Dexmedetomidine as an adjuvant to local anesthetics in brachial plexus blocks: A meta-analysis of randomized controlled trials

Effect of Intraperitoneal Instillation of Dexmedetomidine With Local Anesthetics in Laparoscopic Cholecystectomy: A Systematic Review and Meta-analysis of Randomized Trials

OBJECTIVE

Dexmedetomidine (DEX) can strengthen the analgesic effects of local anesthetics (LAs) when used as an adjuvant through intrathecal, perineural, and intraperitoneal routes. Many studies have used intraperitoneal instillation of DEX with LAs in laparoscopic cholecystectomy (LC) to relieve postoperative pain. We performed a systematic review and meta-analysis to synthesize evidence of the efficacy and safety of intraperitoneal instillation of DEX as an adjuvant of LAs in patients undergoing LC.

METHODS

A comprehensive literature search of the MEDLINE, PubMed, EMBASE, and Cochrane Library databases was performed to identify randomized controlled trials in which patients received intraperitoneal instillation of DEX combined with LAs during LC. A meta-analysis and sensitivity analysis of the results were conducted. We also performed a subgroup analysis to investigate the source of heterogeneity. The Egger test was used to check for publication bias.

RESULTS

Eleven randomized controlled trials involving 890 patients were analyzed. We found that the addition of DEX to LAs significantly decreased pain scores at six postoperative time points (0.5, 1, 2, 4, 12, and 24 h) and significantly prolonged the time to the first analgesic request by patients. In addition, 24-hour postoperative analgesic consumption was decreased in the experimental group, and no significant difference in the incidence of nausea and vomiting was observed.

CONCLUSION

Our findings indicate that intraperitoneal instillation of DEX with LAs can reduce postoperative pain and prolong the time to first request analgesia after LC.

Comparative Study Between Dexmedetomidine with Bupivacaine and Bupivacaine Alone in Erector Spinae Plane Block for Postoperative Pain Control of Posterior Lumbosacral Spine Fixation Surgeries: A Randomized Controlled Trial

Background

As posterior lumbosacral spine fixation surgeries are common spine procedures done nowadays due to different causes and mostly accompanied with moderate-to-severe postoperative pain, so should find effective postoperative analgesia for these patients. This study aimed to observe analgesic effect of dexmedetomidine combined with bupivacaine versus bupivacaine alone for erector spinae plane block ESPB for postoperative pain control of posterior lumbosacral spine fixation surgeries.

Methods

Double-blind randomized controlled study including 90 patients who were randomly allocated into 3 groups (30 patients for each): Dexmedetomidine combined with bupivacaine (DB group), bupivacaine (B group), and saline (control) (S group). US-guided ESPB was performed preoperatively bilaterally in all patients of the 3 groups. All patients received intravenous patient-controlled postoperative analgesia with morphine and 1 gm intravenous paracetamol every 8 hours. Primary clinical outcomes were active (while mobilization) and passive (at rest) visual analog scale (VAS) pain score at first 24 hours measured every 2 hours, opioid consumption (number of PCA presses), and need for rescue analgesia. Other clinical outcomes included active and passive VAS pain score at second 24 hours, measured every 4 hours, opioid consumption, need for rescue analgesia, postoperative opioid side effects, and intraoperative dexmedetomidine side effects as bradycardia and hypotension.

Results

Active and passive VAS pain scores, postoperative opioid consumption, need for rescue analgesia, and postoperative opioid side effects were significantly lower in DB group when compared to other groups (B and S groups). There were no additional intraoperative dexmedetomidine side effects as bradycardia and hypotension. The estimated effect-size r was -0.58 and Cohen's d was -1.46.

Conclusion

Addition of dexmedetomidine to bupivacaine 0.25% in ESPB for postoperative pain control in patients of posterior lumbosacral spine fixation surgeries resulted in lower active and passive VAS pain scores, decreased postoperative opioid consumption, need for rescue analgesia and postoperative opioid side effects without additional intraoperative dexmedetomidine side effects.

Clinicaltrialsgov Identifier

NCT05590234.

Intrathecal dexamethasone-bupivacaine combination with bupivacaine alone in spinal anesthesia for cesarean delivery

Background

Postoperative pain management can be achieved by adjuvant medications during the analgesia procedure. The study investigated the effect of intrathecal dexamethasone-bupivacaine combination with bupivacaine alone in spinal anesthesia for cesarean delivery.

Methods

This randomized, double-blind clinical examination included 50 females who had previously experienced a cesarean section. The participants were assigned randomly into two categories: the intervention group, received intrathecal bupivacaine-dexamethasone, and the control group, received intrathecal bupivacaine-normal saline. Levels of pain were evaluated using a 10 cm visual analog scale (VAS) at intervals of 30 minutes, 1 hour, 2 hours after the operation. The span of the sensory block and postoperative analgesia were assessed.

Results

The inclusion of intrathecal dexamethasone with bupivacaine resulted in a significant enhancement in the duration of pain relief during the intervention, lasting for an average of 473.4 ± 39.95 minutes (p<0.001). The duration of sensory and motor block analgesia in the intervention group was more than the control group (128.32 ± 7.30 vs. 92.84 ± 7.84) and (155.6±12.34 vs. 126.16±11.89), respectively (p<0.001). Pain score on the VAS scale at 30, 60, and 120 minutes was significantly lower in the intervention group (p<0.001). There was no difference in side effects and onset time between the study groups.

Conclusion

The inclusion of intrathecal dexamethasone alongside bupivacaine has demonstrated enhancement in the duration of sensory block during spinal anesthesia. This improvement was observed without any alterations in the time it takes for the anesthesia to take effect and without any adverse effects during the postoperative period.

Advances in Anesthesia for Shoulder Surgery: A Comprehensive Review of Dexmedetomidine-Enhanced Interscalene Brachial Plexus Block

Surgical procedures on the shoulder pose distinctive challenges in managing pain during the perioperative period, underscoring the importance of exploring innovative anesthesia techniques. This comprehensive review article delves into integrating dexmedetomidine, an alpha-2 adrenergic agonist, within interscalene brachial plexus blocks for shoulder surgery. The review initiates by underscoring the pivotal role of effective anesthesia in shoulder surgery and elucidates the rationale behind investigating dexmedetomidine as an adjunct. It meticulously examines the anatomy and physiology of the brachial plexus, emphasizing its critical significance in shoulder surgery. Furthermore, the article expounds on dexmedetomidine's mechanisms of action and pharmacokinetics, encompassing its safety profile and potential side effects. The conventional interscalene brachial plexus block techniques, along with their limitations and challenges, are discussed, laying the foundation for the integration of dexmedetomidine. The review subsequently delves into exploring the role of dexmedetomidine in regional anesthesia, covering previous studies, mechanisms of action, and the potential advantages of incorporating it into nerve blocks. The review's core concentrates on the practical application of dexmedetomidine-enhanced interscalene brachial plexus blocks. This includes discussions on administration techniques, dosage guidelines, and compelling evidence supporting its utilization. Clinical scenarios where this approach proves most advantageous are thoroughly explored, comparing its effectiveness with traditional techniques in terms of pain control and patient outcomes. A comprehensive examination of relevant clinical trials and case studies highlights the evidence supporting its efficacy. The review also underscores safety considerations associated with dexmedetomidine. It proposes strategies for mitigating risks to ensure patient safety. Insights into future directions and research are provided, encompassing ongoing studies, areas necessitating further investigation, and potential refinements in technique. Finally, the article summarizes key findings, emphasizing the practicality of dexmedetomidine-enhanced interscalene brachial plexus blocks in shoulder surgery and its far-reaching implications for clinical practice and patient care.

Dexmedetomidine versus sufentanil as adjuvants to bupivacaine for brachial plexus block during upper extremity surgery: a randomized clinical trial

BACKGROUND

Brachial plexus block (BPB) has been accepted as a reliable alternative for general anesthesia in upper limb surgeries. Adding adjuvant drugs like dexmedetomidine and sufentanil has been shown to have clinical and pharmacologic advantages. In this randomized parallel clinical trial, we aim to compare the effects of these two adjuvants for bupivacaine in BPB.

METHODS

In this double-blinded study, by using computer-assisted block randomization, 40 patients ranged from 20 to 65 years old and scheduled for elective upper limb surgeries were assigned to two equal study groups (n = 20), receiving 1 mL of 5 ..g.mL-1 sufentanil (group S) or 1 mL of 100 ..g.mL-1 dexmedetomidine (group D) in adjunction to 30 mL of 0.5% bupivacaine for supraclavicular BPB under the guidance of ultrasonography. Characteristics of local anesthesia and postoperative analgesia were evaluated (n = 40).

RESULTS

The duration of blocks significantly improved in group S (sensory: estimated median difference (EMD) [95%CI] = 100.0 [70.0...130.0], p < 0.001; motor: EMD [95%CI] = 120.0 [100.0...130.0], p < 0.001). Group S also had significantly longer postoperative analgesia and lower opioid consumption within 24 hours after the surgery (EMD [95%CI] = 4.0 [3.0...7.0], p < 0.001; EMD [95%CI] = -5.0 [-5.0...-5.0], p < 0.001; respectively). None of the patients showed adverse effects concerning vital signs, nausea, or vomiting.

CONCLUSION

Our study showed that during ultrasound-guided supraclavicular BPB, sufentanil is a fairly better choice than dexmedetomidine as an adjuvant for bupivacaine and can provide preferable sensory and motor blocks. No significant side effects were seen in either of the study groups.

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.

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 effect and safety of dexmedetomidine as an adjuvant to local anesthetics in erector spinae plane block: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine (DEX) has been thought to be an effective adjuvant to local anesthetics (LAs) in erector spinae plane block (ESPB), however, this method of use is not recorded in the drug instructions. Hence, our meta-analysis will evaluate its efficacy and safety for the first time.

METHODS

A systematic search of published articles was conducted in the PubMed, Embase, Web of science, and Cochrane Library databases up to July 17, 2022, using specific keywords related to our aims. The time first to request rescue analgesia, number of patient controlled intravenous analgesia (PCIA) presses, rate of rescue analgesia use, postoperative nausea and vomiting (PONV), arrhythmia, and hypotension were calculated by using random-effect models. This systematic review and meta-analysis was registered with PROSPERO (registration number: CRD42022345488).

RESULTS

Numerous electronic databases were searched and finally 8 studies with a total of 570 patients, 303 in the DEX arm, 267 in the control arm were included. As an adjuvant to LAs, DEX significantly increased the time to first request of rescue analgesia (mean difference [MD] = 8.40, 95% confidence interval [CI] = 4.70-12.10, P < 0.00001), reduced the number of PCIA presses (MD = -4.12, 95% CI = -7.79 to -0.45, P = 0.03) and the rate of rescue analgesia (odds ratio [OR] = 0.33, 95% CI = 0.17-0.65, P = 0.002). Moreover, the combination reduced the risk of PONV (OR = 0.57, 95% CI = 0.36-0.91, P = 0.02). In addition, there was no difference in the incidence of hypotension (OR = 1.01, 95% CI = 0.37-2.74, P = 0.99) and arrhythmia (OR = 0.76, 95% CI = 0.19-3.07, P = 0.70).

CONCLUSION

DEX can reduce analgesic requirements after various surgical procedures when used as an adjuvant to LAs for ESPB. Moreover, there was no significant difference between the two groups in terms of safety indicators (arrhythmia, hypotension).

The role of dexmedetomidine as an adjuvant for high-thoracic erector spinae plane block for analgesia in shoulder arthroscopy; a randomized controlled study

BACKGROUND

Management of postoperative pain after shoulder arthroscopy is an important issue. Dexmedetomidine, as an adjuvant, improves nerve block efficacy and decreases postoperative consumption of opioids. As a result, we designed this study to determine if adding dexmedetomidine to an erector spinae plane block (ESPB) that is guided by ultrasound (US) is beneficial for treating immediate postoperative pain following shoulder arthroscopy.

METHODS

This randomized controlled double-blind trial recruited 60 cases 18-65 years old of both sexes, American Society of Anesthesiologists (ASA) physical status I-II, scheduled for elective shoulder arthroscopy. Random allocation of 60 cases was done equally into two groups according to the solution injected in US-guided ESPB at T2 before general anesthetic induction. Group (ESPB): 20 ml 0.25% bupivacaine. Group (ESPB + DEX): 19 ml bupivacaine 0.25% + 1 mL dexmedetomidine 0.5 µg/kg. The primary outcome was The total rescue morphine consumption in the first 24 postoperative hours.

RESULTS

The mean intraoperative fentanyl consumption was significantly lower in the group (ESPB + DEX) compared to the group (ESPB) (82.86 ± 13.57 versus 100.74 ± 35.07, respectively, P = 0.015). The median (IQR) time of the 1^st rescue analgesic request was significantly delayed in the group (ESPB + DEX) compared to group (ESPB) [18.5 (18.25-18.75) versus 12 (12-15.75), P = 0.044]. The number of cases that required morphine was significantly lower in the group (ESPB + DEX) than in the group (ESPB) (P = 0.012). The median (IQR) of total postoperative morphine consumption in 1^st 24 h was significantly lower in the group (ESPB + DEX) compared to the group (ESPB) [0 (0-0) versus 0 (0-3), P = 0.021].

CONCLUSION

The dexmedetomidine as an adjuvant to bupivacaine in ESPB produced adequate analgesia by reducing the intraoperative and postoperative opioid requirements in shoulder arthroscopy.

TRIAL REGISTRATION

This study is registered on ClinicalTrials.gov (NCT05165836; principal investigator: Mohammad Fouad Algyar; registration date: 21/12/ 2021).

Role of adjuvants in regional anesthesia: A systematic review

The combination of drugs and routes of administration produces a synergistic effect, and one of the most important components of multimodal analgesic strategies are, therefore, nerve blocks for pain management. The effect of a local anaesthetic can be prolonged by administering an adjuvant. In this systematic review, we included studies on adjuvants associated with local anaesthetics in peripheral nerve blocks published in the last 5 years in order to evaluate their effectiveness. The results were reported according to the PRISMA guidelines. The 79 studies selected using our criteria showed a clear prevalence of dexamethasone (n=24) and dexmedetomidine (n=33) over other adjuvants. Different meta-analyses comparing adjuvants suggest that dexamethasone administered perineurally achieves superior blockade with fewer side effects than dexmedetomidine. Based on the studies reviewed, we found moderate evidence to recommend the use of dexamethasone as an adjuvant to peripheral regional anaesthesia in surgeries that can cause moderate to severe pain.

Dexmedetomidine as an adjunct to peripheral nerve blocks in pediatric patients

BACKGROUND

Combining local anesthetics with dexmedetomidine (DEX) for nerve blocks has been tested and confirmed as an alternative technique to strengthen analgesia in adults, but the evidence supported this proposal in pediatrics was not convincing enough. Thus, we intend to conduct a meta-analysis to make an appraisal of the effects of DEX as a local anesthetic adjuvant on peripheral nerve blocks in children.

METHODS

The analysis has been registered on https://www.crd.york.ac.uk/prospero/ with the registration number CRD42021254029 on June 10th, 2021. PubMed, Ovid MEDLINE, Embase and Cochrane central register were searched for the randomized controlled trials (RCTs) that are relevant to child/pain/DEX or block up to April 30, 2021.

RESULTS

Eight RCTs were included for data analysis. The pooled results showed a significantly reduced number of patients who required postoperative analgesics within DEX groups [odds ratio = 0.1, 95% confidence interval (CI) 0.03-0.32, P < 0.001]. And DEX significantly prolonged the duration of analgesia of local anesthetics in the meantime [standardized mean difference (SMD) = 4.93, 95% CI 3.02-6.83, P < 0.001]. Nevertheless, adding DEX as an adjunct to local anesthetics would significantly decrease heart rate (SMD = - 0.95, 95% CI - 1.45 to - 0.45, P < 0.001) and increase sedation score (SMD = 1.6, 95% CI 0.53-2.66, P = 0.003) simultaneously.

CONCLUSIONS

Adding DEX as an adjunct to peripheral nerve blocks can prolong analgesia until postoperative 8 hours in pediatric patients. However, the benefits should be weighed against the increasing risk of bradycardia and sedation in critical children.

Dexmedetomidine as an adjuvant to 0.25% bupivacaine in ultrasound guided femoral nerve block for preoperative positioning and postoperative analgesia in patients undergoing elective surgery for fracture shaft of femur

Background:

Femur fracture causes excruciating pain and surgical repair is recommended. To obtain satisfactory patient co-operation in the perioperative period, various analgesics have been used. Femoral nerve block (FNB) provides an excellent alternative for analgesia in the perioperative period. Dexmedetomidine of up to 2 μg.kg⁻¹ has been used in FNB as adjuvants in lower limb surgeries.

Aims:

The aim was to study the effect of addition of Dexmedetomidine to Bupivacaine in FNB on the comfort of positioning for subarachnoid block (SAB) and postoperative analgesia.

Materials and Methods:

Prospective, randomized, double-blind design was followed. Seventy American Society of Anesthesiologist I and II patients aged 18–70 years of either gender were randomly allocated into Group B (20 mL 0.25% Bupivacaine + 2 mL Normal Saline) and Group BD (received 20 mL 0.25% Bupivacaine + Dexmedetomidine 2 μg.kg⁻¹ diluted to 2 mL) for FNB. Numerical rating scale (NRS) was recorded before and after FNB and comfort of positioning graded. After 10 min, subarachnoid block (SAB) was administered. NRS was recorded postoperatively until 24 h.

Results:

The comfort of positioning improved in both the groups after FNB but was statistically not significant when compared among the groups (P = 0.7). Duration of postoperative analgesia was significantly higher in the Group BD (741 min ± 97 min) compared to the Group B (440 min ± 45 min) (P = 0.001) and was statistically significant.

Conclusion:

FNB improved the comfort of positioning for SAB, but the addition of Dexmedetomidine did not have any added advantages with respect to comfort of positioning. However, the addition of Dexmedetomidine significantly increased the duration of postoperative analgesia with minimal hemodynamic changes.

Anesthetic and surgical considerations for staged bilateral nephrectomies in a pediatric patient: A case report

We present a 9-year-old patient with end-stage renal disease, on peritoneal dialysis, who underwent a staged prone retroperitoneoscopic bilateral nephrectomy. Bilateral nephrectomy was indicated in preparation for renal transplant in the context of genetic predisposition malignancy when immunosuppressed. The two mirror-image surgeries enable the comparison of the anesthetic management and outcomes in a single patient. Features of interest to anesthesiologists include approach to a child with chronic kidney disease, different requirements for intraoperative antihypertensives; pain management strategies, including a comparison of erector spinae plane block with and without adjunct dexmedetomidine; anesthetic management of retroperitoneoscopic pediatric surgery and the first description of using a Foley bag attached to a peritoneal dialysis catheter to aid in diagnosis and repair of posterior peritoneal cavity entry.

Optimal dose of perineural dexmedetomidine to prolong analgesia after brachial plexus blockade: a systematic review and Meta-analysis of 57 randomized clinical trials

Background and Objectives

Peripheral injection of dexmedetomidine (DEX) has been widely used in regional anesthesia to prolong the duration of analgesia. However, the optimal perineural dose of DEX is still uncertain. It is important to elucidate this characteristic because DEX may cause dose-dependent complications. The aim of this meta-analysis was to determine the optimal dose of perineural DEX for prolonged analgesia after brachial plexus block (BPB) in adult patients undergoing upper limb surgery.

Method

A search strategy was created to identify suitable randomized clinical trials (RCTs) in Embase, PubMed and The Cochrane Library from inception date to Jan, 2021. All adult patients undergoing upper limb surgery under BPB were eligible. The RCTs comparing DEX as an adjuvant to local anesthetic (LA) with LA alone for BPB were included. The primary outcome was duration of analgesia for perineural DEX. Secondary outcomes included visual analog scale (VAS) in 12 and 24 h, consumption of analgesics in 24 h, and adverse events.

Results

Fifty-seven RCTs, including 3332 patients, were identified. The subgroup analyses and regression analyses revealed that perineural DEX dose of 30-50 μg is an appropriate dosage. With short−/intermediate-acting LAs, the mean difference (95% confidence interval [CI]) of analgesia duration with less than and more than 60 μg doses was 220.31 (153.13–287.48) minutes and 68.01 (36.37–99.66) minutes, respectively. With long-acting LAs, the mean differences (95% CI) with less than and more than 60 μg doses were 332.45 (288.43–376.48) minutes and 284.85 (220.31–349.39) minutes.

Conclusion

30-50 μg DEX as adjuvant can provides a longer analgesic time compared to LA alone and it did not increase the risk of bradycardia and hypotension.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01452-0.

The Effect of Dexmedetomidine in Combination with Bupivacaine on Sensory and Motor Block Time and Pain Score in Supraclavicular Block

Background

Brachial plexus block is frequently recommended for upper limb surgeries. Many drugs have been used as adjuvants to prolong the duration of the block. This study aimed to assess the effect of dexmedetomidine with bupivacaine combination and only bupivacaine on sensory and motor block duration time, pain score, and hemodynamic variations in the supraclavicular block in upper extremity orthopedic surgery.

Methods

This prospective, double-blind clinical trial study was conducted on 60 patients, 20 to 60 years old. Patients were candidates for upper extremity orthopedic surgeries. The sensory and motor block were evaluated by using the pinprick method and the modified Bromage scale. The postoperative pain was assessed by utilizing a visual analog scale.

Results

The mean onset time of sensory and motor block in patients receiving only bupivacaine was, respectively, 31.03 ± 9.65 min and 24.66 ± 9.2 min, and in the dexmedetomidine receiving group, it was about 21.36 ± 8.34 min and 15.93 ± 6.36 minutes. The changes in heart rate and mean arterial blood pressure were similar in both groups. The duration of sensory and motor block and the time of the first analgesia request in the intervention group were longer. Postoperative pain was lower in the intervention group for 24 hours (P = 0.001).

Conclusion

Dexmedetomidine plus bupivacaine reduced the onset time of sense and motor blocks and increased numbness and immobility duration. Also, dexmedetomidine reduced postoperative pain significantly with the use of bupivacaine for supraclavicular blocks. Trial Registration. IRCT, IRCT20160430027677N15. Registered 05/28/2019, https://www.irct.ir/trial/39463.

The Effect of Ultrasound-Guided Erector Spinae Plane Block Combined with Dexmedetomidine on Postoperative Analgesia in Patients Undergoing Modified Radical Mastectomy: A Randomized Controlled Trial

Introduction

One of the most common malignancies in women worldwide is breast cancer. Erector spinae plane block (ESPB) can reduce pain after modified radical mastectomy for breast cancer. The duration of nerve block analgesia is limited if local anesthetic agents are used alone. The purpose of this study was to evaluate the effect of dexmedetomidine on postoperative analgesia during a single injection of local anesthetics.

Methods

In this double-blind, randomized study, 60 female American Society of Anesthesiologists (ASA) I–II patients undergoing modified radical mastectomy were randomized into two groups: ultrasound (US)-guided ESPB with 30 mL of 0.33% ropivacaine (group R) and US-guided ESPB with 30 mL of dexmedetomidine plus 0.33% ropivacaine (group DR). US-guided ESPB at the T3 vertebral level was performed preoperatively in all patients. The indicators were 1-, 6-, 12-, 24-, and 48-h visual analog scale (VAS) pain scores after surgery in the resting state and at 90-degree shoulder abduction. Other measures were a comparison of intraoperative sufentanil and remifentanil, postoperative nausea and vomiting (PONV), flurbiprofen consumption, the lengths of post-anesthesia care unit (PACU) stay and hospital stay, postoperative bradycardia, and hypotension.

Results

The VAS pain score was lower in group DR than group R at any time in the resting state, except at 1 h after surgery. The VAS pain score was lower in group DR than group R at 12 and 24 h in an active state after surgery (P < 0.05 for each time interval). The intraoperative dosages of remifentanil and sufentanil in group DR were lower than that in group R. The postoperative dosage of flurbiprofen in group DR was lower than that in group R (P = 0.038). The lengths of PACU stay were longer in group DR than in group R. No significant difference was found in PONV and hospital stay between the two groups. No sinus bradycardia or hypotension after surgery occurred in the two groups.

Conclusions

Dexmedetomidine as an adjunctive to ESPB can effectively relieve pain and significantly reduce the need for opioids during modified radical mastectomy for breast cancer.

Trial Registration

The study was registered in the Chinese Clinical Trial Registry (ChiCTR2000031134, principal investigator: Yao Lu, date of registration: 2020-3-22).

Future in regional anesthesia and pain medicine: the pharmacological view

Local anesthetics are still incompletely understood, and none of the currently available drugs are optimal. The primary target of local anesthetics is the voltage-gated sodium channel (VGSC), where they lead to a temporary interruption of nerve conduction. Unfortunately, local anesthetics are neither specific at blocking a specific VGSC isoform, nor a specific cell type. We realize now that the old classification of A and C fibers according to myelin thickness is outdated, that next to differing myelin configuration, cells differ also by their molecular biology, and that there are close to 20 different neuronal subgroups when function is concerned. The ideal local anesthetic would only block sensory impulses, or even only painful impulses. In the search for that drug, several research avenues have been followed. First, efforts have been undertaken to extend duration of local anesthetics, by additives or extended-release formulation. Second, blockade of specific pain fibers has been attempted by targeting permanently charged anesthetics specifically into nociceptors. Third, blockade of specific isoforms using antibodies, and adaptation of naturally occurring neurotoxins has shown promise. Lastly, combination of local anesthetics with other analgesics may improve their duration of action.

A Comprehensive Review and Update of the Use of Dexmedetomidine for Regional Blocks

PURPOSE OF REVIEW

This evidence-based systematic review will focus on the use of dexmedetomidine and its role as adjuvant anesthetics in regional blocks to help better guide physicians in their practice. This review will cover background and mechanism of dexmedetomidine as well as the use in various regional blocks.

RECENT FINDINGS

Local anesthetics are preferred for nerve blocks over opioids; however, both due come with its own side effects. Local anesthetics may be toxic as they disrupt cell membrane and proteins, but by using adjuvants such as dexmedetomidine, that can prolong sensory and motor blocks can reduce total amount of local anesthetics needed. Dexmedetomidine is an alpha-2-adrenergic agonist used as additive for regional nerve block. It has a relatively low side effect profile and have been researched in various regional blocks (intrathecal, paravertebral, axillary, infraclavicular brachial plexus, interscalene). Dexmedetomidine shows promising results as adjuvant anesthetics in most regional blocks.

SUMMARY

Many studies have been done and many show promising results for the use of dexmedetomidine in regional blocks. It may significantly increase in duration of sensory and motor blocks that correlates with lower pain scores and less need of morphine in various regional blocks.

Dexmedetomidine vs dexamethasone as an adjuvant to 0.5% ropivacaine in ultrasound-guided supraclavicular brachial plexus block

Background and Aims

Both dexmedetomidine and dexamethasone have individually been shown to be beneficial as an adjuvant to ropivacaine. We compared the efficacy of combination of ropivacaine with dexmedetomidine and ropivacaine with dexamethasone in ultrasound-guided supraclavicular brachial plexus (SCBP) block.

Material and Methods

In this prospective randomised double-blind controlled trial, 60 ASA physical status I/II patients undergoing elective upper-limb surgery under ultrasound-guided SCBP block with 30 ml of 0.5% ropivacaine were randomised into three groups. Group 1 (n = 20) received 1 μg/kg of dexmedetomidine, and group 2 (n = 20) received 8 mg of dexamethasone in addition to ropivacaine, while group 3 (n = 20) received only ropivacaine. The primary outcomes studied were onset and duration of sensory and motor block. Secondary outcomes included duration of analgesia, total analgesic consumption in 24 h postoperatively and quality of block. ANOVA and Chi-square test were used to compare results on continuous measurements and categorical measurements, respectively.

Results

Onset of sensory and motor block was faster in group 1 (13.5 ± 4.1 and 17.0 ± 4.1 min) and group 2 (15.6 ± 3.6 and 18.5 ± 3.7 min) as compared to group 3 (20.1 ± 5.3 and 24.9 ± 5.6 min; P < 0.001). Block duration was significantly longer in group 1 and group 2 than in group 3. Duration of analgesia was prolonged in group 1 and 2 (1218.0 ± 224.6 and 1128.0 ± 207.5 min, respectively) as compared to group 3 (768.0 ± 273.7 min; P < 0.001). Twenty-four hours analgesic consumption postoperatively was reduced in the two study groups.

Conclusion

Both dexmedetomidine and dexamethasone when used as adjuvants to ropivacaine for SCBP block, block onset time, and prolong' block duration.

Effect of 5-μg Dose of Dexmedetomidine in Combination With Intrathecal Bupivacaine on Spinal Anesthesia: A Systematic Review and Meta-analysis

PURPOSE

Intrathecal dexmedetomidine (DEX) has been used to improve the quality and duration of spinal anesthesia. The aim of this meta-analysis is to evaluate whether intrathecal DEX could prolong the duration of sensory and motor block during spinal anesthesia.

METHODS

We searched PubMed, EMBASE, Web of Science, and the Cochrane Library for randomized controlled trials that investigated the facilitatory effects of intrathecal administration of DEX compared with those of a placebo on spinal anesthesia from inception to April 2019. Sensory and motor block durations, sensory and motor block onset times, time to first analgesic request, and DEX-related adverse effects were evaluated. Results were combined using fixed-effects or random effects modeling when appropriate.

FINDINGS

A total of 1478 patients from 25 clinical studies were included in the analysis. Compared with placebo, intrathecal DEX significantly prolonged the durations of both sensory block (weighted mean difference [WMD] = 134.42 min; 95% CI, 109.71-159.13 min; P < 0.001) and motor block (WMD = 114.27 min; 95% CI, 93.18-135.35 min; P < 0.001). It also hastened the onset of sensory block (WMD = -0.80 min; 95% CI, -1.21 to -0.40; P < 0.001) and motor block (WMD = -1.03 min; 95% CI, -1.51 to -0.56 min; P < 0.001). Furthermore, it delayed the time to first analgesic request (WMD = 216.90 min; 95% CI, 178.90-254.90 min; P < 0.001) and reduced the incidence of shivering (risk ratio [RR] = 0.39; 95% CI, 0.27-0.55; P < 0.001). DEX was associated with increased risk of transient bradycardia (RR = 1.59; 95% CI, 1.07-2.37; P = 0.022) and hypotension (RR = 1.40; 95% CI, 1.04-1.89; P = 0.026) but did not increase the incidence of postoperative nausea and vomiting (RR = 0.87; 95% CI, 0.62-1.24; P = 0.45).

IMPLICATIONS

Intrathecal DEX can prolong the duration of sensory block, the duration of motor block, and the time to first analgesic request associated with spinal anesthesia.

Comparative evaluation of intrathecal bupivacaine alone and bupivacaine combined with dexmedetomidine in cesarean section using spinal anesthesia: a meta-analysis

Objective

This meta-analysis was performed to evaluate the effect of spinal anesthesia (SA) using bupivacaine combined with dexmedetomidine (DEX) in cesarean section, analyze the adverse drug reactions induced by this mixture, and provide a reference for rational drug use.

Methods

Randomized controlled trials were obtained from the PubMed, Cochrane Library, and Embase databases. The primary outcome measure was the time to the highest sensory block level (min), and the secondary outcome measure was adverse effects.

Results

The time to the highest sensory block level was significantly shorter in the bupivacaine-DEX group than in the control group (standardized mean difference, −0.23; 95% confidence interval, −0.43 to −0.03). The incidence of shivering during the process of anesthesia, especially at a dose of 5 µg DEX, was significantly lower in the bupivacaine-DEX group than in the control group (odds ratio, 0.26; 95% confidence interval, 0.14–0.49). No significant differences were observed in the symptoms of hypotension, bradycardia, nausea/vomiting, or pruritus.

Conclusion

Compared with the use of bupivacaine alone for SA in cesarean section, adding dexmedetomidine during SA can significantly shorten the onset time and decrease the rate of shivering during anesthesia.

Dexmedetomidine as an Adjuvant to Local Anesthetics in Transversus Abdominis Plane Block: A Systematic Review and Meta-analysis

OBJECTIVES

The objective of this meta-analysis was to evaluate the analgesic effects of dexmedetomidine (DEX) in transversus abdominis plane (TAP) blocks for abdominal surgery.

METHODS

Electronic databases, including PubMed, EMBASE, Chinese National Knowledge Infrastructure (CNKI), Wan Fang, and the Cochrane Library, were conducted to collect the randomized controlled trials (RCTs) from inception to March 2018. RCTs investigating the impact of adding DEX to local anesthetics for TAP blocks were included in this analysis. Pain scores (at rest and movement), opioid consumption, the duration of the TAP block and the common adverse effects were analyzed.

RESULTS

Twenty published trials including 1212 patients met the inclusion criteria. The addition of DEX significantly reduced pain scores 8 hours postoperatively at rest (WMD, -0.78; 95% CI, -1.27 to -0.30; P=0.001), 4 hours postoperatively on movement (WMD, -1.13; 95% CI, -1.65 to -0.60; P<0.001), and opioid consumption (WMD, -13.71; 95% CI, -17.83 to -9.60; P<0.001) when compared with control group. Furthermore, perineural DEX significantly prolonged the duration of the TAP block (WMD, 3.33; 95% CI, 2.85 to 3.82; P<0.001). It did not affect the incidence of postoperative nausea and vomiting, hypotension, bradycardia, somnolence, or pruritus.

CONCLUSIONS

DEX is a potential anesthetic adjuvant that can facilitate better postoperative analgesia, reduce postoperative analgesic requirements, and prolong the local anesthetic effect when administered in TAP blocks.

Dexmedetomidine combined with local anesthetics in thoracic paravertebral block: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine (DEX) improves postoperative pain scores and prolongs the duration of blockage when combined with local anesthetics (LAs) for neuraxial and brachial plexus block; however, there is little information about the effectiveness of DEX as an adjuvant to LAs in paravertebral block (PVB). Therefore, a systematic review and meta-analysis were performed to evaluate the safety and efficacy of DEX combined with LAs in PVB.

METHOD

An electronic database search from inception date to February 2018 was performed. Randomized controlled trials (RCTs) comparing DEX as an adjuvant to LAs with LAs alone for PVB in adult patients were included. Postoperative pain scores, duration of analgesia, cumulative perioperative analgesic consumption, and adverse events were analyzed.

RESULT

We identified 7 trials enrolling 350 patients and found that DEX reduced pain scores at rest by standardized mean differences (SMD) -0.86 cm (95% confidence interval [CI] [-1.55, -0.17], P = .01) and SMD -0.93 cm (95% CI [-1.41, -0.26], P =.008) at postoperative 12 hours and 24 hours, respectively. DEX reduced pain scores while dynamic by SMD -1.63 cm (95% CI [-2.92, -0.34], P =.01) and SMD -1.78 cm (95% CI [-2.66, -0.90], P =.007) for postoperative 12 hours and 24 hours, respectively. DEX extended the duration of analgesia by weighted mean differences (WMD) 201.53 minutes (95% CI [33.45, 369.61], P =.02); and reduced cumulative postoperative analgesic consumption by WMD -7.71 mg (95% CI [-10.64, -4.78], P <.001) and WMD -45.64 mg (95% CI [-69.76, -21.53], P < .001) for 24 hours morphine and 48 hours tramadol subgroups, respectively. DEX also increased the odds of hypotension by odds ratio (OR) 4.40 (95% CI [1.37, 14.17], P = .01); however, there was no statistically significant difference for intraoperative fentanyl consumption and the incidence of the bradycardia.

CONCLUSIONS

DEX combined with LAs in PVB significantly improved postoperative pain scores, prolonged the duration of analgesia, reduced postoperative analgesic consumption, and increased the odds of hypotension. However, we cannot neglect the heterogeneity of the included RCTs. More large-scale prospective studies are needed to further clarify the above conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42018090251.

The Effect of Adding Dexmedetomidine as an Adjuvant to Lidocaine in Forearm Fracture Surgeries by Supraclavicular Block Procedure Under Ultrasound-Guided

Background

To improve the brachial plexus block (BPB) performance, different compounds have been used as adjuvants to local analgesics.

Objectives

The aim of the present study was to investigate the effects of adding DEX to lidocaine on effectiveness of nerve block, and postoperative pain in forearm fracture surgery by supraclavicular BPB undergoing ultrasound-guided.

Methods

This was a double-blinded randomized clinical trial conducted on 72 patients with ASA classes I and II, which were candidates for forearm fracture surgery. In group A, patients received 3 mg/kg of lidocaine 2%. In group B, patients received 3 mg/kg of lidocaine 2% and DEX (1 µg/kg). The ultrasound-guided supraclavicular BPB was performed in all patients. The onset of sensory and motor blocks were evaluated with pin prick test and modified Bromage scale, respectively. The sensory and motor block moment was recorded as the onset of the block. The first analgesic request time, total consumed analgesic, adverse effect, and hemodynamic parameters of patients were recorded. A visual analog scale (VAS) was used for recording the severity of pain.

Results

The two groups showed no significant difference in the demographic variables. The onset of sensory and motor block in the DEX groups was shorter. The duration of sensory and motor block, and analgesic request was significantly longer than the control groups. Total analgesic consumption 24 hours after surgery in the DEX groups was significantly lower. Moreover, hemodynamic status of patients in both groups was stable and no significant difference was observed between groups. This study showed that DEX, as an adjuvant to lidocaine, improve the characteristics of supraclavicular BPB and decrease the postoperative pain.

Dexamethasone Compared to Dexmedetomidine as an Adjuvant to Local Anesthetic Mixture in Peribulbar Block for Vitreoretinal Surgery. A Prospective Randomized Study

BACKGROUND

Dexamethasone or dexmedetomidine may improve the quality of peribulbar block.

AIM

The aim of this study is to compare the effects of adding either dexamethasone or dexmedetomidine to peribulbar block on the efficacy, intraocular pressure (IOP), time to first analgesic request, total analgesic requirement, and side effects in patients undergoing vitreoretinal surgery.

DESIGN

This was a clinical prospective randomized study.

PATIENTS AND METHODS

One hundred and fifty adult patients scheduled for vitreoretinal surgery with peribulbar block were randomized into three groups (50 patients each). Group I received 3.5 ml of 0.5% bupivacaine and 3.5 ml of 2% lidocaine + 1 ml normal Saline. 4 mg dexamethasone and 25 μg dexmedetomidine in 1 ml were added to the local anesthetic mixture in Groups II and III respectively. Onset and duration of sensory and motor blocks, adequate time to start surgery, IOP, time to first request of rescue analgesia, total analgesic consumption, and side effects were recorded. The statistical software SPSS 16 was utilized for statistical analysis.

RESULTS

Dexamethasone and dexmedetomidine groups showed significantly prolonged duration of corneal anesthesia (234.07 ± 1.37 and 233.54.1.97 min respectively), prolonged lid and globe akinesia (194.27 ± 1.63 and 194.73 ± 2.35 min respectively) with prolonged time to first request of analgesia and less consumption of rescue analgesia as compared to control group (P < 0.05) with non significant differences between both groups (P > 0.05). The onset of corneal anesthesia as well as lid and globe akinesia were enhanced in dexmedetomidine group compared to the other two groups (P < 0.05). In addition, the measurement of IOP was significantly less in the dexmedetomidine group after 10 min. All the patients were hemodynamically stable with no side effects observed.

CONCLUSION

The addition of dexamethasone and dexmedetomidine to local anesthetic mixture in peribulbar block for vitreoretinal surgeries provided safe and effective block with prolonged duration and decreased requirements of postoperative analgesia with better quality for dexmedetomidine group regarding the fast onset of the block and reduced IOP.