Epidural ropivacaine versus bupivacaine for cesarean sections: a system review and meta-analysis

INTRODUCTION

It is still no consensus on the use of ropivacaine or bupivacaine in epidural anesthesia for cesarean section (CS), because their anesthetic potency and relative complications remains controversial. This system review and meta-analysis aimed to compare the efficacy of epidural ropivacaine and bupivacaine for elective CSs and investigate relative complications for parturients and neonates.

METHODS

We searched PubMed, MEDLINE, Embase, Cochrane Library, Science-Direct, and Google Scholar to June 30, 2023 for randomized controlled trials (RCTs), which compared epidural ropivacaine with bupivacaine for elective CSs. The success rate of epidural anesthesia (EA) was primary outcome. The secondary outcomes included onset times of sensory block, maternal side effects, neonatal Apgar scores and umbilical artery pH.

RESULTS

We analyzed 8 RCTs with 532 parturients. 0.75% ropivacaine is associated with a shorter onset time of sensory block than 0.5% bupivacaine (SMD = -0.43, 95% CI: -0.70 to -0.17; p = .001). 0.5% ropivacaine resulted in a reduced nausea than 0.5% bupivacaine (RR = 0.49, 95% CI: 0.28 to 0.83; p = .008). In addition, there were no significant difference between ropivacaine and bupivacaine groups in terms of success rate of epidural anesthesia, maternal side effects (hypotension, bradycardia, shivering), and neonatal Apgar scores and umbilical artery pH.

CONCLUSIONS

The findings suggest that there were no significant difference between epidural ropivacaine and bupivacaine for elective CSs in terms of the success rate (85.9% vs. 83.5), maternal side effects (hypotension, bradycardia, shivering), and neonatal Apgar scores and umbilical artery pH. But compared with 0.5% bupivacaine, epidural 0.75% ropivacaine was mildly effective for reducing onset time of sensory block and 0.5% ropivacaine reduced the incidence of maternal nausea.

Dose safety and pharmacodynamics of subcutaneous bupivacaine in a novel extended-release microparticle formulation: A phase 1, dose-ascending study in male volunteers

A novel microparticle-based extended-release local anaesthetic containing a bupivacaine/poly-lactic-co-glycolic acid (PLGA; LIQ865A) or plain bupivacaine (LIQ865B) was examined in a first-in-human trial. The objectives were to examine the dose safety/tolerability and pharmacodynamics. Randomized subcutaneous injections of LIQ865A (n = 16) or LIQ865B (n = 12) and diluent, contralaterally, were administered in a dose-ascending manner (150- to 600-mg bupivacaine). Subjects were admitted 24 h post-injection and followed for 30 days post-injection. The risk ratios (RRs; 95% CI) of erythematous reactions for LIQ865A versus diluent was 9.00 (1.81-52.23; P = 0.006) and for LIQ865B versus diluent 2.50 (0.69-9.94; P = 0.37). The RR for the development of hematomas (LIQ865A versus diluent) were 3.25 (1.52-8.16; P = 0.004) and 4.00 (0.72-24.89; P = 0.32) (LIQ865B versus diluent). Subcutaneous indurations persisting for 4-13 weeks were seen in 6/16 subjects receiving LIQ865A. One subject receiving LIQ865A (600-mg bupivacaine) developed intermittent central nervous system (CNS) symptoms of local anaesthetic systemic toxicity (85 min to 51 h post-injection) coinciding with plasma peak bupivacaine concentrations (490-533 ng/ml). Both LIQ865 formulations demonstrated dose-dependent hypoesthesia and hypoalgesia. The duration of analgesia ranged between 37 and 86 h. The overall number of local adverse events, however, prohibits clinical application without further pharmacological modifications.

The 90% effective dose of intrathecal hyperbaric bupivacaine for Cesarean delivery under combined spinal-epidural anesthesia in parturients with super obesity: an up-down sequential allocation study

PURPOSE

To determine the 90% effective dose (ED90) of intrathecal hyperbaric bupivacaine for Cesarean delivery under combined spinal-epidural anesthesia (CSE) in parturients with super obesity (body mass index [BMI] ≥ 50 kg·m-2).

METHODS

We enrolled parturients with BMI ≥ 50 kg·m-2 with term, singleton vertex pregnancies undergoing elective Cesarean delivery under CSE. An independent statistician generated the 0.75% hyperbaric bupivacaine dosing regimen in increments of 0.75 mg using a biased-coin up-down sequential allocation technique. This was combined with 15 μg fentanyl, 150 μg morphine, and normal saline to a volume of 2.05 mL. The initial and maximum doses were 9.75 mg and 12 mg, respectively. Participants, clinical team, and outcome assessors were blinded to the dose. The primary outcome was block success, defined as T6 block to pinprick within ten minutes and no intraoperative analgesic supplementation within 90 min of spinal injection. We determined the ED90 using logistic regression.

RESULTS

We enrolled 45 parturients and included 42 in the analysis. All doses achieved a T6 level within ten minutes, and the primary outcome occurred in 0/1 (0%) of the 9.75-mg doses, 2/3 (67%) of the 10.5-mg doses, 21/27 (78%) of the 11.25-mg doses, and 11/11 (100%) of the 12-mg doses. The ED90 of hyperbaric bupivacaine was 11.56 mg (95% confidence interval, 11.16 to 11.99). Four parturients (9.5%) had sensory level higher than T2, but none was symptomatic or required general anesthesia.

CONCLUSION

The estimated ED90 of hyperbaric bupivacaine with fentanyl and morphine in parturients with super obesity undergoing Cesarean delivery under CSE was approximately 11.5 mg.

STUDY REGISTRATION

ClinicalTrials.gov (NCT03781388); first submitted 18 December 2018.

Population pharmacokinetic-pharmacodynamic model of subcutaneous bupivacaine in a novel extended-release microparticle formulation

The objective of this study was to develop a population pharmacokinetic-pharmacodynamic model of subcutaneously administered bupivacaine in a novel extended-release microparticle formulation for postoperative pain management. Bupivacaine was administered subcutaneously in the lower leg to 28 healthy male subjects in doses from 150 to 600 mg in a phase 1 randomized, placebo-controlled, double-blind, dose-ascending study with two different microparticle formulations, LIQ865A and LIQ865B. Warmth detection threshold was used as a surrogate pharmacodynamic endpoint. Population pharmacokinetic-pharmacodynamic models were fitted to plasma concentration-effect-time data using non-linear mixed-effects modelling. The pharmacokinetics were best described by a two-compartment model with biphasic absorption as two parallel absorption processes: a fast, zero-order process and a slower, first-order process with two transit compartments. The slow absorption process was found to be dose-dependent and rate-limiting for elimination at higher doses. Apparent bupivacaine clearance and the transit rate constant describing the slow absorption process both appeared to decrease with increasing doses following a power function with a shared covariate effect. The pharmacokinetic-pharmacodynamic relationship between plasma concentrations and effect was best described by a linear function. This model gives new insight into the pharmacokinetics and pharmacodynamics of microparticle formulations of bupivacaine and the biphasic absorption seen for several local anaesthetics.

Comparative analysis of low-dose bupivacaine and ropivacaine combined with spinal-epidural anesthesia in cesarean sections for pregnant women with coexisting mental illness

OBJECTIVE

To analyze the application effects of low-dose bupivacaine and ropivacaine combined with epidural anesthesia.

METHODS

The primary outcome measure was the anesthesia effect, assessed by the excellent anesthesia rate. Secondary outcomes included the occurrence of adverse reactions, blood pressure, and serum prolactin levels at different time points. The anesthesia effect, serum prolactin levels, occurrence of adverse reactions, and MAP at various time points [before anesthesia (T0), 5 min after anesthesia (T1), at the start of surgery (T2), at delivery of the fetus (T3), and at closure of the abdomen (T4)] were compared between the two groups.

RESULTS

① Anesthesia effect: The excellent anesthesia rate was 71.88% in the control group and 93.94% in the observation group, with a significantly higher rate in the observation group than in the control group (p = 0.017). ② Serum prolactin levels: The serum prolactin levels in both groups increased significantly after surgery compared to before surgery (p < 0.001); however, there was no statistically significant difference in serum prolactin levels between the two groups before and after surgery (p = 0.651). ③ Occurrence of adverse reactions: The occurrence rate of adverse reactions was 28.13% in the control group and 9.09% in the observation group, with a significantly lower rate in the observation group than in the control group (p = 0.048).

CONCLUSION

In cesarean sections for pregnant women with coexisting mental illness, low-dose ropivacaine demonstrates significantly better anesthesia efficacy, blood pressure stability, and anesthesia safety compared to low-dose bupivacaine. Both low-dose bupivacaine and ropivacaine result in increased prolactin levels postpartum.

The Median Effective Dose of Intrathecal Hyperbaric Bupivacaine for Cesarean Section at Moderately High-Altitude

Objective

Alterations in altitude can lead to an augmented requirement for local anesthesia among patients. Nevertheless, the necessity for an elevated dosage of local anesthetic for parturients at moderately high altitudes during spinal anesthesia for cesarean section remains uninvestigated. This up-down sequential study endeavors to determine the ED50 dose of bupivacaine required for spinal anesthesia during cesarean sections at moderately high-altitude.

Methods

Thirty singleton parturients at moderately high altitude underwent elective cesarean section under combined spinal-epidural anesthesia. The up-and-down sequential method was employed, starting with an initial dose of 12mg (1.6mL) of 0.75% hyperbaric bupivacaine for the first participant. The dose for the next case was adjusted up or down by 0.75mg based on the effectiveness of the previous participant. Effectiveness was defined as the bilateral sensory block reaching T6 within 15 minutes after spinal anesthesia injection, without the need for additional epidural anesthesia before fetal delivery. The ED50 dose and 95% confidence interval were calculated using the Dixon sequential method and isotonic regression, respectively. The incidence of maternal hypotension, nausea, and vomiting during the study period was also recorded.

Results

The ED50 of hyperbaric bupivacaine for spinal anesthesia in cesarean section was calculated as 8.23 mg (95% CI, 6.52-9.32 mg) using the Dixon up-and-down method. Further validation using isotonic regression yielded a value of 8.39 mg (95% CI, 7.48-9.30 mg), confirming the accuracy and sensitivity of the conclusion. During the operation, only 6 parturients experienced hypotension, and no adverse reactions such as nausea, vomiting, and shivering were observed.

Conclusion

The ED50 dose of 0.75% hyperbaric bupivacaine for spinal anesthesia during cesarean section at moderately high altitude is 8.23 mg, which exceeds the ED50 dose typically required by parturients at low altitude. Comprehensive investigations are warranted to ascertain the ED90 or ED95 dose of local anesthetics for cesarean section at moderately high altitudes, thereby offering enhanced guidance for clinical practice.

Absorption and pharmacokinetics of bupivacaine after bilateral topical administration in tonsillar fossae for posttonsillectomy pain relief

No previous studies have investigated the systemic absorption of bupivacaine when used topically for posttonsillectomy pain. The present study was undertaken to investigate the pharmacokinetics of bupivacaine after administration by a swab in the tonsillar fossae over 4 min after tonsillectomy. Eleven adult patients undergoing elective tonsillectomy were recruited. After removal of both tonsils, each of the two tonsillar fossae was covered with a swab moistened with 2 mL of bupivacaine 5 mg/mL, that is, a total of 20 mg bupivacaine. Blood samples were drawn after 0, 5, 10, 20, 30, 45, and 60 min. Bupivacaine was analyzed with an ultra-high-performance liquid chromatography-tandem mass spectrometry method. The highest single measured bupivacaine serum concentration was 23.2 ng/mL and took place 10 min after drug administration. Mean (±SD) Cmax was 11.4 ± 6.0 ng/mL and mean tmax was 11.3 ± 4.7 min. Mean t1/2 was 31.6 ± 9.3 min. As the toxic concentration threshold has been reported to be in the interval 1500-4500 ng/mL, the concentrations measured were well below 2% of the lowest cited toxic threshold. In conclusion, this study shows that applying 4 mL of bupivacaine 5 mg/mL by a swab in the tonsillar fossae posttonsillectomy yields very low plasma concentrations, suggesting its safe application without any risk of systemic toxic effects.

Evaluation of two doses (20 mL and 15 mL) of 0.25% bupivacaine in pericapsular nerve group block for patient positioning for sub-arachnoid block during hip fracture surgery: A single-centre, randomised comparative trial

Background and Aims

Peri-capsular nerve group (PENG) block is a novel ultrasound (US)-guided technique to achieve regional analgesia in hip fractures. We compared the effectiveness of two doses of 0.25% bupivacaine (20 mL and 15 mL) in the US-guided PENG block for positioning patients for sub-arachnoid block (SAB) during hip fracture surgery.

Methods

The randomised trial included 60 patients aged 40-90 years undergoing hip fracture surgery under SAB. PENG block was given by a US-guided approach with the patient in a supine position 20 minutes before SAB, and a total of 20 mL and 15 mL of bupivacaine (0.25%) were given in groups A and B, respectively. The primary outcome was to measure and compare the ease of positioning (EOP) of patients for the conduct of SAB. The secondary outcome was the pain assessment at rest and 15° leg raise position at baseline and 10 and 20 minutes post block using the verbal analogue scale (VAS). Continuous variables were compared using the t-test, and categorical variables were analysed using Pearson's Chi-square test or Fisher's exact test.

Results

The mean (standard deviation) grade of EOP for SAB was significantly better in group A (2.47 (0.73) (95% confidence interval [CI]: 2.19-2.69)) than in group B (1.86 (0.62) (95% CI: 1.65-2.1)) (P = 0.001). The decrease in VAS scores was significantly higher in group A compared to group B at resting and 15° leg raise position at all-time points (P < 0.05).

Conclusion

A dose of 20 mL of 0.25% bupivacaine shows better outcomes than 15 mL regarding the patient's positioning during the SAB.

Assessment of symptomatic response to intravesical alkalinized lidocaine, bupivacaine, heparin and steroids in patients with bladder pain syndrome

Bladder Pain Syndrome (BPS) is a puzzling and complicated disorder. 12 such patients, with a mean age 48.3 years, were treated with weekly intravesical instillation of admixture of alkalinized lidocaine, bupivacaine, heparin and steroids for six weeks. Evaluating the benefits of this therapy, patients experienced 82.2% & 90.9% relief at 3rd & 6th week of instillation. After completion of six cycles of therapy, patients experienced 68.7% & 65.3% relief at 3rd & 6th month follow up, concluding the early and long term relief of BPS.

Lipid emulsion treatment for local anesthetic systemic toxicity in pediatric patients: A systematic review

BACKGROUND

Local anesthetic systemic toxicity (LAST) is rare, but fatal; the current widely used treatment is lipid emulsion (LE). The goal of this study was to analyze and review case reports on LE treatment for LAST in pediatric patients.

METHODS

We performed a systematic review using case reports on LE treatment for LAST in pediatric patients, searching PubMed and Scopus databases to March 2023 using the following keywords: ("local anesthetic toxicity" OR "local anesthetic systemic toxicity" OR LAST") AND ("newborn" OR "infant" OR "child" OR "children" OR "adolescent" OR "pediatric") AND ("lipid emulsion" OR "Intralipid").

RESULTS

Our search yielded 21 cases, revealing that nearly 43% patients with LAST were less than 1 year old, and most cases were caused by bupivacaine (approximately 67% cases). "Inadvertent intravascular injection" by anesthesiologists and "overdose of local anesthetics" mainly by surgeons were responsible for 52% and 24% cases of LAST, respectively. LAST occurred in the awake state (52%) and under general anesthesia (48%), mainly causing seizures and arrhythmia, respectively. Approximately 55% of patients received LE treatment in <10 minutes after LAST, mainly improving cardiovascular symptoms. A 20% LE (1.5 mL/kg) dose followed by 0.25 mL/kg/minutes dose was frequently used. LE and anticonvulsants were mainly used in the awake state, whereas LE with or without vasopressors was mainly used under general anesthesia. LE treatment led to full recovery from LAST in 20 cases; however, 1 patient died due to underlying disease.

CONCLUSION

Consequently, our findings reveal that LE is effective in treating pediatric LAST.

Efficacy of Peripheral Nerve Stimulator Guided Pectoral Nerve Block-1 and Serratus Anterior Plane Block for Post-operative Analgesia in Modified Radical Mastectomy: A Randomized Controlled Study

BACKGROUND

Breast carcinoma is one of the most common cancers in present-day women worldwide, hence surgical intervention for the same is inevitable. General anesthesia being the preferred technique, the selection of appropriate postoperative pain management is a major concern in which superficial fascial plane chest wall blocks play a pivotal role. We aimed to prove the efficacy of peripheral nerve stimulator-guided pectoral nerve-1 (PEC 1) block and serratus anterior plane (SAP) block for postoperative analgesia in modified radical mastectomy.

METHODS

This prospective randomized controlled clinical study comprised 60 females undergoing modified radical mastectomy and was randomly allocated to two groups. Group A patients received general anesthesia while, in addition to general anesthesia, group B patients received PEC 1 and SAP blocks. Postoperatively the active and passive visual analog score (VAS), duration of analgesia, cumulative requirement of rescue analgesics in the first 24 hours and associated perioperative complications were noted. All quantitative data were analyzed by student t-test and qualitative data by chi-square test using MedCalc software 12.5.

RESULTS

VAS score for first 24 hours in group B was lower at rest, on pressure over the surgical site as well as on movements compared with the patients in group A with the p-value being < 0.0001 at all time intervals. Time for receiving first rescue analgesia was shorter (1.25±0.56hour vs 20.05±7.78hour, p<0.001) with the significantly higher requirement of cumulative doses of tramadol in the first 24 hours in patients belonging to group A (233.33±47.95mg vs 110±31.62 mg, p<0.001).

CONCLUSION

PEC 1 and SAP blocks given under peripheral nerve stimulator guidance have a high success rate and are reliable in providing adequate postoperative analgesia for patients undergoing modified radical mastectomy.

Palliation of Intractable Cancer-Related Pain With Low-Dose Epidural Bupivacaine

Introduction: Patients with advanced cancer nearing end of life often present with complex multifactorial pain. Although epidural analgesia is routinely used in inpatient hospital settings for targeted pain control, there is scant description in the literature of the use of low-dose epidural analgesia for relief of cancer-related pain at end of life. In this study, we present a case of difficult to control cancer-related rectal and pelvic pain in a patient who responded well in her last days of life to a low-dose bupivacaine epidural. Case Description: A 66-year-old woman presented for inpatient hospital admission for pain control from home hospice with intractable cancer-related pain from metastatic colorectal adenocarcinoma marked by extensive erosive lesions extending from the anterior perineum to the posterior rectum, with rectovaginal fistula. The patient reported poor tolerance of medications and described spiritual beliefs (based in Buddhism) that caused her and her family to prioritize maintaining a lucid, clear mind above nearly all else while seeking symptom management. The patient was so debilitated by pain at the time of presentation that she was bedbound in a quadruped position. Case Management and Outcome: After 2 weeks of poor pain control in the hospital with multiple failed attempts at palliation-including bilateral pudendal block, as well as opioids and other routine, but potentially sedating or deliriogenic, medications to treat her pain-the patient permitted administration of a low-dose bupivacaine epidural that significantly reduced her pain and allowed the patient to remain clear-headed up until the time of her death. Twenty-three days after admission, and 5 days after initiation of low-dose bupivacaine epidural for pain control, the patient died peacefully in the hospital. Conclusion: Low-dose epidural analgesia for cancer-related pain at end of life from malignancy involving the pelvis-perineum, rectum, or vagina-may be a viable option for patients, particularly those who wish to avoid the risk of somnolence or confusion from systemic opioids and other analgesics.

The impact of timing, type, and method of instillation of intraperitoneal local anaesthetic in laparoscopic abdominal surgery: a systematic review and network meta-analysis

BACKGROUND

Pain is common after laparoscopic abdominal surgery. Intraperitoneal local anaesthetic (IPLA) is effective in reducing pain and opioid use after laparoscopic surgery, although the optimum type, timing, and method of administration remains uncertain. We aimed to determine the optimal approach for delivering IPLA which minimises opioid consumption and pain after laparoscopic abdominal surgery.

METHODS

MEDLINE, Embase, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were systematically searched for randomised controlled trials comparing different combinations of the type (bupivacaine vs lidocaine vs levobupivacaine vs ropivacaine), timing (pre-vs post-pneumoperitoneum at the beginning or end of surgery), and method (aerosol vs liquid) of IPLA instillation in patients undergoing any laparoscopic abdominal surgery. A network meta-analysis was conducted to ascertain the optimum approach for delivering IPLA resulting in the least cumulative opioid consumption and pain (overall and localising to the shoulder) 24 h after surgery. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) assessments (PROSPERO ID: CRD42022307595).

RESULTS

Twenty-five RCTs were included, among which 15 different combinations of delivering IPLA were analysed across 2401 participants. Aerosolised bupivacaine instilled at the end of surgery, before deflation of the pneumoperitoneum, was associated with significantly less postoperative opioid consumption compared with all other approaches for delivering IPLA (98.7% of comparisons; moderate certainty), aside from liquid levobupivacaine instilled before surgery and during or after creation of the pneumoperitoneum (mean difference -11.6, 95% credible interval: -26.1 to 2.5 i.v. morphine equivalent doses). There were no significant differences between different IPLA approaches regarding overall pain scores and incidence of shoulder pain up to 24 h after surgery.

CONCLUSIONS

There are limited studies and low-quality evidence to conclude on the optimum method of delivering IPLA in laparoscopic abdominal surgery. While aerosolised bupivacaine instilled at the end of surgery but before deflation of the pneumoperitoneum minimises postoperative opioid consumption, pain scores up to 24 h did not differ between the different modalities of delivering IPLA. The generalisability of these results is limited by the lack of utilisation of non-opioid analgesics in most trials.

SYSTEMATIC REVIEW PROTOCOL REGISTRATION

PROSPERO CRD42022307595.

Effect of dexmedetomidine added to retrobulbar blockade with lignocaine and bupivacaine in dogs undergoing enucleation surgery

OBJECTIVE

To investigate the effect of the addition of dexmedetomidine (BLD) to retrobulbar blockade with combined lignocaine and bupivacaine on nociception.

ANIMALS

A total of 17 eyes from 15 dogs.

METHODS

Prospective, randomized, masked clinical comparison study. Dogs undergoing unilateral enucleation were randomly assigned into two groups; a retrobulbar administration of lignocaine and bupivacaine in a 1:2 volume ratio combined with either BLD or 0.9% saline (BLS). The total volume of the intraconal injection was calculated at 0.1 mL/cm cranial length. Intraoperative parameters were recorded: heart rate (HR), respiratory rate (RR), end-tidal CO2 (EtCO2 ) arterial blood pressure (BP), and inspired isoflurane concentration (ISOinsp). Pain scores, heart rate and RR were recorded postoperatively.

RESULTS

Dogs receiving BLD (n = 8) had significantly lower intraoperative RR (p = 0.007), and significantly lower ISOinsp (p = 0.037) than dogs in the BLS group (n = 9). Postoperatively heart rate was significantly lower in the BLD group at 1 min (p = 0.025) and 1 h (p = 0.022). There were no other significant differences in intraoperative or postoperative parameters, or in postoperative pain scores (p = 0.354). Dogs receiving BLD had a higher rate of anesthetic events of bradycardia and hypertension (p = 0.027). Analgesic rescue was not needed in either group.

CONCLUSIONS

The addition of BLD to retrobulbar anesthesia did not result in a detectable difference in pain scores relative to blockade with lignocaine and bupivacaine alone. Dogs receiving retrobulbar BLD had a significantly lower intraoperative RR and isoflurane requirement and an increased incidence of intraoperative bradycardia and hypertension.

Spinal Anaesthesia Using Hypobaric Drugs: A Review of Current Evidence

Spinal anesthesia is one of the most widely used techniques in modern anesthesia practice. It involves the injection of local anesthetic drugs into the cerebrospinal fluid (CSF) within the subarachnoid space. The choice of drug, its concentration, and baricity play a crucial role in determining the characteristics of the spinal block and has evolved over the years with continuous advancements in drug formulations and administration methods. Spinal anesthesia with hypobaric drugs represents a valuable technique in the armamentarium of anesthesiologists, offering distinct advantages in terms of targeted action, reduced systemic toxicity, and enhanced hemodynamic stability. This review aims to scan the characteristics of hypobaric drugs, factors influencing their spread within the spinal canal, challenges associated with their use, clinical applications in various surgical scenarios, and potential implications for patient outcomes and healthcare practice. PubMed and Google Scholar databases were searched for relevant articles and a total of 23 relevant articles were selected for the review based on inclusion and exclusion criteria. Hypobaric drugs have many advantages in high-risk morbidly ill patients for some select surgical procedures and daycare surgeries. The concentration and volume of hypobaric drugs need to be selected according to the extensiveness of the surgery and the desired block can be achieved by giving spinal injection in specific positions. The dynamic field of anesthesiology encompasses the integration of emerging technologies and evidence-based practices, which will contribute to further refining the safety and efficacy of spinal anesthesia with hypobaric drugs.

Intrathecal ropivacaine versus bupivacaine in a non-obstetric population- A meta-analysis and trial sequential analysis

Background and Aims

Intrathecal bupivacaine is used for anaesthesia and analgesia but is associated with hypotension. Ropivacaine is an alternative drug that may have fewer cardiotoxic and neurotoxic events. This meta-analysis investigated whether intrathecal ropivacaine is associated with reduced hypotension as compared to bupivacaine.

Methods

The meta-analysis is registered in the International Prospective Register of Systematic Reviews (PROSPERO). The databases PubMed, Cinahl Plus, Google Scholar, and Scopus were searched, and papers from January 1980 to January 2023 were deemed eligible and filtered using predetermined inclusion and exclusion criteria. The primary outcome was the incidence of hypotension. Secondary outcomes were the duration of sensory block, duration of motor block, incidence of bradycardia, ephedrine usage, and duration of analgesia. Jadad scores were used to evaluate the quality of the papers. RevMan statistical software® utilised inverse variance and a random effect model to calculate the standardised mean difference with 95% confidence intervals for continuous variables and the Mantel-Haenszel test and the random effect model to calculate the odds ratio for dichotomous variables.

Results

Thirty-three papers, including 2475 patients in total, were included. The Jadad score was between 1 and 5. The incidence of hypotension was significantly higher with intrathecal bupivacaine than with ropivacaine (P = 0.02). The duration of sensory block (P < 0.001) and motor block (P < 0.001) was prolonged with intrathecal bupivacaine. The duration of analgesia favoured intrathecal bupivacaine (P = 0.003).

Conclusion

Intrathecal ropivacaine has a reduced incidence of hypotension and a reduced duration of sensory block compared to bupivacaine.

Development of an Accelerated Rotator-based Drug Release Method for the Evaluation of Bupivacaine Multivesicular Liposomes

PURPOSE

A multivesicular liposome (MVL) is a liposomal vehicle designed to achieve sustained release characteristics for drugs with short half-lives. For example, a commercial MVL formulation of bupivacaine has been approved by the U.S. Food and Drug Administration for local and regional analgesia. For complex formulations like those containing MVLs, challenges in developing an in vitro release testing (IVRT) method may hinder generic development and regulatory approval. In this study, we developed an accelerated rotator-based IVRT method with the ability to discriminate bupivacaine MVLs with different quality attributes.

METHODS

Three IVRT experimental setups including mesh tube, horizontal shaker, and vertical rotator were screened to ensure that at least 50% of bupivacaine can release from MVLs in 24 h. Sample dilution factors, incubation temperature, and the release media pH were optimized for the IVRT. The reproducibility of the developed IVRT method was validated with commercial bupivacaine MVLs. The discriminative capacity was assessed via comparing commercial and compromised bupivacaine MVL formulations.

RESULTS

The rotator-based release setup was chosen due to the capability to obtain 70% of drug release within 24 h. The optimized testing conditions were chosen with a 50-fold dilution factor, a temperature of 37ºC, and a media pH of 7.4.

CONCLUSIONS

An accelerated rotator-based IVRT method for bupivacaine MVLs was developed in this study, with the discriminatory ability to distinguish between formulations of different qualities. The developed IVRT method was a robust tool for generic development of MVL based formulations.

Prophylactic infusion of norepinephrine does not affect the rostral spread of spinal anesthesia in pregnancy: a prospective, randomized, double-blinded study

Background: The infusion of phenylephrine to prevent spinal-induced hypotension (SIH) in cesarean delivery may decrease the rostral spread of a spinal local anesthetic. We hypothesized that infusion of norepinephrine may decrease the rostral spread of spinal anesthesia, similar to that caused by phenylephrine. The aim of this study was to compare the block height of spinal anesthesia in the presence or absence of norepinephrine infusion administered to prevent SIH during cesarean delivery. Methods: Eighty patients were enrolled and allocated into groups receiving a norepinephrine infusion (group N) or saline infusion (group C). After intrathecal injection of hyperbaric bupivacaine 10 mg, the block height for cold and pinprick sensation was checked 10 and 20 min after the injection. The demographic characteristics, spinal anesthesia, side effects, and neonatal outcomes were also recorded. Results: The block height for cold and pinprick sensation was similar between the two groups, although the incidence of hypotension was significantly lower (p < 0.00) in group N than in group C. Systolic blood pressure was also more stable in group N than in group C, with the incidence of interventions being significantly lower in group N. There was no significant difference in patient satisfaction between the two groups. Conclusion: Evidence from this study suggested that prophylactic norepinephrine infusion does not reduce the rostral spread of spinal anesthesia in pregnancy. We suggest that it is not necessary to increase the dose of an intrathecal local anesthetic for cesarean delivery when prophylactic norepinephrine is administered. Clinical Trial Registration: https://www.chictr.org.cn/bin/project/edit?pid=152899, identifier [ChiCTR2200057439].

Dose effect and duration of action of liposomal bupivacaine administered as a perineural analgesic in a reversible and adjustable frog-pressure model of equine lameness

OBJECTIVE

To determine the dose effect of peri-neural liposomal bupivacaine (LB) in an induced forelimb lameness model.

ANIMALS

12 clinically normal adult horses.

METHODS

A randomized cross-over design was performed with 1 limb receiving saline and the other LB: low dose (6), high dose (6). Lameness was induced in 1 forelimb using a frog-pressure model. In the lame limb, peri-neural injection of the palmar nerves at the proximal sesamoid bones was performed using saline, low dose LB (0.25 mg/kg) (LDLB), or high dose LB (0.5mg/kg) (HDLB) in random order with a 1-week washout period between treatments. Distal limb swelling, mechanical nociceptive thresholds (MNT), and objective lameness data were collected before and up to 72 hours after peri-neural anesthesia. Data analysis was performed with mixed model ANOVA, equality of medians test, and Kaplan Meier survival analysis.

RESULTS

Compared with baseline, horses treated with LDLB and HDLB had improvements in MNT and lameness (P < .001). In the LDLB group, the median duration of analgesia was 4.5 hours (range = 3-6 hours) and the median return to lameness was 7 hours (range = 4-24 hours). In the HDLB group, the median duration of analgesia was 12 hours (range = 4-48 hours) and the median return to lameness was 9 hours (range = 3-48 hours). Mild to moderate swelling was identified in 11/12 (92%) LB limbs.

CLINICAL RELEVANCE

Both LDLB and HDLB resulted in loss of skin sensation and improvement of lameness. There was high variability among horses in duration of action for both doses.

Liposomal bupivacaine for ultrasound-guided rectus sheath blocks after midline laparotomy

Optimal pain management after open abdominal surgery is essential but can be difficult to achieve. The effects of inadequate analgesia go beyond the first few postoperative days; severe acute postoperative pain may contribute to the development of chronic postsurgical pain. Thoracic epidural analgesia is a traditional approach to the management of acute pain after open abdominal surgery but has multiple possible contraindications and can be technically challenging. In our hospital, we typically offer ultrasound-guided rectus sheath blocks with catheters when epidural analgesia is not feasible. However, the recent registration of long-acting liposomal bupivacaine in the Netherlands as well as logistical and equipment-related issues have led us to consider liposomal bupivacaine as an alternative to the use of catheters. Here, we present a short case series to describe our first clinical experiences with the use of liposomal bupivacaine in ultrasound-guided rectus sheath blocks after midline laparotomy for three patients in whom epidural insertion was contraindicated.

YTHDF1-mediated sphingosine kinase 2 upregulation alleviates bupivacaine-induced neurotoxicity via the PI3K/AKT axis

BACKGROUND

Bupivacaine (BUP), a long-acting local anesthetic, has been widely used in analgesia and anesthesia. However, evidence strongly suggests that excessive application of BUP may lead to neurotoxicity in neurons. Sphingosine kinase 2 (SPHK2) has been reported to exert neuroprotective effects. In this study, we intended to investigate the potential role and mechanism of SPHK2 in BUP-induced neurotoxicity in dorsal root ganglion (DRG) neurons.

METHODS

DRG neurons were cultured with BUP to simulate BUP-induced neurotoxicity in vitro. CCK-8, LDH, and flow cytometry assays were performed to detect the viability, LDH activity, and apoptosis of DRG neurons. RT-qPCR and western blotting was applied to measure gene and protein expression. Levels. MeRIP-qPCR was applied for quantification of m6A modification. RIP-qPCR was used to analyze the interaction between SPHK2 and YTHDF1.

RESULTS

SPHK2 expression significantly declined in DRG neurons upon exposure to BUP. BUP challenge substantially reduced the cell viability and increased the apoptosis rate in DRG neurons, which was partly abolished by SPHK2 upregulation. YTHDF1, an N6-methyladenosine (m6A) reader, promoted SPHK2 expression in BUP-treated DRG neurons in an m6A-dependent manner. YTHDF1 knockdown partly eliminated the increase in SPHK2 protein level and the protection against BUP-triggered neurotoxicity in DRG neurons mediated by SPHK2 overexpression. Moreover, SPHK2 activated the PI3K/AKT signaling to protect against BUP-induced cytotoxic effects on DRG neurons.

CONCLUSIONS

In sum, YTHDF1-mediated SPHK2 upregulation ameliorated BUP-induced neurotoxicity in DRG neurons via promoting activation of the PI3K/AKT signaling pathway.

Therapeutic potential of luteolin-loaded poly(lactic-co-glycolic acid)/modified magnesium hydroxide microsphere in functional thermosensitive hydrogel for treating neuropathic pain

Neuropathic pain (NP) is a debilitating condition stemming from damage to the somatosensory system frequently caused by nerve injuries or lesions. While existing treatments are widely employed, they often lead to side effects and lack specificity. This study aimed to alleviate NP by developing an innovative sustained-release thermosensitive hydrogel system. The system incorporates hyaluronic acid (HA)/Pluronic F127 injectable hydrogel and bupivacaine (Bup, B) in combination with poly(lactic-co-glycolic acid; PLGA)/modified magnesium hydroxide (MH)/luteolin (Lut; PML) microspheres (PML@B/Gel). The PML@B/Gel was designed for localized and prolonged co-delivery of Bup and Lut as an anesthetic and anti-inflammatory agent, respectively. Our studies demonstrated that PML@B/Gel had exceptional biocompatibility, anti-inflammatory, and antioxidant properties. In addition, it exhibited efficient pain relief in in vitro cellular assays. Moreover, this functional hydrogel showed substantial sustained drug release while diminishing microglial activation. Consequently, it effectively mitigated mechanical allodynia and thermal hyperalgesia in in vivo rat models of chronic constriction injury (CCI). Based on our research findings, PML@B/Gel emerges as a promising therapeutic approach for the protracted treatment of NP.

Intra-Articular Local Anesthetics in Temporomandibular Disorders: A Systematic Review and Meta-Analysis

This systematic review with meta-analysis was conducted to evaluate the effectiveness of local anesthetic administration into temporomandibular joint cavities in relieving pain and increasing mandibular mobility. Randomized controlled trials were included with no limitation on report publication dates. Final searches were performed on 15 October 2023, using engines provided by the US National Library, Bielefeld University, and Elsevier Publishing House. The risk of bias was assessed using the Cochrane Risk of Bias 2 tool. Articular pain and mandible abduction values and their mean differences were summarized in tables and graphs. Eight studies on a total of 252 patients evaluating intra-articular administration of articaine, bupivacaine, lidocaine, and mepivacaine were included in the systematic review. None of the eligible studies presented a high risk of bias in any of the assessed domains. An analgesic effect of intra-articular bupivacaine was observed for up to 24 h. In the long-term follow-up, there were no statistically significant changes in quantified pain compared to both the baseline value and the placebo group, regardless of the anesthetic used (articaine, bupivacaine, and lidocaine). There is no scientific evidence on the effect of intra-articular administration of local anesthesia on the range of motion of the mandible. Therefore, in the current state of knowledge, the administration of local anesthetics into the temporomandibular joint cavities can only be considered as a short-term pain relief measure.

Depolymerized Chitosan-g-[Poly(MMA-co-HEMA-cl-EGDMA)] Based Nanogels for Controlled Local Release of Bupivacaine

This study is designed to formulate and characterize chitosan-based nanogels that provide the controlled delivery of anesthetic drugs, such as bupivacaine (BPV), for effective postoperative pain management over prolonged periods of time. Drug carriers of chitosan/poly (MMA-co-HEMA-cl-EGDMA) (CsPMH) nanogels were prepared by varying the composition of comonomers such as MMA, HEMA, and redox initiator CAN. The nanogels were then characterized using FTIR, TGA, SEM, and TEM. The CsPMH nanogels showed greater encapsulation efficiencies from 43.20-91.77%. Computational studies were also conducted to evaluate the interaction between the drug and CsPMH nanoparticles. Finally, BPV-loaded nanoparticles were used to examine their in vitro release behavior. At pH 7.4, all the drug carriers displayed the "n" value around 0.7, thus the BPV release follows anomalous diffusion. Drug carrier 7 demonstrated a steady and sustained release of BPV for approximately 24 h and released about 91% of BPV, following the K-P mechanism of drug release. On the other hand, drug carrier 6 exhibited controlled release for approximately 12 h and released only 62% of BPV.

Intraoperative and Postoperative Effects of Dexmedetomidine and Tramadol Added as an Adjuvant to Bupivacaine in Transversus Abdominis Plane Block

Background: We aimed to evaluate the intraoperative hemodynamics, opioid consumption, muscle relaxant use, postoperative analgesic effects, and possible adverse effects (such as nausea and vomiting) of dexmedetomidine and tramadol added as adjuvants to bupivacaine in the transversus abdominis plane block (TAP block) to provide postoperative analgesia. Materials and Methods: This was a prospective, randomized, controlled trial on patients who underwent laparoscopic cholecystectomy. After obtaining ethical approval at the Van Yuzuncu Yil University and written informed consent, this investigation was registered with ClinicalTrials.gov (NCT05905757). The study was conducted with 67 patients with ASA I-II physical status, aged 20-60 years, of either sex who were scheduled for an elective laparoscopic cholecystectomy under general anesthesia. Exclusion criteria were the patient's refusal, ASA III and above, a history of allergy to the study drugs, patients with severe systemic diseases, pregnancy, psychiatric illness, seizure disorder, and those who had taken any form of analgesics in the last 24 h. The patients were equally randomized into one of two groups: Group T (TAP Block group) and Group D (Dexmedetomidin group). Standard general anesthesia was administered. After intubation, Group T (Bupivacaine + adjuvant tramadol) = solutions containing 0.250% bupivacaine 15 mL + adjuvant 1.5 mg/kg (100 mg maximum) tramadol 25 mL and Group D (Bupivacaine + adjuvant dexmedetomidine) = solutions containing 0.250% bupivacaine 15 mL + 0.5 mcg/kg and (50 mcg maximum) dexmedetomidine 25 mL; in total, 40 mL and 20 mL was applied to groups T and D, respectively. A bilateral subcostal TAP block was performed by the same anesthesiologist. Intraoperative vital signs, an additional dose of opioid and muscle relaxant requirements, complications, postoperative side effects (nausea, vomiting), postoperative analgesic requirement, mobilization times, and the zero-hour mark (patients with modified Aldrete scores of 9 and above were recorded as 0 h), the third-hour, and sixth-hour visual analog scale (VAS) scores were recorded. The main outcome measurements were the effect on pain scores and analgesic consumption within the first 6 h postoperatively, postoperative nausea and vomiting (PONV), and time to ambulation. The secondary aim was to evaluate intraoperative effects (on hemodynamics and opioid and muscle relaxant consumption). Results: It was observed that dexmedetomidine and tramadol did not have superiority over each other in terms of postoperative analgesia time, analgesic consumption, side effect profile, and mobilization times (p > 0.05). However, more stable hemodynamics were observed with dexmedetomidine as an adjuvant. Conclusions: We think that the use of adjuvant dexmedetomidine in the preoperative TAP block procedure will provide more stable intraoperative hemodynamic results compared with the use of tramadol. We believe that our study will be a guide for new studies conducted with different doses and larger numbers of participants.

Local Anesthetic Systemic Toxicity During Transversus Abdominis Plane Block With Liposomal Bupivacaine

Local anesthetic systemic toxicity (LAST) is a rare but potentially fatal outcome associated with local anesthetic administration. Liposomal bupivacaine (LB; EXPAREL®) is a widely used local anesthetic with extended-release and liposomal formulation that carries an improved cardiac and central nervous system safety profile. However, there is limited data regarding LAST associated with liposomal bupivacaine. Here is described a case of local anesthetic systemic toxicity in a 68-year-old male who presented with obstructing sigmoid adenocarcinoma and underwent open sigmoidectomy with end descending colostomy. The operation was complicated by LAST following transversus abdominis plane block injection with liposomal bupivacaine resulting in cardiac arrest. Return of spontaneous circulation was achieved following advanced cardiac life support and infusion of 20% I.V. fat emulsion. Given the widespread use of local anesthetics, providers must be aware of the pathophysiology, diagnosis, and immediate treatment of LAST.

Erector spinae plane block for post-operative analgesia in thoracolumbar spine surgery: A randomised controlled trial

Background and Aims

Thoracolumbar spine surgery is one of the most painful surgical procedures. This study's primary objective was to evaluate the effect of erector spinae plane (ESP) block on post-operative cumulative morphine consumption at 24 h in patients undergoing thoracolumbar spine surgery.

Methods

Seventy adults posted for thoracolumbar spine surgery were randomised into the control group [Number of patients (n)=35], who received general anaesthesia without any nerve block, and the intervention group (n = 35), who received bilateral ultrasound (US)-guided ESP block at the level of spine surgery with 0.25% bupivacaine 20 mL after standard general anaesthesia. Along with intravenous patient-controlled analgesia morphine, post-operative analgesia was standardised for both groups. Total morphine consumption, visual analogue scale (VAS) score to evaluate pain, overall patient satisfaction, and any side effects were compared at 24 h. The statistical analysis was done using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL).

Results

Post-operative total morphine consumption at 24 h was significantly decreased in the intervention group compared to the control group [5.69 (1.549) versus 9.51 (1.634) mg; P < 0.001]. Post-operative VAS scores were also significantly decreased in the intervention group at rest (P < 0.001) and on movement (P < 0.001). Patient satisfaction scores were more favourable in the intervention group [3.8 (0.4) versus 3.2 (0.6); P < 0.001]. Post-operative nausea and vomiting were found more in the control group but were not significant (n = 14 versus 8; P = 0.127).

Conclusion

US-guided ESP block significantly reduces post-operative morphine consumption and improves analgesia and patient satisfaction without adverse effects in patients undergoing thoracolumbar spine surgery.

Evaluation of age-based local anaesthetic dosing of bupivacaine for popliteal sciatic nerve block in children undergoing foot and ankle surgery: A prospective single arm interventional study

Background and Aims

Recommendations on paediatric single-injection local anaesthetic (LA) dosing for peripheral nerve blocks (PNBs) are based on the children's weight and limited by weight-based toxicity concerns. In this study, we assessed the extent of circumferential spread and block characteristics following the injection of an age-based volume (age in years = LA volume) of 0.25% bupivacaine following popliteal sciatic nerve block (PSNB).

Methods

Thirty children aged between 2 and 12 years with the American Society of Anesthesiologists (ASA) physical status I and II and undergoing foot and ankle surgical procedures were given single-injection ultrasound-guided subparaneural PSNB using 0.25% bupivacaine at age-based LA volume after the administration of anaesthesia. The circumferential pattern of LA spread (primary objective) was assessed along the nerve (both cephalad and caudal) using ultrasound from the point of administration and the block characteristics in terms of duration of sensory block.

Results

The mean [standard deviation (SD)] cephalic circumferential LA spread distance was 2.52 (0.68) [95% confidence interval (CI): 2.27-2.76] cm. The mean (SD) caudal circumferential LA spread distance was 2.27 (0.48) [95% CI: 2.09-2.44] cm. The mean (SD) duration of the sensory block was 9.03 (0.97) [95% CI: 8.67-9.38] h.

Conclusion

The age-based LA volume of bupivacaine for ultrasound-guided PSNB resulted in a longitudinal circumferential spread of around 4.7 cm (adding both cephalic and caudal spread) and provided adequate analgesia for nine postoperative hours.

Laparoscopic administration of bupivacaine at the uterosacral ligaments during benign laparoscopic and robotic hysterectomy: a randomized controlled trial

BACKGROUND

Postoperative pain continues to be an undermanaged part of the surgical experience. Multimodal analgesia has been adopted in response to the opioid epidemic, but opioid prescribing practices remain high after minimally invasive hysterectomy. Novel adjuvant opioid-sparing analgesia to optimize acute postoperative pain control is crucial in preventing chronic pain and minimizing opioid usage.

OBJECTIVE

This study aimed to determine the effect of direct laparoscopic uterosacral bupivacaine administration on opioid usage and postoperative pain in patients undergoing benign minimally invasive (laparoscopic and robotic) hysterectomy.

STUDY DESIGN

This was a single-blinded, triple-arm, randomized controlled trial at an academic medical center between March 15, 2021, and April 8, 2022. The inclusion criteria were patients aged >18 years undergoing benign laparoscopic or robotic hysterectomy. The exclusion criteria were non-English-speaking patients, patients with an allergy to bupivacaine or actively using opioid medications, patients undergoing transversus abdominis plane block, and patients undergoing supracervical hysterectomy or combination cases with other surgical services. Patients were randomized in a 1:1:1 fashion to the following uterosacral administration before colpotomy: no administration, 20 mL of normal saline, or 20 mL of 0.25% bupivacaine. All patients received incisional infiltration with 10 mL of 0.25% bupivacaine. The primary outcome was 24-hour oral morphine equivalent usage (postoperative day 0 and postoperative day 1). The secondary outcomes were total oral morphine equivalent usage in 7 days, last day of oral morphine equivalent usage, numeric pain scores from the universal pain assessment tool, and return of bowel function. Patients reported postoperative pain scores, total opioid consumption, and return of bowel function via Qualtrics surveys. Patient and surgical characteristics and primary and secondary outcomes were compared using chi-square analysis and 1-way analysis of variance. Multiple linear regression was used to identify predictors of opioid use in the first 24 hours after surgery and total opioid use in the 7 days after surgery.

RESULTS

Of 518 hysterectomies screened, 410 (79%) were eligible, 215 (52%) agreed to participate, and 180 were ultimately included in the final analysis after accounting for dropout. Most hysterectomies (70%) were performed laparoscopically, and the remainder were performed robotically. Most hysterectomies (94%) were outpatient. Patients randomized to bupivacaine had higher rates of former and current tobacco use, and patients randomized to the no-administration group had higher rates of previous surgery. There was no difference in first 24-hour oral morphine equivalent use among the groups (P=.10). Moreover, there was no difference in numeric pain scores (although a trend toward significance in discharge pain scores in the bupivacaine group), total 7-day oral morphine equivalent use, day of last opioid use, or return of bowel function among the groups (P>.05 for all). The predictors of increased 24-hour opioid usage among all patients included only increased postanesthesia care unit oral morphine equivalent usage. The predictors of 7-day opioid usage among all patients included concurrent tobacco use and mood disorder, history of previous laparoscopy, estimated blood loss of >200 mL, and increased oral morphine equivalent usage in the postanesthesia care unit.

CONCLUSION

Laparoscopic uterosacral administration of bupivacaine at the time of minimally invasive hysterectomy did not result in decreased opioid usage or change in numeric pain scores.

The Benefits of Local Anesthesia Used in Mastectomy Without Reconstruction

BACKGROUND

The opioid epidemic has driven renewed interest in local anesthesia to reduce postoperative opioid use. Our objective was to determine if local anesthesia decreased hospital pain scores, oral morphine equivalents (OME), length of stay (LOS), and nausea/vomiting.

METHODS

Single institution retrospective study of females who underwent mastectomy without reconstruction.

RESULTS

Overall, 712 patients were included; 63 (8.8%) received bupivacaine (B), 512 (72%) liposomal bupivacaine (LB), and 137 (19%) no local. 95% were discharged on POD1. Liposomal bupivacaine use increased from 2014 to 2019. Additional factors associated with use of local regimen were surgeon and extent of axillary surgery. Fewer patients used postop opioids during their hospital stay if any local was used compared to none (76 vs 88%; 0.003). Compared to none, local had shorter mean PACU LOS (95 vs 87 min; P = .02), lower mean intraoperative-OME (96 vs 106; P < .001), and lower mean postoperative OME/hr (1.4 vs 1.8 P = .001). Multivariable analysis (MVA) showed lower OME/hr with LB compared to B and none (P = .002); this translates to 22 mg and 30 mg of oxycodone in a 24-hr period, respectively. MVA showed lower POD1 pain scores with LB relative to none (P = .049). Local did not impact nausea/emesis.

CONCLUSION

Local anesthesia was superior to no local in several measures. However, a consistent benefit of a specific local anesthetic agent was not demonstrated (LB vs B). A prospective study is warranted to determine the optimal local regimen for this cohort and further inform clinical relevance.

Analgesic efficacy of intra-peritoneal instillation of dexamethasone and bupivacaine versus bupivacaine following laparoscopic cholecystectomy - A randomised, double-blind controlled study

Background and Aims

Laparoscopy is associated with acute pain. We compared the effectiveness of intra-peritoneal dexamethasone with bupivacaine versus bupivacaine in patients undergoing laparoscopic cholecystectomy for postoperative analgesia.

Methods

This randomised study was conducted after approval from the institutional ethics committee and 84 patients were randomly allocated into bupivacaine with dexamethasone group (BD) (received 40 mL of 0.25% bupivacaine with 16 mg dexamethasone), and bupivacaine group (BB) (received 40 mL of 0.25% bupivacaine intra-peritoneally). Data analysis was done using R version 4.2.1. The visual analogue scale (VAS) score, total rescue analgesic dose, and time required for the first analgesic between groups were compared using the Wilcoxon rank sum test or t-test appropriately.

Results

VAS score was significantly lower in the BD group compared to the BB group until 2 h post-operatively with a mean difference of - 1.0 (95% confidence interval [CI] -1.5, -0.53), P < 0.001. The total rescue analgesic dose consumed was lower in the BD group (60.71 mg [29.80]) compared to the BB group (73.20 mg [11.57]) with a mean difference of - 12.5 mg (95% CI - 22.3, -2.68), P = 0.013. In addition, the time taken for the requirement of the first rescue analgesic was significantly longer in the BD group (417.1 min [276.0]) compared to the BB group (219.4 min [226.1]) with a mean difference of 197.7 (95% CI 75, 320), P = 0.002.

Conclusion

Intra-peritoneal instillation of 16 mg dexamethasone with 0.25% bupivacaine in laparoscopic cholecystectomy significantly reduces post-operative pain and requirement of rescue analgesic compared to 0.25% bupivacaine alone.

Cis-2-Decenoic Acid and Bupivacaine Delivered from Electrospun Chitosan Membranes Increase Cytokine Production in Dermal and Inflammatory Cell Lines

Wound dressings serve to protect tissue from contamination, alleviate pain, and facilitate wound healing. The biopolymer chitosan is an exemplary choice in wound dressing material as it is biocompatible and has intrinsic antibacterial properties. Infection can be further prevented by loading dressings with cis-2-decenoic acid (C2DA), a non-antibiotic antimicrobial agent, as well as bupivacaine (BUP), a local anesthetic that also has antibacterial capabilities. This study utilized a series of assays to elucidate the responses of dermal cells to decanoic anhydride-modified electrospun chitosan membranes (DA-ESCMs) loaded with C2DA and/or BUP. Cytocompatibility studies determined the toxic loading ranges for C2DA, BUP, and combinations, revealing that higher concentrations (0.3 mg of C2DA and 1.0 mg of BUP) significantly decreased the viability of fibroblasts and keratinocytes. These high concentrations also inhibited collagen production by fibroblasts, with lower loading concentrations promoting collagen deposition. These findings provide insight into preliminary cellular responses to DA-ESCMs and can guide future research on their clinical application as wound dressings.

Perioperative Analgesia and Patients' Satisfaction in Spinal Anesthesia for Cesarean Section: Fentanyl Versus Morphine

Perioperative analgesia for cesarean section aims to ensure the mother's comfort, facilitate a smooth surgical experience, and promote a successful recovery. One-hundred-ninety patients were enrolled in a randomized double-blind study designed to assess the quality of perioperative analgesia, level of satisfaction, and incidence of adverse reactions in elective cesarean section under spinal anesthesia when fentanyl or morphine was added to bupivacaine. Two treatment groups comprising 173 subjects were compared in the per-protocol analysis: F (fentanyl, standard dose 25 μg) and M (morphine, standard dose 100 μg). Numerical pain scores were recorded perioperatively for 72 h (both at rest and on mobilization), with overall postoperative satisfaction and analgesic-related side effects. The patients in the morphine group had significantly better pain management (Mann-Whitney U test, p < 0.001) and higher level of satisfaction (Mann-Whitney U test, p < 0.001). The latter was related to the greater need for rescue medication in the fentanyl group (OR = 4.396; p = 0.019). On the other hand, fentanyl had significantly fewer non-life-threatening side effects, such as high-intensity pruritus (Mann-Whitney U test, p < 0.001), nausea (OR = 0.324; p = 0.019), vomiting and dizziness upon first mobilization (OR = 0.256; p < 0.001). It remains for future clinical trials to help establish doses that will tilt the scale to one side or the other.

Comparison of Dexamethasone Versus Methylprednisolone With Bupivacaine in Transversus Abdominis Plane Block for Attenuation of Chronic Postoperative Abdominal Pain

Background  Opioids, which have well-known adverse effects such as drowsiness paralytic ileus and respiratory depression, were mostly utilised to treat postoperative pain in the past. The increased incidence of side effects has led to a rise in interest in pain management techniques that spare opioids. Persistent abdominal pain following surgery has a major detrimental effect on patients' quality of life. While epidural analgesia is widely regarded as the gold standard to combat the pain that is present post abdominal surgeries, it is not devoid of drawbacks. The transversus abdominis plane (TAP) block has developed as a potentially effective treatment for severe abdominal pain. The TAP block acts on the neuro-fascial plane between the internal oblique and transversus abdominis muscles, which is innervated by spinal nerves from T6 to L1. Studies reveal that the addition of corticosteroids to bupivacaine in TAP blocks provides pain relief and improves the quality of life of the patient. Aims and objectives  In this study, the effects of bupivacaine and corticosteroids, particularly dexamethasone and methylprednisolone, on chronic abdominal pain following surgery are examined. Assessing the quality of pain relief is the primary objective. Methodology  Thirty patients who had undergone abdominal surgery and had been having persistent abdominal pain for six to eight months thereafter and had attempted unsuccessfully to treat the pain with alternative pain relief methods participated in the study. They were divided into two groups at random. Dexamethasone and bupivacaine were given to patients in Group D while methylprednisolone and bupivacaine were given to patients in Group M for ultrasonography (USG)-guided bilateral TAP blocks. At various intervals up to 12 weeks after injection, the patient's pain levels were measured using the visual analogue score (VAS), and their quality of life was assessed using the quality-of-life score. Results  Patients in Group M experienced significantly less pain than those in Group D at the fourth, sixth, and 12th weeks of treatment. Furthermore, in the fourth, sixth, and 12th weeks, patients in Group M reported a superior quality of life in comparison to those in Group D. Conclusion  Patients with persistent postoperative abdominal pain receiving bupivacaine and methylprednisolone in an ultrasonography-guided TAP block experience more effective and long-lasting pain relief than those who receive bupivacaine and dexamethasone. The quality of life for patients may be enhanced by using corticosteroids to optimise postoperative pain management strategies and lessen the need for opioids, as this study highlights.

Liposomal versus plain bupivacaine for pain control following vaginal reconstruction

INTRODUCTION

Liposomal bupivacaine (LB) is a depot formulation of bupivacaine, which releases the drug over 72 hours to prolong local pain control. This retrospective study compares the effect of using LB versus plain bupivacaine on postoperative pain control, length of hospital stay and cost among patients undergoing vaginal reconstructive surgery.

MATERIALS AND METHODS

Patients who underwent vaginal reconstructive surgery with levatorplasty and received an injection of 20 cc of either plain bupivacaine or LB for pudendal nerve block were included. The primary outcomes included postoperative narcotic use and subjective pain score. The secondary outcome was postoperative length of stay. Comparisons between groups were performed using the T test, Mann Whitney U and Chi-square tests with p < 0.05 considered significant.

RESULTS

Between June 2016 and December 2021, 25 patients had received LB as a pudendal nerve block and 25 had received plain bupivacaine. Demographics between groups were similar. There was no difference between postoperative morphine equivalent dose (MED) for plain bupivacaine versus LB (25.3 ± 65.8 vs. 24.9 ± 31.7 MED; p = 0.159) or length of hospital stay (15.8 ± 12.0 hours vs. 23.8 ± 20.0; p = 0.094). Furthermore, subjective pain was also similar between groups (0 vs. 1.6 ± 2.6, p = 0.68), (4.6 ± 2.3 vs. 4.9 ± 2.0 average POD 1 pain, p = 0.534) and (4.3 ± 2.1 for vs. 4.9 ± 2.1 average POD 2 pain, p = 0.373).

CONCLUSION

LB is not superior to plain bupivacaine for controlling pain following vaginal reconstructive surgery, and justification for the exponentially greater cost of LB is not supported. Prospective investigations with larger sample sizes are needed to determine the optimal pain management for levatorplasty in vaginal reconstructive surgery.

Improving rat welfare through the development of a peribulbar anaesthesia technique for ophthalmic procedures: A preliminary study

Rats are a commonly used animal model for the study of the pathogenesis and novel treatments of glaucoma, which is induced experimentally using invasive, painful procedures. Peribulbar anaesthesia (PBA) is frequently used in people and domestic animals prior to ophthalmic surgeries to provide excellent perioperative analgesia. Our goal was to develop a PBA technique adapted to rat anatomy, improving the welfare of animals used as a model for glaucoma. Eighteen rat cadavers (n = 36 eyes) were used to establish the optimal needle insertion location. Five injection techniques using 0.1 mL/100 g lidocaine 2% and a contrast agent (1:1 volume ratio) were compared via computed tomography (CT). CT images were scored for injectate distribution at four locations: extraconal, intraconal, around the optic nerve and at the orbital fissure (scale 0-8, where 0 = none and 8 = excellent). Median scores using the dorso-medial-75° (5; range 2-6) and medial-canthus (4.5; range 2-8) injection techniques were not different from the dorso-medial-45° (4; range 3-6) technique and were higher (better distribution) compared with mid-ventral (3; range 2-5) and ventro-lateral (2; range 1-3) techniques. The two superior techniques were used in two experimental rats (n = 4 eyes) to determine the volume of bupivacaine 0.5% necessary to affect corneal touch threshold (CTT) and periocular skin sensitivity (PSS). A volume of 0.05 mL/100 g decreased CTT and PSS for several hours, while a larger volume produced excessively long effects. Dorso-medial-75° or medial-canthus PBA using 0.05 mL/100 g bupivacaine are likely to provide ocular and periocular analgesia in rats, with minor transient adverse effects.

Comparative Evaluation of the Effect of Six Different Low-Surface-Tension Vehicles on the Penetration of Modified Triple Antibiotic Paste in Dentinal Tubules: An In Vitro Study

Background Modified triple antibiotic paste (MTAP) helps in the elimination of microorganisms which is imperative for the success of endodontic therapy. The intracanal medicament powders must be mixed with vehicles for better handling and penetration in the root canals. The purpose of this study is to compare the effect of six low-surface-tension vehicles on the penetration of MTAP in dentinal tubules. Methodology The root apices of 60 single-rooted human mandibular premolars were resected to obtain 12mm length. After biomechanical preparation, intracanal medicaments were prepared by mixing with the six vehicles (Group 1- Bupivacaine, Group 2- Sodium ether lauryl sulfate, Group 3- Neosporin H, Group 4- Chlorhexidine gluconate, Group 5- Chitosan, and Group 6- Polyethylene glycol) with MTAP and Rhodamine B dye. Middle and apical transverse sections were scanned under a confocal laser scanning microscope. The data were statistically analyzed using the one-way ANOVA test and the level of significance was p<0.05. Results The maximum depth of penetration was seen in Group 2 (MTAP with sodium ether lauryl sulfate) followed by Group 5 (MTAP with chitosan), Group 4 (MTAP with chlorhexidine gluconate), Group 1 (MTAP with bupivacaine), and Group 6 (MTAP with polyethylene glycol), and the least penetration by Group 3 (MTAP with Neosporin H). The depth of penetration in the middle level was in the order of Group 2 followed by Group 4, Group 5, Group 3, Group 6, and Group 1. The depth of penetration in the apical level was in the order of Group 2 followed by Group 5, Group 1, Group 4, Group 6, and Group 3. The overall depth of penetration was significantly higher at the middle level than at the apical level. Conclusion Group sodium ether lauryl sulfate showed the maximum depth of penetration in both the middle and apical areas. The least depth of penetration in the middle area was seen in group bupivacaine and the apical area by group Neosporin H.

Resveratrol‑mediated activation of SIRT1 inhibits the PERK‑eIF2α‑ATF4 pathway and mitigates bupivacaine‑induced neurotoxicity in PC12 cells

Endoplasmic reticulum (ER) stress and apoptosis play significant roles in the development of neurotoxicity caused by bupivacaine (BUP). By activating sirtuin 1 (SIRT1), resveratrol (RSV) can regulate various cellular processes associated with anti-oxidative stress, anti-apoptosis and anti-inflammatory responses, thereby exerting neuroprotective effects. However, it remains unknown whether the activation of SIRT1 by RSV is able to attenuate BUP-induced ER stress and apoptosis. Therefore, the present study aimed to explore the effect of RSV on BUP-induced cytotoxicity in PC12 cells and the underlying mechanism. Cell Counting Kit-8 assays, flow cytometry and inverted phase-contrast microscopy were used to assess the viability, apoptosis rate and morphological changes of the cells, respectively. Western blotting and immunofluorescence staining were used to analyze the levels of SIRT1, the apoptosis-related proteins Bax, Bcl-2 and cleaved caspase-3, the ER stress-related proteins glucose-regulated protein 78, caspase-12 and CHOP, and the protein kinase RNA-like ER kinase (PERK)-eukaryotic translation initiation factor 2 α (eIF2α)-activating transcription factor 4 (ATF4) pathway-associated proteins phosphorylated (p)-PERK, PERK, p-eIF2α, eIF2α and ATF4. The results revealed that BUP induced cell apoptosis and decreased cell viability, accompanied by the downregulation of SIRT1. However, RSV restored SIRT1 protein expression, downregulated the expression of the pro-apoptotic protein Bax, upregulated the expression of the anti-apoptotic protein Bcl-2, decreased the apoptosis rate of the cells and increased cell viability. Furthermore, the anti-apoptotic effects exhibited by RSV were associated with inhibition of the PERK-eIF2α-ATF4 pathway of ER stress. However, the protective effect of RSV was significantly mitigated by the SIRT1 inhibitor EX527. These results indicate that the activation of SIRT1 by RSV alleviates BUP-induced PC12 cell ER stress and apoptosis via regulation of the PERK-eIF2α-ATF4 pathway. These findings offer insights into the molecular mechanism underlying BUP-induced apoptosis and suggest the potential of RSV as a therapeutic agent against the neurotoxicity caused by BUP.

A Randomised Controlled Study on Epidural Morphine and Bupivacaine for Post-Operative Analgesia After Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

Randomised control study.

OBJECTIVE

Different parenteral analgesics are used to alleviate post-operative pain after transforaminal lumbar interbody fusion (TLIF) but limited by their efficacy and side effects. We performed a RCT to evaluate the safety and efficacy of epidural Morphine-Bupivacaine on post-operative pain management after TLIF.

METHODS

Consecutive patients (n=100) of TLIF were divided randomly into study (SG) and control groups (CG). At the end of procedure, SG (n=50) received epidural instillation of morphine 5 mg and bupivacaine .25% - 2 mL, along with 6 mL of .25% bupivacaine infiltration in the deep fascia before wound closure. The functional outcomes were assessed at regular intervals (4, 8, 12, 24, 36, 48, 72, 96 hours) with VAS, nausea and vomiting scale, Ramsay sedation scale and breakthrough analgesia needed, time to ambulation and other complications.

RESULTS

The mean VAS score at 4 hours in SG was significantly less (1.16 ± .88) than the CG (3.32 ± 1.0) (P = .000). This significant difference was maintained at each time point during the first 48 hours (P < .004). Similarly, the mean NRS score in SG at 4 hours was 1.02 ± .89, and in CG 3.3 ± .69 (P = .0000) which was maintained at all intervals of assessment till 48 hours (P = .0137). The mean time to first ambulation was significantly less in the SG (4.46 ± 1.04 hours) than CG (11.64 ± 2.3 hours) (P < .001). There were no drug-related complications.

CONCLUSION

Epidural instillation of bupivacaine and morphine is safe and enables better pain relief in the initial 48 hours which helps in early mobilisation, and enhanced functional recovery.

Liposomal bupivacaine is both safe and effective when administered via local infiltration at surgical site and mesovarium for laparoscopic ovariectomy in mares

BACKGROUND

Liposomal local anaesthetic solutions may provide extended-duration analgesia postoperatively but have not been assessed following intra-peritoneal local infiltration in any species.

OBJECTIVES

To evaluate two doses of 1.33% liposomal bupivacaine (LB) versus 0.75% bupivacaine HCL (BHCl) for analgesia following laparoscopic ovariectomy in mares.

STUDY DESIGN

Prospective cohort study.

METHODS

Fifteen healthy Quarter Horse mares (age 2-20 years) with normal bilateral ovarian palpation and appearance were enrolled. Horses were restrained in standing stocks and administered an α-2 agonist, butorphanol, and flunixin meglumine, followed by a variable rate infusion of sedation with α-2 agonists. Bilateral paralumbar fossa ovariectomies were performed. Treatment with either 30 ml 0.75% BHCl followed by 20 or 40 ml LB 13.3% (LB20 and LB40) volume expanded with saline to 80 ml total (n = 6/group) or 80 ml BHCl alone (n = 3, BCHL) was infused around incision sites and each mesovarium (LB or BHCl) prior to ovariectomy. Horses were monitored for 72 h by physical examination, algometry, and pain scoring (composite pain scale by Bussieres et al., Horse Grimace Scale). Abdominocentesis with peritoneal fluid analysis was performed at 72 h.

RESULTS

Analgesia achieved with all treatment protocols allowed completion of ovariectomy procedures. Pressure algometry scores were lower in BHCl-treated horses versus both LB groups overall. Pain scores were improved with LB-treated horses in a dose-dependent fashion (Horse Grimace Scale scores LB40 < LB20 < BHCL; composite pain scale scores LB40 < BHCL, LB20 < BHCL, BHCL, and LB20 did not differ). Peritoneal fluid total protein was lower in LB40 versus LB20 and BHCL horses. No complications from LB administration were appreciated.

MAIN LIMITATIONS

Small patient sample size, lack of follow-up past 72 h or histopathology.

CONCLUSIONS

Analgesia duration was extended and pain scores improved postoperatively with LB versus BHCl in a dose-dependent fashion. Further clinical evaluation of extended-duration local anaesthetics in horses for improved postoperative pain management is warranted.

Narcotic Utilization After Cleft Lip Repair: Does Local Anesthetic Choice Matter?

To analyze whether the choice of intraoperative local anesthetic for cleft lip repair is associated with the amount of perioperative narcotic utilization.

Retrospective cohort study.

Hospitals participating in the Pediatric Health Information System.

Primary cleft lip repairs performed in the United States from 2010 to 2020.

Local anesthesia injected-treatment with lidocaine alone, bupivacaine alone, or treatment with both agents.

Perioperative narcotic administration.

During the study interval, 8954 patients underwent primary cleft lip repair. Narcotic utilization for unilateral (P < .001) and bilateral (P = .004) cleft lip repair has decreased over the last 5 years. Overall, 21.8% (n = 1950) of infants were administered perioperative narcotics for cleft lip repair, such that 14.3% (n = 1282) required narcotics on POD 0, and 7.2% (n = 647) required narcotics on POD 1.In this study, 36.5% (n = 3269) patients received lidocaine, 22.0% (n = 1966) patients received bupivacaine, and 19.7% (n = 1762) patients received both local anesthetics. Administration of any perioperative narcotic was significantly lower in patients receiving both lidocaine and bupivacaine than those receiving only lidocaine (P = .001, 17.5% vs 21.7%) or only bupivacaine (P < .001, 17.5% vs 22.9%). Narcotic utilization on the day of surgery was significantly lower in patients receiving both lidocaine and bupivacaine than those receiving only lidocaine (P < .001, 11.5% vs 15.1%) or only bupivacaine (P = .004, 11.5% vs 14.6%). Narcotic utilization on the first postoperative day was significantly lower in patients receiving both lidocaine and bupivacaine than those receiving only bupivacaine (P = .009, 5.9% vs 8.1%).

CONCLUSIONS

In children undergoing cleft lip repair, local anesthetic combination of lidocaine and bupivacaine is associated with decreased perioperative narcotic use compared to lidocaine or bupivacaine alone.

The Effect of Local Anesthetics on Neutrophils in the Context of Different Isolation Techniques

Various functions of polymorphonuclear neutrophils (PMNs) are related to diseases and postoperative plasma changes. The influence of some local anesthetics (LAs) on PMNs obtained by conventional isolation methods and their functions has already been demonstrated. This study investigates the effect of selected LAs on PMNs, comparing a new isolation method with conventional ones. To obtain the PMNs, we performed either gelafundin sedimentation, hypotonic lysis or density gradient centrifugation. Subsequently, PMNs were mixed with different concentrations of bupivacaine, levobupivacaine, lidocaine or ropivacaine. Live cell imaging and flow cytometry were performed to quantify the migration, ROS production, NETosis and antigen expression of PMNs. We found the inhibition of chemotaxis and ROS production by LAs. PMNs showed a strong reduction in time to half maximal NETosis in response to bupivacaine and lidocaine, but not to levobupivacaine and ropivacaine. We also found distinct differences in survival time and migration duration between the isolation methods. This suggests that the careful selection of LAs has a short-term impact on in vitro PMNs.

Transglutaminase 2 Facilitates Murine Wound Healing in a Strain-Dependent Manner

Transglutaminase 2 (TG2) plays a role in cellular processes that are relevant to wound healing, but to date no studies of wound healing in TG2 knockout mice have been reported. Here, using 129T2/SvEmsJ (129)- or C57BL/6 (B6)-backcrossed TG2 knockout mice, we show that TG2 facilitates murine wound healing in a strain-dependent manner. Early healing of in vivo cutaneous wounds and closure of in vitro scratch wounds in murine embryonic fibroblast (MEF) monolayers were delayed in 129, but not B6, TG2 knockouts, relative to their wild-type counterparts, with wound closure in 129 being faster than in B6 wild-types. A single dose of exogenous recombinant wild-type TG2 to 129 TG2-/- mice or MEFs immediately post-wounding accelerated wound closure. Neutrophil and monocyte recruitment to 129 cutaneous wounds was not affected by Tgm2 deletion up to 5 days post-wounding. Tgm2 mRNA and TG2 protein abundance were higher in 129 than in B6 wild-types and increased in abundance following cutaneous and scratch wounding. Tgm1 and factor XIIA (F13A) mRNA abundance increased post-wounding, but there was no compensation by TG family members in TG2-/- relative to TG2+/+ mice in either strain before or after wounding. 129 TG2+/+ MEF adhesion was greater and spreading was faster than that of B6 TG2+/+ MEFs, and was dependent on syndecan binding in the presence, but not absence, of RGD inhibition of integrin binding. Adhesion and spreading of 129, but not B6, TG2-/- MEFs was impaired relative to their wild-type counterparts and was accelerated by exogenous addition or transfection of TG2 protein or cDNA, respectively, and was independent of the transamidase or GTP-binding activity of TG2. Rho-family GTPase activation, central to cytoskeletal organization, was altered in 129 TG2-/- MEFs, with delayed RhoA and earlier Rac1 activation than in TG2+/+ MEFs. These findings indicate that the rate of wound healing is different between 129 and B6 mouse strains, correlating with TG2 abundance, and although not essential for wound healing, TG2 facilitates integrin- and syndecan-mediated RhoA- and Rac1-activation in fibroblasts to promote efficient wound contraction.

Comparison of Clonidine with Bupivaicaine vs Plain Bupivaicaine in Transversus Abdominis Plane (TAP) Block in Women Undergoing Cesarean Delivery Under Spinal Anesthesia: Randomized Clinical Trial

Introduction

Transversus abdominis plane (TAP) block is a technique of regional anesthesia, introduced by Rafi in 2001. Various additives have been added to prolong the duration of effect of TAP block. We conducted this study to see if addition of clonidine to bupivacaine significantly increases the duration of effect of TAP block.

Materials and Methods

This randomized, parallel group, placebo controlled double blind clinical trial was conducted on 100 healthy participants (ASAII) undergoing LSCS under Spinal anesthesia (SA) from Jan 2021 to July 2021 after consent of Institutional Ethics Committee. Women with contraindications to spinal anesthesia, allergy to any of the drugs or not-suitable for cesarean under SA were excluded. After written informed consent, eligible participants were randomly allocated into two groups using computer generated random number tables using serially numbered opaque sealed envelopes. 48 out of 50 participants in group A (Bupivacaine) were given TAP block with 20 ml of 0.25% bupivacaine bilaterally. 2 women were excluded because of conversion to General Anesthesia. Similarly, 47 out of 50 participants in Group B (Bupivacaine + Clonidine) were given TAP block with 20 ml of 0.25% bupivacaine plus 1.0 mcg/kg clonidine bilaterally after completion of surgery using 18 G Tuohy needle. Separate person used to fill the drugs for block. Participants were assessed for duration of analgesic effect of TAP block measured as the time to request for additional analgesia. Additional analgesic requirement was noted. Participants were assessed for side effects of clonidine like hypotension, bradycardia, sedation and dryness of mouth. Overall patient satisfaction was also noted. Data was analysed using Graphpad Prism 9, using Student's t-test for primary outcome and Mann-Whitney U test for secondary outcomes.

Results

The mean 'duration of analgesic effect with TAP block' was 6.34 (SD1.26) hrs for 'Bupivacaine' group and 10.56 (SD2.12) hrs for 'Bupivacaine + Clonidine' group. None of the patients developed hypotension or bradycardia. 25% participants in Bupivacaine only group and 40.42% in Bupivacaine + Clonidine group were sedated (P < 0.05). 20.8% in 'Bupivacaine' group and 51.06% in 'Bupivacaine + Clonidine' group had dryness of mouth (P < 0.001). Patient satisfaction was equal in both the groups.

Conclusion

Addition of clonidine to bupivacaine in the dose of 1 mcg/kg significantly increases the duration of analgesic effect of TAP block, decreases analgesic usage without significant increase in side effects.

Efficacy of analgesia using ilioinguinal-iliohypogastric (IIIH) nerve block, transversus abdominis plane (TAP) block and diclofenac after caesarean delivery under spinal anaesthesia: A non-randomised clinical trial

Background and Aims

Our aim was to assess the efficacy of analgesia using ilioinguinal-iliohypogastric (IIIH) nerve block, transversus abdominis plane (TAP) block and diclofenac after caesarean delivery (CD) under spinal anaesthesia (SA).].

Methods

A total of 457 healthy parturients undergoing CD under SA were included in this prospective, observational study. Groups differed in the postoperative analgesic strategies received by the parturient at the end of surgery: group D (n = 148) received intramuscular diclofenac sodium, group I (n = 153) received bilateral IIIH block with bupivacaine plus clonidine and group T (n = 156) received bilateral TAP block with bupivacaine plus clonidine. Total duration of postoperative analgesia, numerical pain rating scale (NRS) scores, patient satisfaction score, rescue analgesics in the first 48 h postoperatively and adverse effects were observed. A value of P < 0.05 was taken as significant.

Results

Total duration of analgesia was longest (18.2 ± 1.3 h) in group T and shortest in group D (6.3 ± 0.8 h) compared to group I (13.1 ± 1.2 h) (P < 0.001). Total analgesic requirement in postoperative 48 h was lowest in group T (152.1 ± 34.9 mg), highest in group D (355.0 ± 25.6 mg) and intermediate in group I (221.0 ± 30.0 mg) (P < 0.001). Mean NRS scores were lower in group T compared to those in groups D and I. The patients in group T were extremely satisfied, in group I were satisfied and in group D were dissatisfied (P < 0.001).

Conclusion

Bilateral TAP block with bupivacaine and clonidine after CD under SA increases the duration of postoperative analgesia.

The Comparison of Dexmedetomidine to Dexamethasone as Adjuvants to Bupivacaine in Ultrasound-Guided Infraclavicular Brachial Plexus Block in Upper Limb Surgeries

Background The clinical utility of adjuvants with local anesthesia produces an excellent nerve block with prolonged duration and faster onset. Brachial plexus block is widely used nowadays in patients undergoing upper limb surgery There are several approaches to achieve brachial plexus block such as interscalene, supraclavicular, infraclavicular, and axillary. The objective of this study is to compare the effectiveness of dexamethasone to dexmedetomidine as adjuvants to bupivacaine in patients undergoing ultrasound-guided infraclavicular brachial plexus (USG-ICBP) block. Methods A randomized, prospective, double-blind study was undertaken on the patients posted for upper limb surgeries under ultrasound-guided infraclavicular brachial plexus block. Sixty patients with the American Society of Anesthesiologists (ASA) classes I and II were randomly allocated into two groups. Group A received 25 mL of 0.5% bupivacaine and 1.5 mL (6 mg) of dexamethasone, and group B received 25 mL of 0.5% bupivacaine and 0.75 mL (75 mcg) of dexmedetomidine along with 0.75 mL of 0.9% normal saline (NS). Student's t test or Mann-Whitney test and chi-square test were used for statistical analysis. Results The onset of sensory block was significantly faster in the patients in group B as compared to the patients in group A. In terms of the duration of the block, sensory and motor blocks were maintained for a significantly longer duration in the group A patients as compared to those in group B. Moreover, the duration of postoperative analgesia was significantly longer-lasting in the group A patients. In terms of adverse effects, procedure-related complications such as the failure of the block and inadequate block were comparable across the groups. However, drug-related adverse effects were significantly more common in group B. Conclusion As compared to 75 mcg of dexmedetomidine, the addition of 6 mg of dexamethasone as adjuvant to 25 mL of 0.5% bupivacaine resulted in significantly longer-lasting sensory and motor blocks, postoperative analgesia, and a delayed time for first rescue analgesia without increasing undue adverse effects. Dexmedetomidine use is associated with more sedation as compared to dexamethasone.

The Effectiveness of Liposome-Encapsulated Bupivacaine Compared to Standard Bupivacaine for Anesthesia of the Maxilla in Dogs

Medical and surgical procedures involving the canine maxilla can be painful both during and for several hours post-procedure. The length of this pain may exceed the predicted duration of standard bupivacaine or lidocaine. The goal of this study was to determine the duration and efficacy of sensory blockade of the maxilla produced by liposome-encapsulated bupivacaine (LB), compared to standard bupivacaine (B) or saline (0.9% NaCl) (S), when administered as a modified maxillary nerve block in dogs. Eight maxillae were studied bilaterally from 4 healthy dogs of the same breed and similar age. This prospective, randomized, crossover, blinded study evaluated a modified maxillary nerve block using 1.3% LB at 0.1 mL/kg, 0.5% B, or S at an equivalent volume. An electronic von Frey aesthesiometer (VFA) was used to evaluate mechanical nociceptive thresholds at 4 locations on each hemimaxilla at baseline and at specific intervals up to 72-h post-treatment. Both B and LB treatments resulted in significantly higher VFA thresholds when compared to S. Dogs that received B had VFA thresholds significantly higher than S for 5 to 6 h. Dogs that received LB had thresholds significantly higher than S for 6 to 12 h depending on the site of measurement. No complications were observed. Maxillary nerve block with B provided up to 6 h, and LB 12 h, of sensory blockade depending on the site tested.

Bupivacaine Dosing for Cesarean Delivery in Parturients of Short Stature: A Retrospective Case-Control Study

The ED50 and ED95 of spinal bupivacaine for cesarean delivery has been well described in the literature; however, parturients with extremes of stature have been excluded. Parturients of short stature are a height of ≤ 148 cm. This retrospective, case-control study evaluated anesthetic outcomes for parturients of short stature and controls who underwent cesarean delivery over a 10-year period. Women were matched for anesthetic type and body mass index. Data extracted included patient demographics and obstetric and anesthetic information. The primary outcome was dose of intrathecal bupivacaine. Categorical data were compared using a chi-squared test, continuous data were compared using a t-test or Mann-Whitney U test. Data for 26 women of short stature and 52 controls were evaluated. The mean dose of bupivacaine used for spinal anesthesia in parturients of short stature was 9.8 ± 1.0 mg (P <.0001). The mean intrathecal bupivacaine dose used in combined spinal epidural anesthesia was 10.5 mg (interquartile range, 9-10.9) in parturients of short stature (P = .002). All but one patient of short stature achieved an adequate surgical level; there were no instances of high spinal blockade. Adequate surgical anesthesia was achieved with reduced dosing of spinal bupivacaine in parturients of short stature without an increase in adverse outcomes.

Efficacy of Wound Instillation With Bupivacaine Through a Wound Catheter for Postoperative Analgesia in Laparotomy Wounds in Comparison With Conventional Intravenous Analgesics

Introduction A laparotomy can cause severe postoperative pain, which, if treated adequately, can result in reduced incidence of lung atelectasis and ileus promoting early mobilization and faster recovery and in turn reducing the duration of hospital stays. Hence, effective postoperative analgesia is important to reduce postoperative stress and improve early surgical outcomes. Therefore, the hypothesis is based on the fact that following a midline laparotomy, instillation of local anaesthetic agent 0.25% bupivacaine through a wound catheter placed in the subcutaneous plane may provide better analgesia compared to the conventional intravenous analgesics and improve the early surgical outcomes. Methodology A prospective, comparative, quasi-experimental study was conducted on 80 patients planned for emergency or elective midline laparotomy procedures over a period of 18 months, who were randomly distributed into two groups of 40 each. The bupivacaine group consisted of 40 patients who received 10ml of 0.25% bupivacaine instilled through a wound catheter placed in the subcutaneous plane following a midline laparotomy. This was repeated every six hours for the first 24 hours followed by every 12 hours for the next 24 hours. The conventional intravenous (IV) analgesics group involved 40 patients who received conventional IV analgesics routinely used. Pain scores were recorded every four hours for 60 hours using the visual analogue scale (VAS) and dynamic visual analogue scale (DVAS). The parameters assessed were mean VAS and DVAS scores, number of rescue analgesic demands, cumulative rescue analgesic requirement, and early surgical outcomes. Wound complications were also assessed. Results Both groups shared similar demographic characteristics in terms of age, gender, comorbidities, and duration of operation. In comparison to patients who got standard IV analgesics, those who received 0.25% bupivacaine had improved postoperative analgesia. Between the two groups, there were statistically significant results in the number of rescue analgesic demands in the first 24 hours, but in the next 24 hours, it was statistically insignificant. The study also showed that bupivacaine instillation led to a significant decrease in postoperative lung complications and the length of hospital stays; however as hypothesised, it did not improve early surgical outcomes. Conclusion This modality, the instillation of bupivacaine through a wound catheter, is an efficient and technically simple method to provide optimal postoperative analgesia. It substantially reduces the need for systemic analgesics and can potentially avoid their related side effects. Hence, the armamentarium of multimodal analgesia can therefore include this method of delivering postoperative analgesia.