Local anaesthetic adjuncts for peripheral regional anaesthesia: a narrative review

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.

Combination of dexamethasone and dexmedetomidine as adjuvants of transversus abdominis plane block for postoperative analgesia in gastric cancer patients: A double-blinded randomized controlled trial

STUDY OBJECTIVE

We conducted this double-blinded randomized controlled trial to examine whether the combination of dexamethasone and dexmedetomidine as adjuvants of transversus abdominis plane (TAP) block could improve analgesia efficacy and duration for gastric cancer patients.

DESIGN

Randomized controlled trial.

SETTING

The preoperative area, operating room, postanesthesia recovery room and bed ward.

PATIENTS

A total of 312 adult patients (104 per group) with gastric cancer were included.

INTERVENTIONS

Patients received bilateral subcostal TAP block with three different anesthetics (60 ml 0.25% ropivacaine added with 10 mg dexamethasone and 1 μg·kg-1 dexmedetomidine [A] or 10 mg dexamethasone [B] or 1 μg·kg-1 dexmedetomidine [C]).

MEASUREMENTS

The primary outcome was the incidence of moderate-to-severe pain 24 h on movement. Secondary outcomes included incidence of moderate-to-severe pain, pain score, opioids use, recovery quality and adverse events.

MAIN RESULTS

The incidence of moderate-to-severe pain on movement 24 h postoperatively of group A was significantly lower than group B (45.19% vs 63.46%; RR 0.71; 95% CI, 0.55 to 0.92) and group C (45.19% vs 73.08%, RR 0.62; 95% CI, 0.49 to 0.79). The median moving pain scores decreased significantly at 24 h (3.00 [3.00,5.00] vs 4.00 [3.00,6.00] vs 4.00 [3.00,5.00]; P < 0.001). There were significant differences in the opioids consumption within the first 24 h (27.5 [17.0,37.2] vs 30.0 [20.0,42.0] vs 32.0 [25.0,44.0] mg; P = 0.01) and the duration to first rescue analgesia (65.5 ± 26.7 vs 45.9 ± 34.5 vs 49.2 ± 27.2 h; P = 0.04).

CONCLUSIONS

The combination with dexamethasone and dexmedetomidine as adjuvants for TAP block reduced the incidence of moderate-to-severe pain and pain score both on movement and at rest at 24 h with prolonged duration to first rescue analgesia after gastric cancer surgery.

TRIAL REGISTRATION NUMBER

ChiCTR2000037981.

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.

Comparison between low-volume local anesthetic with intravenous dexamethasone and conventional volume without dexamethasone for superior trunk block after arthroscopic shoulder surgery: a randomized controlled non-inferiority trial

INTRODUCTION

This study aimed to investigate whether low-volume local anesthetic with intravenous dexamethasone can reduce the incidence of diaphragmatic paresis while maintaining the analgesic duration compared with conventional volume of local anesthetic without intravenous dexamethasone when performing ultrasound-guided superior trunk block in patients undergoing arthroscopic shoulder surgery.

METHODS

Eighty-four adult patients undergoing arthroscopic shoulder surgery under general anesthesia were randomly assigned to receive ultrasound-guided superior trunk block using 7 mL of 0.5% ropivacaine with 0.15 mg/kg of intravenous dexamethasone (treatment group), or 15 mL of 0.5% ropivacaine with intravenous normal saline (control group). The co-primary outcomes were (1) the duration of analgesia (time between block completion and onset of surgical pain with a Numeric Rating Scale pain score of 4 or higher), which was compared against a non-inferiority margin of 3 hours, and (2) the incidence of diaphragmatic paresis evaluated using M-mode ultrasonography in the post-anesthesia care unit.

RESULTS

The mean duration of analgesia was 12.4 (6.8) and 11.2 (4.6) hours in the treatment and control groups, respectively (mean difference: -1.2 hours; 95% CI -3.8 to 1.3]; p for non-inferiority<0.001), meeting the non-inferiority criteria. The incidence of diaphragmatic paresis was 45.2% and 85.4% in the treatment and control groups, respectively (relative risk: 0.53; 97.5% CI 0.35 to 0.80; p<0.001).

CONCLUSIONS

Superior trunk block using low-volume local anesthetic with intravenous dexamethasone can reduce the incidence of diaphragmatic paresis while providing non-inferior analgesic duration compared with the conventional volume of local anesthetic in patients undergoing arthroscopic shoulder surgery.

TRIAL REGISTRATION NUMBER

Clinical Research Information Service of Republic of Korea Registry (KCT0005998).

Mapping Theme Trends and Research Frontiers in Dexmedetomidine Over Past Decade: A Bibliometric Analysis

Background

Dexmedetomidine, an α2-adrenergic receptor (α2-AR) agonist, is extensively used in clinical and animal studies owing to its sedative, analgesic, and anxiolytic effects. The diverse range of research domains associated with dexmedetomidine poses challenges in defining pivotal research directions. Therefore, this study aimed to conduct a qualitative and quantitative bibliometric study in the field of dexmedetomidine over the past decade to establish current research trends and emerging frontiers.

Methods

Relevant publications in the field of dexmedetomidine between 2014 and 2023 were extracted from the Web of Science Core Collection database. The bibliometric analysis, incorporating statistical and visual analyses, was conducted using CiteSpace (6.1.R6) and R (4.3.1).

Results

The present study encompassed a total of 5,482 publications, exhibiting a consistent upward trend over the past decade. The United States and its institutions had the highest centrality. Ji, Fuhai, and Ebert, Thomas J. were identified as the most productive author and the most cited author, respectively. As anticipated, the most cited journal was Anesthesiology. Moreover, cluster analysis of cited references and co-occurrence of keywords revealed that recent studies were primarily focused on sedation, delirium, and opioid-free anesthesia. Finally, a timeline view of keywords clusters and keywords burst demonstrated that primary research frontiers were stress response, neuroinflammation, delirium, opioid-free anesthesia, peripheral nerve block, and complications.

Conclusion

Current research trends and directions are focused on sedation, delirium, and opioid-free anesthesia, as evidenced by our results. The frontier of future research is anticipated to encompass basic investigations into dexmedetomidine, including stress response and neuroinflammation, as well as clinical studies focusing on delirium, opioid-free anesthesia, peripheral nerve block, and associated complications.

Ultrasound-guided serratus anterior plane block enhances postoperative analgesia and recovery in thoracoscopic surgery

BACKGROUND

The serratus anterior muscle, located in the lateral aspect of the thorax, plays a crucial role in shoulder movement and stability. Thoracoscopic surgery, while minimally invasive, often results in significant postoperative pain, complicating patient recovery and potentially extending hospital stays. Traditional anesthesia methods may not adequately address this pain, leading to increased complications such as agitation due to inadequate pain management.

AIM

To evaluate the application value of ultrasound-guided serratus anterior plane block (SAPB) in patients undergoing thoracoscopic surgery, focusing on its effects on postoperative analgesia and rehabilitation.

METHODS

Eighty patients undergoing thoracoscopic surgery between August 2021 and December 2022 were randomly divided into two groups: An observation group receiving ultrasound-guided SAPB and a control group receiving standard care without SAPB. Both groups underwent general anesthesia and were monitored for blood pressure, heart rate (HR), oxygen saturation, and pulse. The primary outcomes measured included mean arterial pressure (MAP), HR, postoperative visual analogue scale (VAS) scores for pain, supplemental analgesic use, and incidence of agitation.

RESULTS

The observation group showed significantly lower cortisol and glucose concentrations at various time points post-operation compared to the control group, indicating reduced stress responses. Moreover, MAP and HR levels were lower in the observation group during and after surgery. VAS scores were significantly lower in the observation group at 1 h, 4 h, 6 h, and 12 h post-surgery, and the rates of analgesic supplementation and agitation were significantly reduced compared to the control group.

CONCLUSION

Ultrasound-guided SAPB significantly improves postoperative analgesia and reduces agitation in patients undergoing thoracoscopic surgery. This technique stabilizes perioperative vital signs, decreases the need for supplemental analgesics, and minimizes postoperative pain and stress responses, underscoring its high application value in enhancing patient recovery and rehabilitation post-thoracoscopy.

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).

Observation on the Analgesic Effect of Different Doses of a Combination of Esketamine and Dexmedetomidine Administered for Percutaneous Endoscopic Transforaminal Discectomy: A Randomized, Double-Blind Controlled Trial

BACKGROUND

Percutaneous endoscopic transforaminal discectomy (PETD) is an effective method for treating lumbar disc herniation, and is typically performed under local anesthesia. However, inadequate analgesia during the procedure remains a concern, prompting the search for a medication that can provide optimal pain control with minimal impact on the respiratory and circulatory systems.

OBJECTIVES

The aim of this study was to observe the effects of different doses of esketamine combined with dexmedetomidine on reducing visual analog scale (VAS) scores during surgical interventions.

METHODS

One hundred two patients who underwent PETD were randomly divided into a control group (group C: normal saline + dexmedetomidine), an E1 group (0.1 mg kg-1 esketamine + dexmedetomidine), and an E2 group (0.2 mg kg-1 esketamine + dexmedetomidine). The primary outcome was the maximum visual analogue scale (VAS) (score: 0 = no pain and 10 = worst pain) at six time points. The secondary outcomes included the Assessment of Alertness/Sedation Scale (OAA/S) score and mean arterial pressure (BP), heart rate (HR), respiratory rate (RR), and oxygen saturation (SpO2) at 11 time points. The incidence of adverse reactions during and 24 h after the operation and patient satisfaction with the anesthesia were also recorded.

RESULTS

Compared with those in group C, the VAS scores of patients in groups E1 and E2 were lower at T6, T7, and T9 (P < 0.05). From T4 to T10, the OAA/S scores of the E1 and E2 groups were both lower than those of group C (P < 0.05), and at the T4-T6 time points, the OAA/S score of the E2 group was lower than that of group E1 (P < 0.05). At T4 and T5, the HR and BP of patients in groups E1 and E2 were greater than those in group C (P < 0.05). Compared with those in group C, the incidences of intraoperative illusion, floating sensation, postoperative dizziness, and hyperalgesia in groups E1 and E2 were significantly greater (P < 0.01). There was no significant difference in patient RR, SpO2, or postoperative satisfaction with anesthesia among the three groups (P > 0.05).

CONCLUSION

The combination of esketamine and dexmedetomidine can reduce VAS scores during certain stages of this type of surgery; it has minimal impact on respiration and circulation. However, this approach is associated with increased incidences of postoperative dizziness and psychiatric side effects, which may also affect patients' compliance with surgical instructions from medical staff. Patient satisfaction was not greater with dexmedetomidine combined with esketamine than with dexmedetomidine alone.

TRIAL REGISTRATION

http://www.chictr.org.cn . Identifier: ChiCTR2300068206. Date of registration: 10 February 2023.

Combined Dexamethasone and Dexmedetomidine as Adjuncts to Popliteal and Saphenous Nerve Blocks in Patients Undergoing Surgery of the Foot or Ankle: A Randomized, Blinded, Placebo-controlled Clinical Trial

BACKGROUND

Both dexamethasone and dexmedetomidine increase the duration of analgesia of peripheral nerve blocks. The authors hypothesized that combined intravenous dexamethasone and intravenous dexmedetomidine would result in a greater duration of analgesia when compared with intravenous dexamethasone alone and placebo.

METHODS

The authors randomly allocated participants undergoing surgery of the foot or ankle under general anesthesia and with a combined popliteal (sciatic) and saphenous nerve block to a combination of 12 mg dexamethasone and 1 µg/kg dexmedetomidine, 12 mg dexamethasone, or placebo (saline). The primary outcome was the duration of analgesia measured as the time from block performance until the first sensation of pain in the surgical area as reported by the participant. The authors predefined a 33% difference in the duration of analgesia as clinically relevant.

RESULTS

A total of 120 participants from two centers were randomized and 119 analyzed for the primary outcome. The median [interquartile range] duration of analgesia was 1,572 min [1,259 to 1,715] with combined dexamethasone and dexmedetomidine, 1,400 min [1,133 to 1,750] with dexamethasone alone, and 870 min [748 to 1,138] with placebo. Compared with placebo, the duration was greater with combined dexamethasone and dexmedetomidine (difference, 564 min; 98.33% CI, 301 to 794; P < 0.001) and with dexamethasone (difference, 489 min; 98.33% CI, 265 to 706; P < 0.001). The prolongations exceeded the authors' predefined clinically relevant difference. The duration was similar when combined dexamethasone and dexmedetomidine was compared with dexamethasone alone (difference, 61 min; 98.33% CI, -222 to 331; P = 0.614).

CONCLUSIONS

Dexamethasone with or without dexmedetomidine increased the duration of analgesia in patients undergoing surgery of the foot or ankle with a popliteal (sciatic) and saphenous nerve block. Combined dexamethasone and dexmedetomidine did not increase the duration of analgesia when compared with dexamethasone.

EDITOR’S PERSPECTIVE

Research priorities in regional anaesthesia: an international Delphi study

BACKGROUND

Regional anaesthesia use is growing worldwide, and there is an increasing emphasis on research in regional anaesthesia to improve patient outcomes. However, priorities for future study remain unclear. We therefore conducted an international research prioritisation exercise, setting the agenda for future investigators and funding bodies.

METHODS

We invited members of specialist regional anaesthesia societies from six continents to propose research questions that they felt were unanswered. These were consolidated into representative indicative questions, and a literature review was undertaken to determine if any indicative questions were already answered by published work. Unanswered indicative questions entered a three-round modified Delphi process, whereby 29 experts in regional anaesthesia (representing all participating specialist societies) rated each indicative question for inclusion on a final high priority shortlist. If ≥75% of participants rated an indicative question as 'definitely' include in any round, it was accepted. Indicative questions rated as 'definitely' or 'probably' by <50% of participants in any round were excluded. Retained indicative questions were further ranked based on the rating score in the final Delphi round. The final research priorities were ratified by the Delphi expert group.

RESULTS

There were 1318 responses from 516 people in the initial survey, from which 71 indicative questions were formed, of which 68 entered the modified Delphi process. Eleven 'highest priority' research questions were short listed, covering themes of pain management; training and assessment; clinical practice and efficacy; technology and equipment.

CONCLUSIONS

We prioritised unanswered research questions in regional anaesthesia. These will inform a coordinated global research strategy for regional anaesthesia and direct investigators to address high-priority areas.

Latest Advances in Regional Anaesthesia

Training and expertise in regional anaesthesia have increased significantly in tandem with increased interest over the past two decades. This review outlines the most recent advances in regional anaesthesia and focuses on novel areas of interest including fascial plane blocks. Pharmacological advances in the form of the prolongation of drug duration with liposomal bupivacaine are considered. Neuromodulation in the context of regional anaesthesia is outlined as a potential future direction. The growing use of regional anaesthesia outside of the theatre environment and current thinking on managing the rebound plane after regional block regression are also discussed. Recent relevant evidence is summarised, unanswered questions are outlined, and priorities for ongoing investigation are suggested.

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.

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.

Effects of combined dexamethasone and dexmedetomidine as adjuncts to peripheral nerve blocks: a systematic review with meta-analysis and trial sequential analysis

BACKGROUND/IMPORTANCE

The effects of combining dexamethasone and dexmedetomidine on block duration are unclear.

OBJECTIVE

To investigate the effects of combining dexamethasone and dexmedetomidine on block duration.

EVIDENCE REVIEW

Systematic review of randomized controlled trials (RCTs) from Medline, Embase, CENTRAL, CINAHL, the Web of Science, and BIOSIS until June 8, 2023. RCTs with adults undergoing surgery with a peripheral nerve block randomized to combined dexamethasone and dexmedetomidine versus placebo or other adjuncts were eligible. Primary outcome was duration of analgesia. We performed meta-analysis, trial sequential analysis, risk of bias-2, and Grading Recommendations Assessment, Development, and Evaluation assessment.

FINDINGS

We included 9 RCTs with 14 eligible comparisons. The combination of dexamethasone and dexmedetomidine was compared with placebo in three RCTs (173 participants), dexamethasone in seven (569 participants), and dexmedetomidine in four (281 participants). The duration of analgesia was likely increased with the combination versus placebo (mean difference 460 min, 95% CI 249 to 671) and versus dexmedetomidine (mean difference 388 min, 95% CI 211 to 565). The duration was likely similar with the combination versus dexamethasone (mean difference 50 min, 95% CI -140 to 239). The certainty of the evidence was moderate because most trials were at high risk of bias.

CONCLUSIONS

Combined dexamethasone and dexmedetomidine likely increased the duration of analgesia when compared with placebo and dexmedetomidine. The combination likely provided a similar duration of analgesia as dexamethasone. Based on this systematic review, it seems reasonable to use dexamethasone as the sole adjunct if the goal is to increase the duration of analgesia.

Prolonged Anesthesia Effects of Locally Administered Ropivacaine via Electrospun Poly(caprolactone) Fibrous Membranes

Prolonged analgesia is important to safeguard the patient's comfort and safety during and after surgery in clinical practice. To meet the demand for prolonged analgesia, medical professionals often resort to increasing drug frequency, which may lead to poor patient compliance and serious complications due to drug overdose. Therefore, it is of great interest to develop controlled-release drug delivery systems for local anesthetics, enabling slow and controlled drug release to prolong the analgesic effect and minimize systemic toxicity. In this study, we utilized an electrospinning technique to fabricate nonwoven poly(caprolactone) (PCL) fibrous membranes loaded with Ropivacaine and performed proof-of-principle experiments on both in vitro drug release tests and in vivo animal tests, to further prolong the analgesic effect of Ropivacaine and improve postoperative local pain management and chronic pain treatment. Material characterization and in vitro drug release studies confirmed the feasibility of the Ropivacaine-loaded PCL fibrous membranes for sustained release. The drug loading content and drug loading efficiency of Ropivacaine-loaded fibrous membrane are 8.7 ± 0.3 wt% and 96 ± 3 wt%, respectively. Evaluation in an animal model demonstrated prolonged anesthesia effects along with excellent biocompatibility and stability. At 72 h, the cumulative release accounted for approximately 50% of the drug loading content. This study offers novel approaches and strategies for clinical postoperative pain management and chronic pain treatment, while providing new insights and directions for the design of local anesthetic controlled-release delivery systems.

Pain relief after major ankle and hindfoot surgery with repetitive peripheral nerve blocks: A feasibility study

BACKGROUND

Major ankle and hindfoot surgery (e.g., ankle, triple and subtalar arthrodesis) typically causes severe postoperative pain, especially the first two postoperative days. Current modalities of postoperative analgesic treatment often include continuous peripheral nerve blocks of the saphenous and sciatic nerves via catheters in order to extend the duration of pain- and opioid-free nerve blockade to 48 h. Unfortunately, the 48 h-efficacy of continuous infusion via a catheter is reduced by a high displacement rate. We hypothesised that one-time repetition of the single injection peripheral nerve blocks would provide effective analgesia with a low opioid consumption the first 48 postoperative hours.

METHODS

Eleven subjects preoperatively received a popliteal sciatic and a saphenous single injection nerve block with a protracted local anaesthetic mixture. Surgery was performed under general anaesthesia. The one-time repetition of the single injection nerve block was carried out approximately 24 h after the primary nerve block. The main outcomes were pain and cumulative opioid consumption during the first 48 postoperative hours.

RESULTS

Nine of the 11 (82%) patients had effective analgesia without opioids during the first 48 postoperative hours. Two patients each required a single dose of 7.5 mg of oral morphine equivalents after 43 h.

CONCLUSION

One-time repetition of single injection saphenous and sciatic nerve blocks consistently provided effective analgesia practically without opioids for 48 h after major elective ankle and hindfoot surgery.

Local anaesthetic adjuncts for peripheral nerve blockade

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Dexamethasone and dexmedetomidine as adjuvants to ropivacaine do not prolong analgesia in wound infiltration for lumbar spinal fusion: a prospective randomized controlled study

BACKGROUND AND OBJECTIVES

Local anesthetics (LAs) are widely used to infiltrate into surgical wounds for postoperative analgesia. Different adjuvants like dexamethasone and dexmedetomidine, when added to LA agents, could improve and prolong analgesia. The aim of this trial was to evaluate the analgesic efficacy and opioid-sparing properties of dexamethasone and dexmedetomidine when added to ropivacaine for wound infiltration in transforaminal lumbar interbody fusion (TLIF).

METHODS

We conducted a controlled study among 68 adult patients undergoing TLIF, which was prospective, randomized and double-blind in nature. The participants were divided into four equal groups at random. Group R was given 150 mg of 1% ropivacaine (15 mL) and 15 mL of normal saline. Group R + DXM received 150 mg of 1% ropivacaine (15 mL) and 10 mg of dexamethasone (15 mL). Group R + DEX received 150 mg of 1% ropivacaine (15 mL) and 1 µg/kg of dexmedetomidine (15 mL). Lastly, group R + DXM + DEX was given 150 mg of 1% ropivacaine (15 mL), 10 mg of dexamethasone and 1 µg/kg of dexmedetomidine (15 mL). The primary focus was on the length of pain relief provided. Additionally, secondary evaluations included the amount of hydromorphone taken after surgery, the numerical rating scale and safety assessments within 48 h after the operation.

RESULTS

Based on the p value (P > 0.05), there was no significant variance in the duration of pain relief or the total usage of hydromorphone after surgery across the four groups. Similarly, the numerical rating scale scores at rest and during activity at 6-, 12-, 24- and 48-h post-surgery for all four groups showed no difference (P > 0.05). However, the incidence of delayed anesthesia recovery was slightly higher in group R + DEX and group R + DXM + DEX when compared to group R or group R + DXM. Furthermore, there were no significant differences between the four groups in terms of vomiting, nausea, dizziness or delayed anesthesia recovery.

CONCLUSION

For wound infiltration in TLIF, the addition of dexamethasone and dexmedetomidine to ropivacaine did not result in any clinically significant reduction in pain or opioid consumption and could prompt some side effects.

Long-duration pain block for postoperative anesthesia after endoscopic sinus surgery

KEY POINTS

A long-duration pain block did not decrease postoperative pain or opioid consumption. Extended sinus procedures do not lead to additional postoperative pain or opioid consumption.

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.

Esketamine opioid-free intravenous anesthesia versus opioid intravenous anesthesia in spontaneous ventilation video-assisted thoracic surgery: a randomized controlled trial

Background

Opioid-free anesthesia (OFA) provides adequate analgesia and can reduce postoperative opioid consumption, but its efficacy in spontaneous ventilation video-assisted thoracic surgery (SV-VATS) has not been demonstrated. We aimed to investigate the hypothesis that OFA could provide the same perioperative pain control as opioid anesthesia (OA), maintain safe and stable respiration and hemodynamics during surgery, and improve postoperative recovery.

Methods

Sixty eligible patients (OFA group: n=30; OA group: n=30) treated between September 15, 2022, and December 15, 2022, at The First Hospital of Guangzhou Medical University were included. They were randomized to receive standard balanced OFA with esketamine or OA with remifentanil combined with sufentanil. The primary outcome was the pain numeric rating score (NRS) at postoperative 24 h, and the secondary outcomes were intraoperative respiratory and hemodynamic data, opioid consumption, vasoactive drug dosage, and recovery in the post-anesthesia care unit and ward.

Results

There was no significant difference in the postoperative pain scores and recovery quality between the two groups. The OFA group had a significantly lower dose of phenylephrine (P=0.001) and a lower incidence of hypotension (P=0.004) during surgery. The OFA group resumed spontaneous respiration faster (P<0.001) and had a higher quality of lung collapse (P=0.02). However, the total doses of propofol and dexmetomidine were higher (P=0.03 and P=0.02), and the time to consciousness was longer (P=0.039) in the OFA group.

Conclusions

OFA provides the same level of postoperative pain control as OA, but it is more advantageous in maintaining circulatory and respiratory stability and improving the quality of pulmonary collapse in SV-VATS.

The Effects of Intravenous Dexamethasone on Rebound Pain After Nerve Block in Patients with Ankle Fracture: A Randomized Controlled Trial

Purpose

A single-injection nerve block provides excellent analgesia in a short time, but rebound pain after the nerve block disappears has attracted researchers' attention. The aim of this study is to evaluate the effect of intravenous dexamethasone on rebound pain after adductor canal block (ACB) and popliteal sciatic nerve block in patients with ankle fracture.

Methods

We recruited 130 patients with ankle fractures scheduled for open reduction and internal fixation (ORIF), each of whom received ACB and popliteal sciatic nerve block. Patients were divided into two groups: C (ropivacaine only) and IV (ropivacaine with intravenous dexamethasone). The primary outcome was the incidence of rebound pain. Secondary outcomes included the following: pain scores at 6 h (T₁), 12 h (T₂), 18 h (T₃), 24 h (T₄), and 48 h (T₅) after operation; duration of the nerve block; number of presses of the analgesia pump and rescue analgesic consumption in the three-day postoperative period; quality of recovery scale (QoR-15 score); postoperative sleep quality; satisfaction of patients; and levels of serum inflammatory markers (IL-1β, IL-6, and TNF-α) six hours after surgery.

Results

Compared with group C, the incidence of rebound pain in group IV was significantly reduced, and the duration of nerve block was extended by approximately nine hours (P<0.05). Moreover, patients in group IV had significantly lower pain scores at T₂-T₄, lower levels of serum inflammatory markers (IL-1β, IL-6, and TNF-α), higher QoR-15 score two days after the operation, and satisfactory sleep quality the night after surgery (P<0.05).

Conclusion

Intravenous dexamethasone can reduce the rebound pain after adductor block and sciatic popliteal nerve block in patients with ankle fracture surgery, prolong the duration of nerve block, and improve the quality of early postoperative recovery.

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

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

Measures to prolong duration of sensory block after regional anaesthesia

PURPOSE OF REVIEW

The duration of single-injection regional anaesthesia is limited due to the inherent pharmacological properties of local anaesthetics. The ideal duration of a regional anaesthesia block lasting for the first 24 h postoperatively can be stated, while a residual analgesic effect thereafter is desirable.The aim of this review is to present current options to prolong the duration of action of single-injection peripheral regional anaesthesia in the ambulatory setting. Secondly, this review outlines and discusses the latest evidence regarding the clinical use of adjuvants and sustained-release local anaesthetics.

RECENT FINDINGS

Extended-release formulations of local anaesthetics such as liposomal bupivacaine have been developed to prolong regional anaesthesia up to 96 h. Recent studies, however, show that the actual effects remain far behind expectations and that the efficacy is only marginally better than bupivacaine hydrochloride.Adjuvants to local anaesthetics have been studied extensively with heterogenous results. Dexamethasone and alpha-2 agonists range among the most effective measures to prolong single-injection nerve blocks.Continuous nerve blocks and catheter techniques may prolong regional anaesthesia very effectively, but are less cost-effective regarding block procedure, postoperative care and handling logistical issues especially in ambulatory surgery.

SUMMARY

In conclusion, adjuvants are the recommended measure to prolong regional anaesthesia where needed. With good evidence supporting it, dexamethasone is the most effective adjuvant, followed by dexmedetomidine. Both have few side effects and a favourable safety profile. However, a preferable duration of analgesia lasting for the first 24 h postoperatively is still not reliably achievable.

Relationship between ANI and qNOX and between MAC and qCON during outpatient laparoscopic cholecystectomy using remifentanil and desflurane without muscle relaxants: a prospective observational preliminary study

This study was designed to investigate qCON and qNOX variations during outpatient laparoscopic cholecystectomy using remifentanil and desflurane without muscle relaxants and compare these indices with ANI and MAC. Adult patients undergoing outpatient laparoscopic cholecystectomy were included in this prospective observational study. Maintenance of anesthesia was performed using remifentanil targeted to ANI 50-80 and desflurane targeted to MAC 0.8-1.2 without muscle relaxants. The ANI, qCON and qNOX and desflurane MAC values were collected at different time-points and analyzed using repeated measures ANOVA. The relationship between ANI and qNOX and between qCON and MAC were analyzed by linear regression. The ANI was comprised between 50 and 80 during maintenance of anesthesia. Higher values of qNOX and qCON were observed at induction and extubation than during all other time-points where they were comprised between 40 and 60. A poor but significant negative linear relationship (r² = 0.07, p < 0.001) was observed between ANI and qNOX. There also was a negative linear relationship between qCON and MAC (r² = 0.48, p < 0.001) and between qNOX and remifentanil infusion rate (r² = 0.13, p < 0.001). The linear mixed-effect regression correlation (r²) was 0.65 for ANI-qNOX and 0.96 for qCON-MAC. The qCON and qNOX monitoring seems informative during general anesthesia using desflurane and remifentanil without muscle relaxants in patients undergoing ambulatory laparoscopic cholecystectomy. While qCON correlated with MAC, the correlation of overall qCON and ANI was poor but significant. Additionally, the qNOX weakly correlated with the remifentanil infusion rate. This observational study suggests that the proposed ranges of 40-60 for both indexes may correspond to adequate levels of hypnosis and analgesia during general anesthesia, although this should be confirmed by further research.

Evaluation of a constant rate intravenous infusion of dexmedetomidine on the duration of a femoral and sciatic nerve block using lidocaine in dogs

Objectives

This study investigated the effects of 1 μg/kg/h intravenous constant rate infusion (CRI) of dexmedetomidine on the sensory and motor blockade for femoral and sciatic nerve blocks in dogs undergoing stifle surgery.

Materials and methods

Client-owned dogs referred for stifle surgery were enrolled in this prospective, randomized, blinded study. Dogs were pre-medicated with acepromazine (0.005-0.01 mg/kg intramuscularly, IM); anesthesia was induced with propofol intravenously and maintained with isoflurane in a mixture of air and oxygen. Electrolocation-guided sciatic and femoral nerve blocks with lidocaine 2% (0.15 mL/kg) were performed using the parasacral and lateral pre-iliac approaches, respectively. After performing local block, a systemic infusion of saline solution (group C) or dexmedetomidine (group D) was started at a CRI at 1 ml/kg/h and continued until the end of surgery. Dexmedetomidine was infused at a dose of 1 μg/kg/h. Respiratory and hemodynamic variables were recorded during surgery. Sensory and motor blockade was evaluated by response to pinching the skin innervated by the sciatic/femoral nerves, with forceps and by observing the dogs' ability to walk and testing proprioception at 30, 60, 120, 180, and 240 min after extubation. Analgesia was monitored with SF-GCPS. Methadone IM was administered as rescue analgesia. Intraoperative data were analyzed by analysis of variance, while postoperative data were analyzed by the independent two-tailed t-test and a Kaplan-Meier test (p < 0.05).

Results

Twenty dogs were included in this study (10/group). A significant difference in the recovery of sensory nerve function was observed between the groups. The mean durations of the sensory blockade for femoral and sciatic nerves, respectively, was longer (p < 0.001) for group D [168 (146-191, 95% CI), 161 (143-179, 95% CI) min] than in group C [120 (96.1-144, 95% CI), 116 (90.9-142, 95% CI]. No differences in the recovery of patellar and tibial reflexes, proprioceptive function, and ability to walk were found among groups. The overall postoperative rescue analgesia requirement was significantly different (p = 0.019) between groups, with an incidence of 5/10 (50%) dogs in group D and 10/10 (100%) dogs in group C.

Conclusion

Dexmedetomidine administered as a CRI (1 μg/kg/h) combined with local lidocaine increases the duration of the sensory component of the sciatic and femoral nerve blocks and reduces the requirement for additional analgesia during the immediate postoperative hours.

Analgesic efficacy of local versus proximal nerve blocks after hallux valgus surgery: a systematic review

Background

Hallux valgus (HV) surgery is an orthopaedic procedure that commonly causes mild to moderate postoperative pain. Effective management of this pain has become an important element of modern hallux valgus surgical treatment. A local anaesthetic (LA) with an antinociceptive effect can control this pain. However, relatively few papers have evaluated this strategy in depth. The objective of the current systematic review was to address this demand by comparing the efficacy of proximal and local blocks in controlling postoperative pain following hallux valgus surgery.

Main text

Ovid-MEDLINE, Cochrane Central, PubMed, Web of Science (WOS), Scopus, and Embase were searched from their inceptions through December 29, 2021. Observational and clinical trial publications in peer-reviewed English-language journals with a sample size of at least 20 were included. The trials involved adults over 18 who could describe their discomfort and had a bunionectomy. The included studies were evaluated using the Cochrane risk of bias 2 method. Descriptive analysis synthesised the results.

Among the 439 articles identified, five studies compromising 459 participants were included. Ankle blocks were superior to control in two studies (P = 0.001, P < 0.001) and superior to local blocks in one study (P < 0.001). Additionally, one study showed that popliteal and ankle blocks administered with lidocaine or levobupivacaine were equivalent (P = 0.123 and P = 0.055, respectively). However, one of these five included studies indicated that ankle blocks were not effective (P = 0.123) in reducing postoperative pain.

Conclusions

The key findings presented herein suggest that regional blocks effectively reduce postoperative pain and that an ankle block has more supportive evidence for its effectiveness. However, an adequate assessment of the effectiveness of various administrative routes was challenging due to the lack of reliable evidence. This needs to be addressed in future studies.

Trial registration

PROSPERO registration: CRD42022307974.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-022-00581-0.

Butorphanol as an Adjuvant to Ropivacaine for Adductor Canal Blocks in Total Knee Arthroplasty Patients: A Randomized, Double, Blind Study

Background

The objective of this study was to observe the effects of butorphanol as an adjuvant to ropivacaine for the adductor canal block (ACB) on postoperative analgesia in patients undergoing total knee arthroplasty (TKA).

Methods

Seventy-four patients undergoing TKA were included and randomly divided into two groups: Group BR received 20 ml of 0.33% ropivacaine plus 1 mg butorphanol and Group R received 20 ml of 0.33% ropivacaine plus 1 ml normal saline for ultrasound-guided adductor canal blocks. The primary outcomes were the duration of the sensory block and the pain visual analogue scale (VAS), and secondary outcomes included the number of PCIA attempts (patient-controlled intravenous analgesia) and the time to first pressing and rescue analgesia. Other outcomes included knee active range of motion (ROM), quadriceps strength, the time to first mobilization, the duration of postoperative hospital stay, Knee Society Score (KSS), and postoperative complications.

Results

Since two patients in each group rejected postoperative assessments, 35 patients were included in each group. Compared with Group R, Group BR had longer duration of sensory blocks (18.42 ± 3.46 vs. 15.36 ± 2.29 h, p < 0.01) and lower postoperative pain scores within 24 hours at rest and within 12 hours with activity (p < 0.01). The number of PCIA attempts decreased within 48 hours after surgery (4.5 ± 1.2 vs. 7.8 ± 1.5 times, p < 0.01), and the time to first pressing was later (20.31 ± 2.59 vs. 16.25 ± 2.31 h, p < 0.01). In addition, Group BR had bigger knee ROM at within 24 hours after the operation than Group R (68.37 ± 4.70°vs. 59.21 ± 6.41,85.67 ± 5.17 vs. 74.37 ± 4.68°, 97.62 ± 5.43 vs. 84.18 ± 4.49°, p < 0.01). There was no significant difference between the two groups (p > 0.05) in terms of rescue analgesia, quadriceps strength, the time to first mobilization, the duration of postoperative hospital stay, the KSS function scores, and postoperative complications.

Conclusions

Butorphanol plus ropivacaine ultrasound-guided adductor canal block can prolong the duration of sensory block, relieve early postoperative pain, and improve the range of motion of the knee joint, without affecting the occurrence of postoperative complications. Name of the Registry. Chinese Clinical Trial Registry. Trial Registration Number. ChiCTR2100041859. URL of Trial Registry Record. http://www.chictr.org.cn/edit.aspx?pid=119731&htm=4. Date of Registration. 08/01/2021 0:00:00.

Ultrasound-guided Bilateral Serratus Anterior Plane Block for Postoperative Analgesia in Ear Reconstruction after Costal Cartilage Harvest: A Randomized Controlled Trial

BACKGROUND

Costal cartilages harvest for ear reconstruction is accompanied by severe pain in chest. However, there is no perfect solution for reducing this chest pain.

OBJECTIVE

Evaluate the efficacy and safety of analgesia using ultrasound-guided bilateral serratus anterior plane block (SAPB) in children receiving costal cartilage harvest for ear reconstruction.

METHODS

Sixty children undergoing ear reconstruction using costal cartilage were randomized to an SAPB group (SAPB with 3 mg/kg 0.25% ropivacaine) or an incision infiltration (II) group (II with 3 mg/kg 0.75% ropivacaine), and 29 in each group completed the study. All children received patient-controlled intravenous analgesia (PCIA). The primary outcomes were numerical rating scale (NRS) scores of pain while rest and coughing at 1, 6, 12, 24, and 48 h after surgery. The secondary outcomes were sufentanil use within 24 h, duration of analgesia, use of oral rescue analgesics, first time out of bed, and incidence of treatment-related adverse effects.

RESULTS

The SAPB group had lower rest and coughing NRS scores at 6 and 12 h after surgery (all P < 0.001), but the scores were similar at other times. The SAPB group used less sufentanil within 24 h, but had a longer duration of analgesia (both P < 0.001). The II group used more oral rescue analgesics within 48 h, had a longer time until first time out of bed, and had more opioid-related side effects (all P < 0.01). There were no SAPB-related complications.

CONCLUSION

Ultrasound-guided SAPB can provide safe and effective regional pain relief after costal cartilage harvest for ear reconstruction.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266 .

Peripheral Nerve Blockade for Medial Patellofemoral Ligament Reconstruction in Pediatric Patients: The Addition of a Proximal Single-Injection Sciatic Nerve Block Provides Improved Analgesia

Purpose

We tested the hypothesis that the addition of a single-injection proximal sciatic nerve block to an adductor canal block would significantly reduce pain scores and opioid requirements compared to a group of patients that received only an adductor canal or femoral nerve block for medial patellofemoral ligament reconstruction in pediatric patients. The primary end-point is the number of patients achieving a Patient Acceptable Symptom State (PASS) (pain score less than four) for the entire 24-hour postoperative period in patients with and without a proximal sciatic block.

Patients and Methods

This is a retrospective cohort study of 144 consecutive pediatric patients, ages 10 to 18 years, undergoing medial patellofemoral ligament reconstruction with peripheral nerve blockade for postoperative analgesia from 2016–2020 at a pediatric orthopedics children’s hospital. Patients were divided into 2 cohorts with and without a proximal sciatic nerve block: group A/F: adductor canal or femoral CPNB and group AS: adductor canal CPNB and a proximal single-injection sciatic nerve block.

Results

There was strong evidence for an increase in the number of patients who reported a pain score less than four for the entire 24-hour postoperative period in the group that received the additional proximal sciatic block. (PASS: A/F 13/62 (21%) vs AS 43/82 (52%), p<0.001) There was strong evidence for a reduction in mean and maximum pain scores and opioid requirements in the first 24-hours after surgery in the proximal sciatic group.

Conclusion

The addition of a proximal sciatic nerve block was associated with significantly reduced mean and maximum pain scores and opioid requirements after medial patellofemoral ligament reconstruction in pediatric patients and supports a randomized clinical trial to confirm these findings. Based on the results of this study we recommend the addition of a proximal sciatic nerve block, anterior or posterior, to an adductor canal block to provide improved analgesia and reduced opioid requirements in the 24-hours after MPFLR in pediatric patients.

Efficacy of dexmedetomidine as an adjunct to ropivacaine in bilateral dual-transversus abdominis plane blocks in patients with ovarian cancer who underwent cytoreductive surgery

OBJECTIVE

We sought to evaluate the postoperative control of pain and recovery in patients with ovarian cancer who underwent cytoreductive surgery by adding dexmedetomidine to ropivacaine in bilateral dual-transversus abdominis plane (Bd-TAP) blocks.

METHODS

We enrolled 90 patients with an American Society of Anesthesiologists physical status I to III undergoing open abdominal cytoreductive surgery in this study. Patients were randomized and assigned into three groups (TAP-R, TAP-DR, or CON) of 30 participants each. All of the patients received standardized general anesthesia, and postoperative Bd-TAP blocks were performed. The TAP-R, TAP-DR, and CON groups received Bd-TAP blocks with 0.3% ropivacaine, 0.3% ropivacaine and 0.5 μg/kg of dexmedetomidine, and 0.9% normal saline, respectively. All of the patients received patient-controlled analgesia (PCA) (formula, 100 μg of sufentanil and 16 mg of ondansetron diluted with normal saline to 100 mL). Flurbiprofen axetil was used as a rescue drug if the visual analog scale (VAS) score was more than four points. The first request time for PCA bolus; the VAS scores at 0, 6, 12, 24, and 48 h after operation; and the cumulative sufentanil consumption within 24 and 48 h, respectively, were compared. Pulmonary function was evaluated preoperatively and at 24 h after the operation. The use of the rescue drug was recorded. Postoperative functional recovery, including time to stand, time to walk, time to return of bowel function, time to readiness for discharge, and postoperative complications, were recorded.

RESULTS

Median values of the first request time for PCA of the TAP-R group was significantly prolonged compared to that of the CON group (median [interquartile range], 7.3 [6.5-8.0] hours vs. 3.0 [2.3-3.5] hours) (P < .001), while the TAP-DR group has the longest request time among the three groups (median [interquartile range], 13.5 [12.4-14.5] hours) (P < .001). The VAS scores at rest and upon coughing of the TAP-R group in the first 12 h were significantly lower than those of the CON group (P < 0.05), but showed no significant difference compared to those of the TAP-DR group. The VAS scores at rest and upon coughing were lower in the TAP-DR group at each time point compared to those of the CON group (P < .05). The cumulative sufentanil consumption in the TAP-DR group was significantly lower at 48 h (P = .04) after surgery than in the CON group, while there was no significant difference compared to that in the TAP-R group (P > .05). Less rescue analgesic was required by patients in the TAP-DR group than in the CON group (P < .05). Postoperative mean measured forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity values in the TAP-DR group were significantly higher than those of the CON group (P = .009), while there was no significant difference compared to those of the TAP-R group (P = .10). There was no significantly difference in postoperative functional recovery between TAP-DR and CON group (P > 0.05).

CONCLUSION

TAP blocks can provide effective pain relief up to 12 h postoperatively without a significant improvement in postoperative pulmonary function. The addition of dexmedetomidine to ropivacaine for Bd-TAP block prolonged the first bolus time of PCA when compared to that in the TAP-R group and decreased sufentanil consumption and the need of rescue analgesia relative to in the CON group at 48 h postoperative. The procedure provided better postoperative analgesia and improved postoperative pulmonary function relative to the CON group. Our results indicate that dexmedetomidine as an adjuvant of Bd-TAP can provide effective pain relief up to 48 h.

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%.

Intravenous versus perineural dexmedetomidine in prolongation of analgesia with regional anesthesia: a meta-analysis and systematic review

Background and Objective. It is unclear whether perineural administration offers advantages when compared to intravenous dexmedetomidine in local anesthesia. To compare the efficacy of perineural versus intravenous dexmedetomidine as local anesthetic adjuvant, we conducted the meta analysis and systematic review. Materials and Methods. Two researchers searched MEDLINE, OVID, PubMed, Embase, Cochrane Central, Web of Science and Wanfang data for randomized controlled trials comparing the effect of intravenous versus perineural dexmedetomidine as local anesthetic adjuvant without any language restrictions. Results. We identified 14 randomized controlled trials (801 patients). The results revealed that the duration of analgesia (SMD: -1.76, 95 % CI, [-2.7, -0.83] P = 0.000, I2 = 96 %), the duration of sensory block (SMD:- 3.99, 95 % CI, [-5.88, -2.0], P = 0.000, I2 = 97.6 %), the duration of motor block (SMD: -1.6, 95 % CI, [-2.78, -0.41] P = 0.008, I 2 = 95.5 %) were significantly longer in the perineural group, when compared to systematic dexmedetomidine. The onset time of sensory block (SMD: 1.55, 95 % CI, [0.16, 2.94] P = 0.028, I2 = 96.7 %) and the onset time of motor block (SMD: 0.84, 95 % CI, [0.17, 1.5] P = 0.013, I2 = 88.3 %) were shorter in perineural group compared to intrave nous dexmedetomidine. Meanwhile, analgesic consumption in 24 hours (SMD: 0.37, 95 % CI, [0.05, 0.69] P = 0.023, I 2 = 55.6 %) and the incidence of patients of Ramsay Sedation Scale > 3 (RR: 3.8, 95 % CI, [1.45, 9.97] P = 0.000, I 2 = 26.9 %), hypotension (RR: 1.74, 95 % CI, [1.15, 2.65] P= 0.009, I2 = 32.7 %) and bradycardia (RR: 3.71, 95 % CI, [1.27, 10.86] P = 0.017, I2 = 0 %) were lower in perineural dexmedetomidine compared to the intravenous group. Conclusions. Our meta-analysis generates the evidence that perineural dexmedetomidine is a superior adminstration for prolonging the duration of analgesia. Perineural dexmedetomidine also shows the advantages in duration of sensory block and the onset time of sensory and motor block, when compared to the intravenous administration. Simultaneously, dexmedetomidine as a local anesthetic adjuvant for perineural injection may be much safer than intravenous application because of the lower incidence of patients of Ramsay Sedation Scale > 3 and lower incidence of hypotension and bradycardia.

Ultrasound-guided genicular nerve blocks following total knee arthroplasty: a randomized, double-blind, placebo-controlled trial

INTRODUCTION

Local anesthetic blockade of the genicular nerves, known targets of radiofrequency ablative techniques for knee pain, has not previously been studied in a randomized controlled trial evaluating acute pain after knee arthroplasty. We hypothesized that genicular nerve blockade added to an existing block regimen in total knee arthroplasty would result in a reduction in 24 hours opioid consumption.

METHODS

Patients (American Society of Anesthesiologists 1-3, aged 18-85 years) undergoing primary total knee arthroplasty were randomized to receive single-injection nerve blocks of the superolateral, superomedial, and inferomedial genicular nerves with injectate (15 mL 0.25% bupivacaine and 2 mg dexamethasone or 15 mL saline placebo). All subjects received a standard oral analgesic regimen, spinal anesthetic with 12.5 mg isobaric bupivacaine, infiltration between the popliteal artery and capsule of the knee with 0.2% ropivacaine, and postoperative adductor canal perineural infusion with 0.2% ropivacaine. The primary outcome was 24 hours opioid consumption (measured in morphine milliequivalents).

RESULTS

Forty (40) subjects were enrolled. Opioid consumption at 24 hours was significantly lower in the BLOCK group compared with the SHAM group (23±20 vs 58±35, p<0.001), and this difference remained significant at 48 hours (50±40 vs 98±56, p=0.004). Pain scores were reduced in the BLOCK group at time 6 hours (2.6±1.9 vs 4.3±2.2, p=0.012), but were otherwise similar at remaining time points. Patient satisfaction at 24 hours and 20 m walk test times were similar between groups.

DISCUSSION

Genicular nerve blockade was associated with a reduction in opioid consumption at 24 hours in primary total knee arthroplasty patients.

TRIAL REGISTRATION NUMBER

NCT03706313.

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

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

The analgesic efficacy of iPACK after knee surgery: A systematic review and meta-analysis with trial sequential analysis

STUDY OBJECTIVE

The novel infiltration between the popliteal artery and the capsule of the posterior knee (iPACK) has been described to relieve posterior knee pain after knee surgery. The study objective is to determine whether iPACK provides analgesia after knee surgery when compared with a control group.

DESIGN

Systematic review, meta-analysis and trial sequential analysis.

SETTING

Operating room, postoperative recovery area and ward, up to 24 postoperative hours.

PATIENTS

Patients scheduled for knee surgery under general or spinal anaesthesia.

INTERVENTIONS

We searched five electronic databases for randomized controlled trials comparing iPACK with a control group.

MEASUREMENTS

The primary outcome was rest pain score scores on a visual analogue scale (VAS) of 0-10 at 12 h postoperatively, analysed according to the nature of surgery (total knee arthroplasty vs. anterior cruciate ligament reconstruction) and the use of multimodal analgesia. Secondary outcomes included rest and dynamic pain scores, intravenous morphine-equivalent consumption at 2 h and 24 h, and functional outcomes including ambulation distance and range of motion at discharge.

MAIN RESULTS

Six trials involving 687 patients were included, all of which received total knee arthroplasty only. When compared with a control group, iPACK significantly reduced rest pain scores at 12 h, with a mean difference (95% CI) of -1.0 (-1.5 to -0.5), I² = 93%, p = 0.0003, without subgroup differences for postoperative multimodal analgesia (p = 0.15). Secondary pain outcomes were inconsistently improved with iPACK. Functional outcomes were either similar between groups or had clinically unimportant differences. The overall quality of evidence was moderate.

CONCLUSIONS

There is moderate level evidence that iPACK might provide analgesia for posterior pain after total knee arthroplasty when compared with a control group at 12 h, but was not associated with any other meaningful benefits. Based on these results, there is currently limited evidence supporting the use of iPACK as a complement to adductor canal block for analgesia after total knee arthroplasty.

Perioperative Pain Management and Opioid Stewardship: A Practical Guide

Surgical procedures are key drivers of pain development and opioid utilization globally. Various organizations have generated guidance on postoperative pain management, enhanced recovery strategies, multimodal analgesic and anesthetic techniques, and postoperative opioid prescribing. Still, comprehensive integration of these recommendations into standard practice at the institutional level remains elusive, and persistent postoperative pain and opioid use pose significant societal burdens. The multitude of guidance publications, many different healthcare providers involved in executing them, evolution of surgical technique, and complexities of perioperative care transitions all represent challenges to process improvement. This review seeks to summarize and integrate key recommendations into a "roadmap" for institutional adoption of perioperative analgesic and opioid optimization strategies. We present a brief review of applicable statistics and definitions as impetus for prioritizing both analgesia and opioid exposure in surgical quality improvement. We then review recommended modalities at each phase of perioperative care. We showcase the value of interprofessional collaboration in implementing and sustaining perioperative performance measures related to pain management and analgesic exposure, including those from the patient perspective. Surgery centers across the globe should adopt an integrated, collaborative approach to the twin goals of optimal pain management and opioid stewardship across the care continuum.