Perineural dexamethasone reduces rebound pain after ropivacaine single injection interscalene block for arthroscopic shoulder surgery: a randomized controlled trial

Evaluation of the effect of intraoperative tropisetron on postoperative rebound pain after brachial plexus block: a randomized controlled trial

Introduction

Postoperative rebound pain after peripheral nerve block increases patient suffering and delays recovery after surgery.

Objectives

We tested whether the 5HT-3 receptor antagonist and α7nAChR agonist tropisetron could prevent postoperative rebound pain.

Methods

A total of 115 patients were randomized to receive 5-mg/5-mL tropisetron or the same volume of normal saline. Pain intensity was measured with the numerical rating scale of pain (NRS). Rebound pain was defined as a change from mild pain (NRS ≤ 3) measured in the postanesthesia care unit to severe pain (NRS ≥ 7) within 24 hours after peripheral nerve blockade. Logistic regression was used to identify relevant factors associated with postoperative rebound pain.

Results

Tropisetron did not affect the NRS score or the incidence of rebound pain after peripheral nerve block. Logistic regression revealed that preoperative pain, bone surgery, and length of incision were risk factors for postoperative rebound pain, and patient-controlled analgesia was protective against postoperative rebound pain.

Conclusion

Tropisetron does not affect the incidence of rebound pain after peripheral nerve block. Patients at high risk of postoperative rebound pain should be identified for appropriate management. Registration site: www.chictr.org.cn (ChiCTR2300069994).

Prophylactic dexamethasone for rebound pain after peripheral nerve block in adult surgical patients: systematic review, meta-analysis, and trial sequential analysis of randomised controlled trials

BACKGROUND

Rebound pain occurs after the resolution of peripheral nerve block and hampers patient recovery in the postoperative period. We sought to synthesise available data from randomised controlled trials (RCTs) evaluating the efficacy of prophylactic dexamethasone for rebound pain in adult patients undergoing surgery with a peripheral nerve block.

METHODS

In this systematic review and meta-analysis, RCTs reporting rebound pain and use of dexamethasone in the context of a peripheral nerve block were searched in various databases and updated in May 2023. The primary outcome was the incidence of rebound pain; secondary outcomes included the severity and time to onset of rebound pain, patient satisfaction with pain control, sleep disturbance because of pain, and adverse effects of dexamethasone. Subgroup analysis was conducted based on the effect of route of administration (intravenous or perineural) on the incidence of rebound pain. Trial sequential analysis was performed to rule out the possibility of a false positive result.

RESULTS

Seven RCTs comprising 574 patients were included in this review. The dexamethasone group was associated with a reduction in the incidence of rebound pain with an odds ratio of 0.16 (95% confidence interval 0.10-0.27, P=0.00, I2=0%) compared with the control group. Trial sequential analysis confirmed the adequate information size for the beneficial effect of dexamethasone. Subgroup analysis showed that both intravenous and perineural administration were associated with a significant reduction in the incidence of rebound pain.

CONCLUSIONS

Current evidence suggests that both intravenous and perineural dexamethasone reduce the incidence of rebound pain after a peripheral nerve block provided for postoperative analgesia.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42023424031.

Continuous Superior Trunk Block versus Single-Shot Superior Trunk Block with Intravenous Dexmedetomidine for Postoperative Analgesia in Arthroscopic Shoulder Surgery: A Prospective Randomized Controlled Trial

Background/Objectives: Intravenous dexmedetomidine (DEX) can increase the analgesia duration of peripheral nerve block; however, its effect in combination with superior trunk block (STB) remains unclear. We examined whether combining single-shot STB (SSTB) with intravenous DEX would provide noninferior postoperative analgesia comparable to that provided by continuous STB (CSTB). Methods: Ninety-two patients scheduled for elective arthroscopic rotator cuff repair were enrolled in this prospective randomized trial. Patients were randomly assigned to the CSTB or SSTB + DEX group. Postoperatively, each CSTB group patient received 15 mL of 0.5% ropivacaine and a continuous 0.2% ropivacaine infusion. Each SSTB group patient received a 15 mL postoperative bolus injection of 0.5% ropivacaine. DEX was administered at 2 mcg/kg for 30 min post anesthesia, then maintained at 0.5 mcg/kg/h till surgery ended. Pain scores were investigated every 12 h for 48 h post operation, with evaluation of rebound pain incidence and opioid consumption. Results: The SSTB + DEX group had significantly higher median pain scores at 12 h post operation (resting pain, 8.0 vs. 3.0; movement pain, 8.0 vs. 5.0) and a higher incidence of rebound pain (56% vs. 20%) than the CSTB group. However, no significant between-group differences were observed in pain scores postoperatively at 24, 36, or 48 h. The CSTB group required less opioids and fewer rescue analgesics within 12-24 h post operation than the SSTB + DEX group. Conclusions: Compared with CSTB, SSTB + DEX required additional adjuvant or multimodal analgesics to reduce the risk and intensity of postoperative rebound pain in patients who underwent arthroscopic rotator cuff repair.

Efficacy of Intravenous Administration of Esketamine in Preventing and Treating Rebound Pain After Thoracic Paravertebral Nerve Block: A Prospective Randomized, Double-Blind, Placebo-Controlled Trial

Purpose

Investigating the efficacy of intraoperative fractionated intravenous esketamine in the prevention of rebound pain after cessation of thoracic paravertebral nerve blockade.

Methods

One hundred and twenty patients who underwent elective thoracoscopic lobectomy were selected for the study and were randomly divided into two groups, the esketamine group was given 0.5 mg/kg and 0.3 mg/kg of esketamine at the induction of anaesthesia and 30 minutes before the end of the operation, respectively, and the control group was given an equal amount of saline. The incidence of rebound pain (RP) 7 days after surgery and postoperative recovery were compared between the two groups.

Results

The NRS pain scores at 24 and 48 hours postoperatively in the esketamine group were significantly lower than those in the control group (P < 0.05). The incidence of postoperative rebound pain was significantly lower in the esketamine group than in the control group (P < 0.05). The consumption of sufentanil was less in the esketamine group in the postoperative 48 hours (P < 0.05). Postoperative recovery was compared between the two groups and the difference was not statistically significant.

Conclusion

Intravenous esketamine reduces postoperative pain scores, decreases the incidence of rebound pain after cessation of thoracic paravertebral block, and reduces opioid consumption.

The effects of dexamethasone added to ilioinguinal/iliohypogastric nerve (IIN/IHN) block on rebound pain in inguinal hernia surgery: a randomized controlled trial

PURPOSE

The purpose of the present study was to evaluate the effects of IV dexamethasone added to one single injection Ilioinguinal/Iliohypogastric Nerve (IIN/IHN) block on tramadol consumption and Modified Rebound Pain Score (MRPS) in the first postoperative 24 h in inguinal hernia surgery.

METHODS

Five mg IV dexamethasone as an analgesic adjunct in the multimodal analgesia was administered to the patients who were scheduled for Inguinal Hernia Surgery and randomized to Group Dex and normal saline was administered to the patients who were randomized to the Control Group in addition to IIN/IHN Block. Postoperative tramadol consumption, Modified Rebound Pain Score (MRPS), the incidence of Rebound Pain, Rebound Pain time, postoperative 48-h opioid consumption, Numerical Rating Scale (NRS) scores, Quality of Recovery Score (QoR-15), Sleep Quality, and adverse events were evaluated in the patients.

RESULTS

The mean scores of MRPS were lower in Group Dex than in the Control Group, both at rest (p = 0.001) and with motion (p = 0.001). Tramadol consumption in the first postoperative 24 h was 45.17 ± 49.59 mg in Group Dex and 95 ± 59.23 mg in the Control Group. The difference between the groups was statistically significant (p < 0.001).

CONCLUSIONS

In conclusion, adding IV dexamethasone as a part of multimodal analgesia to IIN/IHN block for inguinal hernia surgery resulted in lower MRPS and lower postoperative opioid (tramadol) consumption. For this reason, IV dexamethasone can be added to the IIN/IHN block after inguinal hernia surgery to reduce the incidence of rebound pain, rebound pain scores, and NRS scores for pain, decrease postoperative opioid consumption, and improve the quality of recovery.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: Ref; NCT05172908, Date: December 29, 2021.

Does intravenous patient-controlled analgesia or continuous block prevent rebound pain following infraclavicular brachial plexus block after distal radius fracture fixation? A prospective randomized controlled trial

BACKGROUND

The purpose of this study was to investigate the role of opioid-based intravenous patient-controlled analgesia (IV PCA) or continuous brachial plexus block (BPB) in controlling rebound pain after distal radius fracture (DRF) fixation under BPB as well as total opioid consumption.

METHODS

A total of 66 patients undergoing surgical treatment for a displaced DRF with volar plate fixation were randomized to receive a single infraclavicular BPB (BPB only group) (n = 22), a single infraclavicular BPB with IV PCA (IV PCA group) (n = 22), or a single infraclavicular BPB with continuous infraclavicular BPB (continuous block group) (n = 22). The visual analog scale (VAS) for pain and the amount of pain medication were recorded at 4, 6, 9, 12, 24, and 48 h and two weeks postoperatively.

RESULTS

At postoperative 9 h, the pain VAS score was significantly higher in the BPB only group (median: 2; Q1, Q3 [1, 3]) than in the IV PCA (0 [0, 1.8], P = 0.006) and continuous block groups (0 [0, 0.5], P = 0.009). At postoperative 12 h, the pain VAS score was significantly higher in the BPB only group (3 [3, 4]) than in the continuous block group (0.5 [0, 3], P = 0.004). The total opioid equivalent consumption (OEC) was significantly higher in the IV PCA group (350.3 [282.1, 461.3]) than in the BPB only group (37.5 [22.5, 75], P < 0.001) and continuous block group (30 [15, 75], P < 0.001); however, OEC was not significantly different between the BPB only group and the continuous block group (P = 0.595).

CONCLUSIONS

Although continuous infraclavicular BPB did not reduce total opioid consumption compared to BPB only, this method is effective for controlling rebound pain at postoperative 9 and 12 h following DRF fixation under BPB.

Rebound pain and postoperative pain profile following brachial plexus block compared to general anaesthesia-An observational study

BACKGROUND

Regional anaesthesia has the benefit of reducing the need for systemic analgesia and therefore, potentially reducing undesired side effects. With the end of the sensory nerve block however, many patients report severe pain that requires therapy with opioids and often compromise the initial opioid sparing effect. This study aimed to characterise the postoperative pain profile and the phenomenon of rebound pain after axillary brachial plexus anaesthesia (RA) compared to general anaesthesia (GA).

DESIGN

Single-centre observational, stratified cohort study.

SETTING

The study was conducted at University Hospital Marburg from May 2020 until September 2022.

PARTICIPANTS

One hundred thirty-two patients receiving elective hand and forearm surgery were enrolled in this study.

INTERVENTIONS

Group RA received ultrasound-guided brachial plexus anaesthesia via the axillary approach with 30 mL of prilocaine 1% and 10 mL ropivacaine 0.2%. Group GA received balanced or total intravenous general anaesthesia.

MAIN OUTCOME MEASURES

Primary endpoint were integrated pain scores (IPS) within 24 h postoperatively. Secondary endpoints were pain scores (NRS 0-10), morphine equivalents, patient satisfaction, quality of recovery and opioid-related side effects.

RESULTS

One hundred thirty-two patients were analysed of which 66 patients received brachial plexus block and 66 patients received general anaesthesia. Following RA significantly lower IPS were seen directly after surgery (p < .001) and during the post-anaesthesia care unit interval (p < .001) but equalised after 3 h at the ward. No overshoot in pain scores or increased opioid consumption could be detected. Patient satisfaction and postoperative recovery were comparable between both groups.

CONCLUSION

The IPS and NRS was initially lower in the RA group, increased with fading of the block until equal to the GA group and equal thereafter. Although various definitions of rebound pain were met during this phase, the opioid sparing effect of regional anaesthesia was not counteracted by it. The incidence of episodes with uncontrolled, severe pain did not differ between groups. We found no clinical implications of rebound pain in this setting, since the RA group did not show higher pain scores than the GA group at any time point.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS00021764).

Rebound pain after interscalene brachial plexus block for shoulder surgery: a randomized clinical trial of the effect of different multimodal analgesia regimens

BACKGROUND

Rebound pain is characterized by sudden, significant acute postoperative pain occurring after the resolution of inter-scalene block (ISB); it affects the quality of recovery postoperatively. Dexamethasone increases ISB resolution time and decreases opioid consumption and the incidence of rebound pain.

OBJECTIVE

Evaluate whether multimodal analgesia including intravenous dexamethasone administration with preoperative ISB reduces the incidence of rebound pain.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Tertiary university hospital.

SAMPLE SIZE

60 patients.

PATIENTS AND METHODS

Patients who underwent shoulder surgery under general anesthesia were assigned randomly to two different multimodal analgesia protocols. Thirty patients received 5 mg IV dexamethasone with non-steroid, paracetamol, and ISB with 15 mL 0.5% bupivacaine, while the control patients received the same regimen and ISB with 15 mL 0.5% bupivacaine without dexamethasone. Postoperative opioids were given to any patient on demand.

MAIN OUTCOMES MEASURES

Effect of IV dexamethasone on pain score and incidence of rebound pain after ISB resolution and postoperative opioid consumption at 0-48 hours, numerical pain rating scale (NPRS) scores, sleep scale scores, and quality of recovery-15 scores (QoR-15).

RESULTS

The incidence of rebound pain was lower in the dexamethasone group than in the control group (73.3% and 30%, respectively, P=.001). NPRS scores after ISB resolution were lower in the dexamethasone group (5 ([4-7]), 8 ([5.75-8]), P<.001, respectively). Those who received IV dexamethasone had less sleep disturbances (P<.001) and higher QoR-15 on day 1 (P<.001) and day 7 (P=.020) postoperatively.

CONCLUSIONS

IV dexamethasone added to the ISB block resulted in a lower incidence of rebound pain. In addition, better results were obtained in postoperative sleep quality and QoR-15.

LIMITATIONS

Single-center study.

Reducing rebound pain severity after arthroscopic shoulder surgery under general anesthesia and interscalene block: a two-centre randomized controlled trial of pre-emptive opioid treatment compared with placebo

PURPOSE

Although a single-injection interscalene block provides effective early postoperative analgesia following shoulder surgery, patients may experience "rebound pain" when the block resolves. Our objective was to determine if oral hydromorphone (2 mg) given six hours after a single-injection interscalene block for arthroscopic shoulder surgery leads to a clinically significant reduction in the severity of rebound pain.

METHODS

After approval from research ethics boards, we conducted a two-centre, parallel-group, double-blind, randomized, placebo-controlled superiority trial. Patients received preoperative interscalene block, general anesthesia, and either hydromorphone or placebo six hours after the block. The primary outcome was the worst pain score in the first 24 hr postoperatively, measured on an 11-point (0-10) numerical rating scale.

RESULTS

A total of 73 participants were randomly assigned to either the hydromorphone or placebo group. There was no statistically significant difference in the mean (standard deviation) worst pain score within 24 hr between the hydromorphone and placebo groups (6.5 [2.4] vs 5.9 [2.3]; mean difference, 0.6; 95% confidence interval, -0.5 to 1.8). Similarly, we did not find any significant difference in the pain trajectory, opioid use, or incidence of nausea and vomiting between the groups. The mean time to worst pain was 14.6 hr, and the mean time to first rescue analgesia was 11.3 hr after interscalene block.

CONCLUSION

Hydromorphone 2 mg given six hours after interscalene block did not reduce the severity of rebound pain postoperatively compared with placebo in patients undergoing arthroscopic shoulder surgery.

STUDY REGISTRATION

ClinicalTrials.gov (NCT02939209); registered 19 October 2016.

Postoperative Rebound Pain: Our Current Understanding About the Role of Regional Anesthesia and Multimodal Approaches in Prevention and Treatment

PURPOSE OF REVIEW

Rebound pain (RP) is a common occurrence after peripheral nerve block placement, especially when blocks are used for orthopedic surgery. This literature review focuses on the incidence and risk factors for RP as well as preventative and treatment strategies.

RECENT FINDINGS

The addition of adjuvants to a block, when appropriate, and starting patients on oral analgesics prior to sensory resolution are reasonable approaches. Using continuous nerve block techniques can provide extended analgesia through the immediate postoperative phase when pain is the most intense. Peripheral nerve blocks (PNBs) are associated with RP, a frequent phenomenon that must be recognized and addressed to prevent short-term pain and patient dissatisfaction, as well as long-term complications and avoidable hospital resource utilization. Knowledge about the advantages and limitations of PNBs allows the anesthesiologists to anticipate, intervene, and hopefully mitigate or avoid the phenomenon of RP.

Effect of Intravenous Dexamethasone Dose on the Occurrence of Rebound Pain after Axillary Plexus Block in Ambulatory Surgery

Rebound pain (RP) remains a challenge in ambulatory surgery, characterized by severe pain upon resolution of a peripheral nerve block (PNB). Intravenous (IV) administration of Dexamethasone (DEXA) potentiates PNB analgesic effect and reduces RP incidence although preventive effective dose remains undetermined. This retrospective analysis evaluates the preventive effect of IV DEXA on RP in outpatients undergoing upper limb surgery under axillary block. DEXA was divided into high (HD > 0.1 mg/kg) or low (LD < 0.1 mg/kg) doses. RP was defined as severe pain (NRS ≥ 7/10) within 24 h of PNB resolution. DEXA HD and LD patients were matched with control patients without DEXA (n = 55) from a previous randomized controlled study. Records of 118 DEXA patients were analyzed (DEXA dose ranged from 0.05 to 0.12 mg/kg). Intraoperative IV DEXA was associated with a significant reduction of the pain felt when PNB wore off as well as to a significant reduction of RP incidence (n = 27/118, 23% vs. 47% in controls, p = 0.002) with no effect related to the dose administered (p = 0.053). Our results support the administration of intraoperative DEXA as a preventive measure to reduce the occurrence of RP.

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.

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

Introduction

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

Methods

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

Results

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

Discussion

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

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.

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.

Recent updates on interscalene brachial plexus block for shoulder surgery

Interscalene brachial plexus block (ISBPB) provides optimal analgesia for shoulder surgery. However, several limitations still exist, including the short duration of analgesia, rebound pain, a high incidence of unilateral diaphragmatic paresis, and potential risk of nerve damage, prompting the search for alternative techniques. Many alternatives to ISBPB have been studied to alleviate these concerns, and clinicians should choose an appropriate option based on the patient's condition. In this mini-review, we aimed to present recent updates on ISBPB while discussing our clinical experiences in shoulder surgery.

Effects of esketamine on postoperative rebound pain in patients undergoing unilateral total knee arthroplasty: a single-center, randomized, double-blind, placebo-controlled trial protocol

Introduction

Rebound pain, transient and acute postoperative pain after the disappearance of regional block anesthesia, has been a concern in recent years. Insufficient preemptive analgesia and hyperalgesia induced by regional block are the main mechanisms. At present, the evidence for the treatment of rebound pain is limited. The esketamine, as an antagonist of the N-methyl-D-aspartate receptor, has been proven to prevent hyperalgesia. Therefore, this trial aims to evaluate the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty.

Methods/design

This study is a single-center, prospective, double-blind, randomized, placebo-controlled trial. Participants who plan to undergo total knee arthroplasty will be randomly assigned to the esketamine group (N = 178) and placebo group (N = 178) in a ratio of 1:1. This trial aims to evaluate the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty. The primary outcome of this trial is the incidence of rebound pain within 12 h after the operation in the esketamine group and the placebo group. The secondary outcome will be to compare (1) the incidence of rebound pain 24 h after the operation; (2) the time to enter the pain cycle for the first time within 24 h after the procedure; (3) the first time of rebound pain occurred within 24 h after surgery; (4) the modified rebound pain score; (5) NRS score under rest and exercise at different time points; (6) the cumulative opioid consumption at different time points; (7) patient's prognosis and knee joint function evaluation; (8) blood glucose and cortisol concentration; (9) patient's satisfaction score; (10) adverse reactions and adverse events.

Discussion

The effect of ketamine on preventing postoperative rebound pain is contradictory and uncertain. The affinity of esketamine to the N-methyl-D-aspartate receptor is about four times higher than levo-ketamine, the analgesic effect is 3 times higher than levo-ketamine, and there are fewer adverse mental reactions. To our knowledge, there is no randomized controlled trial to verify the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty. Therefore, this trial is expected to fill an important gap in relevant fields and provide novel evidence for individualized pain management.

Clinical Trial Registration

http://www.chictr.org.cn, identifier ChiCTR2300069044.

Clinical care pathways for ambulatory total shoulder arthroplasty

PURPOSE OF REVIEW

Total shoulder arthroplasty (TSA) is growing in popularity and is increasingly done on an ambulatory basis. This review examines recent developments in anesthesia and analgesia for ambulatory shoulder surgery. Pathway components are discussed and a sample pathway is described.

RECENT FINDINGS

Adoption of pathways for shoulder surgery improves patient experience by reducing pain, opioid use, and side effects while improving patient satisfaction. Long-acting nerve blockade using adjuvants like dexamethasone provide long-lasting analgesia without rebound pain. Peripheral nerve blockade provides better analgesia than peri-articular injection of local anesthetic. There are multiple approaches to nerve blockade for shoulder surgery to consider, including interscalene, superior trunk, supraclavicular, and anterior suprascapular nerve blocks. Multimodal analgesia should include acetaminophen and nonsteroidal anti-inflammatory drugs, but routine gabapentinoids should not be used.

SUMMARY

Anesthesiologists should lead the way to create and implement pathways for ambulatory total shoulder arthroplasty, incorporating appropriate patient selection, patient education, long-lasting nerve blockade, and multimodal analgesia.

Rebound Pain After Peripheral Nerve Blockade-Bad Timing or Rude Awakening?

Patients who have perioperatively benefited from regional anesthesia frequently report moderate to severe pain when the nerve block effects fade away. Over the past years, the term "rebound pain" has been introduced, suggesting a specific pathologic process. It is debated whether significant pain on block resolution reflects a separate and distinct pathologic mechanism potentially involving proinflammatory and neurotoxic effects of local anesthetics, or is simply caused by the recovery of sensory function at a timepoint when nociceptive stimuli are still intense, and moderate to severe pain should be anticipated. In that latter case, the phenomenon referred to as rebound pain could be considered a failure of pain management providers to devise an adequate analgesia plan. Whatever the ultimate designation, management of rebound pain should be proactive, by implementing multimodal analgesia, or tailoring the blockade to the expected trajectory of postoperative pain and managing patient expectations accordingly. Until we know more about the etiology and impact of this phenomenon, the authors suggest a more neutral designation such as "pain on block resolution."

Effect of Transauricular Vagus Nerve Stimulation on Rebound Pain After Ropivacaine Single Injection Femoral Nerve Block for Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

Purpose

The aim of this study was to investigate whether transauricular vagus nerve stimulation (taVNS) could reduce the incidence of rebound pain in patients undergoing anterior cruciate ligament reconstruction (ACLR) under general anesthesia combined with preoperative femoral nerve block.

Methods

In total, 78 patients were enrolled in this prospective, randomized, double-blind, and sham-controlled study. Patients were randomly assigned to 2 groups (n=39): Group taVNS received taVNS (1h /1time, 6times) within the first 12 h after surgery; Group SS received sham stimulation (SS) in the same manner. Pain scores at 0, 4, 8, 12, 24, 48 h after surgery were assessed with Numeric Pain Rating Scale (NRS). The incidence, duration and onset of rebound pain were recorded. In addition, additional analgesic requirements and side effects in the first 48 h postoperatively, as well as sleep disturbance on the night of surgery, were examined.

Results

The incidence and duration of rebound pain were lower in the taVNS group than in the SS group (P=0.025 and P=0.015, respectively). Pain scores at 8 h and 12 h postoperatively were significantly lower in the taVNS group compared with the SS group (P<0.05). The number of times to press the patient-controlled analgesia (PCA) pump and the number of patients requiring additional analgesic were significantly lower in the taVNS group than in the SS group until 12 h after surgery (P=0.021 and P=0.004, respectively). The number of patients with sleep disturbance in the taVNS group was lower than that in the SS group (P=0.030).

Conclusion

The taVNS exerts beneficial effect on rebound pain after femoral nerve block in patients undergoing ACLR, which reduces the incidence and duration of rebound pain, the need for postoperative additional analgesic, and the number of complications.

Is There a Difference between Perineural Dexamethasone with Single-Shot Interscalene Block (SSIB) and Interscalene Indwelling Catheter Analgesia (IICA) for Early Pain after Arthroscopic Rotator Cuff Repair? A Pilot Study

Interscalene block is applied to control acute postoperative pain after arthroscopic rotator cuff repair (ARCR), typically with single-shot interscalene block (SSIB) or continuous interscalene indwelling catheter analgesia (IICA), and dexamethasone (Dex) for extending the analgesic effect. This study investigated whether perineural Dex can extend the postoperative analgesic effect of SSIB to match that of IICA. A total of 130 patients were recruited and divided into two groups (Group D, SSIB with perineural Dex, n = 94; Group C, IICA, n = 36). The surgical and anesthetic processes were identical except for the method of nerve block. Pain was measured by a visual analog scale (VAS) at 6, 12, 24, and 48 h after ARCR. The number of each and the total analgesics used and adverse effects were compared. The duration of ARCR was longer in group D. The VAS score was higher in group C 6 h after ARCR, but there was no difference at other time points. More postoperative analgesics were administered to group C, and there was no difference in the number of adverse effects. In conclusion, combining perineural Dex with SSIB can reduce rebound hyperalgesia after 6 h and extend the duration of the analgesic effect to that of IICA. Therefore, IICA could be substituted with SSIB and Dex between at 6 and 48 h after ARCR.

Comparison of iPACK and periarticular block with adductor block alone after total knee arthroplasty: a randomized clinical trial

PURPOSE

The infiltration between the popliteal artery and the capsule of the posterior knee (iPACK) has been described to provide analgesia without loss of muscle strength and is effective in functional recovery. This study compared iPACK + ACB (adductor canal block) with PAI (periarticular infiltration) + ACB and ACB alone in terms of postoperative analgesia and functional improvement.

METHODS

This double-blinded randomized controlled trial included 105 patients undergoing unilateral total knee arthroplasty. Patients received ACB, iPACK + ACB, and PAI + ACB along with spinal anesthesia. The primary outcome was the area under the curve (AUC) numeric rating scale (NRS) at 48 h. Secondary outcomes were cumulative postoperative analgesic consumption within 48 h, timed up-and-go test, range of motion, length of hospital stay, patient satisfaction, and adverse events.

RESULTS

The 48-h AUC movement NRS score in the iPACK + ACB group was significantly lower than in the PAI + ACB and ACB groups (p < 0.05). At the postoperative 48th h, the opioid consumption of the iPACK + ACB group was lower than those of the ACB and PAI + ACB groups (p < 0.001). The patients in the iPACK + ACB group had significantly shorter discharge and mobilization days than the ACB and PAI + ACB groups (p < 0.001).

CONCLUSIONS

The adding of an iPACK block to the ACB improves postoperative analgesia and reduces opioid consumption. In addition, this approach improves functional performance and reduces hospital stay.