Effects of dexmedetomidine versus ketorolac as local anesthetic adjuvants on the onset and duration of infraclavicular brachial plexus block

Utility of dexmedetomidine on surgical site wound pain undergoing thoracoscopic surgery: A meta-analysis

We conducted this study aimed to evaluate the analgesic effect of dexmedetomidine in thoracoscopic surgery on postoperative wound pain, and to provide a reference for clinical use of the drug. We searched PubMed, Embase, Cochrane Library, Web of Science, Wanfang, Chinese Biomedical Literature Database and China National Knowledge Infrastructure databases, and supplemented with manual searching. We searched from database inception to October 2023, to collect the randomised controlled trials (RCTs) on dexmedetomidine application in thoracoscopic surgery. Two researchers screened all the literature according to the inclusion and exclusion criteria and the literature included in the study was evaluated for quality, extracted information and required data. Stata 17.0 software was employed for data analysis and the outcomes were 2 6, 12, 24 and 48 h postoperative wound visual analog scores (VAS). Twenty-four RCTs totalling 2246 patients undergoing thoracoscopic surgery were finally included. The analysis revealed dexmedetomidine applied to thoracoscopic surgery significantly reduced the postoperative wound VAS scores at 2 h (SMD: -0.96, 95% CI: -1.57 to -0.36, p = 0.002), 6 h (SMD: -0.98, 95% CI: -1.27 to -0.69, p < 0.001), 12 h (SMD: -1.19, 95% CI: -1.44 to -0.94, p < 0.001), 24 h (SMD: -0.91, 95% CI: -1.16 to -0.66, p < 0.001) and 48 h (SMD: -0.75, 95% CI: -1.02 to -0.48, p < 0.001). Our results suggest dexmedetomidine applied to thoracoscopic surgery can significantly reduce postoperative wound pain, which is worthy of clinical application.

The effect of adjuvants added to local anaesthetics for single-injection upper extremity peripheral regional anaesthesia: A systematic review with network meta-analysis of randomised trials

BACKGROUND

Peripheral regional anaesthesia is frequently used for upper extremity surgery. To prolong the duration of analgesia, adjuvants can be added to single-injection local anaesthetics. Despite attempts to compare several adjuvants in pairwise meta-analyses, a comprehensive comparison is still missing.

OBJECTIVE

The objective of this network meta-analysis was to determine the effectiveness of adjuvants in upper extremity peripheral nerve blocks.

DESIGN

A systematic review of randomised controlled trials with network meta-analyses.

DATA SOURCES

A literature search in Embase, CENTRAL, MEDLINE and Web of Science was performed up to March 2023.

ELIGIBILITY CRITERIA

Randomised trials comparing different adjuvants injected perineurally in peripheral upper extremity nerve blocks were eligible. Frequentist network meta-analysis was conducted using a random effects model with physiological saline as the comparator. The primary endpoint was the ratio of means (ROM) of the duration of analgesia.

RESULTS

The review included 242 randomised controlled trials with a total of 17 391 patients. Twenty-eight adjuvants were compared in the largest networks. Most network estimations consisted of a high proportion of direct evidence. Fourteen adjuvants increased the duration of analgesia significantly by the following factors, ROM [95% confidence interval (CI)]: dexamethasone 1.95 (1.79 to 2.13), buprenorphine 1.83 (1.51 to 2.24), butorphanol 1.84 (1.41 to 2.39), potassium chloride 1.89 (1.15 to 3.11), dexmedetomidine 1.70 (1.59 to 1.81), sufentanil 1.70 (1.27 to 2.29), ketorolac 1.68 (1.24 to 2.27), midazolam 1.55 (1.24 to 1.94), tramadol 1.52 (1.32 to 1.75), nalbuphine 1.50 (1.30 to 1.72), morphine 1.43 (1.09 to 1.88), magnesium sulfate 1.42 (1.20 to 1.67), clonidine 1.36 (1.24 to 1.50) and fentanyl 1.23 (1.08 to 1.40). Inconsistency in network meta-analysis was substantial. Overall side effect rates were low with all adjuvants.

CONCLUSION

The best interventions to prolong the duration of analgesia were dexamethasone, followed by dexmedetomidine, opioids, electrolytes, ketorolac and midazolam. There are general concerns about the quality of underlying studies and the risk of publication bias.

TRIAL REGISTRATION

PROSPERO 2018 CRD42018115722.

Dexmedetomidine as an Adjuvant in Peripheral Nerve Block

Peripheral nerve block technology is important to balanced anesthesia technology. It can effectively reduce opioid usage. It is the key to enhance clinical rehabilitation as an important part of the multimodal analgesia scheme. The emergence of ultrasound technology has accelerated peripheral nerve block technology development. It can directly observe the nerve shape, surrounding tissue, and diffusion path of drugs. It can also reduce the dosage of local anesthetics by improving positioning accuracy while enhancing the block's efficacy. Dexmedetomidine is a highly selective drug α₂-adrenergic receptor agonist. Dexmedetomidine has the characteristics of sedation, analgesia, anti-anxiety, inhibition of sympathetic activity, mild respiratory inhibition, and stable hemodynamics. Numerous studies have revealed that dexmedetomidine in peripheral nerve blocks can shorten the onset time of anesthesia and prolong the time of sensory and motor nerve blocks. Although dexmedetomidine was approved by the European Drug Administration for sedation and analgesia in 2017, it has not yet been approved by the US Food and Drug Administration (FDA). It is used as a non-label drug as an adjuvant. Therefore, the risk-benefit ratio must be evaluated when using these drugs as adjuvants. This review explains the pharmacology and mechanism of dexmedetomidine, the effect of dexmedetomidine on various peripheral nerve block as an adjuvant, and compare it with other types of adjuvants. We summarized and reviewed the application progress of dexmedetomidine as an adjuvant in nerve block and look forward to its future research direction.

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.

Hertling A. Adding Dexmedetomidine to Bupivacaine in Ultrasound-guided Thoracic Paravertebral Block for Pain Management after Upper Abdominal Surgery: A Double-blind Randomized Controlled Trial

Background

Paravertebral blocks are one of the possible postoperative pain management modalities after laparotomy. Adjuvants to local anesthetics, including alpha agonists, have been shown to lead to better pain relief and increased duration of analgesia.

Objectives

The aim of this study is to examine the effect of adding dexmedetomidine to bupivacaine for ultrasound-guided paravertebral blocks in laparotomy.

Methods

In this double-blind, randomized controlled trial (RCT), we enrolled 42 patients scheduled for T6 to T8 thoracic paravertebral block (TPVB) for analgesia after laparotomy. The patients were randomly assigned into two groups of BD (bupivacaine 2.5 mg/mL 20 mL plus dexmedetomidine 100 µg) and B (bupivacaine 20 mL alone). Following surgery, intravenous fentanyl patient-controlled analgesia was initiated. The numerical rating scale (NRS) for pain, sedation score, total analgesic consumption, time to first analgesic requirement, side effects (such as nausea and vomiting), respiratory depression, and patients’ satisfaction during the first 48 hours of evaluation were compared in the two groups.

Results

Pain scores and mean total analgesic consumption at the first 48 hours in the BD group were significantly lower than Group B (P = 0.03 and P < 0.001, respectively). The time of first analgesic request was significantly longer in BD group (P < 0.001). Sedation scores and side effects did not differ significantly between the two groups.

Conclusions

Adding dexmedetomidine to bupivacaine for TPVB after laparotomy yielded better postoperative pain management without significant complications.

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.

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.

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.

Adjuvants in pain medicine. Selection of the drug depending on the desired effect – so which drug to choose?

To date, much research has focused on finding the ideal adjuvant for local anesthetics. Each of them can have different effects. In anesthesiology and pain medicine, depending on the purpose, one or another effect may be desirable. For example, in some situations it is desirable to accelerate the onset of action or prolong the duration of the block, in others the desired effect may be a “response to intravascular administration”, it should also be borne in mind that not all adjuvants are allowed for intrathecal administration.

Review of adjuvants to local anesthetics in peripheral nerve blocks: Current and future trends

In recent anesthetic practice, peripheral nerve blocks (PNBs) are used extensively for surgical anesthesia and nonsurgical analgesia. PNBs offer many benefits over other anesthetic techniques in a certain population of patients, and in some specific clinical setting, that may contribute to faster and safer pain relief, increased patient satisfaction, reduced hospital stay, and decreased overall healthcare cost. The technique involves the injection of the anesthetic in the vicinity of a specific nerve or bundle of nerves to block the sensation of pain transmitting to a specific portion of the body. However, the length of analgesia when a single anesthetic is used for PNB may not last long. Therefore, the practice of adding an additional agent called adjuvant has been evolved to prolong the analgesic effect. There are many such adjuvants available that are clinically being used for this purpose imparting great efficacy and safety to the anesthetic process. The adjuvants molecules are generally classified as opioids, alpha-2 agonist, steroids, etc. Most of them are safe to use and show little or no adverse event related to neurotoxicity and tissue damage. Although there is extensive use of such adjuvants in the clinical field, none of the molecules is approved by the FDA and is used as an off-label drug. The risk to benefit ratio must be assessed while using such an agent. This review will try to delineate the basic need of adjuvant in peripheral nerve block and will discuss the advantages and limitations of using different adjuvants and will discuss the future prospect of such application.

Comparative Evaluation of Dexamethasone and Dexmedetomidine as Adjuvants for Bupivacaine in Ultrasound-Guided Infraorbital Nerve Block for Cleft Lip Repair: A Prospective, Randomized, Double-Blind Study

Purpose

To compare dexamethasone (DA) to dexmedetomidine (DE) as adjuvants for bupivacaine during infraorbital nerve block (IONB) in a randomized clinical trial.

Patients and Methods

One hundred patients were randomized into two equal groups. By the guidance of ultrasound, the IONB was performed bilaterally in all patients, using 1 mL of the solution on each side. In DA group, 1 mL of 0.5% bupivacaine was added to 0.1 mg.kg-1 DA and diluted to 2 mL in DE group; 1 mL of 0.5% bupivacaine was added to 0.5 μg.kg^-1 DE and diluted to 2 mL. The primary outcome was time to first rescue analgesic. The secondary outcomes included face legs activity cry consolability (FLACC) score rating during the first 24 h, hemodynamic variables, the incidence of postoperative vomiting, sedation score, and parent satisfaction.

Results

During the first 24 h postoperatively, the DE group showed a significantly lower FLACC score and a longer time to first analgesic request compared to DA group. Sedation and parent satisfaction scores were significantly higher while heart rate and mean blood pressure were significantly lower in DE group compared to DA group. There were no differences in other secondary outcomes.

Conclusion

The use of DE as an adjuvant to bupivacaine in IONB for cleft lip repair resulted in lower pain score and more prolonged duration of analgesia compared to DA.

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.

Comparison of Magnesium Sulfate and Dexmedetomidine as an Adjuvant to 0.5% Ropivacaine in Infraclavicular Brachial Plexus Block

Background:

Magnesium sulfate and dexmedetomidine were used as adjuvants to local anesthesia to improve the quality of regional anesthesia.

Aims:

The aim of this study is to evaluate and compare the effects of magnesium sulfate and dexmedetomidine when added to ropivacaine on the quality of infraclavicular brachial plexus block (BPB).

Settings and Design:

This was a prospective randomized double-blinded controlled study.

Patients and Methods:

A total of 105 adult patients undergoing surgery in hands, wrist, and forearm using infraclavicular BPB were randomly assigned into three groups. Ultrasound-guided infraclavicular BPB was performed using 35 ml ropivacaine 0.5% diluted with 4 ml normal saline 0.9%. Magnesium sulfate 150 mg and dexmedetomidine 100 μg were added in the magnesium sulfate group and dexmedetomidine group, respectively. Duration of analgesia, onset times and durations of sensory block (SB) and motor block (MB), patient's satisfaction, and complications were recorded.

Statistical Analysis:

Statistical software SPSS 16 was used for statistical analysis.

Results:

Dexmedetomidine and magnesium sulfate provided longer duration of analgesia and lesser consumption of postoperative rescue analgesia than the control group (P = 0. 000); dexmedetomidine provided the longest duration of analgesia versus control and magnesium sulfate groups (P = 0.000). Dexmedetomidine provided the quickest onset times and the longest durations of both SB and MB than control and magnesium sulfate groups (P = 0.000). Dexmedetomidine group had higher incidences of bradycardia and hypotension.

Conclusions:

Magnesium sulfate or dexmedetomidine is a useful adjuvant to ropivacaine for infraclavicular BPB in lengthening the duration of analgesia. Dexmedetomidine provided quicker onset and longer duration of both SB and MB and longer duration of analgesia with lesser consumption of postoperative rescue analgesia; however, it showed a higher incidence of intraoperative hypotension and bradycardia than magnesium sulfate.

Multilevel Thoracic Paravertebral Block Using Ropivacaine With/Without Dexmedetomidine in Video-Assisted Thoracoscopic Surgery

OBJECTIVES

Thoracic paravertebral block (TPVB) is reported to have advantages in postoperative pain management in unilateral thoracic surgeries. Previous studies have demonstrated that dexmedetomidine could be used as an adjuvant to local anesthetics, with the aim of prolonging the duration of neural blockade. However, little is known about whether such a combination could improve the quality of postoperative analgesia compared with local anesthetic only when TPVB is used for patients undergoing video-assisted thoracoscopic surgery (VATS).

DESIGN

A prospective, randomized, controlled study.

SETTING

Single-center university hospital.

PARTICIPANTS

The study included 60 patients undergoing VATS under general anesthesia.

INTERVENTIONS

The patients were allocated randomly into the following 2 groups: 0.375% ropivacaine, 20 mL only (group R, n = 30), and 0.375% ropivacaine, 20 mL plus 1 μg/kg of dexmedetomidine (group RD, n = 30). At the end of surgery, TPVB guided using ultrasound was performed at 4 points-T4-5, T5-6, T6-7, and T7-8-of the surgical side; 5 mL of solution were injected at each point. Postoperatively, the intravenous nonsteroidal anti-inflammatory drug flurbiprofen was used as part of multimodal analgesia.

MEASUREMENTS AND MAIN RESULTS

Pain scores at rest and during coughing were evaluated by a blinded observer in the postanesthesia care unit postoperatively at 1, 2, 4, 8, 12, 24, 36, and 48 hours, and the dermatomal levels of sensory blockade, postoperative requirements for rescue analgesia, adverse events, and patient satisfaction also were recorded. There was a significant reduction in postoperative pain scores at rest starting from the postoperative 8th hour until the 48th hour and during coughing starting at the postoperative 4th hour until the 48th hour in the group RD compared with those in group R (p = 0.043). The dermatomal levels of sensory blockade were comparable in the 2 groups. Patient satisfaction after surgery was significantly higher in the group RD than in group R (p < 0.001). Total consumption of the intravenous rescue analgesic morphine and adverse events were not significantly different between the 2 groups.

CONCLUSIONS

Compared with ropivacaine only, the addition of dexmedetomidine, 1 μg/kg, to local anesthetic for multilevel TPVB in patients undergoing VATS prolonged the duration of postoperative analgesia and improved patient satisfaction without serious side effects when combined with postoperative intravenous nonsteroidal anti-inflammatory drug administration.

The Effect of Magnesium Sulfate on Postoperative Pain in Upper Limb Surgeries by Supraclavicular Block Under Ultrasound Guidance

BACKGROUND

Previous studies have been conducted to evaluate the effect of different adjuvants on brachial plexus block.

OBJECTIVES

This study investigated the effect of adding magnesium sulfate to lidocaine on postoperative pain in upper limb surgeries by supraclavicular brachial plexus block under ultrasound guidance.

METHODS

This study was carried out on patients who were candidate for upper limb surgeries. This was a controlled double-blind study conducted on a number of 52 patients aged 18 - 75 years with ASA class I or II. The first group (M) received lidocaine 1% (4 mg/kg) plus fentanyl 50 micg and magnesium sulfate 20% (5 mL) while the second group (N) received lidocaine 1% (4 mg/kg) plus fentanyl 50 micg and normal saline (5 mL) to supraclavicular brachial plexus block under ultrasound guidance. Postoperative pain was evaluated by visual analog scale (VAS) until 24 hours. Sensory and motor blocks onset and duration, rescue analgesics, hemodynamic variables, and side effects were recorded for all the patients.

RESULTS

Postoperative VAS values at 24 hours were significantly lower in group M than group N (P < 0.0001). Sensory and Motor blocks onset and duration were statistically longer in group M than group N (P < 0.0001).

CONCLUSIONS

The addition of magnesium sulfate to lidocaine decreased the postoperative pain and increased the onset and duration of sensory and motor blocks in supraclavicular brachial plexus block under ultrasound guidance in upper limb surgeries.

The Effect of Perineural Administration of Dexmedetomidine on Narcotic Consumption and Pain Intensity in Patients Undergoing Femoral Shaft Fracture Surgery; A Randomized Single-Blind Clinical Trial

Dexmedetomidine is a selective α-2 adrenoceptor agonist with anxiolytic, sedative, and analgesic properties that prolongs analgesia and decreases opioid-related side effects when used in neuraxial and perineural areas as a local anesthetics adjuvant. The current study was designed to evaluate the effects of a single perineural administration of dexmedetomidine without local anesthetics on narcotic consumption and pain intensity in patients with femoral shaft fractures undergoing surgery. This prospective randomized single-blind clinical trial was conducted in patients undergoing femoral fracture shaft surgery. Based on block permuted randomization, the patients were randomly divided into intervention and control groups. The intervention group received 100µg dexmedetomidine, for a femoral nerve block without any local anesthetics. Total intraoperative opioid consumption, postoperative opioid consumption, visual analogue score (VAS) for pain, and hemodynamic parameters were recorded and compared. Finally the data from 60 patients with a mean age of 30.4±12.3 were analyzed (90% male). There were no significant differences between the baseline characteristics of the two groups (p>0.05). The mean total consumption of narcotics was reduced during induction and maintenance of anesthesia in the intervention group (p<0.05). The amount of postoperative narcotics required showed a significant difference in the intervention group compared with the control group (p<0.05). It is likely that perineural administration of dexmedetomidine significantly not only reduced intra and postoperative narcotic requirement but also decreased postoperative pain intensity in patients undergoing femoral shaft surgery. Femoral blockade by dexmedetomidine can provide excellent analgesia while minimizing the side-effects of opioids.

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

BACKGROUND

Brachial plexus block (BPB) for upper extremity surgery provides superior analgesia, but this advantage is limited by the pharmacological duration of local anesthetics. Dexmedetomidine (DEX) as a local anesthetics adjuvant for BPB has been utilized to prolong the duration of the nerve block in some randomized controlled trials (RCTs) but is far from unanimous in the efficacy and safety of the perineural route. Hence, an updated meta-analysis was conducted to assess the efficacy and safety of DEX as local anesthetic adjuvants on BPB.

METHODS

A search in electronic databases was conducted to collect the RCTs that investigated the impact of adding DEX to local anesthetics for BPB. Sensory block duration, motor block duration, onset time of sensory and motor block, time to first analgesic request, the common adverse effects were analyzed.

RESULTS

Eighteen trails (1014 patients) were included with 515 patients receiving perineural DEX. The addition of DEX prolonged the duration of sensory block (WMD 257 minutes, 95%CI 191.79-322.24, P < 0.001), motor block (WMD 242 minutes, 95%CI 174.94-309.34, P < 0.001), and analgesia (WMD 26 6 minutes, 95%CI 190.75-342.81, P < 0.001). Perineural DEX also increased the risk of bradycardia (OR=8.25, 95%CI 3.95-17.24, P < 0.001), hypotension (OR = 5.62, 95%CI 1.52-20.79, P < 0.01), and somnolence (OR = 19.67, 95%CI 3.94-98.09, P < 0.001). There was a lack of evidence that perineural DEX increased the risk of other adverse events.

CONCLUSIONS

DEX is a potential anesthetic adjuvant that can facilitate better anesthesia and analgesia when administered in BPB. However, it also increased the risk of bradycardia, hypotension, and somnolence. Further research should focus on the efficacy and safety of the preneural administration of DEX.

Emergency Corrective Surgery of Congenital Diaphragmatic Hernia With Pulmonary Hypertension: Prolonged Use of Dexmedetomidine as a Pharmacologic Adjunct

INTRODUCTION

Underdevelopment of the lung parenchyma associated with abnormal growth of pulmonary vasculature in neonates with congenital diaphragmatic hernia results in pulmonary hypertension which mandates smooth elective mechanical ventilation in postoperative period, for proper alveolar recruitment and oxygenation, allowing lungs to mature enough for its functional anatomy and physiology. Dexmedetomidine is sympatholytic, reduces pulmonary vascular resistance and exerts sedative and analgesic property to achieve stable hemodynamics during elective ventilation. Neonatal experience with dexmedetomidine has been predominately in the form of short term or procedural use as a sedative.

CASE PRESENTATION

The preliminary clinical experience with pre-induction to 48 hours postoperative use of dexmedetomidine infusion as a pharmacologic adjunct in the emergency corrective surgery of three such neonates are presented.

CONCLUSIONS

Hemodynamics remained virtually stable during the whole procedure and post-operative pain relief and recovery profile were satisfactory. The prolonged infusion was well tolerated with a gradual trend towards improved oxygen saturation. Careful planning of the anesthetic management and the ability to titrate the adjunct utilized for smooth postoperative ventilation are the keys to ameliorate the complications encountered and favorable outcomes achieved in such patients.

Intrathecal Dexmedetomidine and Fentanyl as Adjuvant to Bupivacaine on Duration of Spinal Block in Addicted Patients

Background:

Addicted patients have innate tolerance to local anesthetics in both neuraxial and peripheral blocks. Dexmedetomidine (Dex) is a highly selective α₂ adrenergic receptor agonist used as additive to increase quality and duration of peripheral nerve blocks.

Objectives:

The current study aimed to compare the effect of dexmedetomidine and fentanyl additives on bupivacaine to prolong the duration of block and minimizing side effects.

Patients and Methods:

Patients were candidates for elective surgery less than three hours of lower abdomen or lower extremities surgeries. Patients were randomly allocated to receive dexmedetomidine 5 µg added to 12.5 mg (2.5 mL) of 0.5% hyperbaric bupivacaine (DEX group), or 25 µg (0.5 mL) fentanyl added to 12.5 mg (2.5 mL) of 0.5% hyperbaric bupivacaine (F group) or only 12.5 mg of 0.5% hyperbaric bupivacaine. Data were recorded based on sensory block. Motor block was tested using modified Bromage scale every 30 minutes until the end of block. Time to return of sensory block to 4 dermatomes below and time to return of Bromage scale to 0 were recorded. All vital measurements (oxygen saturation, heart rate, electrocardiogram, and non-invasive blood pressure) were performed at 0, 30, 60, 90, 120 and 180 minutes in all three groups of the study. Group DEX received dexmedetomidine additive and group F received fentanyl additive and group C (control) received normal saline.

Results:

Totally, 84 patients were randomly divided into three groups of 28 patients. Onset of sensory block in DEX group was significantly lower than those of fentanyl (P = 0.012) and control groups (P = 0.001). Duration of sensory block was significantly longer in DEX group compared to Fentanyl (P = 0.043) and control (P = 0.016) groups. Duration of motor block in the DEX group was significantly longer than those of the fentanyl (P = 0.014) and control groups. Heart rate and mean arterial pressure were significantly higher in the DEX group at 30, 60, 90,120, and 180 minutes compared to those of the other two groups (P < 0.05).

Conclusions:

Dexmedetomidine added to bupivacaine in spinal anesthesia is more effective to increase duration of block, providing more appropriate sedation and less postoperative pain scale and post-operative nausea and vomiting (PONV) compared to fentanyl additive.

Do the Concentration and Volume of Local Anesthetics Affect the Onset and Success of Infraclavicular Anesthesia?

Background:

Although local anesthesia is a suitable method for upper limb surgeries, there is debate regarding the effects of appropriate dosing.

Objectives:

In the current study, we investigated the effects of the concentration and volume of a local anesthetic on the beginning and quality of anesthesia during upper limb orthopedic surgeries.

Patients and Methods:

This double-blinded, randomized, clinical trial was conducted on 60 patients aged between 18 and 85 years candidated for upper limb orthopedic operations. The patients were equally and randomly distributed into two groups (n = 30). Under ultrasound imaging guidance, the first group received 7 mL of 2% lidocaine and the second group 10 mL of 1.3% lidocaine into the brachial plexus cords. The onset of block and the level of sensory and motor block were documented for each nerve territory.

Results:

The onset of sensory and motor block was significantly shorter in the 1.3% lidocaine group than in the 2% lidocaine group (P ≤ 0.05). The success rate of sensory and motor block was not different. The quality (completeness) of sensory block for the musculocutaneous nerve and that of motor block for the radial nerve were significantly better in the 1.3% lidocaine group than in the 2% lidocaine group.

Conclusions:

The volume of the injected anesthetic accelerated the onset of sensory and motor block without affecting the rate of success in our patients.