Co-administration of dexamethasone with peripheral nerve block: intravenous vs perineural application: systematic review, meta-analysis, meta-regression and trial-sequential analysis

Local anesthesia nerve block for managing burning mouth syndrome: a scoping review

OBJECTIVE

To assess the clinical scenarios in which nerve blocks are employed in the context of burning mouth syndrome (BMS).

STUDY DESIGN

This scoping review followed the PRISMA-ScR. A protocol was generated on Open Science Framework. Electronic searches were performed in the following databases: PubMed, Scopus, EMBASE, Web of Science, LILACS, and Cochrane, in addition to the grey literature and citations from Grémeau-Richard et al. (2010).

RESULTS

Nerve blocks were used for treatment purposes in all cases. The mandibular nerve and the stellate ganglion were both blocked in 50% studies, while the maxillary nerve and lingual nerve were blocked in 25% study each. The anesthetics used were lidocaine (50%) and bupivacaine (50%). Relief was generally reported after immediate block, and at a mean follow-up of 4.5 weeks, there was considerable improvement compared to the initial conditions when the mandibular and/or maxillary nerve were targeted.

CONCLUSIONS

The use of nerve blocks has been employed in the treatment of patients with refractory BMS. Clinical studies with standardized methodology are necessary to validate and understand the potential role of mandibular and maxillary nerve block in this setting.

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.

The effect of perineural dexamethasone on nerve injury and recovery of nerve function after surgery: A randomized controlled trial

Background

While numerous studies have examined the influence of perineural dexamethasone on nerve block duration, its potential impact on postoperative nerve injury has not been adequately addressed.

Objective

This study aims to elucidate the effect of perineural dexamethasone on nerve injury and nerve function recovery after surgery.

Design

A prospective randomized double-blinded trial.

Setting

The First Affiliated Hospital of Chengdu Medical College, Chengdu, China. The study was conducted between 14 June and 30 December 2022.

Participants

Patients aged 18 - 80 years, ASA I - II, scheduled for elective orthopedic or burn and plastic surgery.

Interventions

Patients were randomized to receive either perineural dexamethasone (D group) or no dexamethasone (ND group).

Main outcome measures

Primary outcomes were the incidence and recovery of nerve injury. Secondary outcomes included postoperative pain scores, analgesic consumption, and adverse events.

Results

Initial postoperative nerve injury rates were similar between groups (D: 30.4 %, ND: 33.3 %, P > 0.05). At 12 weeks post-discharge, significantly more patients in the ND group recovered from nerve deficits (78.8 % vs 60.3 %; OR = 2.45, 95 % CI = 1.05 - 5.72, P < 0.05). No significant differences were observed in postoperative hyperglycemia or surgical site infection rates.

Conclusion

Perineural dexamethasone may impede nerve function recovery, suggesting caution in its use, particularly for patients with pre-existing nerve damage or diabetes. Further research is needed to elucidate the long-term effects of dexamethasone on nerve tissue recovery.

Trial registration

chictr.org.cn, ChiCTR2200059424.

Pain Predictors in Patients in the Postanesthesia Care Unit

PURPOSE

To analyze the effects of pain-predicting factors on patients in the postanesthesia care unit (PACU).

DESIGN

This is an observational and prospective study.

METHODS

This study was conducted at a University Hospital in the state of Minas Gerais (Brazil). To collect data on demographic, clinical, and surgical factors, a collection instrument was devised. The verbal numerical scale was employed to measure pain levels before and after surgery in the PACU. A path analysis was used to assess a predictive model.

FINDINGS

A total of 226 patients were included in this study. The incidence of pain in the PACU was 31.9%. A model with demographic, clinical, and surgical variables was tested. The final model, after including modification indices, obtained results that indicated an acceptable data fit (comparative fit index = 0.996; root mean square error of approximation = 0.08). Age (being young), sex (being a woman), oncological diagnosis as an indication for the surgical procedure, type of surgery (surgery of the digestive system), duration of surgery (longer surgeries), and high intraoperative doses of opioids were predictive variables for pain in the PACU.

CONCLUSIONS

This study's findings provide support for pain management in the PACU. Furthermore, the results of this research can be used to anticipate the occurrence of acute postoperative pain and personalized perioperative analgesia needs.

Prevention and management of rebound pain after resolution of regional block: a systematic review

Background

An extreme pain known as rebound pain develops after regional blockage wears off. Patient, surgical, and anesthesia-related factors influence the occurrence and intensity of rebound pain. Prior to the peripheral nerve block (PNB) being resolved, multimodal therapy should use. The objective of this review was to explore rebound pain prevention and management following PNB resolution.

Methods

We conducted a thorough search across Pub Med, Hinari, Google Scholar, and Cochrane review databases, utilizing relevant keywords and search parameters to identify studies meeting our inclusion criteria. These studies aimed to provide sufficient evidence regarding the prevention and management of rebound pain following the resolution of regional blocks. Duplicate entries were removed using Endnote software. Screening of the literature was performed using a rigorous appraisal checklist. The findings of this review are reported in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement.

Results

Using an electronic search, 3526 items were found from databases and websites. After removing duplicates (n=500), 3026 articles remained. Of these, 2813 were excluded after going through their titles and abstracts. Of the 213 articles screened, 126 were removed for such reasons as ineligibility or similarity in objectives. Of the remaining 87 studies, 37 were excluded for such reasons as the inaccessibility of free full texts. Finally, 50 studies were included for review.

Conclusions and recommendation

Proper patient education about rebound pain, combined with the utilization of multimodal systemic analgesia before the resolution of PNBs, perineural dexamethasone, and employing a combination of nerve blocks, has been demonstrated to decrease the incidence of rebound pain. Therefore, clinicians should aim to prevent and manage rebound pain by implementing perioperative multimodal strategies before the resolution of regional blocks.

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).

Dose-response relationships of intravenous and perineural dexamethasone as adjuvants to peripheral nerve blocks: a systematic review and model-based network meta-analysis

BACKGROUND

Superiority of perineural over intravenous dexamethasone at extending nerve block analgesia has been suggested but without considering the dose-response relationships for each route of administration.

METHODS

Randomised control studies that evaluated intravenous or perineural dexamethasone as an adjuvant to unilateral peripheral nerve blocks in adults were searched up to October 2023 in MEDLINE, Central, Google Scholar, and reference lists of previous systematic reviews. The Cochrane Risk-of-Bias tool was used. A maximum effect (Emax) model-based network meta-analysis was undertaken to evaluate the dose-response relationships of dexamethasone.

RESULTS

A total of 118 studies were selected (9284 patients; 35 with intravenous dexamethasone; 106 with perineural dexamethasone; dose range 1-16 mg). Studies with unclear or high risk of bias overestimated the effect of dexamethasone. Bias-corrected estimates indicated a maximum fold increase in analgesia duration of 1.7 (95% credible interval (CrI) 1.4-1.9) with dexamethasone, with no difference between perineural and intravenous routes. Trial simulations indicated that 4 mg of perineural dexamethasone increased the mean duration of analgesia for long-acting local anaesthetics from 11.1 h (95% CrI 9.4-13.1) to 16.5 h (95% CrI 14.0-19.3) and halved the rate of postoperative nausea and vomiting. A similar magnitude of effect was observed with 8 mg of intravenous dexamethasone.

CONCLUSIONS

Used as an adjuvant for peripheral nerve block, intravenous dexamethasone can be as effective as perineural dexamethasone in prolonging analgesic duration, but is less potent, hence requiring higher doses. The evidence is limited because of the observational nature of the dose-response relationships and the quality of the included studies.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42020141689.

Intravenous injection of dexamethasone is non-inferior to perineural administration for popliteal sciatic nerve and saphenous nerve blocks: A randomized, controlled, triple-blind study

Background

The aim of this study was to assess whether intravenous dexamethasone was noninferior to perineural dexamethasone as an adjuvant to ropivacaine for a combination of saphenous and sciatic nerve blocks in patients undergoing foot and ankle surgery.

Methods

This was a prospective, blinded, randomized noninferiority study. Seventy-five patients, aged 18-75 years, with an American Society of Anesthesiologists (ASA) physical status I-III who underwent foot and ankle surgery were involved. Patients scheduled for ultrasound-guided popliteal sciatic nerve block and saphenous nerve block were randomized to receive 0.375% ropivacaine with 7.5 mg of dexamethasone perineurally (Dex-PN), 10 mg of dexamethasone intravenously (Dex-IV) or neither (Placebo). The primary outcome was the duration of analgesia. The major secondary outcomes were the composite pain intensity and opioid consumption score at 0-48 h intervals after anesthesia.

Results

The mean analgesic duration was 26.2 h in the Dex-IV group and 27.9 h in the Dex-PN group (duration difference, -1.7; 95% CI, -3.8 to 0.43; P = 0.117), and both durations were significantly longer than that in the placebo group (17.6 h, P < 0.001). Conditions for establishing non-inferiority were met.

Conclusions

Our findings indicate that a single 10-mg intravenous dose of dexamethasone was noninferior to the combined dose of ropivacaine plus deaxmethasone in terms of duration of analgesia for foot and ankle surgery.

Comparing preoperative and postoperative dexamethasone effects on analgesia duration in shoulder surgery

Dexamethasone is commonly used as an adjuvant to prolong peripheral nerve block analgesia, but the optimal timing is unclear. This randomized equivalence trial tested whether preoperative versus postoperative intravenous dexamethasone have equivalent analgesic effects when combined with interscalene brachial plexus block for shoulder surgery. 168 patients were randomized to receive 5 mg dexamethasone either preoperatively or postoperatively. The primary outcome was duration of analgesia, analyzed for equivalence with a 2-h margin. The mean durations were equivalent between groups (11.5 h preoperative versus 10.7 h postoperative). The confidence intervals fell within the equivalence margin. There were no other clinically significant differences in secondary outcomes like time to first analgesia, motor recovery, opioid consumption, blood glucose, or complications. In conclusion, as an adjuvant for nerve block, preoperative and postoperative intravenous dexamethasone provide equivalent analgesic duration, allowing for flexibility in clinical use. This addresses previous uncertainty about timing while demonstrating equivalent efficacy.

A comparative evaluation of the effect of addition of 8 mg dexamethasone to 2% lignocaine with adrenaline in mandibular third molar surgery: a split mouth randomised double blind study

Background

Impacted lower third molar surgeries involve trauma in a highly vascularized zone with loose connective tissue leading to inflammatory sequelae including postoperative pain, swelling, trismus and generalised oral dysfunction during the post-operative phase. In minor oral surgical procedures, an all-inclusive method to protract anaesthesia and reduce the inevitable post-operative sequelae is yet to be explored substantially.

Aim

To evaluate the efficacy of dexamethasone added to local anaesthetics in extending the depth and duration of anaesthesia and decreasing the postoperative complications after surgical removal of impacted third molars.

Methodology

A controlled, randomized, split-mouth, double-blind prospective study involving lower third molar surgery was performed in 35 patients wherein the test group (Group I) received 8 mg dexamethasone added to 2 ml of 2% lignocaine with epinephrine and the control group (Group II) received 2 ml of sterile water added to 2 ml of 2% lignocaine with epinephrine. Onset and duration of anaesthesia were evaluated; followed by evaluation of pain, swelling and trismus for 7 days post-surgery, using independent t-test and ANOVA for repeated measures.

Results

Test group had a faster onset of anaesthesia by 69 s and a lengthier duration of 128.4 min (p < 0.001). Pain scores (Visual Analogue Scale) in the first 24 h were 4.9 and 7.5 in the test and control group respectively (p < 0.001). The average dosing of analgesics until postoperative day 7 in the test and control group were 12.6 and 18.4 respectively (p < 0.001). The swelling was significantly lesser in the test group, in addition, trismus was significantly lesser by 1 cm on postoperative days 1 and 2 and 0.2 cm on day 7.

Conclusion

The addition of dexamethasone to lignocaine in the nerve block reduces the time of onset and significantly prolongs the duration of anaesthesia with decreased pain, swelling and trismus. Steroids mixed directly with the local anaesthetic agent can minimise the post-operative sequelae associated with third molar surgery with a single needle prick.

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

Background

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

Methods

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

Results

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

Conclusion

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

Clinicaltrialsgov Identifier

NCT05590234.

The nuts and bolts of multimodal anaesthesia in the 21st century: a primer for clinicians

PURPOSE OF REVIEW

This review article explores the application of multimodal anaesthesia in general anaesthesia, particularly in conjunction with locoregional anaesthesia, specifically focusing on the importance of EEG monitoring. We provide an evidence-based guide for implementing multimodal anaesthesia, encompassing drug combinations, dosages, and EEG monitoring techniques, to ensure reliable intraoperative anaesthesia while minimizing adverse effects and improving patient outcomes.

RECENT FINDINGS

Opioid-free and multimodal general anaesthesia have significantly reduced opioid addiction and chronic postoperative pain. However, the evidence supporting the effectiveness of these approaches is limited. This review attempts to integrate research from broader neuroscientific fields to generate new clinical hypotheses. It discusses the correlation between high-dose intraoperative opioids and increased postoperative opioid consumption and their impact on pain indices and readmission rates. Additionally, it explores the relationship between multimodal anaesthesia and pain processing models and investigates the potential effects of nonpharmacological interventions on preoperative anxiety and postoperative pain.

SUMMARY

The integration of EEG monitoring is crucial for guiding adequate multimodal anaesthesia and preventing excessive anaesthesia dosing. Furthermore, the review investigates the impact of combining regional and opioid-sparing general anaesthesia on perioperative EEG readings and anaesthetic depth. The findings have significant implications for clinical practice in optimizing multimodal anaesthesia techniques (Supplementary Digital Content 1: Video Abstract, http://links.lww.com/COAN/A96 ).

The effect of oral dexamethasone on duration of analgesia after upper limb surgery under infraclavicular brachial plexus block: a randomised controlled trial

The effects of oral dexamethasone on peripheral nerve blocks have not been investigated. We randomly allocated adults scheduled for forearm or hand surgery to oral placebo (n = 61), dexamethasone 12 mg (n = 61) or dexamethasone 24 mg (n = 57) about 45 min before lateral infraclavicular block. Mean (SD) time until first pain after block were: 841 (327) min; 1171 (318) min; and 1256 (395) min, respectively. Mean (98.3%CI) differences in time until first postoperative pain for dexamethasone 24 mg vs. placebo and vs. dexamethasone 12 mg were: 412 (248-577) min, p < 0.001; and 85 (-78 to 249) min, p = 0.21, respectively. Mean (98.3%CI) difference in time until first postoperative pain for dexamethasone 12 mg vs. placebo was 330 (186-474) min, p < 0.001. Both 24 mg and 12 mg of oral dexamethasone increased the time until first postoperative pain compared with placebo in patients having upper limb surgery under infraclavicular brachial plexus block.

Peripheral nerve block adjuncts: which medication to choose? A narrative review of the current literature

Enhancing the effect of peripheral nerve blockade by adding other classes of medications has long history of trial and error. Studies have identified multiple potentially beneficial adjuncts that work to either speed the onset of analgesia or prolong its duration. The benefits of these adjuncts must be weighed against the risks of systemic negative side effects. To date, the most commonly used adjuncts, and ones with the most robust scientific efficacy are, dexamethasone, dexmedetomidine and buprenorphine. This narrative review will discuss several classes of local anesthetic adjuncts and provide evidence for the clinical efficacy and side effect profile of the most commonly studied medications.

Crystallization of short-acting and intermediate-acting local anesthetics when mixed with adjuvants: a semiquantitative light microscopy analysis

INTRODUCTION

The addition of adjuvants to short-acting local anesthetics (LA) is common practice in clinical routine to speed up block onset and decrease pain on injection. In a previous study, we observed the development of microscopic crystal precipitations after bupivacaine or ropivacaine were mixed with adjuvants; this follow-up study is intended to clarify whether crystallization (A) also occurs in short-acting or intermediate-acting LA-adjuvant mixtures, (B) changes over time, and (C) is associated with the solutions' pH.

METHODS

Lidocaine 2%, prilocaine 2%, mepivacaine 2%, procaine 2% and chloroprocaine 2% were individually mixed with clonidine, dexamethasone, dexmedetomidine, epinephrine, fentanyl, morphine or sodium bicarbonate 8.4% in clinically established ratios. For each mixture, we measured initial pH and recorded crystallization patterns at 0, 15, 30 and 60 min using a standardized, semiquantitative light microscopy approach.

RESULTS

Lidocaine 2% and mepivacaine 2% plus sodium bicarbonate 8.4%, and mepivacaine 2% plus dexamethasone developed delayed grade 5 crystallization over 1 hour. Prilocaine-based, procaine-based and chloroprocaine-based mixtures showed much less pronounced crystallization, with a maximum of grade 2. Initial pH and grade of crystallization showed weak monotonic relationships at time points t0, t15 and t30 (ρ=-0.17, 0.31 and 0.32, (all p>0.05)) and a moderate relationship time point t60 (ρ=0.57 (p=0.0003)) CONCLUSIONS: Our study revealed high grades of crystallization in lidocaine/mepivacaine-bicarbonate and mepivacaine-dexamethasone mixtures, although these were previously considered safe for local, perineural or neuraxial use. Our findings cast particular doubt on the safety of preparing these formulations for later use.

How Does the Addition of Dexamethasone to a Brachial Plexus Block Change Pain Patterns After Surgery for Distal Radius Fractures? A Randomized, Double-blind Study

BACKGROUND

Although brachial plexus block in volar plating surgery for distal radius fractures is reportedly associated with lower postoperative pain scores, rebound pain has been reported to occur after the initial block wears off. Dexamethasone can be used in multimodal strategies for antiemesis and to control pain postoperatively. Although prior studies have suggested that anesthesia can be prolonged by adding dexamethasone to regional blocks, no randomized trials we are aware of have ascertained whether doing so will make a clinically important difference in pain after surgery for distal radius fractures.

QUESTIONS/PURPOSES

Do patients who receive supplemental dexamethasone in a brachial plexus block for volar plating of unstable distal radius fractures have (1) better pain scores at 4, 8, 24, and 48 hours postoperatively than patients who have not received dexamethasone, and (2) lower fentanyl consumption and administration of antiemetic drugs without change in serum blood glucose, as well as a longer analgesic duration from the block after surgery than patients who have not received dexamethasone?

METHODS

This randomized, double-blind trial included 69 patients undergoing surgery for distal radius fractures under ultrasound-guided supraclavicular brachial plexus blocks who were randomly allocated into two groups: a nondexamethasone group receiving a brachial plexus block with 0.5% ropivacaine and a dexamethasone group receiving 0.5% ropivacaine and 5 mg of dexamethasone. Thirty-four patients were allocated to the dexamethasone group and 35 were allocated to the nondexamethasone group. Nine patients (four in the dexamethasone group and five in the nondexamethasone group) were excluded after randomization because local anesthetics were used during their surgical procedures owing to an incomplete block or they requested patient-controlled analgesia after surgery. The treatment groups did not differ in any important ways, including age, gender, BMI, hand dominance, and AO/Orthopaedic Trauma Association classification. All patients received the same surgical procedure and perioperative care protocol, except for the injected agents during their brachial plexus block. The primary outcome was postoperative pain, evaluated using a 10-mm VAS at 4, 8, 12, 24, and 48 hours after surgery. The minimum clinically important difference for the VAS score was 2 of 10 points. Secondary outcome variables included fentanyl administration as a rescue analgesic, the number of patients receiving antiemetic medications because of fentanyl administration, and the duration of brachial plexus block. Serum blood glucose was measured 1 day before, immediately after, and 24 hours after surgery. Patients, surgeons, and outcome assessors were blinded to treatment allocation.

RESULTS

The only clinically important between-group difference in VAS pain scores was at 8 hours, favoring the group that received dexamethasone over the group that did not (1.9 ± 1.6 versus 4.7 ± 2.7; mean difference -2.8 [95% CI -3.9 to -1.6]; p < 0.001). After brachial plexus block, the most severe pain score in both groups was reported at 12 hours postoperatively and gradually diminished over time. There was no between-group difference in fentanyl use between those who received dexamethasone and those who did not (21 ± 38 mcg versus 31 ± 29 mcg; mean difference -10 [95% CI -27.4 to 7.4]; p = 0.26). Furthermore, the use of antiemetics did not differ between the groups (27% [eight of 30] versus 37% [11 of 30]; odds ratio 1.6 [95% CI 0.5 to 4.8]; p = 0.41). Baseline and 24-hour postoperative serum blood glucose level did not differ between the groups. However, the immediately postoperative serum blood glucose level was higher in the dexamethasone group than in the nondexamethasone group (121 ± 29 versus 104 ± 20; mean difference 16 [95% CI 3.3 to 28.8]; p = 0.02). The brachial plexus block duration was 3 hours longer (95% CI 0.8 to 5.2 hours) in the dexamethasone group than that in the nondexamethasone group (11 ± 5 hours versus 8 ± 3 hours; p = 0.01).

CONCLUSION

The postoperative pain level in patients who received supplemental dexamethasone in a regional block was not clinically different from that of patients who received conventional brachial plexus block anesthesia when undergoing volar plating for distal radius fractures. However, patients who received a brachial plexus block with dexamethasone experienced slight prolongation of their block and decrease in pain 8 hours after surgery.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Dexamethasone Plus Bupivacaine Versus Bupivacaine in Bilateral Transincisional Paravertebral Block in Lumbar Spine Surgeries: A Randomized Controlled Trial

OBJECTIVES

Few studies examined the analgesic effects of dexamethasone in lumbar paravertebral block, specifically the transincisional approach. This study aimed to compare dexamethasone with bupivacaine versus bupivacaine alone for bilateral transincisional paravertebral block (TiPVB) for postoperative analgesia in lumbar spine surgeries.

MATERIALS AND METHODS

Fifty patients who were aged 20 to 60 years and had American Society of Anesthesiologists Physical Status (ASA-PS) I or II of either sex were randomly allocated into 2 equal groups. Both groups received combined general anesthesia and bilateral lumbar TiPVB. However, in group 1 (dexamethasone group) (n=25), patients received 14 mL of bupivacaine 0.20% plus 1 mL containing 4 mg of dexamethasone on each side, while, in group 2 (control group) (n=25), patients received 14 mL of bupivacaine 0.20% plus 1 mL of saline on each side. Time to first analgesic need was the primary outcome, while total opioid consumption during the first 24 hours after surgery, the Visual Analog Scale for pain perception (0-10), and the incidence of side effects were secondary outcomes.

RESULTS

The mean time to the first analgesic requirement was significantly prolonged among patients in the dexamethasone group than the control group (mean±SD: 18.4±0.8 vs. 8.7±1.2 h, respectively) ( P <0.001). Patients in the dexamethasone group had lower total opiates consumption than the control) P <0.001). Although nonsignificant, the incidence of postoperative nausea and vomiting was more frequent among the control group ( P =0.145).

DISCUSSION

Adding dexamethasone to bupivacaine in TiPVB resulted in a prolonged analgesia-free period and lower opioid consumption in lumbar spine surgeries with comparable incidence of adverse events.

Optimal dose of perineural dexamethasone for the prolongation of analgesia for peripheral nerve blocks: protocol for a systematic review and meta-analysis

INTRODUCTION

Perineural use of dexamethasone is demonstrated to extend the analgesia duration of peripheral nerve blocks (PNB), but its optimal dose remains unclear. This systematic review and meta-analysis aims to determine the optimal dose of perineural dexamethasone in the prolongation of analgesia for PNB.

METHODS AND ANALYSIS

PubMed, EMBASE, the Cochrane Central Register of Controlled Trials and Web of Science will be searched from their inception to 1 March 2023. Language will be restricted to English. Randomised controlled trials that compared the efficacy and safety of different doses of perineural dexamethasone for PNB in adult patients will be included. Retrospective studies, reviews, meta-analyses, case reports, conference abstracts, comments and studies regarding paediatric surgeries will be excluded. The duration of analgesia will be defined as the primary outcome. Secondary outcomes will include pain scores, the total analgesic requirement over 48 hours and the incidence of adverse effects. Two reviewers will independently perform the study selection, data extraction and quality assessment. RevMan V.5.3 software will be used for data analysis. The quality of evidence will be assessed using the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

ETHICS AND DISSEMINATION

No ethical approval is required. The results of this study will be submitted to peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42022385672.

Translation of Experimental Findings from Animal to Human Biology: Identification of Neuronal Mineralocorticoid and Glucocorticoid Receptors in a Sectioned Main Nerve Trunk of the Leg

The activation of the mineralocorticoid (MR) and glucocorticoid (GR) receptors on peripheral sensory neurons seems to modify pain perception through both direct non-genomic and indirect genomic pathways. These distinct subpopulations of sensory neurons are not known for peripheral human nerves. Therefore, we examined MR and GR on subpopulations of sensory neurons in sectioned human and rat peripheral nerves. Real-time PCR (RT-PCR) and double immunofluorescence confocal analysis of MR and GR with the neuronal markers PGP9.5, neurofilament 200 (NF200), and the potential pain signaling molecules CGRP, Nav1.8, and TRPV1 were performed in human and rat nerve tissue. We evaluated mechanical hyperalgesia after intrathecal administration of GR and MR agonists. We isolated MR- and GR-specific mRNA from human peripheral nerves using RT-PCR. Our double immunofluorescence analysis showed that the majority of GR colocalized with NF200 positive, myelinated, mechanoreceptive A-fibers and, to a lesser extent, with peripheral peptidergic CGRP-immunoreactive sensory nerve fibers in humans and rats. However, the majority of MR colocalized with CGRP in rat as well as human nerve tissue. Importantly, there was an abundant colocalization of MR with the pain signaling molecules TRPV1, CGRP, and Nav1.8 in human as well as rat nerve tissue. The intrathecal application of the GR agonist reduced, and intrathecal administration of an MR agonist increased, mechanical hyperalgesia in rats. Altogether, these findings support a translational approach in mammals that aims to explain the modulation of sensory information through MR and GR activation. Our findings show a significant overlap between humans and rats in MR and GR expression in peripheral sensory neurons.

Prolonged continuous wound infusion of local anesthetic and steroid after major abdominal surgery to reduce opioid consumption: a randomized, double-blind trial

BACKGROUND

Continuous wound infusion (CWI) is effective for post-operative pain management, but the effect of prolonged infusions and the use of steroids in the infused mixture have never been addressed. We investigate the effect of prolonged CWI with ropivacaine 0.2% (R) over seven days and methylprednisolone (Mp) 1 mg/kg infused in the wound in the first 24 hours.

METHODS

This is a randomized, double blind, phase III trial (RCT) in major abdominal surgery with laparotomy. After a 24-hours pre-peritoneal CWI of R-Mp, patients were randomized to receive either R-Mp or placebo for the next 24 hours. Then, patient-controlled CWI with only ropivacaine 0.2% or placebo (according to the randomization group) was planned between 48 hours and seven days after surgery. Morphine equivalents at seven days were analyzed, together with any catheter- or drug-related side effect and PPSP at 3 months.

RESULTS

We enrolled 120 patients (63 in the CWI group, 57 in the placebo group). Prolonged CWI did not reduce opioid consumption in the first seven postoperative days (P=0.08). CWI was associated with reduced consumption of non-opioid analgesics (P=0.03). Most of the patients continued to require bolus in the surgical wound beyond 48 hours. PPSP prevalence was not different between groups.

CONCLUSIONS

Prolonged infusion with R-Mp is safe and effective but did not reduce opioid consumption in the seven days after surgery or PPSP prevalence.

Intravenous Versus Perineural Dexamethasone for Reducing Rebound Pain After Interscalene Brachial Plexus Block: A Randomized Controlled Trial

BACKGROUND

Interscalene brachial plexus block (ISB) is a common regional technique to manage acute postoperative pain for arthroscopic rotator cuff tear repair. However, rebound pain may compromise its overall benefit. Our aim was to investigate the primary hypothesis that perineural and intravenous dexamethasone have different effects on rebound pain after resolution of ISB for arthroscopic rotator cuff tear repair.

METHODS

Patients aged ≥ 20 years scheduled for elective arthroscopic rotator cuff tear repair under general anesthesia with preoperative ISB were included. The participants were randomized to receive dexamethasone either perineurally (perineural group) or intravenously (intravenous group). In the perineural group, patients received ISB with 12 mL of 0.5% ropivacaine containing 5 mg of dexamethasone; simultaneously, 1 mL of 0.9% normal saline was administered intravenously. In the intravenous group, patients received ISB with 12 mL of 0.5% ropivacaine; simultaneously, 1 mL of dexamethasone 5 mg was administered intravenously. The primary outcome was the difference in the pain score (0-10 on numeric rating scale) between before and after ISB resolution. The secondary outcomes were the incidence of rebound pain; onset, duration, and intensity of rebound pain; time to the first analgesic request; and pain-related sleep disturbance.

RESULTS

A total of 71 patients were randomized to either perineural group (n = 36) or intravenous group (n = 35). After block resolution, pain scores increased significantly more in the perineural group (mean ± standard deviation, 4.9 ± 2.1) compared to the intravenous group (4.0 ± 1.7, P = 0.043). The duration of ISB was more prolonged in the perineural group (median [interquartile range], 19.9 [17.2-23.1] hours) than the intravenous group (15.1 [13.7-15.9] hours, P < 0.001). The incidence of rebound pain and pain-related sleep disturbance during the first postoperative week was significantly higher in the perineural group than in the intravenous group (rebound pain: 44.4% vs. 20.0%, P = 0.028; sleep disturbance: 55.6% vs. 25.7%, P = 0.011). The duration and intensity of rebound pain were similar between the two groups.

CONCLUSION

Although perineural dexamethasone provided longer postoperative analgesia, intravenous dexamethasone was more beneficial in reducing pain increase after ISB resolution, incidence of rebound pain, and pain-related sleep disturbance.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0006795.

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.

Dexamethasone Does Not Provide Additional Clinical Analgesia Effect to Local Wound Infiltration: A Comprehensive Systematic Review and Meta-Analysis

Objective: Although the use of dexamethasone as an adjunct agent is associated with alleviating pain and prolonging analgesic duration in local wound infiltration (LWI), efficacy and safety of dexamethasone infiltration have not been fully explored. The study sought to quantify the pooled effects of dexamethasone infiltration on postoperative pain, analgesic consumption, and side effects through a review of randomized controlled trials (RCTs). Approach: RCTs comparing dexamethasone + LWI with LWI alone were retrieved from seven electronic databases. Co-primary outcomes were rest pain scores and cumulative morphine equivalent consumption within 24 h postoperatively. The study followed PRISMA, AMSTAR, and the Cochrane Collaboration. Results: Eight trials comprising 609 patients were included in the final analysis. Results indicated that dexamethasone infiltration effects were only statistical but not clinically significant at individual time points of rest pain and patient satisfaction scores. Notably, the effect of dexamethasone infiltration therapy on other pain-related parameters, including cumulative morphine consumption (mean difference, -9.05 mg; 95% CI: -22.47 to 4.37), was not significantly different compared with the control group. Analysis showed no significant differences in safety indicators between the two groups. The overall quality of evidence was high to very low. Innovation: Although statistically significant effects of dexamethasone infiltration were observed for some outcomes of postoperative wound pain, the overall benefits were below the expected minimal clinically important difference. Conclusions: In summary, the current evidence does not support routine clinical use of dexamethasone in LWI. However, further studies should explore the clinical value of preemptive analgesia and safety of a combination of dexamethasone with ropivacaine for LWI.

Opioid-Free Anesthesia: The Pros and Cons

Appropriate perioperative pain control is essential to aid in patients' recovery after surgery; however, acute postsurgical pain remains poorly treated and there continues to be an overreliance on opiates. Perioperative pain control starts in the operating room, and opiate-free anesthesia (OFA), where no opiates are used intraoperatively, has been proposed as a feasible strategy to further minimize opiates in the perioperative period. In this article, we address the potential benefits and shortcomings of OFA, while exploring tools available to accomplish multimodal anesthesia and ideally OFA, and the evidence behind the techniques proposed.

Effect of multiple analgesic pathways including local infiltration analgesia, peripheral nerve blocks, and intrathecal morphine for controlling pain after total knee arthroplasty

BACKGROUND

We questioned whether the triple analgesic pathways procedure via local infiltration analgesia (LIA), peripheral nerve blocks, and intrathecal morphine (ITM) is superior to LIA only for controlling pain after Total Knee Arthroplasty (TKA).

METHODS

This retrospective study included 192 primary TKA patients. Group A (76 patients) received LIA only, Group B (61 patients) had ITM, adductor canal block and LIA, while Group C (55 patients) received ITM, femoral nerve block and LIA. A propensity score-matched analysis was used to compare visual analog scales (VAS) for pain intensity, total amount of morphine consumption (TMC), angle of knee flexion, and length of hospital stay (LHS).

RESULTS

Group A showed significantly higher VAS than Group B at 12 h (4.27 ± 2.70 vs 2.42 ± 2.35) and 18 h (4.24 ± 2.35 vs 2.18 ± 2.02), and significantly higher than Group C at 6 h (3.46 ± 3.07 vs 0.60 ± 1.50), 12 h (4.27 ± 2.70 vs 0.89 ± 1.48), and 18 h postoperative (4.24 ± 2.35 vs 1.82 ± 2.18). However, the VAS of Group C and B converged to equalize with Group A after 12 and 18 h, respectively. The TMC at 48 h postoperative of Group A was higher than that of Group B (p < 0.01). Nevertheless, there was no difference between groups in terms of knee flexion and LHS, except the LHS of Group B was longer than Group A (p = 0.04).

CONCLUSION

Triple analgesic pathways could provide a better initial analgesic profile. However, the pain seems to be rebound after resolution of nerve block and ITM, with potentially longer LHS.

Analgesic Efficacy of Intravenous Dexamethasone as an Adjunct to Ultrasound-Guided Paravertebral Block with Bupivacaine in Video-Assisted Thoracoscopic Surgery

Purpose

Thoracic paravertebral block (TPVB) is a recommended regional analgesia during video-assisted thoracoscopic surgery (VATS). However, single-injection TPVB does not last long enough to provide sufficient acute postoperative pain relief. Continuous TPVB through a catheter is technically challenging and often unreliable. Intravenous dexamethasone extends the analgesic duration with some peripheral nerve blocks. However, data on the effect of intravenous dexamethasone on pain relief with TPVB are limited. This study aimed to assess the analgesic efficacy of intravenous dexamethasone in patients who received TPVB for VATS.

Patients and Methods

In this multicenter prospective randomized controlled trial, we recruited patients aged between 18 and 80 years with the American Society of Anesthesiologists of physical status class 1–3 and underwent elective VATS. Patients under general anesthesia randomly received 8 mg of intravenous dexamethasone (group D) or normal saline (group C). Ultrasound-guided TPVB (USG-TPVB) was performed at the T4–T5 and T6-T7 spaces. Multimodal analgesia was achieved via paracetamol, tramadol and intravenous morphine for both study groups. The primary outcome was time for the first analgesic requirement. Postoperative pain in terms of numeric rating score (NRS), total morphine consumption and postoperative nausea and vomiting (PONV) were assessed.

Results

After excluding one patient, 59 patients were analyzed. There were no intergroup differences in baseline characteristics. The time to first analgesic requirement was longer in group D (305 [240, 510] minutes) than in group C (270 [180, 300] minutes) (P value = 0.02). The NRS at rest and on movement was lower in group D than in group C at 12 hours but did not differ at other time points. Postoperative morphine consumption was significantly lower in group D than in group C at 6,12,24 and 48 hours. Incidences of PONV were comparable between the groups.

Conclusion

Intravenous dexamethasone, used as an adjunct to a single-injection USG-TPVB prolonged analgesic duration, had an opioid-sparing effect and provided better postoperative pain relief after VATS.

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.

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.

Multimodal Analgesia with Extended-Release Dinalbuphine Sebacate for Perioperative Pain Management in Upper Extremity Trauma Surgery: A Retrospective Comparative Study

Introduction

Patients undergoing upper extremity fracture surgery (UEFS) commonly suffer from unbearable acute pain. Opioids remain the mainstay of moderate to severe pain alleviation, although there is a growing concern regarding the increasing trend in misuse and abuse. This study aimed to observe the safety and efficacy of dinalbuphine sebacate (DS), a novel extended-release analgesic, along with multimodal analgesia (MMA) for post-UEFS pain control.

Methods

We retrospectively reviewed the records of patients undergoing UEFS between August 2020 and January 2021. Eligible patients were included and divided into two groups, depending on the analgesic regimen. In the DS group, 150 mg DS was administered intramuscularly at least 12 h pre-operatively, while in the conventional analgesia (CA) group, 40 mg parecoxib was given within 3 h before surgery. Intraoperative fentanyl administration was guided by the Analgesia Nociception Index System in both groups. For breakthrough pain, fentanyl was used as rescue medicine in the postanaesthesia care unit while tramadol and parecoxib were administered in the ward.

Results

Forty-nine patients were allocated to the DS group and 60 patients were allocated to the CA group. In comparison with the CA group, the proportion of patients requiring opioids for breakthrough pain post-operatively was significantly lower in the DS group (fentanyl: 31% vs. 68%, p < 0.001; tramadol: 27% vs. 70%, p < 0.001). The DS group also consumed lower amounts of post-operative rescue opioids. Furthermore, both mean worst and least pain scores were significantly lower in the DS group from post-operative day (POD) 1 to POD 5. There was no significant difference in intraoperative consumption of fentanyl or incidence of adverse events.

Conclusion

This result suggests that extended-release DS is a suitable analgesic incorporated in MMA and a promising solution to the misuse and abuse of opioids.

Dexmedetomidine combined with ropivacaine for erector spinae plane block after posterior lumbar spine surgery: a randomized controlled trial

Purpose

Due to lumbar spinal surgery is frequently accompanied with moderate-to-severe postoperative pain, it is necessary to find an effective postoperative analgesia for patients with this surgery. This study aimed to observe the analgesic effect of dexmedetomidine combined with ropivacaine erector spinae plane block (ESPB) used in posterior lumbar spine surgery.

Methods

In this clinical trial, patients undergoing posterior lumbar spine surgery were recruited and randomly divided into two groups: intervention and control. The intervention group (Group E) received 0.375% ropivacaine with 1 µg/kg dexmedetomidine in a total of 20 ml for ESPB; the control group (Group C) received 20 ml ropivacaine 0.375% for ESPB. US-guided ESPB was performed preoperatively in all patients. Demographics, anesthesia time, surgery time, and ASA grade from the participants were recorded at baseline. The primary clinical outcome measures were 2-, 4-, 8-, 12-, 24-and 48-h visual analog scale (VAS) pain scores after surgery at rest and movement state. Other end points included opioid consumption, number of PCIA presses, flurbiprofen-axetil consumption, quality of recovery and pain management after surgery.

Results

One hundred twenty patients were enrolled in the study (mean [SD] ages: Group E, 54.77 [8.61] years old; Group C,56.40 [7.87] years old; P = 0.280). The mean anesthesia time was 152.55 (15.37) min in Group E and 152.60 (16.47) min in Group C (P = 0.986). Additionally, the surgery time was 141.70 (15.71) min in Group E compared to 141.48 (17.13) min in Group C (P = 0.943). In addition, we found that the VAS pain scores in the resting state during the postoperative period at 8–48 h were lower in Group E than in Group C. However, the VAS pain scores in the active state were lower in Group E at 12–48 h (P < 0.05). More importantly, the consumption of opioids and flurbiprofen-axetil after surgery was also lower in Group E (P < 0.05). Subsequently, we administered questionnaires on the quality of recovery and pain management after surgery that were positively correlated with the postoperative analgesic effect. It was worth affirming that the QoR-15 scores and APS-POQ-R questionnaire results were different between the two groups, further confirming that the combination of drugs not only could obtain an ideal analgesic effect but also had no obvious adverse reactions (P < 0.05).

Conclusions

All the findings suggested that dexmedetomidine could significantly relieve postoperative pain and reduce the consumption of opioids in patients undergoing posterior lumbar spine surgery without obvious adverse reactions as a local anesthetic adjuvant. Further studies with larger sample sizes and different drug dosages may be useful in understanding the potential clinical benefits of dexmedetomidine.

Interscalene Brachial Plexus Block with Liposomal Bupivacaine versus Standard Bupivacaine with Perineural Dexamethasone: A Noninferiority Trial

BACKGROUND

The interscalene nerve block provides analgesia for shoulder surgery. To extend block duration, provide adequate analgesia, and minimize opioid consumption, the use of adjuvants such as dexamethasone as well as the application of perineural liposomal bupivacaine have been proposed. This randomized, double-blinded, noninferiority trial hypothesized that perineural liposomal bupivacaine is noninferior to standard bupivacaine with perineural dexamethasone in respect to average pain scores in the first 72 h after surgery.

METHODS

A total of 112 patients undergoing ambulatory shoulder surgery were randomized into two groups. The liposomal bupivacaine group received a 15-ml premixed admixture of 10 ml of 133 mg liposomal bupivacaine and 5 ml of 0.5% bupivacaine (n = 55), while the bupivacaine with dexamethasone group received an admixture of 15 ml of 0.5% standard bupivacaine with 4 mg dexamethasone (n = 56), respectively. The primary outcome was the average numerical rating scale pain scores at rest over 72 h. The mean difference between the two groups was compared against a noninferiority margin of 1.3. Secondary outcomes were analgesic block duration, motor and sensory resolution, opioid consumption, numerical rating scale pain scores at rest and movement on postoperative days 1 to 4 and again on postoperative day 7, patient satisfaction, readiness for postanesthesia care unit discharge, and adverse events.

RESULTS

A liposomal bupivacaine group average numerical rating scale pain score over 72 h was not inferior to the bupivacaine with dexamethasone group (mean [SD], 2.4 [1.9] vs. 3.4 [1.9]; mean difference [95% CI], -1.1 [-1.8, -0.4]; P < 0.001 for noninferiority). There was no significant difference in duration of analgesia between the groups (26 [20, 42] h vs. 27 [20, 39] h; P = 0.851). Motor and sensory resolutions were similar in both groups: 27 (21, 48) h versus 27 (19, 40) h (P = 0.436) and 27 [21, 44] h versus 31 (20, 42) h (P = 0.862), respectively. There was no difference in opioid consumption, readiness for postanesthesia care unit discharge, or adverse events.

CONCLUSIONS

Interscalene nerve blocks with perineural liposomal bupivacaine provided effective analgesia similar to the perineural standard bupivacaine with dexamethasone. The results show that bupivacaine with dexamethasone can be used interchangeably with liposomal bupivacaine for analgesia after shoulder surgery.

EDITOR’S PERSPECTIVE

Perineural Dexamethasone as a Peripheral Nerve Block Adjuvant in the Emergency Department: A Case Series

BACKGROUND

Acute pain is one of the most common complaints encountered in the emergency department (ED). Single-injection peripheral nerve blocks are a safe and effective pain management tool when performed in the ED. Dexamethasone has been explored as an adjuvant to prolong duration of analgesia from peripheral nerve blocks in peri- and postoperative settings; however, data surrounding the use of dexamethasone for ED-performed nerve blocks are lacking.

CASE SERIES

In this case series we discuss our experience with adjunctive perineural dexamethasone in ED-performed regional anesthesia. Why Should an Emergency Physician be Aware of This?: Nerve blocks performed with adjuvant perineural dexamethasone may be a safe additive to provide analgesia beyond the expected half-life of local anesthetic alone. Prospective studies exploring the role of adjuvant perineural dexamethasone in ED-performed nerve blocks are needed. © 2021 Elsevier Inc.

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.

The impact of dexamethasone as a perineural additive to ropivacaine for PECS II blockade in patients undergoing unilateral radical mastectomy - A prospective, randomized, controlled and double-blinded trial

STUDY OBJECTIVE

Dexamethasone is commonly used as an adjuvant to local anesthetics to prolong duration of peripheral nerve blocks with minimal side-effects. The present study investigates the efficacy of dexamethasone added to ropivacaine 0.2% as compared to ropivacaine 0.2% alone for pectoral nerves block II (PECS II) in unilateral radical mastectomy.

DESIGN

A prospective, randomized, controlled and double-blinded trial.

SETTING

The study was performed at Innsbruck Medical University Hospital, Austria, between January 2019 and October 2020.

PATIENTS

Sixty female patients with an American Society of Anesthesiologists Score I-II (18-90 years, BMI 18-35) scheduled for unilateral radical mastectomy without one-stage immediate autologous breast reconstruction were randomly assigned to receive PECS II block with ropivacaine 0.2% with or without dexamethasone 8 mg.

INTERVENTIONS

Patients were randomly assigned to receive PECS II block with ropivacaine 0.2% with or without dexamethasone 8 mg.

MEASUREMENTS

Primary outcome parameter was the cumulative opioid consumption during the first 72 postoperative hours. Secondary outcome parameters were the duration of analgesia and the course of the visual analogue scale (VAS) and the area under the curve VAS (AUC-VAS).

MAIN RESULTS

There was no difference in cumulative opioid consumption after 72 h between the ropivacaine 0.2% plus dexamethasone group and the ropivacaine 0.2% plus placebo group (11.89 vs 11.90 morphine milligram equivalent, respectively; p 0.831). Duration of analgesia also did not differ significantly between the ropivacaine 0.2% plus dexamethasone group and the ropivacaine 0.2% plus placebo group (12.75 versus 8.75 h, respectively; p 0.680). There also was no difference in the course of VAS and AUC-VAS.

CONCLUSIONS

Dexamethasone 8 mg when added to ropivacaine 0.2% for PECS II block in unilateral radical mastectomy was not found to reduce total opioid consumption over 72 postoperative hours or to prolong duration of analgesia as compared to pure ropivacaine 0.2%.

The Effect of Intravenous Dexamethasone and Dexmedetomidine on Analgesia Duration of Supraclavicular Brachial Plexus Block: A Randomized, Four-Arm, Triple-Blinded, Placebo-Controlled Trial

Intravenous dexamethasone and dexmedetomidine, in conjunction with peripheral nerve blockade, have each been reported to prolong the duration of analgesia. This study tested whether combined use further prolongs analgesia duration after supraclavicular brachial plexus block (BPB) in patients undergoing orthopedic upper extremity surgery. One hundred twenty patients were randomized 1:1:1:1 to Control (saline bolus and midazolam infusion [0.05 mg/kg loading, 20 µg/kg/h thereafter]); DMED (saline bolus and dexmedetomidine infusion [1 μg/kg loading, 0.4 μg/kg/h thereafter]); DEXA (dexamethasone [10 mg] bolus and midazolam infusion); and DMED-DEXA (dexmedetomidine infusion and dexamethasone bolus) groups. The primary outcome was the duration of postoperative analgesia, defined as the time from the end of the BPB to the first dose of analgesia via a patient-controlled device. Median (interquartile range) times to first dose of analgesia in the Control, DMED, DEXA, and DMED-DEXA groups were 8.1 (6.2–11.6), 9.0 (8.1–11.3), 10.7 (8.1–20.5), and 13.2 (11.5–19.1) hours, respectively (p < 0.001). Pairwise comparisons showed significant prolongation of analgesia in the DEXA included groups compared with the non-DEXA included groups (DEXA vs. control, p = 0.045; DEXA vs. DMED, p = 0.045; DMED-DEXA vs. control, p < 0.001; DMED-DEXA vs. DMED, p < 0.001). A mixed effect model showed that dexamethasone was the only significant factor for the prolongation of analgesia (p < 0.001). Intravenous dexamethasone prolonged the analgesia duration of supraclavicular BPB after orthopedic upper extremity surgery. The concurrent use of mild to moderate sedation dose of intravenous dexmedetomidine in addition to intravenous dexamethasone showed no additional benefit to the prolongation of analgesia.

Effects of the addition of dexamethasone on postoperative analgesia after anterior cruciate ligament reconstruction surgery under quadruple nerve blocks

Background

Anterior cruciate ligament (ACL) reconstruction is an invasive surgical procedure for the knee. Quadruple nerve blocks including continuous femoral nerve block and single-injection sciatic, obturator, and lateral femoral cutaneous nerve blocks can provide effective intraoperative anesthesia and analgesia in the early postoperative period. However, severe pain often appears after the effect of single-injection nerve blocks resolves and that is why we conducted two studies. The first study was to determine whether dexamethasone administered along with local anesthetic for sciatic nerve block could prolong the duration of analgesia in patients given quadruple nerve blocks, including continuous femoral nerve block, for ACL reconstruction using a hamstring tendon autograft. The second study was designed to evaluate any difference in effects from dexamethasone administered perineurally versus intravenously.

Methods

Patients undergoing unilateral arthroscopic ACL reconstruction using a hamstring tendon autograft were enrolled into two studies. The first study was prospectively conducted to see if dexamethasone 4 mg could prolong the duration of analgesia when administered perineurally to the subgluteal sciatic nerve with 0.5% ropivacaine. In the second study, we retrospectively evaluated the effects of intravenous dexamethasone 4 mg as compared with those of perineural dexamethasone to the sciatic nerve block and effects with no dexamethasone.

Results

In the first study, perineural dexamethasone prolonged the duration of analgesia by 9.5 h (median duration: 22.5 and 13.0 h with and without perineural dexamethasone, respectively, P = 0.011). In the second study, the duration of analgesia was similarly prolonged for intravenous and perineural dexamethasone compared with no dexamethasone.

Conclusion

Perineural dexamethasone administered along with local anesthetic for single sciatic nerve block prolonged the duration of analgesia of quadruple nerve blocks for ACL reconstruction, however the effects were not different from those of intravenous dexamethasone.

Trial registration

The protocols of both studies were approved by the Institutional Review Board of Shimane University Hospital, Japan (study number 2821 and 3390 for study 1 and study 2, respectively). Study 1 was registered in University Hospital Medical Information Network Clinical Trials Registry (UMIN000028930). Study 2, which was a retrospective study, was not registered.

Pericapsular nerve group (PENG) block for hip fracture in the emergency department: a case series

Guidelines for the management of hip fractures recommend timely identification, analgesia and optimisation, in order to facilitate prompt surgical repair. In achieving these aims, multidisciplinary care is essential. In this case series, we present five patients who received bedside pericapsular nerve group (PENG) blocks by emergency physicians in collaboration with the anaesthesia team for pain management following hip fracture. The PENG block is a novel motor- and opioid-sparing technique, which offers long-lasting analgesia and requires less volume than other blocks. In all of the cases in this series, the blocks were performed successfully in a short period of time, without complication. All patients reported a clinically important reduction in pain scores. Patients with hip fracture are often medically complex, and while early surgery is not always possible, pain management should be addressed from an early point in their hospital admission. Multidisciplinary input into peri-operative pathways can enhance the provision of analgesia in the emergency department, by allowing anaesthetists and emergency physicians to work together for the benefit of these often-frail patients.

Safety of treatment options available for postoperative pain

IntroductionPostoperative pain is one of the most common adverse events after surgery and has been shown to increase the risk of other complications. On the other hand, liberal opioid use in the perioperative period is also associated with risk of adverse events. The current consensus is therefore to provide multimodal, opioid minimizing analgesia after surgery.Areas CoveredIn this review, we will discuss the benefits and risks associated with non-opioid analgesics, including non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, α-2 agonists, and corticosteroids. In addition, we will discuss the general and block-specific risks associated with regional anesthestic techniques.Expert OpinionAdverse events associated with non-opioid analgesics are rare outside their specific contraindicated patient groups, especially when dosed appropriately. α-2 agonists can cause transient hypotension and bradycardia, and gabapentinoids may cause sedation in higher risk patient populations. Regional anesthesia techniques are generally safe when done by an experienced practitioner. We therefore encourage the development of standardized multimodal analgesic protocols, which may facilitate opioid minimization and lead to better patient outcomes.

Methodologies for systematic reviews with meta-analysis of randomised clinical trials in pain, anaesthesia, and perioperative medicine

Systematic reviews and meta-analyses (SRMAs) are increasing in popularity, but should they be used to inform clinical decision-making in anaesthesia? We present evidence that the certainty of evidence from SRMAs in anaesthesia (and in general) may be unacceptably low because of risks of bias exaggerating treatment effects, unexplained heterogeneity reducing certainty in estimates, random errors, and widespread prevalence of publication bias. We also present the latest methodological advances to help improve the certainty of evidence from SRMAs. The target audience includes both review authors and practising clinicians to help with SRMA appraisal. Issues discussed include minimising risks of bias from included trials, trial sequential analysis to reduce random error, updated methods for presenting effect estimates, and novel publication bias tests for commonly used outcome measures. These methods can help to reduce spurious conclusions on clinical significance, explain statistical heterogeneity, and reduce false positives when evaluating small-study effects. By reducing concerns in these domains of Grading of Recommendations, Assessment, Development and Evaluation, it should help improve the certainty of evidence from SRMAs used for decision-making in anaesthesia, pain, and perioperative medicine.

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.

Factors associated with rebound pain after peripheral nerve block for ambulatory surgery

BACKGROUND

Rebound pain is a common, yet under-recognised acute increase in pain severity after a peripheral nerve block (PNB) has receded, typically manifesting within 24 h after the block was performed. This retrospective cohort study investigated the incidence and factors associated with rebound pain in patients who received a PNB for ambulatory surgery.

METHODS

Ambulatory surgery patients who received a preoperative PNB between March 2017 and February 2019 were included. Rebound pain was defined as the transition from well-controlled pain (numerical rating scale [NRS] ≤3) while the block is working to severe pain (NRS ≥7) within 24 h of block performance. Patient, surgical, and anaesthetic factors were analysed for association with rebound pain by univariate, multivariable, and machine learning methods.

RESULTS

Four hundred and eighty-two (49.6%) of 972 included patients experienced rebound pain as per the definition. Multivariable analysis showed that the factors independently associated with rebound pain were younger age (odds ratio [OR] 0.98; 95% confidence interval [CI] 0.97-0.99), female gender (OR 1.52 [1.15-2.02]), surgery involving bone (OR 1.82 [1.38-2.40]), and absence of perioperative i.v. dexamethasone (OR 1.78 [1.12-2.83]). Despite a high incidence of rebound pain, there were high rates of patient satisfaction (83.2%) and return to daily activities (96.5%).

CONCLUSIONS

Rebound pain occurred in half of the patients and showed independent associations with age, female gender, bone surgery, and absence of intraoperative use of i.v. dexamethasone. Until further research is available, clinicians should continue to use preventative strategies, especially for patients at higher risk of experiencing rebound pain.

Fluid loading therapy to prevent spinal hypotension in women undergoing elective caesarean section: Network meta-analysis, trial sequential analysis and meta-regression

BACKGROUND

Fluid loading is one of the recognised measures to prevent hypotension due to spinal anaesthesia in women scheduled for a caesarean section.

OBJECTIVE

We aimed to evaluate the current evidence on fluid loading in the prevention of spinal anaesthesia-induced hypotension.

DESIGN

Systematic review and network meta-analysis with trial sequential analysis and meta-regression.

DATA SOURCES

Medline, Epub, Embase.com (Embase and Medline), Cochrane Central, Web of Science and Google Scholar were used.

ELIGIBILITY CRITERIA

Only randomised controlled trials were used. Patients included women undergoing elective caesarean section who received either crystalloid or colloid fluid therapy as a preload or coload. The comparator was a combination of either a different fluid or time of infusion.

RESULTS

A total of 49 studies (4317 patients) were included. Network meta-analysis concluded that colloid coload and preload offered the highest chance of success (97 and 67%, respectively). Conventional meta-analysis showed that crystalloid preload is associated with a significantly higher incidence of maternal hypotension than colloid preload: risk ratio 1.48 (95% CI 1.29 to 1.69, P < 0.0001, I = 60%). However, this result was not supported by Trial Sequential Analysis. There was a significant dose-response effect for crystalloid volume preload (regression coefficient = -0.073), which was not present in the analysis of only double-blind studies. There was no dose-response effect for the other fluid regimes.

CONCLUSION

Unlike previous meta-analysies, we found a lack of data obviating an evidence-based recommendation. In most studies, vasopressors were not given prophylactically as is recommended. Studies on the best fluid regimen in combination with prophylactic vasopressors are needed. Due to official european usage restrictions on the most studied colloid (HES), we recommend crystalloid coload as the most appropriate fluid regimen.

TRIAL REGISTRATION

CRD42018099347.

Addition of dexamethasone to local infiltration analgesia in elective total knee arthroplasty: double-blind, randomized control trial

BACKGROUND AND OBJECTIVES

Total knee arthroplasty is associated with significant pain, and effective analgesia is beneficial to patient satisfaction and functional outcomes. Studies have demonstrated that dexamethasone may have a facilitatory role on the action of local anesthesia, but this effect, when added to a local infiltration analgesia (LIA) mixture for patients having knee arthroplasty, is underexplored. Our hypothesis was that the addition of dexamethasone to local anesthetic infiltration would improve analgesic outcomes following total knee arthroplasty.

METHODS

We performed a double-blind, randomized controlled trial of 140 patients undergoing elective, unilateral, total knee arthroplasty. Patients were randomly allocated to receive either 2 mL of saline 0.9% or 2 mL of dexamethasone 4 mg/mL added to a LIA mixture. Our primary outcome was 24 hours of oral morphine equivalent consumption. Our secondary outcomes included short-term and long-term analgesic and functional outcomes and adverse events.

RESULTS

A total of 72 patients were included in the saline group and 68 were included in the dexamethasone group. We found comparable 24 hours of morphine consumption between saline and dexamethasone groups, with a median of 60 (IQR 40-105 (range 16-230)) mg and 56 (IQR 41-75 (range 0-300)) mg, respectively (p=0.096). Dexamethasone was associated with a statistically significant reduction in total inpatient opioid consumption, incidence of requiring rescue patient-controlled analgesia, length of hospital stay, and postoperative nausea, compared with saline. Patients in the dexamethasone group had a greater range of joint movement and distance walked on postoperative day 1 than the saline group. There were no differences in rest or active pain scores, timed up and go or 3-month outcomes.

CONCLUSIONS

Dexamethasone 8 mg was associated with no improvements in 24 hours of morphine consumption but was associated with modest improvements in short-term analgesia, short-term function, length of stay and postoperative nausea. There were no long-term benefits in the use of dexamethasone in LIA for patients undergoing total knee arthroplasty.

TRIAL REGISTRATION NUMBER

NCT02760043.

Perineural and intravenous dexamethasone and dexmedetomidine: network meta-analysis of adjunctive effects on supraclavicular brachial plexus block

Both perineural and intravenous dexamethasone and dexmedetomidine are used as local anaesthetic adjuncts to enhance peripheral nerve block characteristics. However, the effects of dexamethasone and dexmedetomidine based on their administration routes have not been directly compared, and the relative extent to which each adjunct prolongs sensory blockade remains unclear. This network meta-analysis sought to compare and rank the effects of perineural and intravenous dexamethasone and dexmedetomidine as supraclavicular block adjuncts. We sought randomised trials investigating the effects of adding perineural and intravenous dexamethasone or dexmedetomidine to long-acting local anaesthetics on supraclavicular block characteristics, including time to block onset and durations of sensory, motor and analgesic blockade. Data were compared and ranked according to relative effectiveness for each outcome. Our primary outcome was sensory block duration, with a 2-h difference considered clinically important. We performed a frequentist analysis, using the GRADE framework to appraise evidence. One-hundred trials (5728 patients) were included. Expressed as mean (95%CI), the control group (local anaesthetic alone) had a duration of sensory block of 401 (366-435) min, motor block duration of 369 (330-408) min and analgesic duration of 435 (386-483) min. Compared with control, sensory block was prolonged most by intravenous dexamethasone [mean difference (95%CI) 477 (160-795) min], followed by perineural dexamethasone [411 (343-480) min] and perineural dexmedetomidine [284 (235-333) min]. Motor block was prolonged most by perineural dexamethasone [mean difference (95%CI) 294 (236-352) min], followed by intravenous dexamethasone [289 (129-448)min] and perineural dexmedetomidine [258 (212-304)min]. Analgesic duration was prolonged most by perineural dexamethasone [mean difference (95%CI) 518 (448-589) min], followed by intravenous dexamethasone [478 (277-679) min] and perineural dexmedetomidine [318 (266-371) min]. Intravenous dexmedetomidine did not prolong sensory, motor or analgesic block durations. No major network inconsistencies were found. The quality of evidence for intravenous dexamethasone, perineural dexamethasone and perineural dexmedetomidine for prolongation of supraclavicular sensory block duration was 'low', 'very low' and 'low', respectively. Regardless of route, dexamethasone as an adjunct prolonged the durations of sensory and analgesic blockade to a greater extent than dexmedetomidine. Differences in block characteristics between perineural and intravenous dexamethasone were not clinically important. Intravenous dexmedetomidine did not affect block characteristics.

Managing rebound pain after regional anesthesia

Rebound pain after regional anesthesia can be defined as transient acute postoperative pain that ensues following resolution of sensory blockade, and is clinically significant, either with regard to the intensity of pain or the impact on psychological well-being, quality of recovery, and activities of daily living. Current evidence suggests that it represents an unmasking of the expected nociceptive response in the absence of adequate systemic analgesia, rather than an exaggerated hyperalgesic phenomenon induced by local anesthetic neural blockade. In the majority of patients, it does not appear to significantly impact cumulative postoperative opioid consumption, quality of recovery, or patient satisfaction, and is not associated with longer-term sequelae such as persistent post-surgical pain. Nevertheless, it must be considered whenever regional anesthesia is incorporated into perioperative management. Strategies to mitigate the impact of rebound pain include routine prescribing of a systemic multimodal analgesic regimen, as well as patient education on appropriate expectations regarding block offset and expected surgical pain, and timely initiation of analgesic medication. Prolonging the duration of action of regional anesthesia with continuous catheter techniques or local anesthetic adjuncts may also help alleviate rebound pain, although further research is required to confirm this.

Intrathecal hydrophilic opioids for abdominal surgery: a meta-analysis, meta-regression, and trial sequential analysis

Background

Intrathecal hydrophilic opioids decrease systemic opioid consumption after abdominal surgery and potentially facilitate enhanced recovery. A meta-analysis is needed to quantify associated risks and benefits.

Methods

A systematic search was performed to find RCTs investigating intrathecal hydrophilic opioids in abdominal surgery. Caesarean section and continuous regional or neuraxial techniques were excluded. Several subgroup analyses were prespecified. A conventional meta-analysis, meta-regression, trial sequential analysis, and provision of GRADE scores were planned.

Results

The search yielded 40 trials consisting of 2500 patients. A difference was detected in ‘i.v. morphine consumption’ at Day 1 {mean difference [MD] −18.4 mg, (95% confidence interval [CI]: −22.3 to −14.4)} and Day 2 (MD −25.5 mg [95% CI: −30.2 to −20.8]), pain scores at Day 1 in rest (MD −0.9 [95% CI: −1.1 to −0.7]) and during movement (MD −1.2 [95% CI: −1.6 to −0.8]), length of stay (MD −0.2 days [95% CI: −0.4 to −0.1]) and pruritus (relative risk 4.3 [95% CI: 2.5–7.5]) but not in nausea or sedation. A difference was detected for respiratory depression (odds ratio 5.5 [95% CI: 2.1–14.2]) but not when two small outlying studies were excluded (odds ratio 1.4 [95% CI: 0.4–5.2]). The level of evidence was graded as high for morphine consumption, in part because the required information size was reached.

Conclusions

This study showed important opioid-sparing effects of intrathecal hydrophilic opioids. Our data suggest a dose-dependent relationship between the risk of respiratory depression and the dose of intrathecal opioids. Excluding two high-dose studies, intrathecal opioids have a comparable incidence of respiratory depression as the control group.

Clinical trial registration

PROSPERO-registry: CRD42018090682.

Perineural dexamethasone attenuates liposomal bupivacaine-induced delayed neural inflammation in mice in vivo

BACKGROUND

Liposomal bupivacaine (Exparel®) is a sustained-release formulation of bupivacaine for use in surgical infiltration anaesthesia. We analysed the histological nerve toxicity and clinical effectiveness of perineural Exparel® alone or with added dexamethasone in a mouse model.

METHODS

We assigned 98 mice receiving a perineural sciatic nerve injection into seven groups: sham (n=14, perineural saline), B (n=14, perineural bupivacaine), BDIP (n=14, perineural bupivacaine + intraperitoneal dexamethasone), BDPN (n=14, perineural bupivacaine + perineural dexamethasone), E (n=14, perineural Exparel®), EDIP (n=14, perineural Exparel® + intraperitoneal dexamethasone), and EDPN (n=14, perineural Exparel® + perineural dexamethasone). The duration of thermoalgesic and motor block was evaluated in 49 mice (seven mice randomly selected by group) every 30 min until recovery. Mice were killed for sciatic nerve histological assessment at 14 or 28 days.

RESULTS

The median duration of motor block was 90, 120, 120, 120, 180, and 180 min and the duration of thermoalgesic block was 240, 300, 360, 360, 360, and 420 min for groups B, BDIP, BDPN, E, EDIP, and EDPN, respectively. The B group mice showed mild neural inflammation at 14 days and the E group mice showed mild neural inflammation at 28 days. Addition (intraperitoneal or perineural) of dexamethasone reduced neural inflammation induced by bupivacaine, whereas only perineural dexamethasone reduced neural inflammation induced by Exparel®.

CONCLUSIONS

Perineural or systemic dexamethasone had a protective effect against the neural inflammation induced by bupivacaine, and perineural dexamethasone attenuated delayed inflammation induced by perineural Exparel®.

Intrathecal dexmedetomidine and postoperative pain: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

A systematic review and meta-analysis of randomized controlled trials (RCTs) was undertaken to evaluate the effect of intrathecal dexmedetomidine (DEX) on the duration of postoperative analgesia, postoperative pain scores and incidences of adverse effects.

DATABASES AND DATA TREATMENT

Database search was performed from inception until January 2019. All RCTs analysing acute postoperative pain characteristics after intrathecal DEX administration in adults undergoing spinal anaesthesia for elective surgery were included. The primary outcome was postoperative analgesic duration, defined as the time to first analgesic request. The secondary outcomes included pain scores at 6, 12 and 24 postoperative hours and rates of hypotension, bradycardia, shivering and postoperative nausea and vomiting.

RESULTS

Twenty-four studies comprising a total of 1,460 patients were included. Postoperative analgesic duration was prolonged with intrathecal DEX compared to placebo, with a pooled mean difference (MD) of 191.3 min (95% CI 168.8-213.8). Patients who received intrathecal DEX reported lower Visual Analogue Scale scores at 24 postoperative hours compared with those patients receiving placebo, with a MD (95% CI) of -1.05 (-1.89 to -0.20, p = 0.02). There were no differences in the incidence of adverse effects, except for a lower rate of postoperative shivering in the intrathecal DEX group (pooled relative risk 0.58, 95% CI 0.34-0.98, p = 0.04).

CONCLUSIONS

Compared to placebo, intrathecal DEX prolonged postoperative analgesic duration, reduced 24-hr pain intensity and reduced the incidence of shivering without an increase in other adverse effects.

SIGNIFICANCE

The analgesic role of intrathecal DEX is promising due to its ability to significantly increase postoperative analgesic duration when compared with placebo. Its usage can be considered for patients undergoing surgeries with significant postoperative pain, particularly those intolerant of systemic analgesia. However, the optimal dose for various surgeries as well as its long-term neurological effects warrants further studies.