A prospective, randomized, double-blind comparison of epidural levobupivacaine 0.5% with epidural ropivacaine 0.75% for lower limb procedures

Is a Block of the Femoral and Sciatic Nerves an Alternative to Epidural Analgesia in Sheep Undergoing Orthopaedic Hind Limb Surgery? A Prospective, Randomized, Double Blinded Experimental Trial

Peripheral nerve blocks are commonly used in human and veterinary medicine. The aim of the study was to compare the analgesic efficacy of a combined block of the femoral and sciatic nerves with an epidural injection of ropivacaine in experimental sheep undergoing orthopaedic hind limb surgery. Twenty-five sheep were assigned to two groups (peripheral nerve block; sciatic and femoral nerves (P); epidural analgesia (E)). In group P 10 mL ropivacaine 0.5% was injected around the sciatic and the femoral nerves under sonographic guidance and 10 mL NaCl 0.9% into the epidural space while in group E 10 mL ropivacaine 0.5% was injected into the epidural space and 10 mL NaCl 0.9% to the sciatic and the femoral nerves. During surgery, heart rate, respiratory rate and mean blood pressure were used as indicators of nociception. In the postoperative phase, nociception was evaluated every hour by use of a purposefully adapted pain score until the animal showed painful sensation at the surgical site. The mean duration of analgesia at the surgical wound was 6 h in group P and 8 h in group E. Mean time to standing was 4 h in group P and 7 h in group E. In conclusion time to standing was significantly shorter in group P while the duration of nociception was comparable in both groups. The peripheral nerve block can be used as an alternative to epidural analgesia in experimental sheep.

Evaluation of the effects of ketamine on spinal anesthesia with levobupivacaine or ropivacaine

Spinal anesthesia or regional anesthesia is a potent anesthetic procedure. Additional modalities have been sought to increase the duration of block in spinal anesthesia. Ketamine is an N-methyl-D-aspartate (NMDA) receptor blocker that has an anesthetic effect when injected intrathecally and has a synergic effect with bupivacaine. Ketamine also has potent analgesic properties. The present study investigated the effect of intrathecally administered ketamine on spinal anesthesia with levobupivacaine or ropivacaine. Sprague-Dawley rats at post-natal day 21 were exposed to spinal anesthesia with 0.5% levobupivacaine or 0.5% ropivacaine. Separate groups of rats were treated with intrathecal ketamine at a 5 or 10 mg/kg bodyweight dose along with ropivacaine or levobupivacaine. The thermal and mechanical withdrawal latencies of the animals were determined using hot plate and von Frey filaments, respectively. A rotarod apparatus was employed to assess the capacity of the rats to rotate the spindle at 24 h following anesthesia. The gait of the rat pups was also assessed. Intrathecal administration of ketamine resulted in dense blocks and extended the duration of spinal blocks as evidenced by thermal latencies and responses to von Frey filaments. The latency to fall was shorter in rats exposed to ketamine along with ropivacaine or levobupivacaine spinal anesthesia. The gait parameters were also more disturbed upon ketamine administration. In conclusion, ketamine administration with ropivacaine or levobupivacaine increased the intensity and duration of spinal blockade, thereby increasing the anesthetic effects.

Epidural anesthesia for pilonidal sinus surgery: ropivacaine versus levobupivacaine

Background

Epidural anesthesia is one of the best options for lower abdominal and lower limb surgery. However, there have been insufficient reports regarding the use of epidural anesthesia for pilonidal sinus surgery. The present study was performed to compare the clinical profiles of epidural block performed with 0.75% levobupivacaine and 0.75% ropivacaine in this procedure.

Methods

Thirty patients undergoing pilonidal sinus surgery were randomly allocated into two groups: one group received levobupivacaine and the other received ropivacaine at 0.75% in a volume of 10 ml. Arterial blood pressure, heart rate, oxygen saturation, the onset time of analgesia and duration of block, highest sensory block level, perioperative and postoperative side effects, and patients' and surgeons' satisfaction were recorded.

Results

Hemodynamic stability was maintained in both groups throughout surgery. The onset time of analgesia (the time from epidural injection of local anesthetic to reach L₂ sensorial block) was 6.26 ± 3.49 min in the levobupivacaine group and 4.06 ± 1.75 min in the ropivacaine group (P = 0.116). The duration of sensorial block (time for regression of sensory block to L₂) was 297.73 ± 70.94 min in group L and 332.40 ± 102.22 min in group R (P = 0.110). Motor block was not seen in any of the patients in the study groups. Patients' and surgeons' satisfaction with the anesthetic technique were mostly excellent in both groups.

Conclusions

In patients undergoing pilonidal sinus surgery, both levobupivacaine and ropivacaine produce rapid and excellent epidural block without leading to motor block or significant side effects. Although not statistically significant, the onset time of anesthesia was shorter and the duration of effect was longer with ropivacaine than with levobupivacaine in this study.

Clinical profile of levobupivacaine in regional anesthesia: A systematic review

The quest for searching newer and safer anesthetic agents has always been one of the primary needs in anesthesiology practice. Levobupivacaine, the pure S (−)-enantiomer of bupivacaine, has strongly emerged as a safer alternative for regional anesthesia than its racemic sibling, bupivacaine. Levobupivacaine has been found to be equally efficacious as bupivacaine, but with a superior pharmacokinetic profile. Clinically, levobupivacaine has been observed to be well-tolerated in regional anesthesia techniques both after bolus administration and continuous post-operative infusion. The incidence of adverse drug reactions (ADRs) is rare when it is administered correctly. Most ADRs are related to faulty administration technique (resulting in systemic exposure) or pharmacological effects of anesthesia; however, allergic reactions can also occur rarely. The available literary evidence in anesthesia practice indicates that levobupivacaine and bupivacaine produce comparable surgical sensory block, similar adverse side effects and provision of similar labor analgesia with good comparable maternal and fetal outcome. The present review aims to discuss the pharmacokinetic and pharmacological essentials of the safer profile of levobupivacaine as well as to discuss the scope and indications of levobupivacaine based on current clinical evidence.

Hemiarthroplasty in high risk elderly patient under epidural anesthesia with 0.75% ropivacaine-fentanyl versus 0.5% bupivacaine-fentanyl: Clinical trial

Background:

Anesthetic management of elderly patients is a challenge as aging makes them more susceptible to hemodynamic fluctuations during regional anesthesia. This study was aimed to compare the clinical efficacy of epidural 0.75% ropivacaine fentanyl (RF)– with 0.5% bupivacaine–fentanyl (BF) for hemiarthroplasty in high-risk elderly patients.

Methods:

Sixty elderly consented patients of either sex with American Society of Anesthesiologist ASA II and III, scheduled for elective hemiarthroplasty were randomized into two Groups of 30 patients to receive epidural study solution of 15 mL of 0.75% Ropivacaine or 0.5% Bupivacaine with 1 mL fentanyl (50 μg). The hemodynamic variability with onset and duration of sensory and motor blocks were recorded. The adequacy and quality of surgical anesthesia were assessed. The post-epidural nausea and vomiting, shivering, respiratory parameters, or any other side effects were also recorded.

Results:

There was no difference in the demographic profile between groups. The mean onset time to achieve sensory block to the T₁₀ dermatome was rapid in the Group BF (12.4±6.9 vs. 17.5±3.7 min in Group RF). The mean time to achieve motor block was 17.5±3.4 min in Group BF versus 21.7±7.8 min in Group RF. The intraoperative hemodynamic fluctuations showed statistically significant differences between groups. The pruritis was observed in five patients but post-epidural shivering, nausea, vomiting, respiratory depression, or urinary retention were not observed in any patient.

Conclusion:

Epidural 0.75% Ropivacaine with fentanyl showed better clinical profile as compared to 0.5% Bupivacaine with fentanyl for hemiarthroplasty in elderly patients.

Update on local anesthetics: focus on levobupivacaine

In recent years levobupivacaine, the pure S (−)-enantiomer of bupivacaine, emerged as a safer alternative for regional anesthesia than its racemic parent. It demonstrated less affinity and strength of depressant effects onto myocardial and central nervous vital centers in pharmacodynamic studies, and a superior pharmacokinetic profile. Clinically, levobupivacaine is well tolerated in a variety of regional anesthesia techniques both after bolus administration and continuous postoperative infusion. Reports of toxicity with levobupivacaine are scarce and occasional toxic symptoms are usually reversible with minimal treatment with no fatal outcome. Yet, levobupivacaine has not entirely replaced bupivacaine in clinical practice. In anesthesia and analgesia practice, levobupivacaine and bupivacaine produce comparable surgical sensory block with similar adverse side effects, and equal labor pain control with comparable maternal and fetal outcome. The equipotency of the two drugs has been recently questioned, prompting clinicians to increase the dose of levobupivacaine in an attempt to ensure adequate anesthesia and analgesia and offsetting, therefore, the advantages of less motor block with levobupivacaine. In this review we aim to discuss the pharmacological essentials of the safer profile of levobupivacaine, and analyze the evidence regarding the current clinical indications.

Ropivacaine: A review of its pharmacology and clinical use

Ropivacaine is a long-acting amide local anaesthetic agent and first produced as a pure enantiomer. It produces effects similar to other local anaesthetics via reversible inhibition of sodium ion influx in nerve fibres. Ropivacaine is less lipophilic than bupivacaine and is less likely to penetrate large myelinated motor fibres, resulting in a relatively reduced motor blockade. Thus, ropivacaine has a greater degree of motor sensory differentiation, which could be useful when motor blockade is undesirable. The reduced lipophilicity is also associated with decreased potential for central nervous system toxicity and cardiotoxicity. The drug displays linear and dose proportional pharmacokinetics (up to 80 mg administered intravenously). It is metabolised extensively in the liver and excreted in urine. The present article details the clinical applications of ropivacaine and its current place as a local anaesthetic in the group.

The effects of Different Concentrations and Equivalent Volumes of Levobupivacaine in Epidural Anesthesia

BACKGROUND

Levobupivacaine, the S(-) isomer of bupivacaine, is less cardiotoxic than racemic bupivacaine. Previous studies have examined different concentrations of levobupivacaine in similar ways.

OBJECTIVES

This prospective, randomized, double-blind study was designed to determine the clinical efficacy and hemodynamic effects of different concentrations and equivalent volumes of levobupivacaine in epidural anesthesia. To our knowledge, this is the first study to evaluate the effects of concentration lower than 0.5% levobupivacaine.

METHODS

Forty adult patients with an American Society of Anesthesiology (ASA) I-III physical status undergoing transurethral endoscopic surgery were randomly divided into 2 groups to receive either 10 mL of isobaric levobupivacaine (0.5% + 5 mL 0.9% saline [group 1; n = 20]) or 10 mL of isobaric levobupivacaine (0.75% + 5 mL saline 0.9% saline [group 2; n = 20]) for epidural anesthesia. An observer blinded to group division evaluated the time of onset, maximum level, and time to 2-segment regression of sensory block.

RESULTS

There were no differences between the 2 groups in terms of hemodynamic parameters and time of onset of the sensory block. There were significant differences, however, between the 2 groups in the maximum level of the sensory block (group 1, T9; group 2, T8; P = 0.010) and the time to 2-segment regression of sensory block (group 1, 46.35 minutes; group 2, 62.94 minutes; P = 0.013).

CONCLUSION

This study indicated that 10 mL of 0.5% levobupivacaine plus 5 mL of 0.9% saline is a suitable solution for use in epidural anesthesia because it produces a block clinically comparable to that of 10 mL of 0.75% levobupivacaine plus 5 mL of 0.9% saline for transurethral resection of prostate surgery.

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.

[Levobupivacaine for regional anesthesia. A systematic review]

Levobupivacaine [S(-)bupivacaine], the levorotatory S-enantiomer of racemic bupivacaine, is commercially available in the U.S. and in most European countries. We performed a systematic review (MEDLINE database) and identified 88 articles on the clinical application of levobupivacaine in more than 3,000 patients. The use of levobupivacaine is described for epidural, caudal, and spinal anesthesia, for peripheral nerve blocks, for ophthalmic and dental anesthesia, for different pediatric indications and for intravenous regional anesthesia. In these regional techniques, levobupivacaine was used for all common indications in a wide range of clinical settings. Epidural levobupivacaine was combined with fentanyl, morphine, sufentanil, epinephrine, and clonidine, spinal levobupivacaine was combined with sufentanil, fentanyl, and epinephrine. In most studies, levobupivacaine was compared to bupivacaine and/or ropivacaine.