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

Effect of adding dexmedetomidine to 0.75% ropivacaine in peribulbar block for vitreoretinal surgery

Background and Aims

Peribulbar anesthesia is suitable for vitreoretinal (VR) surgery. Dexmedetomidine has been used in peribulbar block (PBB) to improve akinesia and analgesia. We aimed to study the efficacy of adding dexmedetomidine to 0.75% Ropivacaine in PBB for VR surgery. The primary outcome was the requirement of block supplementation and secondary outcome was post-operative analgesic requirement.

Material and Methods

100 adult patients undergoing VR surgery were included in this prospective randomized double-blinded controlled study. The composition of the drug used for PBB in the 3 groups was Group R (8 ml of 0.75% Ropivacaine +0.5 ml normal saline (NS)), Group D25 (8 ml of 0.75% Ropivacaine +25μg Dexmedetomidine) and Group D50 (8 ml of 0.75% Ropivacaine +50 μg Dexmedetomidine).

Results

The groups were comparable in terms of patient demographics. The requirement for block supplementation was 16.7% in Group R (5/30), 12.5% in Group D25 (4/32) and 8.8% in group D50 (3/34) (P = 0.64). The mean time to first request for post-operative analgesia was432 ± 362 min in Group R, 572 ± 339 min in Group D25 and 614 ± 394 min for Group D50 (P = 0.26). There was significant difference in the heart rate (P = 0.047), mean arterial pressure (P = 0.012) at 30 min and sedation (RASS) score at 15, 30, 60 (P < 0.001) and 120 (P = 0.019) min between the D50 and group R. Patients undergoing buckling procedures had significantly shorter time to request for analgesia (P = 0.003).

Conclusion

Addition of dexmedetomidine does not offer advantage over 0.75% Ropivacaine in PBB for vitrectomy. Its benefit in more painful procedures like scleral buckle needs further validation.

Comparison of peribulbar block and general anaesthesia in mechanical vitrectomy: a prospective observational study

INTRODUCTION

Vitrectomy surgery is a common procedure for the treatment of several types of ophthalmologic conditions. It can be performed under regional anaesthesia with peribulbar block (PB) or general anaesthesia (GA). There are no evidence-based recommendations on the optimal anaesthesia strategy for this procedure. The aim of this study was to compare the advantages of PB and GA for vitrectomy surgery.

MATERIALS AND METHODS

A prospective observational study was conducted on adults submitted for mechanical vitrectomy between January 2017 and December 2017. Demographic and perioperative data were collected, namely ASA physical status, median arterial pressure, heart rate, postoperative opioid consumption, postoperative nausea and vomiting, times of induction, surgery, recovery, and hospital stay and costs considering medication and material needed. Statistical analysis was performed using SPSS v.25, with chi-square, Fisher and Mann-Whitney U tests, according to the type of variables analysed.

RESULTS AND DISCUSSION

We included 179 patients submitted for mechanical vitrectomy: 91 (51%) with PB and 88 (49%) under GA. Patients submitted to PB were older (69.0 vs. 64.5 years, p=.006) and presented with higher ASA physical status (p=.001). For haemodynamic outcomes, patients submitted to PB presented with less variation of median arterial pressure (-3.0 vs. -13.5mmHg, p=.000) and with no significant differences in heart rate (-2.0 vs. -3.0 bpm, p=.825). In the postoperative period, the PB group presented with decreased need of postoperative analgesia (0.0 vs. 5.0, p=.026) and a lower incidence of nausea and vomiting (1.0 vs. 12.0, p=.001). Times related to anaesthesia and surgery were better in PB group, with shorter induction time (10.0 vs. 11.0min, p=.000), surgery time (56.5 vs. 62.0min, p=.001), recovery time (10.0 vs. 75.5min, p=.000), and hospital stay (2.0 vs. 3.0 days, p=.000). When analysing costs, PB was less expensive than GA (4.65 vs. 12.09 euros, p=.021) CONCLUSION: PB is a reliable and safe alternative to GA for patients undergoing mechanical vitrectomy, permitting good anaesthesia and akinesia conditions during surgery, better haemodynamic stability, and less postoperative complications, especially in older patients and those with more comorbidities.

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.

Facile fabrication of polyanhydride/anesthetic nanoparticles with tunable release kinetics

This work illustrates a two-step strategy for the fabrication of polymer/drug nanoparticles. Utilizing solvent/non-solvent precipitation and gaseous basification, composite nanoparticles with 0-100% drug loadings are fabricated. Drug release kinetics are dictated by nanoparticle composition allowing future tuning for therapeutic applications.

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.