Primary outcomes and anticipated effect sizes in randomised clinical trials assessing adjuncts to peripheral nerve blocks: A scoping review

BACKGROUND

Prolonging effects of adjuncts to local anaesthetics in peripheral nerve blocks have been demonstrated in randomised clinical trials. The chosen primary outcome and anticipated effect size have major impact on the clinical relevance of results in these trials. This scoping review aims to provide an overview of frequently used outcomes and anticipated effect sizes in randomised trials on peripheral nerve block adjuncts.

METHODS

For our scoping review, we searched MEDLINE, Embase and CENTRAL for trials assessing effects of adjuncts for peripheral nerve blocks published in 10 major anaesthesia journals. We included randomised clinical trials assessing adjuncts for single-shot ultrasound-guided peripheral nerve blocks, regardless of the type of interventional adjunct and control group, local anaesthetic used and anatomical localization. Our primary outcome was the choice of primary outcomes and corresponding anticipated effect size used for sample size estimation. Secondary outcomes were assessor of primary outcomes, the reporting of sample size calculations and statistically significant and non-significant results related to the anticipated effect sizes.

RESULTS

Of 11,854 screened trials, we included 59. The most frequent primary outcome was duration of analgesia (35/59 trials, 59%) with absolute and relative median (interquartile range) anticipated effect sizes for adjunct versus placebo/no adjunct: 240 min (180-318) and 30% (25-40) and for adjunct versus active comparator: 210 min (180-308) and 17% (15-28). Adequate sample size calculations were reported in 78% of trials. Statistically significant results were reported for primary outcomes in 45/59 trials (76%), of which 22% did not reach the anticipated effect size.

CONCLUSION

The reported outcomes and associated anticipated effect sizes can be used in future trials on adjuncts for peripheral nerve blocks to increase methodological homogeneity.

Comparison of intravenous versus perineural dexamethasone as a local anaesthetic adjunct for peripheral nerve blocks in the lower limb: A meta-analysis and systematic review

BACKGROUND

As a local anaesthetic adjunct, the systemic absorption of perineural dexamethasone in the lower limb could be restricted because of decreased vascularity when compared with the upper limb.

OBJECTIVES

To compare the pharmacodynamic characteristics of intravenous and perineural dexamethasone in the lower limb.

DESIGN

Systematic review of randomised controlled trials with meta-analysis.

DATA SOURCES

Systematic search of Central, Google Scholar, Ovid Embase and Ovid Medline to 18 July 2023.

ELIGIBILITY CRITERIA

Randomised controlled trials, which compared the intravenous with perineural administration of dexamethasone as a local anaesthetic adjunct in peripheral nerve blocks for surgery of the lower limb.

RESULTS

The most common peripheral nerve blocks were femoral, sciatic and ankle block. The local anaesthetic was long acting in all trials and the dose of dexamethasone was 8 mg in most trials. The primary outcome, the duration of analgesia, was investigated by all nine trials ( n  = 546 patients). Overall, compared with intravenous dexamethasone, perineural dexamethasone increased the duration of analgesia from 19.54 to 22.27 h, a mean difference [95% confidence interval (CI) of 2.73 (1.07 to 4.38) h; P  = 0.001, I2  = 87]. The quality of evidence was moderate owing to serious inconsistency. However, analysis based on the location of the peripheral nerve block, the type of local anaesthetic or the use of perineural adrenaline showed no difference in duration between intravenous and perineural dexamethasone. No differences were shown for any of the secondary outcomes related to efficacy and side effects.

CONCLUSION

In summary, moderate evidence supports the superiority of perineural dexamethasone over intravenous dexamethasone in prolonging the duration of analgesia. However, this difference is unlikely to be clinically relevant. Consideration of the perineural use of dexamethasone should recognise that this route of administration remains off label.

Effect of adductor canal block combined with infiltration between the popliteal artery and posterior capsular of the knee on chronic pain after total knee arthroplasty: a prospective, randomized, double-blind, placebo-controlled trial

INTRODUCTION

Total knee arthroplasty (TKA) is accompanied by severe postoperative pain, which is reported to be an important cause of chronic pain. Ultrasound-guided adductor canal block (ACB) combined with infiltration between the popliteal artery and posterior capsular of the knee (IPACK) has been proven to have a better effect on relieving acute pain after TKA. However, whether it has a significant effect on the incidence of chronic pain after TKA has not been reported. This trial was designed to investigate the effect of ultrasound-guided ACB combined with IPACK on the incidence and intensity of chronic pain after TKA.

METHODS

In this prospective, randomized, double-blind, placebo-controlled study, 100 subjects scheduled for TKA were randomly (1:1) divided into two groups: the ropivacaine group and the placebo group. Patients in each group received ultrasound-guided ACB + IPACK procedures with 0.25% ropivacaine or equal volume normal saline. All patients received multimodal analgesia. Pain intensity was assessed using the Numerical Rating Scale (NRS). The primary outcome was the incidence of chronic pain at 3 months after TKA by telephone follow-up. In addition, pain intensity in early resting and mobilized states, chronic pain intensity, the time to first rescue analgesia; opioid consumption; CRP and IL-6 after the operation; length of postoperative hospital stay; and cost of hospitalization and postoperative complications; as well as the function of the knee in the early stage after the operation, were recorded.

RESULTS

Ninety-one participants were included in the final analysis. At 3 months, the incidence of chronic pain was 30.4% in the ropivacaine group, significantly lower than 51.1% in the placebo group. Compared with the placebo group, the ACB + IPACK with ropivacaine group had significantly lower pain scores at 4 hours, 8 hours, 16 hours, and 24 hours after the operation; increased the knee range of motion at 8 hours and 24 hours after the operation; and a significantly decreased incidence of chronic pain at 3 months after the operation. During the follow-up period, there were no nerve block-related complications in either group.

CONCLUSION

In the context of multimodal analgesia protocols, ACB combined with IPACK before surgery decreases the incidence and intensity of chronic pain 3 months after TKA compared with placebo injection. In addition, it reduces the NRS scores, whether at rest or during mobilization, and improves knee function within 24 hours after TKA.

TRIAL REGISTRATION

This trial was registered in the China Clinical Trial Center (registration number ChiCTR2200065300) on November 1, 2022.

Comparison of analgesic efficacy of continuous perineural catheter, liposomal bupivacaine, and dexamethasone as an adjuvant for interscalene block in total shoulder arthroplasty: a triple-blinded randomized controlled trial

BACKGROUND

Interscalene catheters (ISC) are considered as the gold standard for perioperative pain control after total shoulder arthroplasty. Liposomal bupivacaine (LB) for interscalene blocks (ISBs) and the addition of dexamethasone to ISBs have both presented as additional options for extended analgesia. We aimed to compare the efficacy of LB to a single-shot ISB (SISB) with added dexamethasone to an ISC. We hypothesized that a single injection of LB or an ISB with dexamethasone would provide noninferior duration and quality of analgesia compared with an ISC.

METHODS

A single-center triple-blinded randomized controlled trial evaluated patients who underwent elective primary total shoulder arthroplasty. Patients were randomized to 3 groups: group A (control): 0.5% bupivacaine 15 mL with a rescue catheter left in situ (0.125% bupivacaine infusion), group B: 0.5% bupivacaine 14 mL with 4 mg (1 mL) dexamethasone with a catheter left in situ (saline infusion), group C: 10 mL of LB (133 mg) with 0.5% bupivacaine 5 mL, with a catheter left in situ (saline infusion). The primary outcome was the worst numeric rating scale measured on arrival to the postanesthesia care unit, 6, 12, 24, and 36 hours postoperatively. Secondary outcomes recorded were time to first analgesic request; intraoperative opioid consumption; total inpatient opioid consumption; arm weakness; arm numbness; time of analgesia duration; time of motor recovery; sensory testing using a pinprick on postoperative day 1, q36, and q48; hand strength assessment using a dynamometer on postoperative day 1, q36, and q48; and postanesthesia care unit and hospital length of stay.

RESULTS

We analyzed 72 patients in 3 groups (group A 24, group B 24, and group C 24). The presurgery physical function scores were similar between the groups. The change in postoperative pain was not different among the 3 groups. All 3 groups demonstrated an increase in the postoperative values, a change that was not statistically significant between the groups. Likewise, no difference in the mental function score was seen within or between the groups. No differences in sleep quality or satisfaction were seen among the groups (P = .405 and 1.00, respectively). No adverse events were reported in all groups.

CONCLUSIONS

No significant difference was demonstrated between a single-injection ISB with dexamethasone, an LB injection, and an ISC. Given the equivalence in analgesia provided with these 3 modalities, providers should carefully consider the option that best fits each patient. Thus, a single injection of LB or a single injection of bupivacaine with dexamethasone provides similar analgesic efficacy to an ISC.

Transversus Abdominis Plane Block Following Cesarean Section: A Prospective Randomized Controlled Study Comparing the Effects on Pain Levels of Bupivacaine, Bupivacaine + Dexmedetomidine, and Bupivacaine + Dexamethasone

Background: The transversus abdominis plane (TAP) block is providing effective postoperative analgesia in patients undergoing cesarean section (CS). This study aims to evaluate and compare the effects on pain levels of bupivacaine alone versus bupivacaine combined with dexmedetomidine and bupivacaine combined with dexamethasone in ultrasound-guided TAP block for postoperative pain after CS. Material and Method: In this randomized controlled trial, 120 patients with American Society of Anesthesiologists (ASA) physical status I and II scheduled for elective cesarean section under spinal anesthesia were randomly divided into three groups. At the end of the surgery, an ultrasound-guided TAP block was performed on all patients: bupivacaine 0.5% (Group B), bupivacaine 0.5% + dexmedetomidine (1 µg/kg) (Group BD), and bupivacaine 0.5% + dexamethasone (4 mg) (Group BDx). Postoperatively, all patients were evaluated at 0, 1, 4, 8, 16, and 24 h for visual analog scores VASs, tramadol consumption, complications, and patient satisfaction. A p value of < 0.05 is statistically significant. Results: At 0 h, VASs in the sitting and supine positions were significantly higher in the BDx group (0.85 ± 1.61 and 0.85 ± 1.36, respectively) compared to the B group (0.05 ± 0.32 in both positions) and the BD group (0.15 ± 0.48 in both positions) (p = 0.005 and p = 0.001, respectively). At the 24th hour, VASs in the sitting and supine positions were significantly lower in the BDx group (1.7 ± 1.2 and 1.43 ± 1.05) compared to the B group (2.3 ± 0.68 and 2.2 ± 0.72) and the BD group (2.57 ± 1.01 and 2.28 ± 0.78) (p = 0.005 and p = 0.001, respectively). At 0 h, the tramadol requirement was highest in the BDx group at 12.5%, while it was not required in the B and BD groups (p = 0.005). At 0 h, the rate of nausea and vomiting was highest in the BDx group at 17.5%, compared to 2.5% in the BD group and 0% in the B group (p = 0.003). Patient satisfaction scores were higher in the dexamethasone group compared to the other groups. This was significant between Group B and Group BDx (p = 0.009 < 0.05). Conclusions: Adding dexmedetomidine or dexamethasone to bupivacaine in ultrasound-guided TAP blocks reduces postoperative pain and increases patient satisfaction after cesarean sections. Dexamethasone, due to its delayed onset but extended duration, achieves lower pain scores and higher satisfaction. Further research is necessary to confirm these findings.

Intravenous versus perineural dexamethasone to prolong analgesia after interscalene brachial plexus block: a systematic review with meta-analysis and trial sequential analysis

BACKGROUND

The efficacy of perineural vs intravenous dexamethasone as a local anaesthetic adjunct to increase duration of analgesia could be particular to specific peripheral nerve blocks because of differences in systemic absorption depending on the injection site. Given this uncertainty, we performed a systematic review with meta-analysis and trial sequential analysis comparing dexamethasone administered perineurally or intravenously combined with local anaesthetic for interscalene brachial plexus block.

METHODS

Following a search of various electronic databases, we included 11 trials (1145 patients). The primary outcome was the duration of analgesia defined as the time between peripheral nerve block or onset of sensory blockade and the time to first analgesic request or initial report of pain.

RESULTS

The primary outcome, duration of analgesia, was greater in the perineural dexamethasone group, with a mean difference (95% confidence interval) of 122 (62-183) min, I2=73%, P<0.0001. Trial sequential analysis indicated that firm evidence had been reached. The quality of evidence was downgraded to low, mainly because of moderate inconsistency and serious publication bias. No significant differences were present for any of the secondary outcomes, except for onset time of sensory and motor blockade and resting pain score at 12 h, but the magnitude of differences was not clinically relevant.

CONCLUSIONS

There is low-quality evidence that perineural administration of dexamethasone as a local anaesthetic adjunct increases duration of analgesia by an average of 2 h compared with intravenous injection for interscalene brachial plexus block. Given the limited clinical relevance of this difference, the off-label use of perineural administration, and the risk of drug crystallisation, we recommend intravenous dexamethasone administration.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023466147).

Anesthesia for the Patient Undergoing Shoulder Surgery

Shoulder surgery introduces important anesthesia considerations. The interscalene nerve block is considered the gold standard regional anesthetic technique and can serve as the primary anesthetic or can be used for postoperative analgesia. Phrenic nerve blockade is a limitation of the interscalene block and various phrenic-sparing strategies and techniques have been described. Patient positioning is another important anesthetic consideration and can be associated with significant hemodynamic effects and position-related injuries.

Ultrasound‑guided erector spinae plane block in posterior lumbar surgery (Review)

The erector spinae plane block (ESPB) is a novel fascial planar block technique, which is used to reduce postoperative pain in several surgical procedures, including breast, thoracic, spine and hip surgery. Due to its recognizable anatomy and low complication rate, the application of ESPB has been significantly increased. However, it is rarely used in clinical practice for postoperative analgesia after posterior lumbar spine surgery, while the choice of adjuvant drugs, block levels and drug doses remain controversial. Based on the current literature review, ropivacaine and dexmedetomidine could be considered as the best available drug combination. The present review aimed to analyze the currently available clinical evidence and summarize the benefits and challenges of ESPB in spinal surgery, thus providing novel insights into the application of ESPB in the postoperative management of posterior lumbar surgery.

Local Anesthetics, Local Anesthetic Systemic Toxicity (LAST), and Liposomal Bupivacaine

Local anesthetics have played a vital role in the multimodal analgesia approach to patient care by decreasing the use of perioperative opioids, enhancing patient satisfaction, decreasing the incidence of postoperative nausea and vomiting, decreasing the length of hospital stay, and reducing the risk of chronic postsurgical pain. The opioid-reduced anesthetic management for perioperative analgesia has been largely successful with the use of local anesthetics during procedures such as peripheral nerve blocks and neuraxial analgesia. It is important that practitioners who use local anesthetics are aware of the risk factors, presentation, and management of local anesthetic systemic toxicity (LAST).

Dexamethasone versus Dexmedetomidine as Adjuvants in Ultrasound Popliteal Sciatic Nerve Block for Hallux Valgus Surgery: A Mono-Centric Retrospective Comparative Study

Background and Aim

Ultrasound popliteal sciatic nerve block (UPSNB) is commonly performed in foot and ankle surgery. This study aims to assess the use of dexmedetomidine and dexamethasone as adjuvants in UPSNB for hallux valgus (HV) surgery, comparing their efficacy in producing motor and sensory block and controlling postoperative pain. The adverse event rate was also evaluated.

Methods

This mono-centric retrospective study included 62 adult patients undergoing HV surgery: 30 patients received lidocaine 2% 200 mg, ropivacaine 0.5% 50 mg and dexamethasone 4 mg (Group 1), whereas 32 patients received lidocaine 2% 200 mg, ropivacaine 0.5% 50 mg, and dexmedetomidine 1 mcg/Kg (Group 2). At first, the visual analogue scale (VAS) was evaluated after 48 hours. The other outcomes were time to motor block regression, evaluation of the first analgesic drug intake, analgesic effect, adverse effects (hemodynamic disorders, postoperative nausea and vomiting (PONV)) and patient satisfaction. The continuous data were analyzed with student's t-test and the continuous one with χ2. Statistical significance was set at a p-value lower than 0.05.

Results

No significant difference was found in VAS after 48 hours (4.5 ± 1.6 vs 4.7 ± 1.7, p = 0.621) to motor block regression (18.9 ± 6.0 vs 18.7 ± 6, p = 0.922). The number of patients that took their first analgesic drug in the first 48 h (p = 0.947 at 6 hours; p = 0.421 at 12 hours; p = 0.122 at 24 hours and p = 0.333 at 48 hours) were not significant. A low and similar incidence of intraoperative hemodynamic disorders was recorded in both groups (hypotension p = 0.593; bradycardia p = 0.881). Neither PONV nor other complication was found. Patients in Group 1 reported a lower degree of interference with sleep (p = 0.001), less interference with daily activities (P = 0.002) and with the affective sphere (P = 0.015) along with a more satisfactory postoperative pain management (p < 0.001) as compared to Group 2.

Conclusion

No significant differences were observed in the duration of motor and sensory blockade between patients in both groups. Additionally, both groups showed good pain control with a low rate of adverse effects, even if there was no clinical difference between the groups. However, patients who received dexamethasone reported experiencing less interference with their sleep, daily activities and overall emotional well-being, and overall pain control.

Effectiveness of perineural administration of dexamethasone with lidocaine on onset time of sensory block and early postoperative analgesia in axillary brachial plexus block: a prospective cohort study, Ethiopia

Introduction

The axillary brachial plexus block is a popular nerve block for forearm, wrist, and hand surgery. The aim of this study was to assess the effectiveness of perineural administration of dexamethasone as an adjunct to lidocaine with adrenaline on the onset of sensory block and early postoperative analgesia in trans-arterial axillary brachial plexus block.

Methodology

This single-centered prospective cohort study recruited 68 adult patients, 34 in each groups. The frequently used 8 mg dexamethasone combined with 1% lidocaine and adrenaline was investigated. The normality of the data was checked using the Shapiro-Wilk test. An independent t-test was used to compare the mean values of symmetric numeric data. Categorical variables between the two groups were analyzed using χ2. The Mann-Whitney U test and Kaplan-Meier method using the log-rank test were used to compare asymmetric numeric data, and a P-value of <0.05 was considered as significant.

Results

The median onset time of sensory block was comparable between the nonexposed (24(6) min) and exposed group (24(6) min) (P=0.068). However, the duration of sensory block was significantly longer in the exposed group (235.5±37.51 min) than the nonexposed group (172.76±28.19 min) (P<0.001). The time to the first analgesic request was significantly longer in the exposed than the nonexposed group (P<0.01). Postoperative pain scores were significantly lower at 4 and 8 h in the exposed group (P<0.05).

Conclusion and recommendations

The addition of 8 mg dexamethasone to 1% lidocaine with adrenaline solution in trans-arterial axillary brachial plexus block for ambulatory elective hand, wrist, and forearm surgeries prolonged the duration of sensory blockade and the first analgesic request time but did not reduce the onset time of sensory block. The authors recommend the addition of 8 mg dexamethasone to 1% lidocaine with adrenaline solution to prolong the duration of sensory block and the first analgesic request time.

Evolution of Perioperative Pain Management in Shoulder Arthroplasty

Historically, opioids have been used as a primary conservative treatment for pain related to glenohumeral osteoarthritis (GHOA). However, this practice is concerning as it often leads to overuse, which has contributed to the current epidemic of addiction and overdoses in the United States. Studies have shown that preoperative opioid use is associated with higher complication rates and worse outcomes following surgery, particularly for shoulder arthroplasty. To address these concerns, perioperative pain management for shoulder arthroplasty has evolved over the years to the use of multimodal analgesia.

A Comparison Between Dexamethasone and Clonidine as Adjuvants to Levobupivacaine in the Supraclavicular Approach to the Brachial Plexus Block: A Double-Blind Study

OBJECTIVE

 The objective of this clinical study is to compare the efficacy of adding dexamethasone or clonidine as an adjuvant drug to levobupivacaine in supraclavicular brachial plexus block (BPB) with regard to the onset and duration of sensory and motor blocks along with duration of postoperative analgesia.

BACKGROUND

 Brachial plexus block (BPB), with or without general anesthesia, has been used widely for multiple upper limb surgical procedures, by virtue of its efficacy in terms of cost-effectiveness, efficiency, safety margins, and good postoperative analgesia. Various adjuvant drugs have been described to potentiate the analgesic effect of local anesthetic agents such as epinephrine, clonidine, dexamethasone, dexmedetomidine, or midazolam.

MATERIALS AND METHODS

This is a prospective, randomized, double-blind study in which a total of 90 American Society of Anesthesiology (ASA) physical status I and II patients of either sex, aged between 18 and 60 years, were scheduled for elective upper limb surgical procedures under supraclavicular BPB. They were divided into three equivalent randomized groups with 30 patients in each group. The patients were administered either normal saline 2 mL (in group L) or clonidine 0.5 mcg/kg body weight (in group LC) or dexamethasone 8 mg (in group LD) with 30 mL of 0.5% levobupivacaine. The time of onset and duration of sensory and motor blockades along with the time duration of analgesia were compared.

RESULTS

All groups were equivalent as per demographic data. The time duration for onset of sensory and motor blocks was comparable among all three included groups (12.77±2.60 minutes and 20.80±3.25 minutes, 15.93±2.08 minutes and 22.43±3.07 minutes, and 12.57±2.62 minutes and 22.47±3.10 minutes for group L, LC, and LD, respectively). The time duration of analgesia and motor blockade was significantly prolonged in the dexamethasone group (1195.33±50.01 minutes and 1173.17±43.57 minutes) and moderately prolonged in the clonidine group (696.33±36.74 minutes and 674.67±34.33 minutes) when compared to levobupivacaine group (416.33±35.98 minutes and 397.00±35.12 minutes), and the difference was statistically significant (p<0.001).

CONCLUSION

 Dexamethasone appears to be a superior adjuvant drug to clonidine for brachial plexus block via supraclavicular approach as it provides prolonged duration of motor block with lesser requirement of postoperative analgesia and lack of adverse effects.

Local anaesthetic adjuncts for peripheral nerve blockade

PURPOSE OF REVIEW

Moderate-to-severe pain is common and remains a significant problem. Compared with opioid analgesia alone, single-shot peripheral nerve blockade has been associated with improved pain relief and the potential of decreased side effects. Single-shot nerve blockade, however, is limited by its relatively short duration of action. In this review, we aim to summarize the evidence related to local anaesthetic adjuncts for peripheral nerve blockade.

RECENT FINDINGS

Dexamethasone and dexmedetomidine exhibit characteristics that most closely resemble the ideal local anaesthetic adjunct. In upper limb block, dexamethasone has been demonstrated to be superior to dexmedetomidine regardless of administration route for the duration of sensory and motor blockade as well as the duration of analgesia. No clinically significant differences between intravenous and perineural dexamethasone were found. Perineural and intravenous dexamethasone have the potential to prolong sensory blockade to a greater extent than motor blockade. The evidence indicates that the mechanism of action of perineural dexamethasone in upper limb block is systemic in nature. Unlike perineural dexmedetomidine, intravenous dexmedetomidine has not been shown to result in differences in the characteristics of regional blockade compared with local anaesthetic alone.

SUMMARY

Intravenous dexamethasone is the local anaesthetic adjunct of choice, increasing the duration of sensory and motor blockade as well as the duration of analgesia by 477, 289 and 478 min, respectively. In view of this, we recommend consideration of the intravenous administration of dexamethasone at a dose of 0.1-0.2 mg/kg for all patients undergoing surgery whatever the level of postoperative pain, mild, moderate or severe. Further research should focus on the potential synergism of action between intravenous dexamethasone and perineural dexmedetomidine.

Continuous peripheral nerve blocks for analgesia following painful ambulatory surgery: a review with focus on recent developments in infusion technology

PURPOSE OF REVIEW

Continuous peripheral nerve blocks (cPNB) decrease pain scores and opioid consumption while improving patient satisfaction following ambulatory surgery. This review focuses on the history and evolution of ambulatory cPNBs, recent developments in infusion technology that may prolong the duration of analgesia, optimal choice of cPNB for various surgical procedures, and novel analgesic modalities that may prove to be alternatives or supplements to cPNBs.

RECENT FINDINGS

The primary factor limiting the duration of an ambulatory cPNB is the size of the local anesthetic reservoir. Recent evidence suggests the use of automated boluses, as opposed to continuous infusions, may decrease the rate of consumption of local anesthetic and, thereby, prolong the duration of analgesia. Utilizing a long-acting local anesthetic (e.g. ropivacaine) for initial block placement and an infusion start-delay timer may further increase this duration.

SUMMARY

Patients undergoing painful ambulatory surgery are likely to have less pain and require fewer opioid analgesics when receiving a cPNB for postoperative analgesia. Advances in electronic pumps used for cPNBs may increase the duration of these benefits.

Adjunctive dexamethasone palmitate use for intercostal nerve block after video-assisted thoracoscopic surgery: A prospective, randomized control trial

Objectives

The efficacy of dexamethasone palmitate in extending durations of local anesthetic blocks is uncertain. In a randomized, double-blind study of patients undergoing video-assisted thoracoscopic surgery, we tested whether intravenous or perineural dexamethasone palmitate caused prolonged analgesia after intercostal nerve block.

Methods

A total of 90 patients subjected to video-assisted thoracoscopic surgery between May and December 2022 were randomly assigned to one of three intercostal nerve blocks study arms (n = 30 each), requiring the addition of 0.5% ropivacaine (23 ml) as follows: controls (C group), 2 ml saline; IV-DXP group, 2 ml saline + 2 ml (8 mg) intravenous dexamethasone palmitate; and PN-DXP group, 2 ml (8 mg) perineural dexamethasone palmitate. Time to first postoperative remedial analgesia served as primary outcome measure. Secondary endpoints included postoperative opioid consumption, pain scores by Visual Analog Scale, analgesia satisfaction, and related adverse effects.

Results

Compared with controls or the IV-DXP group, time to first postoperative remedial analgesia was longer and postoperative opioid consumption for rescue analgesia was lower in the PN-DXP group (p < 0.01). Similarly, the Visual Analog Scale scores in patients at 8, 12, 18, and 24 h postoperatively were lower in the PN-DXP group than in controls and the IV-DXP group (p < 0.01). Patient satisfaction was statistically lower in the PN-DXP group, compared with either the control or IV-DXP group (p < 0.05). Clinically, the three groups did not differ significantly in occurrences of adverse effects during the 48-h postoperative monitoring period (p > 0.05).

Conclusions

Perineural dexamethasone palmitate is a promising adjunct to ropivacaine intercostal nerve block by prolonging analgesia with almost no related adverse effects.

A Comparative Analysis of Pain Control Methods after Ankle Fracture Surgery with a Peripheral Nerve Block: A Single-Center Randomized Controlled Prospective Study

Background and Objectives: Patients experience severe pain after surgical correction of ankle fractures. Although their exact mechanism is unknown, dexamethasone and epinephrine increase the analgesic effect of anesthetics in peripheral nerve blocks. This study aimed to compare the postoperative pain control efficacy of peripheral nerve blocks with ropivacaine combined with dexamethasone/epinephrine and peripheral nerve blocks with only ropivacaine and added patient-controlled analgesia in patients with ankle fractures. Materials and Methods: This randomized, controlled prospective study included patients aged 18-70 years surgically treated for ankle fractures between December 2021 and September 2022. The patients were divided into group A (n = 30), wherein pain was controlled using patient-controlled analgesia after lower extremity peripheral nerve block, and group B (n = 30), wherein dexamethasone/epinephrine was combined with the anesthetic solution during peripheral nerve block. In both groups, ropivacaine was used as the anesthetic solution for peripheral nerve block, and this peripheral nerve block was performed just before ankle surgery for the purpose of anesthesia for surgery. Pain (visual analog scale), patient satisfaction, and side effects were assessed and compared between the two groups. Results: The patients' demographic data were similar between groups. Pain scores were significantly lower in group B than in group A postoperatively. Satisfaction scores were significantly higher in group B (p = 0.003). There were no anesthesia-related complications in either group. Conclusions: Dexamethasone and epinephrine as adjuvant anesthetic solutions can effectively control pain when performing surgery using peripheral nerve blocks for patients with ankle fractures.

Comparison of dexmedetomidine and dexamethasone as adjuvants to the ultrasound-guided interscalene nerve block in arthroscopic shoulder surgery: a systematic review and Bayesian network meta-analysis of randomized controlled trials

Introduction

Interscalene block (ISB) is widely regarded as the gold standard treatment for acute pain following arthroscopic shoulder surgery. However, a single injection of a local anesthetic for ISB may not offer sufficient analgesia. Various adjuvants have been demonstrated to prolong the analgesic duration of the block. Hence, this study aimed to assess the relative efficacy of dexamethasone and dexmedetomidine as adjuncts to prolong the analgesic duration for a single- shot ISB.

Methods

The efficacy of adjuvants was compared using a network meta-analysis. The methodological quality of the included studies was evaluated using the Cochrane bias risk assessment tool. A comprehensive search of the PubMed, Cochrane, Web of Science, and Embase databases was conducted with a search deadline of March 1, 2023. Various adjuvant prevention randomized controlled trials have been conducted in patients undergoing interscalene brachial plexus block for shoulder arthroscopic surgery.

Results

Twenty-five studies enrolling a total of 2,194 patients reported duration of analgesia. Combined dexmedetomidine and dexamethasone (MD = 22.13, 95% CI 16.67, 27.58), dexamethasone administered perineurally (MD = 9.94, 95% CI 7.71, 12.17), high-dose intravenous dexamethasone (MD = 7.47, 95% CI 4.41, 10.53), dexmedetomidine administered perineurally (MD = 6.82, 95% CI 3.43, 10.20), and low-dose intravenous dexamethasone (MD = 6.72, 95% CI 3.74, 9.70) provided significantly longer analgesic effects compared with the control group.

Discussion

The combination of intravenous dexamethasone and dexmedetomidine provided the greatest effect in terms of prolonged analgesia, reduced opioid doses, and lower pain scores. Furthermore, peripheral dexamethasone in prolonging the analgesic duration and lowering opioid usage was better than the other adjuvants when used a single medication. All therapies significantly prolonged the analgesic duration and reduced the opioid dose of a single-shot ISB in shoulder arthroscopy compared with the placebo.

Narcotic Requirements before and after Implementation of Buccal Nerve Blocks for Buccal Mucosa Graft Harvest: Technique and Retrospective Review

The reduction in opioid use has become a public health priority. We aimed to assess if performing buccal nerve blocks (BNB) at the time of buccal mucosa graft (BMG) harvest impacts post-operative narcotic usage in the inpatient setting. We retrospectively reviewed clinical characteristics and morphine milligram equivalents (MMEs) received for all patients that underwent a BMG urethroplasty at our institution. The primary outcome measure was post-operative MMEs for patients before and after implementing the BNB. We identified 74 patients that underwent BMG urethroplasty, 37 of which were before the implementation of the BNB and 37 of which were after. No other changes were made to the peri-operative pathway between these time points. The mean total MMEs per day, needed post-operatively, was lower in the BNB group (8.8 vs. 5.0, p = 0.12). A histogram distribution of the two groups, categorized by number of MMEs received, showed no significant differences between the two groups. In this retrospective analysis, we report our experience using BNBs at the time of buccal mucosa graft harvest. While there were no significant differences between the number of MMEs received before and after implementation, further research is needed to assess the blocks’ impact on pain scores.

Spinal Dexamethasone Effect on Cognitive Disorders After Hip Surgery

Background

Proximal femoral fractures (PrFF) are one of the most common causes of emergency admission in the elderly population. The majority of patients have pre-existing conditions that get worsened by unplanned surgery.

Objective

Purpose of this article was to evaluate if a is single shot of dexamethasone with levobupivacaine administered intrathecally reduces postoperative pain and cognitive complications in patients with proximal femoral fractures.

Methods

The study was performed at a level II trauma center which is a part of a teaching hospital with a catchment population of around 300,000 patients, the first author's affiliation. Around 500 PrFF are performed yearly in the center. All participants gave oral and written informed consent before randomization.

Results

In total, 60 patients with a PrFF, ASA status 2 or 3 were randomized into two groups for spinal anaesthesia as DLSA study group (received 8 mg of dexamethasone and 12.5 mg of 0.5 % levobupivacaine) or LSA control group (received 12.5 mg of 0,5 % levobupivacaine). Postoperative cognitive disturbance was evaluated using simplified Confusion Assessment Method (CAM) scale, pain intensity was measured using Visual Analogue Scale (VAS) and blood samples for defining cortisol concentrations were taken before and after the surgical procedure. The primary outcomes were effects of intrathecal dexamethasone on plasma cortisol affecting cognitive disturbances. Secondary outcomes included pain scores and length of hospital stay. The DLSA group demonstrated a reduced incidence of postoperative cognitive dysfunction (POCD), p=0.043, longer analgesia duration, p<0.001, decreased cortisol levels and shorter hospitalization p=0.045. Intrathecal dexamethasone was the only significant predictor of postoperative delirium, OR 7.76, p=0.019.

Conclusion

Single shot intrathecal administration of dexamethasone with levobupivacaine used in anaesthesia for proximal femoral fractures reduces the stress response by decreasing plasma cortisol concentrations prolonging analgesia. Complications such as delirium and POCD occurred with significantly lower frequency allowing better postoperative rehabilitation and shortening the hospitalization.

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.

What Is the Risk of Postoperative Neurologic Symptoms After Regional Anesthesia in Upper Extremity Surgery? A Systematic Review and Meta-analysis of Randomized Trials

BACKGROUND

The risk of neurologic symptoms after regional anesthesia in orthopaedic surgery is estimated to approach 3%, with long-term deficits affecting 2 to 4 per 10,000 patients. However, current estimates are derived from large retrospective or observational studies that are subject to important systemic biases. Therefore, to harness the highest quality data and overcome the challenge of small numbers of participants in individual randomized trials, we undertook this systematic review and meta-analysis of contemporary randomized trials.

QUESTIONS/PURPOSES

In this systematic review and meta-analysis of randomized trials we asked: (1) What is the aggregate pessimistic and optimistic risk of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery? (2) What block locations have the highest and lowest risk of postoperative neurologic symptoms? (3) What is the timing of occurrence of postoperative neurologic symptoms (in days) after surgery?

METHODS

We searched Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, Web of Science, Scopus, and PubMed for randomized controlled trials (RCTs) published between 2008 and 2019 that prospectively evaluated postoperative neurologic symptoms after peripheral nerve blocks in operative procedures. Based on the Grading of Recommendations, Assessment, Development, and Evaluation guidance for using the Risk of Bias in Non-Randomized Studies of Interventions tool, most trials registered a global rating of a low-to-intermediate risk of bias. A total of 12,532 participants in 143 trials were analyzed. Data were pooled and interpreted using two approaches to calculate the aggregate risk of postoperative neurologic symptoms: first according to the occurrence of each neurologic symptom, such that all reported symptoms were considered mutually exclusive (pessimistic estimate), and second according to the occurrence of any neurologic symptom for each participant, such that all reported symptoms were considered mutually inclusive (optimistic estimate).

RESULTS

At any time postoperatively, the aggregate pessimistic and optimistic risks of postoperative neurologic symptoms were 7% (915 of 12,532 [95% CI 7% to 8%]) and 6% (775 of 12,532 [95% CI 6% to 7%]), respectively. Interscalene block was associated with the highest risk (13% [661 of 5101] [95% CI 12% to 14%]) and axillary block the lowest (3% [88 of 3026] [95% CI 2% to 4%]). Of all symptom occurrences, 73% (724 of 998) were reported between 0 and 7 days, 24% (243 of 998) between 7 and 90 days, and 3% (30 of 998) between 90 and 180 days. Among the 31 occurrences reported at 90 days or beyond, all involved sensory deficits and four involved motor deficits, three of which ultimately resolved.

CONCLUSION

When assessed prospectively in randomized trials, the aggregate risk of postoperative neurologic symptoms associated with peripheral nerve block in upper extremity surgery was approximately 7%, which is greater than previous estimates described in large retrospective and observational trials. Most occurrences were reported within the first week and were associated with an interscalene block. Few occurrences were reported after 90 days, and they primarily involved sensory deficits. Although these findings cannot inform causation, they can help inform risk discussions and clinical decisions, as well as bolster our understanding of the evolution of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery. Future prospective trials examining the risks of neurologic symptoms should aim to standardize descriptions of symptoms, timing of evaluation, classification of severity, and diagnostic methods.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Adding Dexamethasone to Adductor Canal Block Combined with iPACK Block Improve Postoperative Analgesia of Total Knee Arthroplasty

OBJECTIVE

Both adductor canal block (ACB) and infiltration between the popliteal artery and capsule of knee (iPACK) block are mainly sensory blocks, preserved muscle strength and ability to ambulate. This study was designed to evaluate whether adding dexamethasone to ropivacaine could improve postoperative analgesia after total knee arthroplasty (TKA).

METHODS

This prospective double-blind randomized controlled trial included 60 patients who underwent unilateral TKA under general anesthesia. All patients who received ACB and iPACK block were randomly divided into a dexamethasone group (Group D, ropivacaine combined with dexamethasone) and a control group (Group C, ropivacaine only). The primary outcome was the time to first administration of rescue analgesic drugs. Secondary outcomes included the total amount of rescue analgesic drugs and the pain scores at different time points within 72 hours postoperatively; the time to first getting out of bed, quality of recovery scale (QOR-15 score), and the levels of plasma inflammatory markers (IL-6 and CRP) on postoperative day 1.

RESULTS

Compared with Group C, the time to first administration of rescue analgesic drugs of Group D was significantly extended by approximately 10.5 hours. Patients in Group D had significantly lower pain scores at postoperative different time points and consumed significantly smaller total morphine within 72 hours postoperatively. In addition, patients in group D reported significantly higher QoR-15 scores on postoperative days 1 and 3, earlier first time of getting out of bed, and significantly lower levels of CRP and IL-6 on postoperative day 1.

CONCLUSIONS

Compared with using ropivacaine alone, ultrasonic guided ACB combined with iPACK using ropivacaine and dexamethasone could prolong the duration of postoperative analgesia and strength analgesic intensity and promote the early rehabilitation exercise of patients undergoing TKA.

Postoperative neurologic symptoms in the operative arm after shoulder surgery with interscalene blockade: a systematic review

OBJECTIVE

Postoperative neurologic symptoms (PONS) in the operative arm are important complications of shoulder surgery and interscalene blockade (ISB). This systematic review aimed to compare the risk of PONS between ISB and other techniques, and the relative safety of different agents used in ISB.

METHODS

Our systematic review followed Cochrane review methodology and was registered in PROSPERO. A search of MEDLINE (Ovid), EMBASE (Ovid), and CENTRAL (Wiley) from inception to June 2020 was completed. We included randomized or quasi-randomized trials of patients (> five years old) undergoing shoulder surgery with any ISB technique as an intervention, compared with any other nonregional or regional technique, or ISB of alternate composition or technique. The primary outcome was PONS (study author defined) assessed a minimum of one week after surgery.

RESULTS

Fifty-five studies totalling 6,236 participants (median, 69; range, 30-910) were included. Another 422 otherwise eligible trials were excluded because PONS was not reported. Heterogeneity in when PONS was assessed (from one week to one year) and the diagnostic criteria used precluded quantitative meta-analysis. The most common PONS definition, consisting of one or more of paresthesia, sensory deficit, or motor deficit, was only used in 16/55 (29%) trials. Risk of bias was low in 5/55 (9%) trials and high in 36/55 (65%) trials, further limiting any inferences.

CONCLUSION

These findings highlight the need for a standardized PONS outcome definition and follow-up time, along with routine, rigorous measurement of PONS in trials of ISB.

STUDY REGISTRATION

PROSPERO (CRD42020148496); registered 10 February 2020.

Intermittent peri-tubal instillation of dexamethasone and ropivacaine on postoperative analgesia after percutaneous nephrolithotomy: A prospective randomized controlled trial

OBJECTIVES

Percutaneous nephrolithotomy and placement of nephrostomy tube are performed for renal stones >2 cm in diameter. Attempts have been made to infiltrate local anesthetics with or without adjuvants into the surgical site to reduce pain. We hypothesized that there would be a significant prolongation of the analgesic effect of local anesthetic instillation along the nephrostomy tube due to the adjuvant dexamethasone.

METHODS

After ethical approval and Clinical Trials Registry - India registration (CTRI/2020/03/024332), 64 American Society of Anesthesiologists classification 1 and 2 adult patients were enrolled in this randomized double-blinded prospective study divided into Group R-received 20 mL 0.2% Ropivacaine and Group R + D-received 20 mL 0.2% Ropivacaine with dexamethasone 8 mg, injected through a multi-lumen wound infiltration catheter.

RESULTS

The demographic profile of patients was similar in both groups. The mean duration of analgesia was longer in Group R + D (21.3 ± 2.1 hrs) versus Group R (10 ± 1.9 hrs, P = 0.001). The mean numeric rating scale scores of Group R + D were significantly lower at all time intervals (P = 0.001). Also, the cumulative dose of ropivacaine and the total use of fentanyl postoperatively in Group R was much higher (70 ± 10.4 vs 56 ± 8.9 μg, P = 0.02). The C-reactive protein levels were significantly lower in Group R + D (13.8 ± 1.5 vs 23.1 ± 1.2 mg/L, P = 0.001 and 16.5 ± 1.3 vs 28.5 ± 1.7 mg/L, P = 0.001, at 24 and 48 hrs, respectively).

CONCLUSION

We conclude that dexamethasone can be used as a suitable adjuvant to intermittent local anesthetic infiltration after percutaneous nephrolithotomy with a nephrostomy tube for the prolongation of analgesia.

Comparison of the effects of perineural or intravenous dexamethasone on thoracic paravertebral block in Ivor‐Lewis esophagectomy: A double‐blind randomized trial

Efforts to prolong thoracic paravertebral block (TPVB) analgesia include local anesthetic adjuvants, such as dexamethasone (Dex). Previous studies showed that both perineural (PN) and intravenous (i.v.) routes could prolong analgesia. As PN Dex is an off‐label use, anesthesiologists should be fully informed of the clinical differences, if any, on block duration. This study was designed to evaluate the two administration routes of Dex for duration of analgesia in TPVB. Ninety‐five patients scheduled for Ivor‐Lewis esophagectomy were randomized to receive TPVB (0.5% ropivacaine 15 ml), PN or i.v. Dex 8 mg. The primary end point was the duration of analgesia. The secondary end points included pain scores, analgesic consumption, adverse effects rate, and incidence of chronic pain at 3 months postoperatively. The PN‐Dex group showed better analgesic effects than the i.v.‐Dex group (p < 0.05). Similarly, the visual analogue scale scores in patients at 2, 4, 8, and 12 h postoperatively were lower in the PN‐Dex group than the i.v.‐Dex group (p < 0.05). The analgesic consumption in both the PN‐Dex and i.v.‐Dex groups was significantly lower than that in the control group (p < 0.05). Regarding the incidence of chronic pain, regardless of route, Dex decreased the incidence of chronic postsurgical pain and neuropathic pain at 3 months after surgery (p < 0.05), but there were no clinical differences between the i.v.‐Dex and PN‐Dex groups. Perineural dexamethasone improved the magnitude and duration of analgesia compared to that of the i.v.‐Dex group in TPVB in Ivor‐Lewis esophagectomy. However, there were no clinically significant differences between the two groups in the incidence of chronic pain.

Comparison Between Dexamethasone and Fentanyl as an Adjuvant to Bupivacaine and Lignocaine in Supraclavicular Brachial Plexus Block for Upper Limb Surgery

Background:

Interest in supraclavicular brachial plexus blocks has been rekindled using sonographic guidance to locate the brachial plexus. Various adjuncts have been suggested to potentiate the anesthetic and analgesic effects of local anesthetic agents. We designed this randomized double-blind controlled study to compare the effects of dexamethasone and fentanyl when added to a mixture of bupivacaine and lignocaine in supraclavicular blocks in patients undergoing forearm surgeries.

Methods:

Sixty-six patients aged between 20 to 60 years old belonging to ASA one or two were recruited prospectively, double-blinded, and randomized way. Supraclavicular block under sonographic guidance was performed in the three groups by using injection bupivacaine (0.5%) 20 cc + injection lignocaine (2%) 10 cc + injection 0.9% normal saline; 2ml (Group S), injection bupivacaine (0.5%) 20 cc + injection lignocaine (2%) 10 cc + injection dexamethasone 8 mg (Group D), and injection bupivacaine (0.5%) 20 cc + injection lignocaine (2%) 10 cc + injection fentanyl 50 µgm (Group F). The onset time of sensory and motor block, duration of sensory and motor block, and hemodynamic variables were recorded.

Results:

Group D showed a significantly greater sensory and motor block duration than other groups ( P = .001). Comparison of hemodynamic variables failed to reveal any statistically significant differences between all groups.

Conclusion:

Both dexamethasone and fentanyl are good adjuvants in the supraclavicular block, but dexamethasone is better, given faster onset and duration of analgesia.

Local Anesthetics, Local Anesthetic Systemic Toxicity (LAST), and Liposomal Bupivacaine

Local anesthetics have played a vital role in the multimodal analgesia approach to patient care by decreasing the use of perioperative opioids, enhancing patient satisfaction, decreasing the incidence of postoperative nausea and vomiting, decreasing the length of hospital stay, and reducing the risk of chronic postsurgical pain. The opioid-reduced anesthetic management for perioperative analgesia has been largely successful with the use of local anesthetics during procedures such as peripheral nerve blocks and neuraxial analgesia. It is important that practitioners who use local anesthetics are aware of the risk factors, presentation, and management of local anesthetic systemic toxicity (LAST).

Anesthesia for the Patient Undergoing Shoulder Surgery

Shoulder surgery introduces important anesthesia considerations. The interscalene nerve block is considered the gold standard regional anesthetic technique and can serve as the primary anesthetic or can be used for postoperative analgesia. Phrenic nerve blockade is a limitation of the interscalene block and various phrenic-sparing strategies and techniques have been described. Patient positioning is another important anesthetic consideration and can be associated with significant hemodynamic effects and position-related injuries.

Intra-articular injection versus interscalene brachial plexus block for acute-phase postoperative pain management after arthroscopic shoulder surgery

BACKGROUND

The minimally invasive approach of arthroscopic shoulder surgery is beneficial; however, for optimal outcomes, perioperative pain management is essential. This cross-sectional study aimed to examine the analgesic effectiveness of intra-articular injection (IA) versus interscalene brachial plexus block (ISPB) among patients treated with arthroscopic shoulder surgeries.

METHODS

We reviewed 100 consecutive patients who underwent shoulder arthroscopic surgery, of whom 50 each underwent IA (February 2019─January 2020; IA group) and ISPB (October 2018─July 2019; ISPB group). The primary outcome was the postoperative pain score measured using a Wong-Baker FACES Pain Rating Scale preoperatively and at 2, 6, 12, 24, and 48 h postoperatively. We performed multiple regression analysis to examine whether IA/ISPB selection is associated with acute-phase postoperative pain and adjusted for intra-articular injection, interscalene brachial plexus block, postoperative pain management, arthroscopic shoulder surgery, IA with 10 mg of morphine previously reported prognostic factors for postoperative pain (e.g., surgical procedures, operative time, older age, and preoperative pain). Furthermore, we examined induction time, total pentazocine dosage, and total postoperative nausea and vomiting (PONV) events.

RESULTS

There were no significant differences between the IA and ISPB groups in perioperative pain control during the acute-phase periods (p = 0.12, repeated analysis of variance). The difference in anesthesia method was not a prognostic factor for acute-phase postoperative pain (p = 0.11). The IA group (15.06 ± 4.00 min) had a significantly shorter mean anesthesia induction time than the ISPB group (29.23 ± 9.22 min) (p = 0.0001). There was no significant between-group difference in the total pentazocine dosage during the first 7 days (p = 0.3934) postoperatively. PONV was observed in eight (17.0%) and two (4.2%) patients in the IA and ISPB groups, respectively. There was no significant between-group difference in the PONV incidence (p = 0.1582).

CONCLUSIONS

There was no significant difference in acute-phase postoperative pain management between the IA and ISPB groups. The induction time was significantly shorter in IA. IRB: Approval number: UOEHCRB20-078, IRB approval date: September 9th, 2020; study duration: October 2018 to January 2020.

Fabrication of Ropivacaine/Dexamethasone-Eluting Poly(D, L-lactide-co-glycolide) Microparticles via Electrospraying Technique for Postoperational Pain Control

Microencapsulation plays an important role in biomedical technology owing to its particular and attractive characteristics. In this work, we developed ropivacaine and dexamethasone loaded poly(D, L-lactide-co-glycolide) (PLGA) microparticles via electrospraying technique and investigated the release behavior of electrosprayed microparticles. The particle morphology of sprayed particles was assessed using scanning electron microscopy (SEM). The in vitro drug release kinetics were evaluated employing an elution method, and the in vivo pharmaceutical release as well as its efficacy on pain relief were tested using an animal activity model. The microscopic observation suggested that sprayed microparticles exhibit a size distribution of 5-6 µm. Fourier-transform infrared spectrometry and differential scanning calorimetry demonstrated the successful incorporation of pharmaceuticals in the PLGA particulates. The drugs-loaded particles discharged sustainably high concentrations of ropivacaine and dexamethasone at the target region in vivo for over two weeks, and the drug levels in the blood remained low. By adopting the electrospraying technique, we were able to prepare drug-embedded polymeric microparticles with effectiveness and with a sustainable capability for postoperative pain control.

The Assessment of Prolonged Inferior Alveolar Nerve Blockade for Postoperative Analgesia in Mandibular Third Molar Surgery by a Perineural Addition of Dexamethasone to 0.5% Ropivacaine: A Randomized Comparison Study

Background: Perineurally adding dexamethasone to local anesthetics could enable postoperative analgesia. Our aim was to investigate the efficacy of 4 mg dexamethasone and 0.5% ropivacaine on the prolonged duration of mandibular anesthesia for postoperative analgesia during third molar surgery. Materials and method: The patients of both sexes, and in the age range of 17 to 50 yrs of age, received the Gow-Gates anesthesia. Group I received 4 mL of plain 0.5% ropivacaine, with perineurally added 1 mL/4 mg of dexamethasone; group II received 4 mL of plain 0.5% ropivacaine with perineurally added 1 mL of 0.9% saline; group III received 4 mL of plain 0.5 bupivacaine with perineurally added 1 mL of 0.9% saline. The prime anesthesia outcome was the duration of conduction anesthesia (DCA); the secondary outcome was the duration of analgesia (DAN) and analgesia before analgesic intake. Results: In 45 randomly selected subjects (mean age 27.06 ± 8.20), DCA was statistically longest in group I (n = 15) (592.50 ± 161.75 min, p = 0.001), collated with groups II (n = 15) and III (n = 15) (307.40 ± 84.71 and 367.07 ± 170.52 min, respectively). DAN was significantly the longest in group I (mean: 654.9 ± 198.4 min, p = 0.001), compared with group II (345.4 ± 88.0 min) and group III (413.7 ± 152.3 min), with insignificant adverse reactions. One-third of the operated patients absented from the use of analgesics. Conclusion: A amount 0.5% ropivacaine with dexamethasone usefully served as an analgesic with a success rate of 93.4% of the given anesthesia.

Efficacy of greater occipital nerve block for pain relief in patients with postdural puncture headache: A meta-analysis

BACKGROUND

This study aimed at assessing the therapeutic effectiveness of greater occipital nerve block (GONB) against postdural puncture headache (PDPH).

METHODS

Studies investigating analgesic effects of GONB against PDPH in adults were retrieved from the MEDLINE, EMBASE, Google scholar, and Cochrane central databases from their inception dates to May, 2021. Pain score at postprocedural 24 hours was the primary endpoint, while secondary endpoints were pain score at postprocedural 1 hour and 12 hours as well as the risk of intervention failure.

RESULTS

Of the 7 studies (randomized controlled trials [RCTs], n = 4; non-RCTs, n = 3) that recruited 275 patients, 2 investigated female patients undergoing cesarean section and the other 5 were conducted in both obstetric and nonobstetric settings. Pooled results showed a lower mean pain score at 24 hours (i.e., primary outcome) (mean difference [MD] = -2.66, 95%: CI: -3.98 to -1.33, P < .001; I2 = 97%, 6 studies), 1 hour (MD = -4.23, 95% confidence interval [CI]: -5.08 to -3.37, P < .00001; I2 = 86%, 5 studies), and 6 hours (MD = -2.78, 95% CI: -4.99 to -0.57, P = .01; I2 = 98%, 4 studies) in patients with GONB compared to those without. Trial sequential analysis supported the robustness of evidence at postprocedural 24 hours. The use of GONB also decreased the risk of intervention failure (relative ratio [RR] = 0.4, 95% CI: 0.19 to 0.82, P = .01; I2 = 96%, 6 studies, 277 patients).

CONCLUSION

Our results suggested a therapeutic effect of greater occipital nerve block against postdural puncture headache up to postprocedural 24 hours. Further large-scale studies are warranted to evaluate its therapeutic benefit beyond the acute stage.

Interscalene Block for Analgesia in Orthopedic Treatment of Shoulder Trauma: Single-Dose Liposomal Bupivacaine versus Perineural Catheter

Background

Interscalene brachial plexus block is frequently utilized to provide perioperative analgesia to patients undergoing shoulder surgery to optimize recovery, minimize opioid consumption, and decrease overall hospital length of stay. The use of an indwelling perineural interscalene catheter provides extended analgesia and is efficacious in managing severe postoperative pain following major shoulder surgery. Currently, the only alternative to perineural catheters for extended analgesia with interscalene block involves the perineural infiltration of liposomal bupivacaine. However, there is limited published data regarding the overall analgesic effectiveness of using interscalene liposomal bupivacaine in the setting of shoulder surgery.

Methods

We performed a retrospective review of 43 patients in the acute trauma setting who underwent major shoulder surgery and received extended analgesia via perioperative interscalene brachial plexus block with either an indwelling continuous catheter or single-dose liposomal bupivacaine to determine if comparable analgesia can be achieved. The primary outcomes of interest were postoperative pain scores and opioid consumption. Due to the ability to titrate and bolus local anesthetic infusions to a desired clinical effect, we hypothesized that opioid consumption and pain scores would be lower when using the continuous catheter technique.

Results

After statistical analysis, our results demonstrated no significant difference between the two techniques in regards to opioid consumption as well as numeric pain scores during the 48-hour postoperative period, but did note a higher rate of complications with patients who received perineural interscalene continuous catheters. Secondary outcomes showed an increase in time required to complete the regional block procedure with the use of indwelling catheters.

Conclusion

Interscalene brachial plexus block with liposomal bupivacaine may be a viable alternative to indwelling continuous catheters for providing extended analgesia in patients undergoing major shoulder surgery.

Pharmacological and clinical implications of local anaesthetic mixtures: a narrative review

Various techniques have been explored to prolong the duration and improve the efficacy of local anaesthetic nerve blocks. Some of these involve mixing local anaesthetics or adding adjuncts. We did a literature review of studies published between 01 May 2011 and 01 May 2021 that studied specific combinations of local anaesthetics and adjuncts. The rationale behind mixing long- and short-acting local anaesthetics to hasten onset and extend duration is flawed on pharmacokinetic principles. Most local anaesthetic adjuncts are not licensed for use in this manner and the consequences of untested admixtures and adjuncts range from making the solution ineffective to potential harm. Pharmaceutical compatibility needs to be established before administration. The compatibility of drugs from the same class cannot be inferred and each admixture requires individual review. Precipitation on mixing (steroids, non-steroidal anti-inflammatory drugs) and subsequent embolisation can lead to serious adverse events, although these are rare. The additive itself or its preservative can have neurotoxic (adrenaline, midazolam) and/or chondrotoxic properties (non-steroidal anti-inflammatory drugs). The prolongation of block may occur at the expense of motor block quality (ketamine) or block onset (magnesium). Adverse effects for some adjuncts appear to be dose-dependent and recommendations concerning optimal dosing are lacking. An important confounding factor is whether studies used systemic administration of the adjunct as a control to accurately identify an additional benefit of perineural administration. The challenge of how best to prolong block duration while minimising adverse events remains a topic of interest with further research required.

Comparison of Perineural and Intravenous Dexamethasone as an Adjuvant to Levobupivacaine in Ultrasound-Guided Infraclavicular Brachial Plexus Block: A prospective Randomized Trial

Background:

The effect of perineural versus intravenous (i.v.) dexamethasone (4 mg) when added to levobupivacaine as an adjuvant has not been well studied.

Aims:

This study was conducted to compare the analgesic efficacy of perineural and i.v. dexamethasone as an adjuvant to levobupivacaine in infraclavicular brachial plexus (ICBP) block.

Settings and Design:

This was a prospective, randomized, double-blind study.

Materials and Methods:

This study was conducted on 68 patients with the ultrasound-guided ICBP block, randomly allocated into two groups (34 each). Four patients had failed block (2 in each group) that was excluded from the study. Group A received 25 mL of levobupivacaine 0.5% and 1 mL of normal saline for the block and i.v. dexamethasone 4 mg. Group B received 25 mL of levobupivacaine 0.5% with 4 mg of perineural dexamethasone for the block. Postoperative vitals and different block characteristics were assessed.

Statistical Analysis Used:

Student's independent sample t-test and Chi-square test were used for statistical analysis.

Results:

The duration of motor block and analgesia in Group A was 1245.94 ± 153.22 min and 1310.16 ± 151.68 min, respectively. However, in Group B, the duration of motor block and analgesia was 1768.13 ± 309.86 min and 1743.59 ± 231.39 min, respectively, which was more when compared to Group A (P < 0.001). The Visual Analog Scale score of ≥3 in Group A was 37% and in Group B was 9% (P = 0.008). Four cases had delayed regression of motor block in the perineural group.

Conclusions:

Perineural dexamethasone significantly prolonged the duration of motor block promoted by levobupivacaine in infraclavicular brachial plexus block, reduced pain intensity and rescue analgesia needs in the postoperative period when compared with the intravenous dexamethasone.

Dexmedetomidine Added to Ropivacaine for Ultrasound-guided Erector Spinae Plane Block Prolongs Analgesia Duration and Reduces Perioperative Opioid Consumption After Thoracotomy: A Randomized, Controlled Clinical Study

OBJECTIVES

Single-injection erector spinae plane block (ESPB) provides good control of pain relief after open thoracotomy surgeries. However, the duration of pain relief does not last long. For this purpose, we hypothesized that adding α2-adrenoceptor agonist, dexmedetomidine, for interfascial nerve blockade may increase the duration of analgesia. There are only few studies using dexmedetomidine for interfasical nerve blocks in humans. In this study, our aim is to investigate whether addition of dexmedetomidine to ropivacaine for ESPB could effectively prolong the duration of postoperative analgesia and reduce opioid consumption after open thoracotomy.

MATERIALS AND METHODS

Sixty patients with esophageal cancer were randomized to receive ESPB using 28 mL of 0.5% ropivacaine, with 2 mL of normal saline (group R) or 0.5 µg/kg dexmedetomidine in 2 mL (group RD) administered interfascially. ESPB was performed at the fifth thoracic level under ultrasound guidance. The primary outcome was the duration of analgesia. The secondary outcomes were total postoperative sufentanil consumption, Numeric Rating Scale pain scores, Ramsay Sedation Scale scores and adverse effects.

RESULTS

The duration of analgesia in group RD (505.1±113.9) was longer than that in group R (323.2±75.4) (P<0.001). The total postoperative sufentanil consumption was lower in group RD (23.3±10.0) than in group R (33.8±13.8) (P=0.001). There was no significant difference in the incidence of adverse effects between the 2 groups.

CONCLUSION

After open thoracotomy, addition of dexmedetomidine to ropivacaine for ESPB effectively prolonged the duration of postoperative analgesia and reduced opioid consumption without increasing additional incidence of adverse effects.

Apophenia and anesthesia: how we sometimes change our practice prematurely

Human beings are predisposed to identifying false patterns in statistical noise, a likely survival advantage during our evolutionary development. Moreover, humans seem to prefer "positive" results over "negative" ones. These two cognitive features lay a framework for premature adoption of falsely positive studies. Added to this predisposition is the tendency of journals to "overbid" for exciting or newsworthy manuscripts, incentives in both the academic and publishing industries that value change over truth and scientific rigour, and a growing dependence on complex statistical techniques that some reviewers do not understand. The purpose of this article is to describe the underlying causes of premature adoption and provide recommendations that may improve the quality of published science.

Twin Mixed Local Anesthesia in Third Molar Surgery - Randomized Controlled Trial

PURPOSE

The aim of this study was to compare the clinical efficacy of injection of 2 long-acting amide local anesthetic agents - bupivacaine and ropivacaine with and without 4 mg dexamethasone in patients undergoing third molar extraction.

METHODS

A prospective randomized double blind controlled trial was conducted among 68 patients with impacted mandibular third molars. Group A and B were the control groups and received 1.8 mL of 0.5% bupivacaine hydrochloride and 0.75% ropivacaine hydrochloride, respectively. Group A1 and B1 were experimental groups and received modified twin mixes which were 1.8 mL of 0.5% bupivacaine hydrochloride + 1mL/4mg dexamethasone and 0.75% ropivacaine hydrochloride + 1 mL/4mg dexamethasone, respectively. Visual analog pain scale, mouth opening measurement and facial swelling were assessed at the time of injection and postoperative days 1, 3, and 7.

RESULTS

The mean visual analogue scale score for pain on local anesthesia injection was found to be less in both experimental groups- Group A1 (2.94) and B1 (2.41) as compared to control groups- Group A (3.59) and B (3.06). The durations of soft tissue anesthesia were higher as compared to their respective controls for both Group A1 and B1. Patients in both control groups A and B had an increased postoperative swelling, pain and trismus.

CONCLUSIONS

Intraoperative and postoperative comfort in both the experimental groups were higher than those for control groups, thereby establishing the clinical efficacy of both modified twin mixes for use in surgical extraction of mandibular third molars.

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.

Analgesic duration of interscalene block after outpatient arthroscopic shoulder surgery with intravenous dexamethasone, intravenous dexmedetomidine, or their combination: a randomized-controlled trial

PURPOSE

Both intravenous dexamethasone and dexmedetomidine prolong the analgesic duration of interscalene blocks (ISB) after arthroscopic shoulder surgery. This study compared their relative effectiveness and the benefit of their use in combination.

METHODS

This single-centre, double-blinded, parallel three-group superiority trial randomized 198 adult patients undergoing ambulatory arthroscopic shoulder surgery. Patients received preoperative ISB with 30 mL 0.5% bupivacaine and 50 µg dexmedetomidine or 4 mg dexamethasone or both of these agents as intravenous adjuncts. The primary outcome was analgesic block duration. Secondary outcomes included the quality of recovery 15 score (range: 0-150) on day 1 and postoperative neurologic symptoms in the surgical arm.

RESULTS

Block durations (n = 195) with dexamethasone (median [range], 24.5 [2.0-339.5] hr) and both adjuncts (24.0 [1.5-157.0] hr) were prolonged compared with dexmedetomidine (16.0 [1.5-154.0] hr). When analyzed by linear regression after an unplanned log transformation because of right-skewed data, the corresponding prolongations of block duration were 59% (95% confidence interval [CI], 28 to 97) and 46% (95% CI, 18 to 80), respectively (both P < 0.001). The combined adjuncts were not superior to dexamethasone alone (-8%; 95% CI, -26 to 14; P = 0.42). Median [IQR] quality of recovery 15 scores (n = 197) were significantly different only between dexamethasone (126 [79-149]) and dexmedetomidine (118.5 [41-150], P = 0.004), but by an amount less than the 8-point minimum clinically important difference.

CONCLUSION

Dexamethasone is superior to dexmedetomidine as an intravenous adjunct for prolongation of bupivacaine-based ISB analgesic duration. There was no additional benefit to using both adjuncts in combination.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT03270033); registered 1 September 2017.

Comparison of Dexmedetomidine and Dexamethasone as Adjuvants to Ultra-Sound Guided Interscalene Block in Arthroscopic Shoulder Surgery: A Double-Blinded Randomized Placebo-Controlled Study

BACKGROUND

Interscalene block is one of the popular methods for decreasing pain and analgesic consumption after shoulder arthroscopic surgeries.

OBJECTIVES

The objective is to compare the analgesic duration of effects of dexmedetomidine and dexamethasone as adjuvants to 0.5% ropivacaine in ultrasound-guided interscalene blocks for arthroscopic shoulder surgery in an ambulatory setting.

METHODS

In this randomized controlled trial, 117 adult patients candidate for ambulatory arthroscopic shoulder surgery under general anesthesia were divided into three groups to perform an ultra-sound guided interscalene block before the surgery. The ropivacaine (control) group received ropivacaine 0.5% 20 mL, group Dexamethasone received ropivacaine 0.5% 20 mL plus 4mg dexamethasone, and group dexmedetomidine received ropivacaine 0.5% 20 mL plus 75 mcg of dexmedetomidine. Time to return of sensory function, of motor function, of first pain sensation, amount of opioid medication consumed at 24 hours and 48 hours post-operatively were measured.

RESULTS

The 24-hour median (25th- 75th percentile) opioid consumption in morphine equivalents was similar between groups 22.5 mg (10 - 30), 15 mg (0 - 30), and 15 mg (0 - 20.6) in the ropivacaine, dexmedetomidine, and dexamethasone groups, respectively (P = 0.130). The median (25th- 75th percentile) 48 hours post-operatively, the median opioid consumption in morphine equivalents was 40 mg (25 - 67.5) in the ropivacaine group, 30 mg (22 - 50.6) in the dexamethasone group, and 52.5 mg (30 - 75) in the dexmedetomidine group (P = 0.278). The median 24-hour pain scores were 6 (5 - 8) in the ropivacaine control group, 7 (5.5 - 8) in the dexamethasone group, and 7 (4 - 9) in the dexmedetomidine group (P = 0.573).

CONCLUSIONS

There was no statistical difference in opioid consumption at 24 and 48 hours post-operatively when comparing dexmedetomidine, dexamethasone, and no adjuvant. However, intraoperative opioid use was significantly lower with dexmedetomidine compared to dexamethasone and plain 0.5% ropivacaine. The safe side effect profile of dexmedetomidine makes it a reasonable alternative as an adjuvant for peripheral nerve blockade when dexamethasone use may be contraindicated.

Liposomal bupivacaine infiltration in the surgical site for analgesia after rotator cuff repair: a randomized, double-blinded, placebo-controlled trial

INTRODUCTION

Arthroscopic rotator cuff repair is among the most painful of orthopedic surgeries. Liposomal bupivacaine is Food and Drug Administration approved for administration into surgical sites to provide postsurgical analgesia and has been used to address postoperative pain after many types of surgery, including total shoulder arthroplasty. However, its efficacy for pain control after rotator cuff repair is unclear.

METHODS

In this randomized, double-blind, placebo-controlled trial, we compared liposomal bupivacaine with an equivalent volume of saline injected into the subacromial space and arthroscopy portal sites in patients undergoing rotator cuff repair under the interscalene block with sedation. The primary outcome measure was numeric rating pain score at the time of block resolution, as reported during the follow-up phone call on postoperative day 1. Secondary outcomes included mean pain scores at rest as well as oral morphine equivalent requirements on postoperative days 1, 2, and 3. This study provides Level 1 evidence.

RESULTS

There were no statistically significant differences in the primary outcome of numeric rating pain scores on resolution of the interscalene nerve block, nor in those reported on postoperative day 1 or 2. There was a minor but statistically significant difference in mean resting pain scores on day 3, though opioid consumption and patient satisfaction score did not differ between groups. In those instructed to perform passive range-of-motion exercises, there was no difference in reported mean pain scores among the groups.

DISCUSSION

In this study of patients undergoing arthroscopic rotator cuff repair, we found no statistically significant difference in mean pain scores on interscalene block resolution, a result consistent with a number of studies investigating liposomal bupivacaine for total shoulder arthroplasty. A modest reduction in pain was evident only on day 3, and there was no impact on perioperative opioid requirements, opioid-related side effects, or pain with motion. Liposomal bupivacaine, when injected into the subacromial space and the tissues around the arthroscopy port sites, provided minimal improvement in pain control in this patient population.

Comparison of morphine, dexmedetomidine and dexamethasone as an adjuvant to ropivacaine in ultrasound-guided supraclavicular brachial plexus block for postoperative analgesia-a randomized controlled trial

Background and Aims:

An ideal adjuvant to local anesthetic in a nerve block should prolong the duration of analgesia, and hasten the onset of sensory and motor blockade without significant adverse effects. The aim of this study was to compare morphine, dexmedetomidine, and dexamethasone as an additive to ropivacaine in ultrasound-guided supraclavicular brachial plexus block (SBPB) for postoperative analgesia.

Material and Methods:

In this randomized, double-blinded study, 150 patients undergoing upper extremity surgery were randomly divided into three groups: group A (morphine 5 mg), group B (dexmedetomidine 50 μg), and group C (dexamethasone 8 mg). The additives were added to 30 ml of 0.5% ropivacaine solution and administered in SBPB. The duration of postoperative analgesia, onset of sensory and motor blockade, sedation, and adverse effects were observed. The pain was assessed by visual analog scale (VAS) and sedation by Ramsay sedation score. The duration of postoperative analgesia was taken as time consumed from block completion to administration of rescue analgesia (VAS >3).

Results:

The demographic profile was similar in both groups. The duration of analgesia was significantly longer in dexamethasone (867.2 ± 217.6 min) than morphine (739. 2 ± 162.5 min) and dexmedetomidine (654.2 ± 179.9 min) (P < 0.001). The onset of sensory and motor blockade was quicker with dexmedetomidine than dexamethasone and morphine. Three cases of block failure were reported with morphine. No major adverse effects were reported.

Conclusion:

Dexamethasone is an ideal adjuvant to ropivacaine in brachial plexus block to prolong postoperative analgesia and devoid of adverse effects. Dexmedetomidine has a quicker onset of sensory and motor blockade.

Dexamethasone Addition to Popliteal Nerve Blocks: Effects on Duration of Analgesia and Incidence of Postoperative Nerve Complication

Background. The purpose of this prospective, double-blinded randomized control pilot study was to evaluate the effect of adjunctive dexamethasone on analgesia duration and the incidence of postoperative neuropathic complication. Peripheral nerve blocks are an effective adjunct to decrease postoperative pain in foot and ankle surgery, and any possible modalities to augment their efficacy is of clinical utility. Methods. Patients were randomly assigned to a control group (n = 25) receiving nerve blocks of bupivacaine and epinephrine or an experimental group (n = 24) with an adjunctive 8 mg dexamethasone. The patients, surgeons, and anesthesiologists were all blinded to allocation. Patients had a minimum 1 year postoperative follow-up. Results. Forty-nine patients completed the protocol. There was no statistically significant difference in analgesia duration (P = .38) or postoperative neuropathic complication incidence (P = .67) between the 2 groups. Conclusions. The addition of dexamethasone to popliteal nerve blocks does not appear to affect analgesia duration or incidence of postoperative neuropathic complications. However, our study was underpowered, and we recommend a larger scale prospective study for validation.Levels of Evidence: Level II: Prospective, randomized control pilot study.

Comparison of postoperative analgesic effects in response to either dexamethasone or dexmedetomidine as local anesthetic adjuvants: a systematic review and meta-analysis of randomized controlled trials

This review compares the effects of peripheral dexamethasone and dexmedetomidine on postoperative analgesia. We included six randomized controlled trials (354 patients) through a systematic literature search. We found that analgesia duration was comparable between dexamethasone and dexmedetomidine (58.59 min, 95% CI (confidence interval), -  66.13, 183.31 min) with extreme heterogeneity. Secondary outcome was also compared and no significant difference was observed in sensory block onset and duration and motor block duration and also for postoperative nausea and vomiting. It is noteworthy that dexamethasone reduced analgesic consumption (fentanyl) by 29.12 mcg compared with dexmedetomidine. We performed subgroup analyses and found no significant difference between the following: (1) lidocaine vs ropivacaine (P = 0.28), (2) nerve block vs nerve block + general anesthesia (P = 0.47), and (3) upper limb surgery vs thoracoscopic pneumonectomy (P = 0.27). We applied trial sequential analysis to assess the risks of type I and II errors and concluded that the meta-analysis was insufficiently powered to answer the clinical question, and further analysis is needed to establish which adjuvant is better. In conclusion, we believe that existing research indicates that dexamethasone and dexmedetomidine have equivalent analgesic effects in peripheral nerve blocks.

Analgesic Effect of the Topical Use of Dexamethasone in Ultrasound-Guided Axillary Brachial Plexus Blockade: A Prospective, Randomized, Double-Blind, Placebo-Controlled Study

Introduction

Increasing the duration of regional anesthesia in orthopedic surgery is of vital importance, as it prolongs postoperative analgesia, allowing faster rehabilitation of patients. Dexamethasone has been found to extend the block duration in animal and human studies. The aim of this study is the assessment of the effect of the addition of dexamethasone to ropivacaine on the onset and duration of axillary brachial plexus block, along with the intensity of postoperative pain.

Methods

Forty patients undergoing below-elbow surgery under ultrasound-guided axillary brachial plexus block were randomly allocated to receive either 30 mL ropivacaine 0.75% with 2 mL of saline (Group A, n = 20) or 30 mL ropivacaine 0.75% with 2 mL of dexamethasone (4 mg) (Group B, n = 20). Sensory and motor blockade were assessed, with the use of the pinprick test and the modified Bromage scale, at five, 10, 15, and 20 min after the block. The duration of analgesia, intensity of postoperative pain, postoperative opioid consumption, overall satisfaction, and perioperative complications were compared between the two groups.

Results

We found no difference at the mean onset time of the sensory and motor block between the two groups. The mean duration of postoperative analgesia was three hours higher in the dexamethasone group (15.85 ± 4.82 versus 11.75 ± 6.81, p-value = 0.035). Pain intensity was lower in the dexamethasone group, at six and 12 hours after surgery (3.45 ± 1.79 versus 4.65 ± 1.79, p-value = 0.040). Postoperative opioid consumption, patient overall satisfaction, and perioperative complications were not significantly different between groups.

Conclusions

Dexamethasone prolongs the duration of ropivacaine in an axillary brachial plexus block and decreases postoperative pain in patients subjected to below-elbow surgery.

Local anaesthetic adjuncts for peripheral regional anaesthesia: a narrative review

Moderate-to-severe postoperative pain persists for longer than the duration of single-shot peripheral nerve blocks and hence continues to be a problem even with the routine use of regional anaesthesia techniques. The administration of local anaesthetic adjuncts, defined as the concomitant intravenous or perineural injection of one or more pharmacological agents, is an attractive and technically simple strategy to potentially extend the benefits of peripheral nerve blockade beyond the conventional maximum of 8-14 hours. Historical local anaesthetic adjuncts include perineural adrenaline that has been demonstrated to increase the mean duration of analgesia by as little as just over 1 hour. Of the novel local anaesthetic adjuncts, dexmedetomidine and dexamethasone have best demonstrated the capacity to considerably improve the duration of blocks. Perineural dexmedetomidine and dexamethasone increase the mean duration of analgesia by up to 6 hour and 8 hour, respectively, when combined with long-acting local anaesthetics. The evidence for the safety of these local anaesthetic adjuncts continues to accumulate, although the findings of a neurotoxic effect with perineural dexmedetomidine during in-vitro studies are conflicting. Neither perineural dexmedetomidine nor dexamethasone fulfils all the criteria of the ideal local anaesthetic adjunct. Dexmedetomidine is limited by side-effects such as bradycardia, hypotension and sedation, and dexamethasone slightly increases glycaemia. In view of the concerns related to localised nerve and muscle injury and the lack of consistent evidence for the superiority of the perineural vs. systemic route of administration, we recommend the off-label use of systemic dexamethasone as a local anaesthetic adjunct in a dose of 0.1-0.2 mg.kg^-1 for all patients undergoing surgery associated with significant postoperative pain.