The efficacy and safety of 0.75% levobupivacaine vs 0.75% bupivacaine for peribulbar anaesthesia

Catalytic Production of Functional Monomers from Lysine and Their Application in High-Valued Polymers

Lysine is a key raw material in the chemical industry owing to its sustainability, mature fermentation process and unique chemical structure, besides being an important nutritional supplement. Multiple commodities can be produced from lysine, which thus inspired various catalytic strategies for the production of these lysine-based chemicals and their downstream applications in functional polymer production. In this review, we present a fundamental and comprehensive study on the catalytic production process of several important lysine-based chemicals and their application in highly valued polymers. Specifically, we first focus on the synthesis process and some of the current industrial production methods of lysine-based chemicals, including ε-caprolactam, α-amino-ε-caprolactam and its derivatives, cadaverine, lysinol and pipecolic acid. Second, the applications and prospects of these lysine-based monomers in functional polymers are discussed such as derived poly (lysine), nylon-56, nylon-6 and its derivatives, which are all of growing interest in pharmaceuticals, human health, textile processes, fire control and electronic manufacturing. We finally conclude with the prospects of the development of both the design and synthesis of new lysine derivatives and the expansion of the as-synthesized lysine-based monomers in potential fields.

Efficacy and safety of 0.5% levobupivacaine versus 0.5% bupivacaine for peribulbar anesthesia

Background

This randomized double-blind study examined the use of a new anesthetic agent, levobupivacaine 0.5%, which is the S(−)-enantiomer of a racemic mixture of bupivacaine, for peribulbar anesthesia and compared it with racemic bupivacaine 0.5% alone or in combination with hyaluronidase 10 IU/mL.

Methods

A total of 160 patients undergoing ophthalmic surgery were randomized into four groups (n = 40 each) to receive inferotemporal peribulbar injection of levobupivacaine 0.5% (group L), racemic bupivacaine 0.5% (group B), levobupivacaine + hyaluronidase 10 IU/mL (group LH), or racemic bupivacaine + hyaluronidase 10 IU/mL (group BH) by two anesthetists and two ophthalmologists in a ratio of 25% each. Ocular akinesia and orbicularis oculi function were evaluated using a three-point scale; a value < 5 points was considered as requiring surgery, and movements were re-evaluated the day following surgery to confirm regression of the block.

Results

The time to onset (12 ± 2.6 minutes versus 13 ± 2.8 minutes) and duration of anesthesia (185 ± 33.2 minutes versus 188 ± 35.7 minutes) were similar between groups L and B. Complete akinesia (score 0) was obtained more frequently when hyaluronidase was used in addition to the anesthetic, with occurrences of 72.5% versus 57.5% in group LH versus L, respectively, and 67.5% versus 45% in group BH versus B. Moderate hypotension (<30% of baseline) was observed in four patients (10%) in group L, two (5.0%) in group B, one (2.5%) in group LH, and three (7.5%) in group BH. The time to onset was significantly different between groups L and BH, B and BH, and LH and BH, and the duration of anesthesia differed significantly between groups B and LH, B and BH, and L and LH. The akinesia score differed significantly between groups L and LH and between groups B and LH (P = 0.043 and P = 0.018, respectively), and the number of patients with a score of 0 differed significantly between groups B and LH and between groups B and BH (P = 0.004 and P = 0.017, respectively).

Conclusion

Levobupivacaine is a long-lasting local anesthetic with limited cardiotoxicity and neurotoxicity, and may be considered the landmark for vitreoretinal surgery in elderly patients.

Comparison of levobupivacaine 0.5% or bupivacaine 0.5% both in a mixture with lidocaine 2% for superficial extraconal blockade

PURPOSE

To evaluate the quality and efficacy of Peribulbar blockade for superficial extraconal anesthesia with levobupivacaine 0.5% versus bupivacaine 0.5%, both combined with lidocaine 2% for patients undergoing phacoemulsification.

MATERIALS AND METHODS

In this prospective, double blind study, 150 patients were randomly divided into two groups: group-1 received a Peribulbar block (PB) with a mixture of evobupivacaine 0.5% and lidocaine 2% while group-2 received a PB with a mixture of bupivacaine 0.5% and lidocaine 2%. The block was performed by insertion of a short needle (15 mm) in infra-temporal space just above inferior orbital notch. An initial volume of 6 9 ml of either mixture was injected until total upper eyelid drop. Akinesia score was assessed at 2, 5, and 10 min after the block. The degree of pain was assessed by a verbal rating scale immediately after block, at the end of surgery and 4 h postoperatively. The patients and surgeons were asked to rate their satisfaction level of the quality of block postoperatively. Data were analyzed with the unpaired, two-tailed t-test and the Chi-square test as appropriate. P < 0.05 was considered statistically significant.

RESULTS

There were no significant differences between groups with respect to the akinesia score (P = 0.2) at 2, 5, and 10 min, the number of supplementary injections (P = 0.84) and initial and total required volume of local anesthetics (P = 0.80 and 0.81, respectively). There was no significant difference between the groups regarding surgeon and patient satisfaction (P = 0.53 and P = 0.74, respectively). Similarly the verbal rating scales assessed at three different occasions were not significantly different between the groups (P > 0.05 all cases). The need for additional intra-operative topical anesthetic was also similar between the groups. (P = 0.69).

CONCLUSIONS

Superficial extra-conal block with a mixture of levobupivicaine 0.5% and lidocaine 2% or bupivicaine 0.5% and lidocaine 2% provides similar block quality and efficacy.

The efficacy of 0.75% levobupivacaine versus 0.75% ropivacaine for peribulbar anesthesia in vitreoretinal surgery

BACKGROUND

We evaluated the anesthetic efficacy and the postoperative analgesic effects of 0.75% levobupivacaine versus 0.75% ropivacaine for peribulbar anesthesia in patients undergoing primary vitreoretinal surgery.

METHODS

We investigated 120 patients subjected to vitreoretinal surgery under peribulbar anesthesia. They were randomized into two equal groups according to the local anesthetic (LA) used, namely, 0.75% levobupivacaine or 0.75% ropivacaine, both with the addition of hyaluronidase. Nerve block was carried out by injection of 5-7 mL of the LA using single injection percutaneous peribulbar anesthesia with a short needle.

RESULTS

When compared with 0.75% ropivacaine, 0.75% levobupivacaine provided more successful akinesia at 10 min after block (P=0.026), fewer supplementary injections (P=0.026), and less volume (mL) was used (P=0.031). Also, levobupivacaine provided significantly longer motor block duration (342±27 min versus 206±40 min, P=0.001) and significantly longer sensory block duration (513±24 min versus 394±11 min, P=0.001) when compared with ropivacaine. In the postoperative period, the patients in the levobupivacaine group achieved lower values of verbal numeric rating scale of pain compared with patients in the ropivacaine group among the period from 4 to 12 h. Also, there were significantly (P=0.001) lower diclofenac consumption (mg) and the percentage of patients who required tramadol rescue medication were significantly less (P=0.034) in the levobupivacaine group compared with the ropivacaine group.

CONCLUSION

We are concluding that, at equipotent doses and concentrations, 0.75% levobupivacaine provides more effective peribulbar anesthesia and more effective postoperative analgesia for vitreoretinal surgery compared with 0.75% ropivacaine.

Levobupivacaine 0.75% vs. lidocaine 4% for topical anaesthesia

BACKGROUND

The aim of this study was to compare the efficacy of topical levobupivacaine drops 0.75% vs. lidocaine drops 4% in cataract surgery.

METHODS

We examined 203 patients undergoing cataract surgery by phacoemulsification. They were randomized into two groups: one received four drops of lidocaine 4% and the other received four drops of levobupivacaine 0.75%. The onset and offset times of sensory block were evaluated. Application, intraoperative and postoperative subjective pain was quantified by the patients using a verbal pain score. Complications, rates of supplemental anaesthesia, and the satisfaction of surgeon and patients were also recorded.

RESULTS

The mean sensory onset and offset times were significantly higher for the levobupivacaine group (P < 0.01). Pain score was lower in the levobupivacaine group than in the lidocaine one and the difference was statistically significant at all stages (P < 0.01). The mean satisfaction scores of patients and surgeon were also statistically higher for levobupivacaine (P < 0.01). No significant differences for complications and rates of supplemental anaesthesia were found.

CONCLUSIONS

Topical levobupivacaine 0.75% shows the same efficacy and safety as lidocaine 4% in cataract surgery by phacoemulsification. There was an adequate block with a good level of satisfaction of surgeon and patients. Levobupivacaine 0.75% offers a new and acceptable choice for topical anaesthesia in cataract surgery.

Efficacy and comparison of 0.5% levobupivacaine with 0.75% ropivacaine for peribulbar anaesthesia in cataract surgery

BACKGROUND AND OBJECTIVE

The low cardiovascular and neurological toxicity of levobupivacaine has led to its application as a local anaesthetic in a wide variety of specialist applications including peribulbar block for cataract surgery. The aim of this study was to evaluate the efficacy of levobupivacaine 0.5% and to compare block quality vs. ropivacaine 0.75% in peribulbar anaesthesia.

METHODS

We examined 208 patients subjected to cataract surgery by phacoemulsification who were randomized into two groups according to the anaesthetic used for peribulbar block, namely levobupivacaine 0.5% or ropivacaine 0.75%, both with the addition of hyaluronidase. Nerve block was carried out by injection of 6 mL of the anaesthetic mixture equally distributed between the inferotemporal and superonasal areas. The success of the block was evaluated by determining the time of motor and sensory onset, akinesia score, times of motor and sensory offset and satisfaction of the patient and surgeon after 24 h. Pre-block, post-block and postoperative intraocular pressure as well as the duration of surgical intervention was also determined.

RESULTS

With respect to ropivacaine, levobupivacaine showed a significant reduction (P < 0.001) in the average motor and sensory onset. Both the akinesia score (P < 0.01) and mean motor and sensory offset times were also higher (P < 0.001). Neither the average intervention times nor the satisfaction of the patient/surgeon showed any significant differences between the two groups.

CONCLUSIONS

Levobupivacaine (0.5%) has better anaesthetic properties with respect to 0.75% ropivacaine and is well-suited for peribulbar block in cataract surgery.

[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.

Bupivacaine, levobupivacaine and ropivacaine: are they clinically different?

Two new, long-acting local anaesthetics have been developed after the evidence of bupivacaine-related severe toxicity: levobupivacaine and ropivacaine. Both these agents are pure left-isomers and, based on their three-dimensional structure, they have less toxic potential both on the central nervous system and on the heart. Several clinical studies have evaluated their toxicology and clinical profiles: theoretically and experimentally, some differences can be seen, but the reflections of these characteristics into clinical practice have not been evident. Evaluating randomised, controlled trials that have compared these three local anaesthetics, this chapter supports the evidence that both levobupivacaine and ropivacaine have a clinical profile similar to that of racemic bupivacaine, and that the minimal differences observed between the three agents are mainly related to the slightly different anaesthetic potency, with racemic bupivacaine>levobupivacaine>ropivacaine. However, the reduced toxic potential of the two pure left-isomers supports their use in those clinical situations in which the risk of systemic toxicity related to either overdosing or unwanted intravascular injection is high, such as during epidural or peripheral nerve blocks.