Efficacy and safety of dexmedetomidine in peripheral nerve blocks: A meta-analysis and trial sequential analysis

Efficacy and safety of ketamine as an adjuvant to regional anesthesia: A systematic review and meta-analysis of randomized controlled trials

STUDY OBJECTIVE

To identify whether adding ketamine to the local anesthetics (LA) in the regional anesthesia could prolong the duration of analgesia.

DESIGN

A Systematic review and meta-analysis of randomized controlled trials.

SETTING

The major dates were obtained in the operating room and the postoperative recovery ward.

PATIENTS

A total of 1011 patients at ASA physical status I and II were included in the analysis. Procedure performed including cesarean section, orthopedic, radical mastectomy, urological or lower abdominal surgery and intracavitary brachytherapy implants insertion.

INTERVENTIONS

After an extensive search of the electronic database, patients received regional anesthesia combined or not combined general anesthesia and with or without adding ketamine to LA were included in the analysis. The regional anesthesia includes spinal anesthesia, brachial plexus block, pectoral nerve block, transversus abdominis plane block and femoral and sciatic nerve block.

MEASUREMENT

The primary outcome was the duration of analgesia. Secondary outcomes were the duration and onset time of motor and sensory block as well as the ketamine-related adverse effect. Data are expressed in mean differences in continuous data and odds ratios (OR) for dichotomous data with 95% confidence intervals. The risk of bias of the included studies was evaluated using the revised Cochrane risk of bias tool for randomized trials. The quality of evidence for each outcome was rated according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) Working Group system.

MAIN RESULT

Twenty randomized controlled trials were included in the analysis. When ketamine was used as an adjuvant to LA, the duration of analgesia could be prolonged(172.21 min, 95% CI, 118.20 to 226.22; P<0.00001, I2 = 98%), especially in the peripheral nerve block(366.96 min, 95% CI, 154.19 to 579.74; P = 0.0007, I2 = 98%). Secondary outcomes showed ketamine could prolong the duration of sensory block(29.12 min, 95% CI, 10.22 to 48.01; P = 0.003, I2 = 96%) but no effect on the motor block(6.94 min, 95% CI,-2.65 to 16.53;P = 0.16, I2 = 84%), the onset time of motor and sensory block (motor onset time, -1.17 min, 95% CI, -2.67 to 0.34; P = 0.13, I2 = 100%; sensory onset time, -0.33 min, 95% CI,-0.87 to 0.20; P = 0.23, I2 = 96%) as well as the ketamine-related adverse effect(OR, 1.97, 95% CI,0.93 to 4.17;P = 0.08, I2 = 57%).

CONCLUSION

This study indicates that ketamine could be an ideal adjuvant to local anesthetics regardless of the types of anesthesia. Overall, the quality of the evidence is low.

Multisite prospective study of perioperative pain management practices for anterior cruciate ligament reconstruction in adolescents: Society for Pediatric Anesthesia Improvement Network (SPAIN) Project Report

INTRODUCTION

Although 200 000 adolescents undergo anterior cruciate ligament reconstruction (ACLR) surgery annually, no benchmarks for pediatric post-ACLR pain management exist. We created a multicenter, prospective, observational registry to describe pain practices, pain, and functional recovery after pediatric ACLR.

METHODS

Participants (n=519; 12-17.5 years) were enrolled from 15 sites over 2 years. Data on perioperative management and surgical factors were collected. Pain/opioid use and Lysholm scores were assessed preoperatively, on postoperative day 1 (POD1), POD3, week 6, and month 6. Descriptive statistics and trends for opioid use, pain, and function are presented.

RESULTS

Regional analgesia was performed in 447/519 (86%) subjects; of these, adductor canal single shot was most frequent (54%), nerve catheters placed in 24%, and perineural adjuvants used in 43%. On POD1, POD3, week 6, and month 6, survey response rates were 73%, 71%, 61%, and 45%, respectively. Over these respective time points, pain score >3/10 was reported by 64% (95% CI: 59% to 69%), 46% (95% CI: 41% to 52%), 5% (95% CI: 3% to 8%), and 3% (95% CI: 1% to 6%); the number of daily oxycodone doses used was 2.8 (SD 0.19), 1.8 (SD 0.13), 0, and 0. There was considerable variability in timing and tests for postdischarge functional assessments. Numbness and weakness were reported by 11% and 4% at week 6 (n=315) and 16% and 2% at month 6 (n=233), respectively.

CONCLUSION

We found substantial variability in the use of blocks to manage post-ACLR pain in children, with a small percentage experiencing long-term pain and neurological symptoms. Studies are needed to determine best practices for regional anesthesia and functional assessments in this patient population.

Efficacy of adjuvant dexmedetomidine on penile block for pediatric hypospadias repair

INTRODUCTION

The management of postoperative pain, particularly in younger children, presents a challenge due to their limited ability to articulate the intensity of pain, lower pain threshold, and restricted availability of approved analgesics for pediatric use. Peripheral nerve blocks may be favored over neuraxial blocks because they allow quicker mobilization after surgery.

OBJECTIVE

The present study aims to investigate the potential impact of adding dexmedetomidine to a local anesthetic (bupivacaine) on the analgesic efficacy in dorsal penile nerve block in hypospadias repair surgery.

METHOD

In this prospective double-blinded clinical trial, 50 children aged between 6 months and 6 years old undergoing hypospadias repair surgery participated. Analgesia was administered through a dorsal penile nerve block (DPNB) at the end of surgery. Participants were divided into two groups; one received bupivacaine alone, and the other received dexmedetomidine and bupivacaine in DPNB. Pain and sedation levels were assessed with FLACC score and MOAA/S score, respectively, at 0,1,2 and 4 h after surgery. Vital signs and adverse effects were also recorded, including hemodynamic changes, nausea, and vomiting.

RESULT

There was no statistically significant difference in demographic variables. As illustrated in Figure, the median of FLACC score in group BD was significantly lower compared to group B at every measured time point. MOAA/S score was significantly lower in group BD than in group B (p < 0.001), indicating a higher sedation level. None of the participants in either group experienced any adverse effect except for vomiting, which was not statistically significant (8 % in group B vs. 4 % in group BD, p > 0.999).

DISCUSSION

Several studies have documented the supplementary analgesic properties of dexmedetomidine when used in conjunction with local anesthetic during various surgical procedures and nerve blocks. The present study provides evidence for the additional analgesic efficacy of dexmedetomidine and bupivacaine in the context of dorsal penile nerve block during hypospadias repair surgery while not yielding any significant adverse outcomes. Although the patients in our study were monitored for 4 h in the postanesthesia care unit (PACU), conducting a more comprehensive assessment of patients is advisable.

CONCLUSION

The findings of our study indicate that incorporating dexmedetomidine alongside bupivacaine in dorsal penile nerve block during hypospadias repair surgery may lead to enhanced management of postoperative pain. The lack of adverse effects implies it may be a potentially safe supplementary pain reliever for surgical procedures.

Dexmedetomidine versus clonidine as an adjuvant to local anaesthetic in brachial plexus blocks: a meta-analysis of randomised controlled trials

OBJECTIVE

This meta-analysis aimed to compare the efficacy and safety of dexmedetomidine and clonidine as an adjuvant to local anesthetics in BPBs.

METHODS

Two investigators independently searched databases to identify all RCTs comparing the efficacy and/or safety of dexmedetomidine and clonidine as an adjuvant to local anesthetics in BPBs. All outcomes were pooled using the inverse variance method with a random-effect model. An I2 test was used to assess heterogeneity. The source of heterogeneity was explored through meta-regression. The quality of the evidence was assessed using the GRADE approach.

RESULTS

Out of 123 full texts assessed, 24 studies (1448 patients) were included in the analysis. As compared to clonidine, dexmedetomidine groups showed significantly longer sensory block duration (MD = 173.31; 95% CI 138.02‒208.59; I2 = 99%; GRADE approach evidence: high); motor block duration (MD = 158.35; 95% CI 131.55‒185.16; I2 = 98%; GRADE approach evidence: high), duration of analgesia (MD = 203.92; 95% CI 169.25‒238.58; I2 = 99%; GRADE approach evidence- high), and provided higher grade quality of block (RR = 1.97; 95% CI 1.60‒2.41; I2 = 0%; GRADE approach evidence: moderate). The block positioning technique (regression coefficient: 51.45, p = 0.005) was observed as a significant predictor of the heterogeneity in the case of sensory block duration. No significant difference was observed for the risk of hypotension (RR = 2.59; 95% CI 0.63‒10.66; I2 = %).

CONCLUSION

Moderate to high-quality evidence suggests dexmedetomidine is a more efficacious adjuvant to local anesthetic in BPBs than clonidine.

Perineural dexmedetomidine in femoral nerve blocks increases the duration of postoperative analgesia for anterolateral thigh flap donor sites in patients with oral cancer

Although the duration of analgesia provided by a single-shot nerve block is limited, perineural dexmedetomidine significantly enhances nerve blocks during extremity surgery. This study aimed to investigate the role of dexmedetomidine added to ropivacaine in femoral nerve blocks for postoperative analgesia of the anterolateral thigh (ALT) flap donor site in patients with oral cancer. Fifty-two participants scheduled for maxillofacial tumor resection and reconstruction using an anterolateral thigh flap were randomly allocated to either the Ropi group (femoral nerve block with ropivacaine) or the Ropi + Dex group (femoral nerve block with ropivacaine plus dexmedetomidine). The primary outcome was the duration of the sensory block, while the secondary outcomes were 24 h postoperative sufentanil use, number of patients using rescue analgesics, vital signs, postoperative pain score, incidence of agitation, and presence of adverse effects. Dexmedetomidine plus ropivacaine significantly prolonged the duration of sensory block compared with ropivacaine alone (10.4 ± 0.9 h vs 14.0 ± 1.3 h; P < 0.001). Age was positively correlated with increased duration of sensory block (r = 0.300; P = 0.033). Postoperative pain scores at the donor sites were lower in the Ropi + Dex group than in the Ropi group, at 12 h after surgery (P < 0.001). Although there were no statistically significant differences in the incidence of bradycardia between the two groups, four patients treated with dexmedetomidine experienced episodes of bradycardia. Perineural dexmedetomidine prolonged the duration of femoral nerve block and reduced postoperative pain scores at the ALT flap donor sites in patients with oral cancer.

Regional Anesthesia in Upper-Limb Surgery

BACKGROUND

Local and regional anesthesia is associated with numerous clinical and institutional advantages relative to general anesthesia. As anesthesiologists and surgeons increasingly integrate local and regional anesthesia into their clinical practice, an understanding of the principles, evolution, and trends underpinning modern anesthetic techniques continues to be relevant.

METHODS

A review of the literature in databases Medline, PubMed, and EMBASE identified recent developments, ongoing trends, and historical milestones in upper-limb regional anesthesia.

RESULTS

Advances in regional anesthetic techniques in the last century have led to reduced postoperative pain, improved safety, and improved outcomes in upper-limb surgery. The development of ultrasound-guided techniques, as well as pharmacological advances in local anesthetic drugs and adjuncts, has further advanced the role of regional anesthesia. Wide-awake local anesthesia with no tourniquet has allowed certain procedures to be performed on select patients in outpatient and low-resource settings.

CONCLUSIONS

This review provides an overview of local and regional anesthesia in the upper-limb from its historical origins to its contemporary applications in upper-limb surgery, particularly during the COVID-19 pandemic.

Combinations of nerve blocks in surgery for post COVID-19 pulmonary sequelae patient: A case report and review of literature

BACKGROUND

Regional anesthesia is a promising method in patients with post coronavirus disease 2019 (COVID-19) pulmonary sequelae for preserving pulmonary function and preventing postoperative pulmonary complications, compared with general anesthesia.

CASE SUMMARY

We provided surgical anesthesia and analgesia suitable for breast surgery by performing pectoral nerve block type II (PECS-II), parasternal, and intercostobrachial nerve blocks with intravenous dexmedetomidine administration in a 61-year-old female patient with severe pulmonary sequelae after COVID-19 infection.

CONCLUSION

Sufficient analgesia for 7 h was provided via PECS-II, parasternal, and intercostobrachial blocks perioperatively.

Peripheral Regional Anesthesia Using Local Anesthetics: Old Wine in New Bottles?

During the past decade, numerous efforts were undertaken aiming at prolonging the analgesic effect of regional anesthesia. With the development of extended-release formulations and enhanced selectivity for nociceptive sensory neurons, a very promising contribution to the development of pain medications has been achieved. At present, liposomal bupivacaine is the most popular, non-opioid, controlled drug delivery system, but its duration of action, which is still controversially discussed, and its expensiveness have decreased initial enthusiasm. Continuous techniques can be seen as an elegant alternative for providing a prolonged duration of analgesia, but for logistic or anatomical reasons, they are not always the best choice. Therefore, focus has been directed towards the perineural and/or intravenous addition of old and established substances. As for perineural application, most of these so-called 'adjuvants' are used outside their indication, and their pharmacological efficacy is often not or only poorly understood. This review aims to summarize the recent developments for prolonging the duration of regional anesthesia. It will also discuss the potential harmful interactions and side effects of frequently used analgesic mixtures.

The potential value of exosomes as adjuvants for novel biologic local anesthetics

The side effects of anesthetic drugs are a key preoperative concern for anesthesiologists. Anesthetic drugs used for general anesthesia and regional blocks are associated with a potential risk of systemic toxicity. This prompted the use of anesthetic adjuvants to ameliorate these side effects and improve clinical outcomes. However, the adverse effects of anesthetic adjuvants, such as neurotoxicity and gastrointestinal reactions, have raised concerns about their clinical use. Therefore, the development of relatively safe anesthetic adjuvants with fewer side effects is an important area for future anesthetic drug research. Exosomes, which contain multiple vesicles with genetic information, can be released by living cells with regenerative and specific effects. Exosomes released by specific cell types have been found to have similar effects as many local anesthetic adjuvants. Due to their biological activity, carrier efficacy, and ability to repair damaged tissues, exosomes may have a better efficacy and safety profile than the currently used anesthetic adjuvants. In this article, we summarize the contemporary literature about local anesthetic adjuvants and highlight their potential side effects, while discussing the potential of exosomes as novel local anesthetic adjuvant drugs.

Low-dose dexmedetomidine as a perineural adjuvant for postoperative analgesia: a randomized controlled trial

Purpose

Dexmedetomidine has been proposed as an additive to local anesthetics to prolong peripheral nerve block duration; however, perineural dexmedetomidine has been associated with an increased risk of bradycardia and hypotension This randomized controlled study investigated the effects of low-dose dexmedetomidine as a perineural adjuvant for postoperative analgesia.

Methods

Fifty-five patients who had undergone elective upper extremity surgery were randomized to receive an ultrasound-guided supraclavicular brachial plexus block with 20 mL 0.5% ropivacaine with or without 30 μg dexmedetomidine. The primary outcome was the duration of analgesia. Secondary outcomes included the onset time and duration of the motor and sensory blocks, incidence of hypotension and bradycardia, total postoperative analgesics, and safety assessment during the 24 h after surgery.

Results

Dexmedetomidine significantly prolonged the duration of analgesia (887 ± 92 min vs 661 ± 83 min, P < 0.0001). The onset time and the duration of motor and sensory block were significantly different between the groups (all P < 0.001). No episodes of hypotension or bradycardia were detected in the dexmedetomidine group. The total postoperative analgesic use and side effect profiles in the first 24 h postoperative period were similar for both groups.

Conclusions

Low-dose dexmedetomidine (30 μg) as a perineural adjuvant significantly prolonged the analgesic duration of a brachial plexus block without inducing hemodynamic instability.

Trial registration

This trial was registered at ClinicalTrial.gov (NCT02630290).

Network Meta-Analysis of Perioperative Analgesic Effects of Different Interventions on Postoperative Pain After Arthroscopic Shoulder Surgery Based on Randomized Controlled Trials

Background

Shoulder arthroscopic surgery is a common surgical method used in orthopedics. However, severe postoperative pain can significantly limit the early joint movement of patients and adversely affect the impact of the surgery. At present, there is no consistent and effective analgesic scheme for the management of postoperative pain after arthroscopic surgery of the shoulder.

Purpose

The aim of this study was to search for the most effective analgesic scheme to control pain in the perioperative period of arthroscopic surgery of the shoulder.

Study Design

Network meta-analysis.

Methods

We searched 5 different databases (i.e., Medline, PubMed, Embase, Web of Science, and the Cochrane Library) from January 2011 to January 2021 for English literature. Thereafter, we sifted out randomized controlled trials (RCTs), which compared different intervention schemes for pain management after shoulder arthroscopy and selected only 12 h, 24 h, or 48 h after the patient leaves the operating room as an optimal period for administration of analgesic intervention schemes. Only patients with shoulder disease who have undergone arthroscopic shoulder surgery were included in this study. The Cochrane “risk of bias” was used for the quality assessment. Moreover, some additional tests were performed to enhance the credibility of the results.

Results

Twenty-nine RCTs involving 1,885 patients were included in this frequentist network meta-analysis (NMA). These articles mainly were divided into two distinct groups, namely, the nerve block group and the non-nerve block group. Regarding the nerve block group, at postoperative 12 h, the intervention suprascapular nerve block + interscalene nerve block (SSNB + INB) was ranked first, whereas INB + intra-articular injection (INB + IAI) was ranked first at 24 h and 48 h postoperation. In the non-nerve block group, external application (EA) was ranked first at postoperative 12 h, but oral administration (OA) exhibited a better analgesic effect at postoperative 24 h and postoperative 48 h.

Conclusion

We conclude that the analgesic effect of SSNB+INB was the best at postoperative 12 h, and INB+IAI was the best at postoperative 24 h and 48 h in the nerve block group. For the non-nerve block group, the effect of EA was the best at postoperative 12 h, and the analgesic effect of OA at postoperative 24 h and 48 h was significantly better than any other interventions.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021286777.

Assessment of the effect of perineural dexmedetomidine on oxidative stress during peritoneal dialysis catheter insertion: a randomized, controlled trial

Purpose

This study aimed to evaluate the effect of the addition of dexmedetomidine to ropivacaine on oxidative stress during transversus abdominis plane (TAP) and rectus sheath (RS) blockades for patients with end-stage renal disease (ESRD) undergoing peritoneal dialysis (PD) catheter insertion.

Methods

Sixty patients with ESRD undergoing PD catheter insertion to receive left ultrasound-guided TAP and RS blockades were randomly divided into two groups: the dexmedetomidine plus ropivacaine group (25 mL of 0.3% ropivacaine + 1 μg/kg dexmedetomidine) and the ropivacaine group (25 mL of 0.3% ropivacaine). Primary outcomes were oxidative stress marker levels during the procedure.

Results

A total of 60 patients (30 patients in each group) were evaluated. Compared with the ropivacaine group, the dexmedetomidine plus ropivacaine group had significantly lower serum malondialdehyde levels (P < 0.05) and increased glutathione peroxidase (P < 0.01) and superoxide dismutase levels at 24 h after the procedure (P < 0.01).

Conclusion

The addition of 1 μg/kg of dexmedetomidine to ropivacaine for ultrasound-guided TAP and RS blockades could inhibit oxidative stress in patients with ESRD undergoing PD catheter insertion.

Trial registration This study was registered at www.chictr.org.cn on June 7, 2021 (ChiCTR2100047050).

The Use of Multimodal Perineural Adjuvants in Pediatric Peripheral Nerve Blocks: Technique and Experiences

Background

Postoperative pain management in pediatric population can be very challenging. How to prolong the duration of single-injection peripheral nerve blocks has been widely discussed. Multiple medications are under investigation to accomplish this, yet data specifically focused on their use in pediatric peripheral nerve blocks are limited.

Methods

Anesthetic electronic medical records were queried for any instances where adjuvant drug(s) were used in peripheral nerve blocks during a two-year period at a pediatric surgical specialty hospital. These included buprenorphine, clonidine, dexamethasone, and dexmedetomidine. 

Results

Out of 1,845 blocks placed during the study period, 1,148 (62.2%) utilized perineural adjuvants. Buprenorphine as a sole agent was the most common choice (49.5%), followed by buprenorphine and dexmedetomidine combined (39.9%), dexmedetomidine alone (10.1%), and the rare combination of all three drugs, buprenorphine, dexmedetomidine, and dexamethasone (0.5%). The mean dose of buprenorphine given was 3.6 mcg/kg total, 2.8 mcg/kg/block. The mean dose of dexmedetomidine given was 0.9 mcg/kg total, 0.6 mcg/kg/block. The mean dose of dexamethasone utilized was 2 mg total, 1 mg/block. 

Conclusions

This report examined one institution’s use of multimodal perineural adjuvants in over 1,000 pediatric peripheral nerve blocks. Buprenorphine was the agent most commonly used to prolong the single-injection peripheral nerve block. This highlights the need for future prospective trials evaluating efficacy and safety.

Alpha2 -receptor agonists as adjuvants for brachial plexus nerve blocks-A systematic review with meta-analyses

BACKGROUND

We review the efficacy and safety of dexmedetomidine and clonidine as perineural or systemic adjuvants for brachial plexus blocks (BPB).

METHODS

We included randomised controlled trials on upper limb surgery with BPBs in adults, comparing dexmedetomidine with clonidine or either drug with placebo. The primary outcome was duration of analgesia. Secondary outcomes included adverse and serious adverse events. The review was conducted using Cochrane standards, trial sequential analyses (TSA) and Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

We included 101 trials with 6248 patients. Overall, duration of analgesia was prolonged with both clonidine (176 min [TSA adj. 95% CI: 118, 205, p < .00001; 33 trials]) and dexmedetomidine (292 min [TSA adj. 95% CI: 245 329, p < .00001; 53 trials]), but was longer for dexmedetomidine than clonidine (205 min [TSA adj. 95% CI: 157, 254, p < .00001; 19 trials]). Compared with placebo, dexmedetomidine was associated with bradycardia (RR 4.2 [95% CI 2.2, 8.3]), and both clonidine (RR 4.5 [95% CI 1.1, 18.3]) and dexmedetomidine (RR 3.9 [95% CI 2.0, 7.5]) were associated with hypotension. Serious adverse events were mostly related to block technique. GRADE-rated quality of evidence was low or very low.

CONCLUSION

Alpha2-receptor agonists used as adjuvants for BPBs lead to a prolonged duration of analgesia, with dexmedetomidine as the most efficient. Alpha2-receptor agonists were associated with increased risk of cardiovascular adverse events. The quality of evidence was low to very low.

Pharmacokinetics and Pharmacodynamics of Dexmedetomidine Administered as an Adjunct to Bupivacaine for Transversus Abdominis Plane Block in Patients Undergoing Lower Abdominal Cancer Surgery

Background

Despite the growing interest in dexmedetomidine as an adjunct to truncal blocks, little is known about the systemic absorption of dexmedetomidine after these blocks and its role in analgesia and in hemodynamics.

Objective

We investigated the pharmacokinetics and pharmacodynamics of dexmedetomidine as an adjunct to transversus abdominis plane (TAP) block in patients undergoing lower abdominal cancer surgery.

Methods

Twenty-four adult patients were randomized to receive a bilateral single-injection TAP block before surgery with 20 mL of bupivacaine 0.5% (TAP group, n = 12) or combined with 1 µg/kg dexmedetomidine (TAP-DEX group, n = 12) and diluted with saline to a volume of 40 mL (20 mL on each side). Plasma concentrations of dexmedetomidine and its pharmacokinetics were investigated using non-compartmental methods, postoperative analgesia, hemodynamics, and adverse events (nausea, vomiting, itching, hypotension, bradycardia, and respiratory depression).

Results

Dexmedetomidine was detected in the plasma of 11 patients in the TAP-DEX group. The mean dexmedetomidine peak plasma concentration (Cmax) was 0.158 ± 0.085 (range, 0.045-0.31) ng/mL. The median time to reach peak plasma concentration of dexmedetomidine (Tmax) was 15 (15-45) min. From 2 to 8 h postoperatively, visual analog pain scale (VAS) scores at rest and during movement were significantly lower in the TAP-DEX group. Analgesia time was (11.3 ± 3.12 vs 9.0 ± 4.69 h; P = 0.213) and postoperative morphine consumption was (7.4 ± 3.24 vs 11.5 ± 4.46 mg; P = 0.033) in TAP-DEX and TAP groups, respectively. Lower mean heart rate and mean blood pressure were recorded in the TAP-DEX group intraoperatively and 2 h postoperatively (P < 0.05). Except for mild nausea and vomiting, no adverse events were recorded in either group.

Conclusion

Systemic absorption of dexmedetomidine administered in a TAP block is common. Direct central effects on the locus coeruleus caused by this systemic absorption may play a role in the analgesia and hemodynamic effects produced by TAP-dexmedetomidine in addition to local mechanisms.

Trial Registration

ClinicalTrial.gov (identifier: NCT03328299).

Postoperative Pain Management in Enhanced Recovery Pathways

Postoperative pain is a common but often inadequately treated condition. Enhanced recovery pathways (ERPs) are increasingly being utilized to standardize perioperative care and improve outcomes. ERPs employ multimodal postoperative pain management strategies that minimize opioid use and promote recovery. While traditional opioid medications continue to play an important role in the treatment of postoperative pain, ERPs also rely on a wide range of non-opioid pharmacologic therapies as well as regional anesthesia techniques to manage pain in the postoperative setting. The evidence for the use of these interventions continues to evolve rapidly given the increasing focus on enhanced postoperative recovery. This article reviews the current evidence and knowledge gaps pertaining to commonly utilized modalities for postoperative pain management in ERPs.

The Efficacy and Safety of Ultrasound-Guided, Bi-Level, Erector Spinae Plane Block With Different Doses of Dexmedetomidine for Patients Undergoing Video-Assisted Thoracic Surgery: A Randomized Controlled Trial

Background: The anesthetic characteristics of ultrasound-guided bi-level erector spinae plane block (ESPB) plus dexmedetomidine (Dex) remain unclear. We compared the efficacy and safety of ultrasound-guided bi-level ESPB plus different doses of Dex in patients undergoing video-assisted thoracic surgery (VATS).

Methods: One-hundred eight patients undergoing VATS were randomized into three groups: R group (n = 38, 15 ml of 0.375% ropivacaine with 0.1 mg/kg dexamethasone), RD1 group (n = 38, 15 ml of 0.375% ropivacaine plus 0.5 μg/kg DEX with 0.1 mg/kg dexamethasone) and RD2 group (n = 38, 15 ml of 0.375% ropivacaine plus 1.0 μg/kg DEX with 0.1 mg/kg dexamethasone). The primary outcome was the pain 12 h after surgery. Secondary outcomes included the Prince Henry Hospital Pain Score; hemodynamics; consumption of sufentanil; anesthetized dermatomal distribution; recovery time; rescue analgesia; satisfaction scores of patients and surgeon; quick recovery index; adverse effects; the prevalence of chronic pain and quality of recovery.

Results: The visual analog scale (VAS) and the Prince Henry pain score were significantly lower in both the RD1 and RD2 groups during the first 24 h after surgery (P < 0.05). Both VAS with coughing and the Prince Henry pain score were significantly lower in the RD2 group than in the RD1 group 8–24 h after surgery (P < 0.05). Both heart rate and mean arterial pressure were significantly different from T2 to T6 in the RD1 and RD2 groups (P < 0.05). The receipt of remifentanil, propofol, Dex, and recovery time was significantly reduced in the RD2 group (P < 0.05). The requirement for sufentanil during the 8–72 h after surgery, less rescue medication, and total press times were significantly lower in the RD2 group (P < 0.05). The time to the first dose of rescue ketorolac was significantly longer in the RD2 group (P < 0.05). Further, anal exhaust, removal of chest tubes, and ambulation were significantly shorter in the RD2 group (P < 0.05). The incidence of tachycardia, post-operative nausea and vomiting, and chronic pain was significantly reduced in the RD2 group, while the QoR-40 score was significantly higher in the RD2 group (P < 0.05).

Conclusions: Pre-operative bi-level, single-injection ESPB plus 1 μg/kg DEX provided superior pain relief and long-term post-operative recovery for patients undergoing VATS.

Clinical Trial Registration:http://www.chictr.org.cn/searchproj.aspx.

Efficacy of dexmedetomidine as an adjuvant in femoral nerve block for post-op pain relief in hip surgery: A prospective randomized double-blind controlled study

Background and Aims:

To determine whether the addition of dexmedetomidine either in peripheral block or via systemic route leads to prolongation of the duration of analgesia is inconclusive. The present study aimed to assess the duration of postoperative analgesia with dexmedetomidine used as an additive with bupivacaine for ultrasound-guided femoral nerve block (FNB) and to compare it with intramuscular dexmedetomidine along with FNB.

Material and Methods:

A prospective, double-blind randomized clinical trial involving adult patients undergoing elective hip surgery, performed under subarachnoid block. When sensory block receded to T12 after the surgery, FNB was given for postoperative analgesia. Patients were randomized into three groups; Group A received FNB with 40 mL 0.25% bupivacaine and 0.5 mL saline as IM injection, Group B received FNB with 39.5 mL of 0.25% bupivacaine + 0.5 mL (50 mcg) of dexmedetomidine in the affected limb and 0.5 mL saline IM injection, and Group C received FNB with 40 mL of 0.25% bupivacaine and 0.5 mL (50 mcg) of dexmedetomidine as IM injection. Postoperative pain was assessed and for pain with VAS score >3, intravenous tramadol was given as rescue analgesia. Chi-square test for categorical variables and one-way ANOVA for continuous variables.

Results:

The mean duration of analgesia in groups A, B, and C was 671, 676, and 490 min, respectively which was not significant. A 24 h analgesic requirement was also not different between the groups.

Conclusion:

The use of dexmedetomidine perineurally or systemically did not prolong the duration of analgesia as compared to bupivacaine alone for femoral nerve block.

Practical Considerations for Dexmedetomidine Sedation in Adult Cataract Surgery Under Local/Regional Anesthesia: A Narrative Review

Cataract surgery is predominantly performed under local/regional anesthesia, with or without sedation. The practice pattern of sedation is unknown and seems to vary significantly among institutions and countries, routinely administered in some parts of the world to the other extreme of none at all. The selection of sedative agents and techniques varies widely. Currently, there is no ideal sedative agent. Dexmedetomidine has gained recent attention for sedation in ophthalmic local/regional anesthesia due to its alleged advantages of effective sedation with minimal respiratory depression, decreased intraocular pressure, and reduced pain during the local anesthetic injection; however, they are subject to differing interpretations. Published literature also suggests that although dexmedetomidine sedation for cataract surgery under local/regional anesthesia is potentially useful, its role may be limited due to logistical difficulties in administering the recommended dose.

Comparing the effects of dexmedetomidine and dexamethasone as perineural adjuvants on peripheral nerve block: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Dexmedetomidine (Dexm), a selective alpha-2 adrenoceptor agonist, and dexamethasone (Dexa), a very potent and highly selective glucocorticoid, have both been proven effectively to prolong the duration of local anesthetics (LA) in regional anesthesia. However, data comparing the efficacy of Dexm and Dexa as perineural adjuvants are inconsistent. Therefore, this systematic review and meta-analysis of randomized and quasi-randomized controlled trials (RCTs) was conducted to compare the effects of Dexm and Dexa when used as LA adjuvants on peripheral nerve block (PNB).

METHODS

We systematically searched PubMed, Cochrane Library, EMBASE, Web of Science, and ScienceDirect databases up to October, 2020. The primary outcome was the duration of analgesia. Secondary outcomes included incidence of rescue analgesia, cumulative opioid consumption, time required for onset of sensory and motor blockades, duration of sensory and motor blockades, incidence of postoperative nausea and vomiting (PONV), and side effect-associated outcomes (e.g., bradycardia, sedation, hypotension, rates of infection, and neurological complications). The study was registered on PROSPERO, number CRD42020188796.

RESULTS

After screening of full-text relevant articles, 13 RCTs that met the inclusion criteria were retrieved for this systematic review. It was revealed that perineural Dexm provided equivalent analgesic duration to perineural Dexa. Besides, the intake of Dexm increased the incidence of rescue analgesia in limbs surgery, as well as the cumulative opioid consumption, and decreased the time required for onset of sensory and motor blockades for long-acting LA (all P < .05). Other analysis revealed insignificant difference between the 2 groups in terms of the incidence of PONV (P > .05). Additionally, 2 studies demonstrated that Dexm possesses more sedative properties than Dexa (P < .05).

CONCLUSIONS

This meta-analysis indicated that the analgesic duration of Dexm and Dexa as LA adjuvants in PNB is the same. Meanwhile, the effects of perineural Dexm and Dexa on some secondary outcomes, including the incidence of rescue analgesia, cumulative opioid consumption, and time required for onset of sensory and motor blockades, are associated with the surgical site and type of LA.

Techniques and strategies for regional anesthesia in acute burn care-a narrative review

Burn injuries and their treatments result in severe pain. Unlike traumatic injuries that are characterized by a discrete episode of pain followed by recovery, burn-injured patients endure pain for a prolonged period that lasts through wound closure (e.g. background pain, procedural pain, breakthrough pain, neuropathic pain and itch). Regional anesthesia, including peripheral nerve blocks and neuraxial/epidural anesthesia, offers significant benefits to a multimodal approach in pain treatment. A 'regional-first' approach to pain management can be incorporated into the workflow of burn centers through engaging regional anesthesiologists and pain medicine practitioners in the care of burn patients. A detailed understanding of peripheral nerve anatomy frames the burn clinician's perspective when considering a peripheral nerve block/catheter. The infra/supraclavicular nerve block provides excellent coverage for the upper extremity, while the trunk can be covered with a variety of blocks including erector spinae plane and quadratus lumborum plane blocks. The lower extremity is targeted with fascia iliaca plane and sciatic nerve blocks for both donor and recipient sites. Burn centers that adopt regional anesthesia should be aware of potential complications and contraindications to prevent adverse events, including management of local anesthetic toxicity and epidural infections. Management of anticoagulation around regional anesthesia placement is crucial to prevent hematoma and nerve damage. Ultimately, regional anesthesia can facilitate a better patient experience and allow for early therapy and mobility goals that are hallmarks of burn care and rehabilitation.

Adjuvant Drugs for Peripheral Nerve Blocks: The Role of Alpha-2 Agonists, Dexamethasone, Midazolam, and Non-steroidal Anti-inflammatory Drugs

Adjuvant drugs for peripheral nerve blocks are a promising solution to acute postoperative pain and the transition to chronic pain treatment. Peripheral nerve blocks (PNB) are used in the brachial plexus, lumbar plexus, femoral nerve, sciatic nerve, and many other anatomic locations for site-specific pain relief. However, the duration of action of a PNB is limited without an adjuvant drug. The use of non-opioid adjuvant drugs for single-shot peripheral nerve blocks (sPNB), such as alpha-2 agonists, dexamethasone, midazolam, and non-steroidal anti-inflammatory drugs, can extend the duration of local anesthetics and reduce the dose-dependent adverse effects of local anesthetics. Tramadol is a weak opioid that acts as a central analgesic. It can block voltage-dependent sodium and potassium channels, cause serotonin release, and inhibit norepinephrine reuptake and can also be used as an adjuvant in PNBs. However, tramadol's effectiveness and safety as an adjuvant to local anesthetic for PNB are inconsistent. The effects of the adjuvants on neurotoxicity must be further evaluated with further studies to delineate the safety in their use in PNB. Further research needs to be done. However, the use of adjuvants in PNB can be a way to help control postoperative pain.

Dexmedetomidine as an Adjunct for Regional Anesthetic Nerve Blocks

PURPOSE OF REVIEW

This article will review current evidence related to the use of dexmedetomidine as an adjuvant for regional anesthesia.

RECENT FINDINGS

Adjuvants, frequently used during regional anesthesia, act synergistically with local anesthetics thus enhancing the quality of regional anesthesia while minimizing adverse effects. These adjuvants may be administered via different routes including topical, perineural, neuraxial, and systemic. Recent studies indicate that dexmedetomidine prolongs the duration of intravenous regional anesthesia, peripheral nerve blocks, and spinal analgesia. Controversy regarding potential neurotoxicity of perineural dexmedetomidine in patients with diabetic neuropathy requires further evaluation.

Lateral popliteal block in foot and ankle surgery: Comparing ultrasound guidance to nerve stimulation. A prospective randomized trial

BACKGROUND

The popliteal block has several benefits in foot and ankle surgery. It reduces postoperative pain, limits the use of narcotics and facilitates early discharge. The aim of this prospective randomized trial was to evaluate whether ultrasound guidance improves block characteristics compared to the nerve stimulation technique in lateral popliteal blocks.

METHODS

Patients were randomized to receive either a lateral popliteal block using neurostimulation or ultrasound guidance. Block performance time, number of needle pricks, number of redirections were recorded. Pain upon admission to and discharge from post anesthesia care unit (PACU) was recorded. Block duration, patient satisfaction, pain at block site and amount of opioids used in PACU and between subsequent followup visits was recorded. Patients were followed for 12 weeks postoperatively.

RESULTS

There was no statistically significant difference between the two groups in terms of number of pricks, time for the block to wean, pain upon admission to PACU, amount of opioids received in PACU, pain upon discharge from PACU, pain at the operative site, pain at the block site, toe motor function and toe sensation. There was a statistically significant difference in the block procedure performance time between the two groups, with the control group being faster (P<0.0001). A significantly larger number of patients in the control group required more than three needle redirections (P=0.0060).

CONCLUSIONS

The lateral sciatic popliteal block using nerve stimulation had similar block characteristics and patient satisfaction with a significantly faster performance time compared to the ultrasound guided technique.

LEVEL OF EVIDENCE

Level I, prospective randomized study.

Efficacy and safety of dexmedetomidine as an adjuvant to local wound infiltration anaesthesia: A meta-analysis with trial sequential analysis of 23 randomised controlled trials

To further identify the real efficacy and safety of dexmedetomidine as an adjuvant to local wound infiltration anaesthesia, we conducted this meta‐analysis. The systematic search strategy was performed using PubMed, Embase, Cochrane Library, and Chinese databases. As a result, a total of 23 RCTs (1445 patients) were included. Patients receiving dexmedetomidine combined with local anaesthetics had a lower rescue analgesia rate [risk ratio (RR): 0.48; 95% confidence interval (CI): 0.36‐0.65] and lower rescue analgesic consumption [weighted mean difference (WMD): −10.80 mg; 95%CI: −13.28 to −8.31 mg] than patients receiving local anaesthetics alone. The dexmedetomidine‐related adverse reactions included bradycardia (RR: 1.33; 95%CI: 0.32‐5.56) and hypotension (RR: 3.00; 95%CI: 0.49‐18.42). In addition, the time to first analgesic request (WMD: 296.16 minutes; 95%CI: 165.69 minutes ~ 426.63 minutes), incidence of postoperative nausea and vomiting (PONV) and pain scores at 4 hours postoperatively were also significantly lower in patients receiving dexmedetomidine combined with local anaesthetics. This meta‐analysis demonstrated that the use of dexmedetomidine as an adjuvant to wound infiltration is effective for reducing the rescue analgesia rate, rescue analgesic consumption and PONV. In addition, limited evidence shows that dexmedetomidine can prolong postoperative analgesia for approximately 5 hours. Further investigations on dexmedetomidine‐related adverse reactions and the dose–response effect of dexmedetomidine in wound infiltration are warranted.

Total knee arthroplasty under quadruple nerve block with ropivacaine 0.32%: effect of addition of intravenous dexmedetomidine to intravenous dexamethasone on analgesic duration

BACKGROUND AND OBJECTIVES

Peripheral nerve blocks reduce postoperative pain and enhance recovery after total knee arthroplasty (TKA). This study aims to assess the benefits of addition of intravenous dexmedetomidine (DexM) to intravenous dexamethasone on the analgesic duration of quadruple nerve blocks.

METHODS

This double-blind, randomized, controlled trial prospectively enrolled 90 patients scheduled for TKA under quadruple nerve blocks (sciatic, femoral, obturator, and lateral femoral cutaneous nerves blocks) with 70 mL, 0.32% ropivacaine. All patients received systemic dexamethasone 10 mg. Patients were randomized to receive DexM (2 µg/kg, intravenous) or placebo (1:1 ratio). The primary endpoint was the duration of analgesia defined as the time to first request for rescue analgesia (oxycodone).

RESULTS

Kaplan-Meier curves for the first analgesic request were similar between groups (log-rank test; p=0.27). Median (IQR) duration of analgesia was similar between placebo (1575 min (1211-1952)) and DexM (1470 min (1263-1700)) groups (p=0.56). Cumulative consumption of oxycodone at the 48th hour was 20 mg (10-30) and 30 mg (20-40) in placebo and DexM groups, respectively (p=0.14). The day after surgery, 93% and 89% of patients were able to walk in placebo and DexM groups, respectively (p=0.46). Intravenous DexM was associated with bradycardia, hypotension and longer recovery room stay (p<0.05 for all comparisons).

CONCLUSIONS

In a multimodal analgesic regimen, addition of systemic DexM (2 µg/kg) to systemic dexamethasone does not prolong the analgesic duration of quadruple nerve block with ropivacaine 0.32% after TKA.

TRIAL REGISTRATION NUMBER

NCT03834129.

Effects of dexmedetomidine as a perineural adjuvant for femoral nerve block: A systematic review and meta-analysis

Background

Femoral nerve block (FNB) is one of the first-line analgesic methods for patients following lower extremity surgery. However, FNB with local anesthetics alone exert limited potency and supplemental opioids are often required. Dexmedetomidine (DEX) has been used to improve the analgesic effects of FNB. The present systematic review and meta-analysis were conducted to evaluate the effectiveness of DEX as an adjuvant to local anesthetics for FNB.

Methods

Randomized controlled trials comparing the effects of DEX versus sham control in combination with local anesthetics for FNB were included in this meta-analysis. Postoperative pain scores, duration of analgesic effects, and postoperative narcotic consumption were outcomes of interest. This research was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements.

Results

A total of 9 studies encompassing 580 participants were included for data synthesis after critical evaluation. DEX as an adjuvant with local anesthetics for FNB significantly relieved pain intensity at 12, 24 and 48 hours after surgery, both at rest (standardized mean difference -1.34 [95% CI -1.87 to -0.82], P<0.00001 at 12 h; -1.26 [-1.90 to -0.0.63], P<0.0001 at 24 h; and -1.34; [-2.18 to -0.50], P = 0.002 at 48 h) and with movement (-1.30 [-2.17 to -0.43], P = 0.004 at 12 h; -1.02 [-1.31 to -0.72], P<0.00001 at 24h; and -1.33 [-2.03 to -0.63], P = 0.0002); it also significantly prolonged analgesic duration (mean difference 7.23 h [95% CI 4.07 to 10.39], P<0.00001) and decreased opioid consumption (mean difference of morphine equivalent -12.13 mg [95% CI -23.36 to -0.89], P<0.00001). Regarding safety, DEX use increased the rate of hypotension (odds ratio 4.10, 95% CI 1.40 to 12.01, P = 0.01).

Conclusion

DEX as an adjuvant to local anesthetics for FNB improves analgesia, prolongs analgesic duration and reduces supplemental opioid consumption; but increases hypotension.

Bilateral Erector Spinae Plane Block for Postoperative Analgesia in Laparoscopic Cholecystectomy: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Erector spinae plane (ESP) block is a novel regional anesthetic technique. Its application for postoperative analgesia has been increasing since 2016; however, its effectiveness remains uncertain and varies according to the type of surgery. This meta-analysis aimed to assess the analgesic efficacy of ESP block in patients undergoing laparoscopic cholecystectomy.

METHODS

Literature searches of electronic databases and manual searches up to June 1, 2020 were performed. Review Manager Version 5.3 was used for pooled estimates. We included only randomized controlled trials (RCTs) in this meta-analysis. The random-effects meta-analysis model was used, and metaregression was applied when appropriate.

RESULTS

A total of five RCTs consisting of 250 patients were included (124 in the ESP block group vs. 126 in the control group). Bilateral ESP block showed a significant reduction in postoperative intravenous opioid consumption reported up to 24 hours after surgery (mean difference [MD] = -4.46, 95% confidence interval [CI] [-5.50 to -3.42], P < 0.001) and in the time to first rescue analgesic (MD = 73.27 minutes, 95% CI [50.39 to 96.15], P < 0.001). According to the results of four studies, the postoperative pain score was lower in the ESP group compared with the control group at both rest and movement. There were no differences between the two groups as concerns nausea (odds ratio [OR] = 0.45, 95% CI [0.13 to 1.52], P = 0.20) and vomiting (OR = 0.37, 95% CI [0.10 to 1.35], P = 0.13). No block-related complications were noted.

CONCLUSION

This meta-analysis showed that bilateral ultrasound-guided ESP block could be considered as an effective option to reduce opioid consumption and the time to first rescue analgesic and seems to be also a safe technique in adults undergoing laparoscopic cholecystectomy.

The effect of ultrasound-guided erector spinae plane block on postsurgical pain: a meta-analysis of randomized controlled trials

Background

The effect of erector spinae plane block has been evaluated by clinical trials leading to a diversity of results. The main objective of the current investigation is to compare the analgesic efficacy of erector spinae plane block to no block intervention in patients undergoing surgical procedures.

Methods

We performed a quantitative systematic review of randomized controlled trials in PubMed, Embase, Cochrane Library, and Google Scholar electronic databases from their inception through July 2019. Included trials reported either on opioid consumption or pain scores as postoperative pain outcomes. Methodological quality of included studies was evaluated using Cochrane Collaboration’s tool.

Results

Thirteen randomized controlled trials evaluating 679 patients across different surgical procedures were included. The aggregated effect of erector spinae plane block on postoperative opioid consumption revealed a significant effect, weighted mean difference of − 8.84 (95% CI: − 12.54 to − 5.14), (P < 0.001) IV mg morphine equivalents. The effect of erector spinae plane block on post surgical pain at 6 h compared to control revealed a significant effect weighted mean difference of − 1.31 (95% CI: − 2.40 to − 0.23), P < 0.02. At 12 h, the weighted mean difference was of − 0.46 (95% CI: − 1.01 to 0.09), P = 0.10. No block related complications were reported.

Conclusions

Our results provide moderate quality evidence that erector spinae plane block is an effective strategy to improve postsurgical analgesia.

Intravenous infusion of dexmedetomidine amplifies thoracic epidural analgesic effect after open thoracotomy: A prospective, double-blind, randomized controlled trial

BACKGROUND

The anesthetic-sparing effect of dexmedetomidine has led to its use as a general adjuvant. The present study aimed to determine intravenous infusion of dexmedetomidine to epidural analgesia after open thoracotomy.

METHODS

Forty-four patients scheduled for admission to the intensive care unit after open thoracotomy were divided into 2 groups. An epidural catheter was placed at T4 to T7. Thirty minutes before the end of thoracotomy, group D was injected with 0.3 μg/kg/h of dexmedetomidine and group C received an equal dose of normal saline. For patient-controlled epidural analgesia (PCEA), 150 mL of levobupivacaine 300 mg was infused at a rate of 1 mL/h, plus a bolus dose of 3 mL with a lockout time of 30 minutes. The primary outcome evaluated was analgesic efficacy using a visual analog scale (VAS) 48 hours postoperatively. Other outcomes included additional analgesic use, total consumed local analgesia via PCEA, sedation score, blood pressure, heart rate, arterial blood gases, patient satisfaction, and adverse effects.

RESULTS

The VAS scores in group D were significantly lower than that in group C immediately, 1, 4, 12, 36, and 48 hours after admission to the intensive care unit (P = .016, .009, .015, .002, .001, and .042, respectively). The total dose of additional analgesic was also significantly lower in group D (P = .011). Patient satisfaction was higher in group D (P < .05). There were no significant differences in the other outcomes between groups.

CONCLUSION

Intravenous infusion of dexmedetomidine amplifies thoracic epidural analgesic effect after open thoracotomy.

The Role of Neuroinflammation in Postoperative Cognitive Dysfunction: Moving From Hypothesis to Treatment

Postoperative cognitive dysfunction (POCD) is a common complication of the surgical experience and is common in the elderly and patients with preexisting neurocognitive disorders. Animal and human studies suggest that neuroinflammation from either surgery or anesthesia is a major contributor to the development of POCD. Moreover, a large and growing body of literature has focused on identifying potential risk factors for the development of POCD, as well as identifying candidate treatments based on the neuroinflammatory hypothesis. However, variability in animal models and clinical cohorts makes it difficult to interpret the results of such studies, and represents a barrier for the development of treatment options for POCD. Here, we present a broad topical review of the literature supporting the role of neuroinflammation in POCD. We provide an overview of the cellular and molecular mechanisms underlying the pathogenesis of POCD from pre-clinical and human studies. We offer a brief discussion of the ongoing debate on the root cause of POCD. We conclude with a list of current and hypothesized treatments for POCD, with a focus on recent and current human randomized clinical trials.