group B compared to Group R.

Conclusion

In patients undergoing major lower limb orthopedic surgery under subarachnoid block, epidural ropivacaine 0.2% produces effective postoperative analgesia similar to bupivacaine 0.2% with a distinct sensory-motor dissociation resulting in analgesia without motor blockade.

Comparative Efficacy of Minimal Concentration of Racemic Bupivacaine (0.0625%) with Fentanyl and Ropivacaine (0.1%) with Fentanyl for Epidural Labor Analgesia

Background and Aims:

This study aims to compare the minimum effective concentration of local anesthetic (LA) bupivacaine and ropivacaine with highly lipid soluble opioids fentanyl for providing optimal labor epidural analgesia.

Settings and Design:

The objective of this study was to evaluate the efficacy of racemic bupivacaine 0.0625% and 0.1% of ropivacaine both mixed with 2 μg/ml of fentanyl for epidural labor analgesia in parturients with spontaneous labor and normal fetal heart rate tracing.

Methodology:

Sixty parturients requesting for labor analgesia were divided into two groups. Group B (n = 30) received racemic bupivacaine (0.0625%) and fentanyl 2 μg/ml of 10 ml and Group R (n = 30) received ropivacaine (0.1%) and fentanyl 2 μg/ml. In both groups, the drug was given in 5 ml fractionated doses at 5 min interval. Parturients not experiencing analgesia within 15 min of initial bolus were supplemented with additional 5 ml of the same concentration of the solution. Epidural analgesia was maintained by timed top ups at the end of 90 min with the dosage equal to the initial dose of the drug. Duration of labor analgesia, motor block, visual analog scale, maternal hemodynamic parameters, mode of delivery, and maternal satisfaction was assessed.

Statistical Analysis:

Data were analyzed with odds variance, unpaired t-test, and Chi-square tests. P < 0.05 was considered statistically significant.

Results:

In our study, results indicate that both drugs were equally effective clinically. Maternal demographic characteristics were comparable. There were no statistically significant differences in visual analog pain score, highest sensory block, maternal satisfaction, mode of delivery, total dose of LAs during labor and motor block at delivery between the groups.

Conclusions:

In our study, both the drugs produced equivalent analgesia for labor at low concentration when used with highly lipid soluble opioid such as fentanyl.

Double blind comparison of combination of 0.1% ropivacaine and fentanyl to combination of 0.1% bupivacaine and fentanyl for extradural analgesia in labour

BACKGROUND AND AIMS

Ropivacaine is considered as a safe alternative to bupivacaine for labor analgesia. The aim was to compare epidural ropivacaine and bupivacaine in intermittent doses for obstetric analgesia.

MATERIAL AND METHODS

In this prospective, randomized, double-blind study, 60 women in labor were randomly allocated to receive either bupivacaine 0.1% with fentanyl 2 μg/mL (BF), or ropivacaine 0.1% with fentanyl 2 μg/mL (RF). Bromage scale, loss of cold sensation to ether swab in midclavicular line, visual analog scale were used to test for motor block, sensory block and pain, respectively. Hemodynamic parameters, onset of analgesia, dose requirement of drug to produce analgesia, duration of labor, and incidence of side effects were also recorded. Data were expressed as mean ± standard deviation and analyzed using students unpaired t-test, Chi-square and Mann-Whitney U-tests at P < 0.05.

RESULTS

Both drugs were similar with respect to hemodynamic stability, onset of analgesia, quality of analgesia, sensory blockade, neonatal outcome, requirement of drugs, duration of labor, and incidence of side effects. Three parturient in bupivacaine (B-F) group had a motor block of Bromage 1 and were delivered using forceps. None of the parturient in ropivacaine (R-F) group had any motor block, and all had spontaneous vaginal delivery, but this difference was not statistically significant (P = 0.081).

CONCLUSIONS

Bupivacaine and ropivacaine provide equivalent analgesia in low (0.1%) concentration.

Comparison of intravenous morphine, epidural morphine with/without bupivacaine or ropivacaine in postthoracotomy pain management with patient controlled analgesia technique

BACKGROUND AND OBJECTIVES

The aim of this randomized, double-blinded, prospective study was to determine the effectiveness and side effects of intravenous or epidural use of morphine, bupivacaine or ropivacaine on post-thoracotomy pain management.

METHODS

Sixty patients undergoing elective thoracotomy procedure were randomly allocated into 4 groups by the sealed envelope technique. Group IVM, EM, EMB and EMR received patient controlled intravenous morphine, and epidural morphine, morphine-bupivacaine and morphine-ropivacaine, respectively. Perioperative heart rate, blood pressure and oxygen saturation and postoperative pain at rest and during cough, side effects and rescue analgesic requirements were recorded at the 30(th) and 60(th) minutes and the 2(nd), 4(th), 6(th), 12(th), 24(th), 36(th), 48(th), and 72(nd) hour.

RESULTS

Diclofenac sodium requirement during the study was lower in Group EM. Area under VAS-time curve was lower in Group EM compared to Group IVM, but similar to Group EMB and EMR. Pain scores at rest were higher at the 12, 24, 36, and 48(th) hour in Group IVM compared to Group EM. Pain scores at rest were higher at the 30(th) and 60(th) minutes in Group EM and Group IVM compared to Group EMB. Pain scores during cough at the 30(th) minute were higher in Group EM compared to Group EMB. There was no difference between Group IVM and Group EMR.

CONCLUSIONS

Morphine used at the epidural route was found more effective than the intravenous route. While Group EM was more effective in the late period of postoperative, Group EMB was more effective in the early period. We concluded that epidural morphine was the most effective and preferred one.

A comparative study between bupivacaine (S75-R25) and ropivacaine in spinal anesthesia for labor analgesia

BACKGROUND AND OBJECTIVES

Spinal anesthesia is used for relief of pain during labor and it is associated with low indices of complications. Studies with levorotatory enantiomers of local anesthetics demonstrate higher safety due to the lower cardiotoxicity. The objective of this study was to evaluate the latency and duration of analgesia and maternal and fetal repercussions with bupivacaine (S75-R25) and ropivacaine in spinal anesthesia for labor analgesia.

METHODS

A prospective, double-blind, randomized clinical assay was undertaken with 49 labouring parturients with low risk, with indication of vaginal delivery, ages 15 to 35 years, ASA I or II, divided into two groups: GI - 0.25% bupivacaine (S75-R25); GII - 0.20% ropivacaine.

RESULTS

A statistically significant difference was observed between the two groups 30 minutes after the spinal anesthesia, and pain scores were higher in the ropivacaine group. Statistically significant differences were not observed regarding the latency of analgesia, sensorial level of the blockade, volume of local anesthetic, rescue dose, duration of labor and analgesia, frequency of instrument-assisted labor, hemodynamic changes, Apgar scores or umbilical cord blood pH, and incidence of adverse events.

CONCLUSIONS

The use of bupivacaine (S75-R25) and ropivacaine in labor analgesia provided good conditions for spinal anesthesia with small indices of adverse events.

Randomized controlled trial of patient-controlled epidural analgesia after orthopaedic surgery with sufentanil and ropivacaine 0.165% or levobupivacaine 0.125%

BACKGROUND

Ropivacaine, and to a lesser extent also levobupivacaine, is commonly used for postoperative epidural analgesia. Despite ED50 data suggesting a potency difference between these drugs, clinically they can be difficult to distinguish. As a consequence, it is unclear which concentration of each drug to use when comparing them for long-term analgesia.

METHODS

One hundred patients undergoing total hip or knee replacement were selected to participate in a double-blind randomized study comparing ropivacaine 0.165% with levobupivacaine 0.125% to which was added sufentanil 1 microg ml(-1) for postoperative analgesia by the epidural route. Patient-controlled epidural analgesia (PCEA) was offered for 48 h. After the first 24 h, the basal infusion was omitted.

RESULTS

Pain scores both at rest and on mobilization were similar between both groups. The volume of local anaesthetic solution consumed during the first 48 h after surgery was 25% higher in those patients receiving ropivacaine (P=0.02). Patients receiving ropivacaine made a mean (SD) of 38.5 (16) PCEA demands in the first 48 h after surgery compared with 28 (13) in the levobupivacaine group (P=0.04).

CONCLUSIONS

Both local anaesthetics provided effective postoperative analgesia but, even in a 25% weaker concentration, a small volume of levobupivacaine and opiate substance was consumed. These differences may be explained by a potency difference or by the duration of action of levobupivacaine.

Neuraxial drug administration: a review of treatment options for anaesthesia and analgesia

Neuraxial drug administration describes techniques that deliver drugs in close proximity to the spinal cord, i.e. intrathecally into the CSF or epidurally into the fatty tissues surrounding the dura, by injection or infusion. This approach was initially developed in the form of spinal anaesthesia over 100 years ago. Since then, neuraxial drug administration has evolved and now includes a wide range of techniques to administer a large number of different drugs to provide anaesthesia, but also analgesia and treatment of spasticity in a variety of acute and chronic settings. This review concentrates on the pharmacological agents used and the clinical basis behind currently utilised approaches to neuraxial drug administration. With regard to local anaesthetics, the main focus is on the development of the enantiomer-specific compounds ropivacaine and levobupivacaine, which provide similar efficacy to bupivacaine with a reduced risk of severe cardiotoxicity. Opioids are the other group of drugs widely used neuraxially, in particular to provide analgesia alone or more commonly in combination with other agents. The physicochemical properties of the various opioids explain the main differences in efficacy and safety between these drugs when used intrathecally, of which morphine, fentanyl and sufentanil are most commonly used. Another group of drugs including clonidine, dexmedetomidine and epinephrine (adrenaline) provide neuraxial analgesia via alpha-adrenergic receptors and are used mainly as adjuvants to local anaesthetics and opioids. Furthermore, intrathecal baclofen is in routine clinical use to treat spasticity in a number of neurological conditions. Beside these established approaches, a wide range of other drugs have been assessed for neuraxial administration to provide analgesia; however, most are in various early stages of investigation and are not used routinely. These drugs include neostigmine, ketamine, midazolam and adenosine, and the conotoxin ziconotide. The latter is possibly the most unusual compound here; it has recently gained registration for intrathecal use in specific chronic pain conditions.

Comparison of maternal and neonatal outcomes with epidural bupivacaine plus fentanyl and ropivacaine plus fentanyl for labor analgesia

BACKGROUND

Several studies have been performed to find a safe method of labor analgesia with minimal side effects and toxicity in mother and fetus. We aimed to compare the efficacy and side effects of epidural bupivacaine plus fentanyl and ropivacaine plus fentanyl at low concentrations.

METHOD

Forty ASA I-II parturients' were included in this prospective, double-blind, trial and randomized to receive either bupivacaine or ropivacaine for labor analgesia. Analgesia was initiated with 8 mL of 0.125% solution plus fentanyl 50 microg and maintained with a continuous infusion of 0.0625% solution with fentanyl 2 microg/mL.

RESULTS

There were no differences in pain scores, total dose of local anesthetics used, sensory or motor blockade, labor duration, mode of delivery, side effects, patient satisfaction, or neonatal outcome between the two local anesthetics at these dosages, but at the end of the second stage and delivery, adequate analgesia quality could not be ensured.

CONCLUSION

We found no major advantage of continuous epidural infusion of ropivacaine 0.0625% plus fentanyl 2 microg/mL over bupivacaine 0.0625% plus fentanyl 2 microg/mL for labor analgesia. We believe that different methods or dosages may be tried in order to improve comfort at the second stage of labor and the delivery.

Patient-controlled epidural analgesia during labor using ropivacaine and fentanyl provides better maternal satisfaction with less local anesthetic requirement

PURPOSE

To test the hypothesis that patient-controlled epidural analgesia (PCEA) using ropivacaine and fentanyl provides better maternal satisfaction and less anesthetic requirement than conventional continuous epidural infusion (CEI) during labor, we studied 58 uncomplicated parturients (singleton, vertex presentation).

METHODS

After establishing effective epidural analgesia with 11 ml of 0.2% ropivacaine, all parturients were randomly divided into one of two groups: the PCEA group (n = 29) or the CEI group (n = 29). In the PCEA group, the pump was initiated to deliver a basal infusion at 6 ml x h(-1) and a demand dose of 5 ml; the lockout interval was 10 min, and there was a 31 ml x h(-1) limit. The drugs used were 0.1% ropivacaine + fentanyl 2 microg x ml(-1). In the CEI group, epidural analgesia was maintained with the same solution as the PCEA group at a constant rate of 10 ml x h(-1). If parturients requested additional analgesia in the CEI group, we added 8 ml of epidural 0.2% ropivacaine without fentanyl.

RESULTS

Parturients' demographic data, such as duration of labor, mode of delivery, Apgar score, and umbilical arterial pH did not differ between the two groups. However, the hourly requirement of ropivacaine was significantly less in the PCEA group than in the CEI group (9.3 +/- 2.5 vs. 17.6 +/- 7.6 mg x h(-1); P < 0.05). Parturients' satisfaction assessed by the Visual Analogue Scale tended to be higher in the PCEA group than in the CEI group. Side effects such as nausea, hypotension, and itching were similar for the two groups.

CONCLUSION

We found that PCEA was an effective means of providing optimal analgesia, with better satisfaction during labor and less local anesthetic requirement.

A randomized comparison of a five-minute versus fifteen-minute lockout interval for PCEA during labor

BACKGROUND

The best combination of bolus size and lockout interval for patient-controlled epidural analgesia (PCEA) is not known. This study compared a 5-min with a 15-min lockout interval.

METHODS

Parturients were randomly assigned to receive PCEA with either a 5-min or a 15-min interval. All had a 15-mL loading dose, continuous background infusion 6 mL/h of 0.125% bupivacaine plus fentanyl 2 mug/mL, PCEA bolus volume 5 mL, maximum hourly dose 26 mL. Visual analogue scores for pain, nausea and pruritus, sensory levels to ice, sacral analgesia, motor power, blood pressure and fetal heart rate were assessed pre-epidural and regularly thereafter until delivery. The numbers of boluses and attempts and patient satisfaction were recorded.

RESULTS

29 patients were assigned to the 5-min group and 31 to the 15-min group, but the 15-min group contained twice as many nulliparous women. Side-effect and complication rates did not differ between groups. VAS pain scores were reduced from a median of 79 in the 15-min group and 82 in the 5-min group to a median of zero 30 min after epidural insertion. Bolus/attempt ratio was 0.88 in the 5-min vs. 0.70 in the 15-min group. The numbers of requests for physician intervention were similar. No differences in pain scores, side-effects, drug use or patient satisfaction were demonstrated.

CONCLUSION

The 5-min lockout interval appears the more efficient and has been used safely in our practice for 15,000 parturients, although a larger study is required to confirm the relative efficacy, efficiency and safety of this regimen.

0.2% Ropivacaine and levobupivacaine provide equally effective epidural labour analgesia

PURPOSE

To compare the duration of epidural analgesia induced by levobupivacaine and ropivacaine at clinically relevant doses.

METHODS

Forty healthy nulliparous parturients with cervical dilatation of 3 to 5 cm and at least one contraction every two or three minutes were recruited. Patients were randomly assigned to receive either 10 mL of 0.2% ropivacaine or 10 mL of 0.2% levobupivacaine. Preblock visual analogue scale (VAS) score (0-100) and VAS score after five, ten, 15, 20, 25 and 30 min from time(0) and VAS at time of request for additional analgesia (time(end)) were recorded. During the first 30 min after the completion of epidural injection, the systolic blood pressure, highest sensory level to cold and the maximum degree of motor block based on a 0 to 3 modified Bromage scale were collected every five minutes. The duration of analgesia was defined as the time from time(0) to time(end).

RESULTS

There was no difference in the duration of analgesia between the two groups; similarly, there was no significant difference found in the area under the curve (AUC) time(15)-time(0) and AUC time(30)-time(0) for VAS. The highest sensory block to cold and the degree of motor block were also indistinguishable between the two groups. No difference in the serial systolic blood pressures was found.

CONCLUSION

Ten millilitres of either 0.2% ropivacaine or levobupivacaine can be used to induce epidural labour analgesia effectively without a difference in the duration of pain relief.

Anaesthetic Agents for Advanced Regional Anaesthesia

Interest in the use of regional anaesthesia, particularly peripheral nerve blocks (PNBs) and continuous PNBs, has increased in recent years. Accompanying this resurgence in interest has been the development of new local anaesthetics and additives designed to enhance block duration and quality. This manuscript provides a literature-based review on accepted uses of local anaesthetics and adjuncts for a variety of regional anaesthesia techniques. A brief review of local anaesthetic pharmacodynamics describes the action of these drugs in preventing nerve depolarisation, thus blocking nerve impulses. Toxic adverse effects of local anaesthetics, specifically CNS and cardiac manifestations of excessive local anaesthetic blood concentrations and the direct neurotoxic properties of local anaesthetics, are discussed generally and specifically for many commonly used local anaesthetics. Clinically useful ester and amide local anaesthetics are evaluated individually in terms of their physical properties and toxic potential. How these properties impact on the clinical uses of each local anaesthetic is explored. Particular emphasis is placed on the long-acting local anaesthetic toxic potential of racemic bupivacaine compared with levobupivacaine and ropivacaine, which are both levorotatory stereoisomers. Guidelines for using ropivacaine and mepivacaine, based on the authors' experience using advanced regional anaesthesia in a busy practice, is provided. Finally, epinephrine (adrenaline), clonidine and other local anaesthetic additives and their rationale for use is covered along with other future possibilities.

Patient-controlled epidural analgesia for labor pain: effect on labor, delivery and neonatal outcome of 0.125% bupivacaine vs 0.2% ropivacaine

The objective was to evaluate the influence of patient-controlled epidural analgesia (PCEA) using low doses of bupivacaine vs. ropivacaine, on labor pain, motor blockade, progression of labor, delivery and neonatal outcome. This randomized double blind study included 565 parturients. All received a 5-mL/h infusion and PCEA (5-mL boluses with a 20-min lockout, maximum volume 20 mL/h) of either 0.125% bupivacaine (n = 313: 165 nulliparous, 148 parous) or 0.2% ropivacaine (n = 252: 113 nulliparous, 139 parous). Pain score, lower limb motor block, sensory levels, local analgesic doses required, hemodynamic parameters, side effects and complications were assessed. Obstetric variables included cervical dilation at epidural insertion, incidence of ruptured membranes and their duration, use of oxytocin, fetal heart rate changes, duration of labor, mode and outcome of delivery, and use of invasive and non-invasive fetal monitoring. Neonatal characteristics included birth weight, Apgar scores, umbilical artery pH, serum bilirubin, hypoglycemia, need for assisted ventilation, sepsis or sepsis study, feeding difficulties and respiratory distress syndrome. Ropivacaine 0.2% was equianalgesic with 0.125% bupivacaine, but produced less motor block (P < 0.0001). There were no significant differences, however, in duration of labor, delivery type or neonatal outcome.

Epidural Infusions of Ropivacaine and Bupivacaine for Labor Analgesia: A Randomized, Double-Blind Study of Obstetric Outcome

Studies have shown better obstetric outcome when ropivacaine 0.25% was used for labor epidural analgesia compared with bupivacaine 0.25%, but it is controversial whether there is any difference at smaller concentrations. In a prospective, double-blind trial, we randomized 350 ASA physical status I and II parturients with term cephalic singleton pregnancies to receive epidural labor analgesia using ropivacaine or bupivacaine. Analgesia was initiated with a 0.25% solution and maintained with a continuous infusion of a 0.1% solution with fentanyl 0.0002%. Supplementary boluses of 0.25% solution were given when requested. Labor was managed according to institutional standard labor ward protocols. Among patients who delivered vaginally, the duration of the first stage of labor was shorter in the ropivacaine group (median, 520 min; interquartile range, 377-745 min) compared with the bupivacaine group (645 min; interquartile range, 460-820 min; P = 0.009), but there was no difference in any other obstetric or neonatal outcomes. The mode of delivery was similar between groups, with operative (instrumental vaginal and cesarean) delivery rates of 61.8% (95% confidence interval, 54.4%-68.8%) in the ropivacaine group and 58.4% (95% confidence interval, 50.9%-65.5%) in the bupivacaine group (P = 0.72).

IMPLICATIONS

In a randomized-controlled study, we found no major outcome advantage of continuous epidural infusion of ropivacaine 0.1% with fentanyl 0.0002% over bupivacaine 0.1% with fentanyl 0.0002% for labor analgesia. Although ropivacaine was associated with a shorter first stage of labor, the relative difference is probably of limited clinical importance, and there was no difference in the mode of delivery.

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

Ropivacaine is a long-acting amide-type local anaesthetic, released for clinical use in 1996. In comparison with bupivacaine, ropivacaine is equally effective for subcutaneous infiltration, epidural and peripheral nerve block for surgery, obstetric procedures and postoperative analgesia. Nevertheless, ropivacaine differs from bupivacaine in several aspects: firstly, it is marketed as a pure S(-)-enantiomer and not as a racemate, and secondly, its lipid solubility is markedly lower. These features have been suggested to significantly improve the safety profile of ropivacaine, and indeed, numerous studies have shown that ropivacaine has less cardiovascular and CNS toxicity than racemic bupivacaine in healthy volunteers. Extensive clinical data have demonstrated that epidural 0.2% ropivacaine is nearly identical to 0.2% bupivacaine with regard to onset, quality and duration of sensory blockade for initiation and maintenance of labour analgesia. Ropivacaine also provides effective pain relief after abdominal or orthopaedic surgery, especially when given in conjunction with opioids or other adjuvants. Nevertheless, epidurally administered ropivacaine causes significantly less motor blockade at low concentrations. Whether the greater degree of blockade of nerve fibres involved in pain transmission (Adelta- and C-fibres) than of those controlling motor function (Aalpha- and Abeta-fibres) is due to a lower relative potency compared with bupivacaine or whether other physicochemical properties or stereoselectivity are involved, is still a matter of intense debate. Recommended epidural doses for postoperative or labour pain are 20-40 mg as bolus with 20-30 mg as top-up dose, with an interval of >or=30 minutes. Alternatively, 0.2% ropivacaine can be given as continuous epidural infusion at a rate of 6-14 mL/h (lumbar route) or 4-10 mL/h (thoracic route). Preoperative or postoperative subcutaneous wound infiltration, during cholecystectomy or inguinal hernia repair, with ropivacaine 100-175 mg has been shown to be more effective than placebo and as effective as bupivacaine in reducing wound pain, whereby the vasoconstrictive potency of ropivacaine may be involved. Similar results were found in peripheral blockades on upper and lower limbs. Ropivacaine shows an identical efficacy and potency to that of bupivacaine, with similar analgesic duration over hours using single shot or continuous catheter techniques. In summary, ropivacaine, a newer long-acting local anaesthetic, has an efficacy generally similar to that of the same dose of bupivacaine with regard to postoperative pain relief, but causes less motor blockade and stronger vasoconstriction at low concentrations. Despite a significantly better safety profile of the pure S(-)-isomer of ropivacaine, the increased cost of ropivacaine may presently limit its clinical utility in postoperative pain therapy.

A Comparison of Duration of Analgesia of Intrathecal 2.5 mg of Bupivacaine, Ropivacaine, and Levobupivacaine in Combined Spinal Epidural Analgesia for Patients in Labor

We assessed the duration of labor analgesia rendered by intrathecal (IT) local anesthetics as the sole drugs. In this randomized, controlled, and double-blinded study, labor analgesia was induced using combined spinal-epidural technique in 60 ASA physical status I nulliparous parturients with IT bupivacaine 2.5 mg (group B), ropivacaine 2.5 mg (group R), or levobupivacaine 2.5 mg (group L). Pain scores (0-100 visual analog scale) and blood pressure were recorded pre-block and for the first 30 min post-block. The degree of motor block and the highest sensory block were also monitored. The duration of analgesia (our primary outcome) was the longest in group B but was similar between groups R and L (mean +/- SE, 76.3 +/- 5.9 min versus 52.6 +/- 4.0 min and 51.5 +/- 3.4 min, respectively, P < 0.05). Group B had the most frequent incidence of lower limb motor block but there was no difference between groups R and L (5 of 20 parturients versus 2 of 20 and 0 of 20, respectively, P < 0.05). The profile of the other side effects was indistinguishable between the groups. With the current regimen, IT bupivacaine produced the longest duration of labor analgesia.

IMPLICATIONS

Intrathecal 2.5 mg bupivacaine significantly prolongs the duration of analgesia in laboring patients compared with ropivacaine or levobupivacaine. This suggests that, at clinically relevant doses, bupivacaine may have greater potency.

Epidural levobupivacaine, ropivacaine and bupivacaine in combination with sufentanil in early labour: a randomized trial

BACKGROUND AND OBJECTIVE

To evaluate the efficacy, delay and duration of analgesia of three equianalgesic epidural doses of levobupivacaine, ropivacaine and bupivacaine during the first stage of labour.

METHODS

One hundred and twenty-nine healthy primigravida in spontaneous labour who requested epidural analgesia were enrolled in a randomized observer-blinded study. Parturients were allocated to receive epidural levobupivacaine 0.0625%, ropivacaine 0.1% or bupivacaine 0.06259%. Sufentanil 10 microg was added to all solutions; the total volume of epidural solution was 20 mL. Pain was measured using a 100 mm visual analogue pain scale immediately before the epidural block, and at 5, 10, 15, 20 and 30 min thereafter. Motor block was evaluated using a modified Bromage scoring system. The adequacy of motor function for ambulation was also evaluated. Delay of analgesia was the time interval between the injection of the solution and the first painless contraction. Duration of analgesia was the time from the first painless contraction to the parturients' requests for further analgesia.

RESULTS

Twelve parturients failed to complete the study. Eleven parturients had inadequate analgesia (four in Group Levobupivacaine, four in Group Ropivacaine and three in Group Bupivacaine; P > 0.05). Data was analysed from 34 parturients in Group Levobupivacaine, from 37 in Group Ropivacaine and from 35 in Group Bupivacaine. There were no differences in the delay of analgesia or in the number of parturients who were able to walk unaided. Levobupivacaine and ropivacaine produced more prolonged analgesia than bupivacaine (114 and 119 min, respectively, versus 89 min; P < 0.01).

CONCLUSIONS

During early labour, equipotent low concentrations of levobupivacaine, ropivacaine and bupivacaine, all with the addition of sufentanil 10 microg, produced similar pain relief and motor block, but levobupivacaine and ropivacaine produced a longer lasting analgesia. About 10% of parturients had inadequate analgesia with a single bolus of the tested solutions.

Epidural ropivacaine versus bupivacaine for labor: a meta-analysis

Numerous studies have compared ropivacaine with bupivacaine for labor analgesia. Early studies suggested that obstetrical and some neonatal outcomes were improved when ropivacaine was used. We systematically reviewed and combined the results of the randomized controlled trials that compared ropivacaine with bupivacaine to determine whether or not there was a difference in these outcomes. We searched electronic databases and journals for randomized controlled trials composed of laboring parturients. The primary outcome was the incidence of spontaneous vaginal delivery. We examined other obstetrical, neonatal, and analgesic outcomes. Where possible, these were combined by using metaanalytic techniques and random effects modeling. We found 23 randomized controlled trials composed of 1043 patients receiving ropivacaine and 1031 receiving bupivacaine. There was no significant difference in the incidence of spontaneous vaginal delivery (odds ratio, 1.17; 95% confidence interval, 0.98-1.41; P = 0.12) or any of the other outcomes. Although more studies reported a more frequent incidence of motor block with bupivacaine, the results were heterogeneous and therefore not combined. We conclude that there is no statistically significant difference between the two drugs in the incidence of any obstetrical or neonatal outcome. Further studies using clinically appropriate concentrations of drugs are required to determine whether or not there is a difference in the incidence of motor block.

IMPLICATIONS

This metaanalysis of 23 randomized controlled trials shows that both ropivacaine and bupivacaine provide excellent labor analgesia. There was no significant difference between the two drugs in mode of delivery, maternal satisfaction, or neonatal outcomes. Whether or not there is a difference in motor block at clinically relevant doses is unresolved.

New local anesthetics. Are they worth the cost?

Epidural analgesia that uses dilute concentrations of bupivacaine with fentanyl or sufentanil provides excellent analgesia, good sensory-motor discrimination, and minimal toxicity and is inexpensive. The new local anesthetic agents, ropivacaine and levobupivacaine, offer potential improvements in the risk of toxicity when administered in large doses but probably no important clinical difference when used in dilute concentrations for labor analgesia. After accounting for the potency difference, ropivacaine offers little or no motor-sparing advantage over bupivacaine. Currently, epidural anesthesia with concentrated bupivacaine is rarely used for cesarean section, so there is little indication for the newer anesthetic agents in this setting either. The authors believe that large difference in cost cannot be justified on the basis of currently available data.

A comparison of 0.1% and 0.2% ropivacaine and bupivacaine combined with morphine for postoperative patient-controlled epidural analgesia after major abdominal surgery

Ropivacaine (ROPI), which is less toxic and produces less motor block than bupivacaine (BUPI), seems attractive for epidural analgesia. Few data are available concerning dose requirements of epidural ROPI when combined with morphine. In this study, we compared the dose requirements and side effects of ROPI and BUPI combined with small-dose morphine after major abdominal surgery. Postoperatively, 60 patients were randomly allocated (double-blinded manner) to four groups: patient-controlled epidural analgesia with the same settings using 0.1% or 0.2% solution of ROPI or BUPI combined with an epidural infusion of 0.1 mg/h of morphine. Pain scores, side effects, motor block, and local anesthetic consumption were measured for 60 h. Pain scores and the incidence of side effects did not differ among the groups. Consumption of ROPI and BUPI were similar in both 0.1% groups. Doubling the concentration significantly reduced the consumption (milliliters) of BUPI (P < 0.05) but not of ROPI. Consequently, using ROPI 0.2% significantly increased the dose administered as compared with ROPI 0.1% (ROPI 0.1% = 314 +/- 151 mg and ROPI 0.2% = 573 +/- 304 mg at Hour 48; P < 0.05). Patient-controlled epidural analgesia with the 0.1% or 0.2% solution of ROPI or BUPI combined with epidural morphine resulted in comparable analgesia. As compared with ROPI 0.1%, the use of ROPI 0.2% increased consumption of local anesthetic without improving analgesia.

IMPLICATIONS

Small-dose (0.1%) ropivacaine and bupivacaine have similar potency and result in comparable analgesia and incidence of side effects.

Membrane effects of ropivacaine compared with those of bupivacaine and mepivacaine

We compared the effects of ropivacaine, bupivacaine and mepivacaine on membrane lipids in an attempt to determine the anaesthetic mechanism of ropivacaine with structure-dependent potency. The membrane effects were determined by measuring anaesthetic-induced changes in the phase transition temperature and the fluorescence polarization of liposomal membranes prepared with cholesterol and phosphatidylcholine. Bupivacaine, ropivacaine and mepivacaine depressed the membrane lipid phase transition and decreased the polarization of liposomal membranes at 0.0625-1.0 mg/mL, indicating that these anaesthetics fluidize membranes at concentrations lower than those in clinical use. Ropivacaine and bupivacaine were effective in fluidizing the membrane core rather than the membrane surface, whereas mepivacaine was a membrane fluidizer acting equally on both regions. In the comparison of membrane fluidization at an equimolar concentration (3.0 mmol/L), ropivacaine was found to be less potent than bupivacaine and more potent than mepivacaine. This membrane-fluidizing potency was also consistent with the hydrophobic properties of these substances evaluated by reversed-phase chromatography. Structure-dependent membrane fluidization associating with hydrophobicity appears to underlie the local anaesthetic effect of ropivacaine as well as those of bupivacaine and mepivacaine.

Epidural analgesia with 0.15% ropivacaine plus sufentanil 0.5 microgram ml-1 versus 0.10% bupivacaine plus sufentanil 0.5 microgram ml-1: a double-blind comparison during labour

BACKGROUND

Ropivacaine has been claimed to produce less motor block than bupivacaine during epidural analgesia. However, this advantage has not been clearly confirmed in obstetric studies using low analgesic concentrations in a ratio close to that suggested to be equianalgesic.

METHODS

This double-blind, randomized, prospective study was performed in 140 parturients who requested epidural analgesia. After a lumbar epidural catheter had been placed, patients received either 0.10% bupivacaine plus sufentanil 0.5 microgram ml-1 or 0.15% ropivacaine plus sufentanil 0.5 microgram ml-1 followed by a continuous infusion. Additional boluses were used for inadequate levels of analgesia. Visual analogue pain scores, motor block, level of sensory block, supplementary boluses and main characteristics of labour were recorded.

RESULTS

No differences were observed between the two groups for pain scores, total volume of anaesthetic solution used [59 (23) and 57 (24) ml in the bupivacaine and ropivacaine groups respectively], duration of labour, mode of delivery, side-effects or satisfaction score. The incidence of motor block was not statistically different between the groups (54 and 69% in the bupivacaine and ropivacaine groups respectively, P = 0.07). However, when motor block occurred, survival analysis showed that it occurred sooner in the course of labour with ropivacaine compared with bupivacaine (log rank test, P = 0.012).

CONCLUSION

Combined with sufentanil 0.5 microgram ml-1, 0.10% bupivacaine and 0.15% ropivacaine produce effective and equivalent analgesia during labour, with similar incidences of motor block.

Combined spinal-epidural analgesia for labor: breakthrough or unjustified invasion?

The combined spina-epidural (CSE) technique has become increasingly popular for labor analgesia. The advantages of the CSE include more rapid onset of analgesia, reduced total drug dosage, minimal or no motor blockade, and increased patient satisfaction. CSE has also been associated with more rapid cervical dilation when compared to epidural analgesia in nulliparous women in early labor. Despite these potential advantages, the indications for CSE versus epidural analgesia remain unclear and controversial. This review should allow better understanding of the benefits and risks of this technique, and bearing in mind that no ultimate neuraxial analgesic exists, it would seem that CSE should be considered a major breakthrough in the management of labor analgesia.

Ropivacaine 2 mg/mL vs. bupivacaine 1.25 mg/mL with sufentanil using patient-controlled epidural analgesia in labour

BACKGROUND

In recent studies, minimum local analgesic concentrations have been defined as 0.93 mg/mL for bupivacaine and 1.56 mg/mL for ropivacaine for epidural analgesia for the first stage of labour, resulting in an analgesic potency ratio of 1 : 0.6. In the current study we compared ropivacaine and bupivacaine in a PCEA system (combined with sufentanil) taking this potency ratio into account but administering drug doses providing sufficient analgesia for all stages of labour.

METHODS

In a prospective, double-blinded study 114 parturients were randomised to receive either ropivacaine 2 mg/mL with sufentanil 0.75 microg/mL or bupivacaine 1.25 mg/with sufentanil 0.75 microg/mL. After epidural catheter placement, PCEA was available with boluses of 4 mL, a lock-out time of 20 min and no basal infusion rate. We evaluated pain intensity during contractions, sensory and motor function, duration of labour, mode of delivery and neonatal outcome. Consumption of local anaesthetic and opioid drugs and PCEA system variables were recorded.

RESULTS

Mean total consumption as well as mean hourly drug consumption was significantly increased in the ropivacaine-sufentanil group. No differences in analgesic quality, sensory or motor blocking potencies or neonatal outcome variables between groups were detected. Frequency of instrumental deliveries was significantly increased in the ropivacaine-sufentanil group.

CONCLUSIONS

The results support the findings of previously published studies postulating ropivacaine to be 40-50% less potent for labour epidural analgesia compared to bupivacaine. However, we observed an increased frequency of instrumental deliveries with ropivacaine. To evaluate the clinical relevance of these findings, further investigations are warranted.

Ropivacaine 0.075% and bupivacaine 0.075% with fentanyl 2 microg/mL are equivalent for labor epidural analgesia

Fifty percent effective dose estimates for ropivacaine and bupivacaine suggest that ropivacaine is 40% less potent than bupivacaine to initiate labor analgesia. At clinically used concentrations, however, the drugs seem indistinguishable for initiating and maintaining labor analgesia. We designed this study to evaluate a concentration near the reported 50% effective dose values for ropivacaine and bupivacaine in an attempt to detect differences between the drugs during routine clinical use. Fifty-nine nulliparous women in labor were randomized to receive 0.075% ropivacaine or bupivacaine, each with fentanyl 2 microg/mL. After epidural placement and the administration of a lidocaine/epinephrine test dose, 20 mL of study solution was administered and a patient-controlled epidural infusion was initiated with the following settings: 6 mL/h basal rate, 5 mL bolus, 10 min lockout, and 30 mL/h limit. Breakthrough pain was treated with 10-mL boluses of study solution. By using a study design to detect a 40% difference in hourly drug use between groups, we found no statistically significant differences in the amount of local anesthetic used, verbal pain scores, sensory levels, motor blockade, labor duration, mode of delivery, side effects, or patient satisfaction. We conclude that 0.075% ropivacaine and bupivacaine, with fentanyl, are equally effective for labor analgesia using the patient-controlled epidural analgesia technique.

IMPLICATIONS

At small concentrations, ropivacaine and bupivacaine when combined with fentanyl are equally effective for labor analgesia. Patients self-administered similar volumes of 0.075% ropivacaine or bupivacaine solutions containing fentanyl (2 microg/mL) suggesting that at this concentration, and with the addition of fentanyl, ropivacaine and bupivacaine can be used interchangeably.

Parturient-controlled epidural analgesia during labour: bupivacaine vs. ropivacaine

In this randomised, controlled study, we compared the hourly dose requirement of ropivacaine 0.125% (group R, n = 16) with bupivacaine 0.125% (group B, n = 16) provided by demand-only (bolus 5 ml, lockout 10 min) parturient-controlled epidural analgesia during labour. The hourly dose requirement was comparable although group R had a lower successful to total demands ratio (p < 0.05). We also found that both groups were clinically indistinguishable in terms of pain relief and side-effects. No difference in maternal or fetal outcome was detected. We conclude that, at a concentration of 0.125%, ropivacaine and bupivacaine were equally effective when self-administered using this patient-controlled regimen.

A comparison of five solutions of local anaesthetics and/or sufentanil for continuous, postoperative epidural analgesia after major urological surgery

BACKGROUND AND OBJECTIVE

The aim of the present study was to compare and assess the quality of analgesia, the safety and the side-effects after the use of a continuous, thoracic epidural infusion of sufentanil (5 microg h(-1)), 0.25% bupivacaine (10 mL h(-1)), 0.2% ropivacaine (10 mL h(-1)) alone or in combination in patients who had undergone major urological surgery. This prospective, randomized, double-blinded study investigated the efficacy of thoracic epidural infusions after major urological surgery.

METHODS

Patients received a 72-h continuous infusion (10 mL h(-1)) of 0.25% bupivacaine (B), 0.2% ropivacaine (R), 0.25% bupivacaine with 0.5 microg mL(-1) sufentanil (BS), 0.2% ropivacaine with 0.5 microg mL(-1) sufentanil (RS) or 0.5 microg mL(-1) sufentanil only (S). The analysis included 109 patients.

RESULTS

The mean visual analogue scale (VAS) scores for pain were highest in the groups R and S (P < 0.001). The PaCO2 values were significantly higher in the groups RS and S (P = 0.003). Motor block occurred more frequently in the groups B and BS than in the other groups (P < 0.001). Sedation, nausea and pruritus were more common in the groups that received sufentanil.

CONCLUSIONS

A continuous, epidural infusion with these drugs was safe and effective in our patients. The combination of 0.2% ropivacaine plus sufentanil appeared preferable because of the low incidence of motor block.