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

Levobupivacaine Combined with Cisatracurium in Peribulbar Anaesthesia in Cats Undergoing Corneal and Lens Surgery

The aims of the study included evaluating the effects of levobupivacaine combined with cisatracurium on akinesia and mydriasis when administered by peribulbar injection, and evaluating if the chosen dose of cisatracurium is enough to avoid the use of systemic neuromuscular blockade in cats. The animals were divided into four groups as follows: group L received 1.25 mg kg^-1 levobupivacaine administered by peribulbar injection; group LC received the same dose of levobupivacaine combined with 0.01 mg kg^-1 of cisatracurium administered by peribulbar injection; group C received 0.01 mg kg^-1 of cisatracurium administered by peribulbar injection; group GC received 0.01 mg kg^-1 of cisatracurium intravenously. Physiological variables, intraocular pressure, akinesia, and mydriasis were measured before and up to 30 min after peribulbar injection. The onset of akinesia, duration of akinesia, and train of four (TOF) were evaluated. Physiological variables remained in the physiological range in all groups. Effective akinesia and mydriasis were observed in all groups. The (TOF) was 0.9 in all groups. Throughout the study was observed in group LC a shortened onset of akinesia and a prolonging its duration. The peribulbar injection of cisatracurium and levobupivacaine provided effective akinesia and mydriasis, and shortened the onset of akinesia while prolonging its duration.

Postoperative Analgesic Efficacy of Sub-Tenon's Block with Levobupivacaine in Retinal Surgery under General Anesthesia

Background:

Vitreoretinal surgery is associated with undesirable intraoperative and postoperative complications including pain, postoperative nausea and vomiting, and oculocardiac reflex (OCR). Systemic analgesics have side effects and are contraindicated in some cases. We hypothesized that the preoperative sub-Tenon's injection of levobupivacaine with general anesthesia would decrease postoperative pain and intraocular pressure as well as the incidence of complication.

Methods:

Eighty patients who were presented for vitreoretinal surgery, aged 30–60 years, were enrolled in the study. General anesthesia was administrated to all patients; then, they were randomized into two equal groups (40 each) – Group I: patients received 5 mL placebo solution for sub-Tenon's block and Group II: patients received 4 mL levobupivacaine 0.5% in 1 mL saline for sub-Tenon's block. Postoperative pain was evaluated using a verbal pain scale. Surgeon satisfaction, postoperative analgesic consumption, and perioperative hemodynamics were also reported.

Results:

Verbal rating pain scores were significantly lower at the first 6 h postoperative in Group II (sub-Tenon's levobupivacaine) compared to Group I (sub-Tenon's placebo). First analgesic rescue time and total dose of analgesic consumption were significantly reduced in Group II compared to Group I. There was a lower incidence of OCR with sub-Tenon's levobupivacaine (Group II), also surgeon satisfaction was significantly superior in the same group.

Conclusion:

The combination of general anesthesia with sub-Tenon's block using levobupivacaine in retinal surgery patients reduces pain scores after surgery; total analgesia requirement also decreases the incidence of OCR.

Bupivacaine in alginate and chitosan nanoparticles: an in vivo evaluation of efficacy, pharmacokinetics, and local toxicity

Objective

This study reports a preclinical evaluation of an alginate/chitosan nanoparticle formulation containing NovaBupi®, a racemic bupivacaine (BVC) containing 25% dextrobupivacaine and 75% levobupivacaine.

Methods

New Zealand White rabbits (n=6) received intraoral or intrathecal injections of BVC 0.5% or BVC 0.5%-loaded alginate–chitosan nanoparticles (BVC_ALG). BVC plasma levels and pharmacokinetic parameters were determined in blood samples of these rabbits. An infraorbital nerve blockade was performed in male Wistar rats (n=7) with the same formulations and the vehicle (NP_ALG). Histological evaluation of local toxicity after 6 hours and 24 hours of the treatments was performed in rats’ (n=6) oral tissues.

Results

No statistically significant difference was observed between plasma concentrations and pharmacokinetic parameters (p>0.05) after intraoral injections. However, after intrathecal injection BVC_ALG changed approximately three times the values of volume of distribution and area under the curve (AUC_0–t; p<0.05). The total analgesic effect of BVC after infraorbital nerve blockade was improved by 1.4-fold (p<0.001) with BVC_ALG. BVC and BVC_ALG did not induce significant local inflammatory reaction.

Conclusion

The encapsulation of BVC prolongs the local anesthetic effect after infraorbital nerve blockade and altered the pharmacokinetics after intrathecal injection.

Flap motility as a sign of posterior capsule rupture in peripherally extended anterior capsular tears

Purpose

To describe various types of anterior capsular tears and an early diagnostic, flap motility, as a sign of posterior capsular rupture following posterior extension of radial tears.

Design

This was a prospective study carried out in 4,331 eyes that underwent phacoemulsification in a private practice setting from April 2015 to February 2016. Twenty six consecutive cases of anterior capsular tears were included. Morphological features of anterior capsular tears and resultant complications were evaluated. Parameters studied were surgical step during which the tear occurred, shape of tear, its extension in relation to the equator, and flap nature and motility in tear extending up to equator.

Main outcome measures

The main outcome measures were motility and nature of flaps in anterior capsular radial tears and the relation to posterior capsule rupture.

Results

Based on shape, extent, and angulation, anterior capsular tears were categorized into 5 types: Type I, pre-equatorial radial tear (26.92%); Type II, post-equatorial radial tear (3.85%); Type III, Argentinean flag sign pre-equatorial tear (57.69%); Type IV, Argentinean flag sign post-equatorial tear (7.69%), and Type V, mini punch (3.85%). Flaps were either seen to be everted and fluttering or inverted and non-fluttering. In all cases with everted fluttering flaps no posterior capsular rupture (PCR) was observed, while in cases with inverted non-fluttering flaps a PCR was observed (p<0.05).

Conclusion

Everted and fluttering flaps of the anterior capsular tears indicate pre-equatorial tear, while inverted and non-fluttering flaps indicate posterior capsule rupture following tear extension beyond the equator.