Current Status and Global Trend of Rebound Pain After Regional Anesthesia: A Bibliometric Analysis

Purpose

Rebound pain after regional anesthesia, a common phenomenon when the analgesic effect wears off, has been recognized in the last a few years. The aim of this study is to analyze the status and tendency of this area in a macroscopic perspective.

Methods

Bibliometric analysis is the primary methodology of this study. Literature retrieval was conducted in Web of Science (WoS) Core Collection. WoS, Excel, VOSviewer and CiteSpace were employed to do the analyses and visualization. Parameters were analyzed, such as publications, citations, journals, and keywords, etc.

Results

In total, 70 articles in the past 10 years were identified eligible. Most articles (14 pieces) were published in 2021, followed by 2022 and 2023 with 13 articles. Researchers come from 134 institutions and 20 countries. Huang Jung-Taek, Hallym College, and USA are the most productive author, institution and country, respectively. The articles were mainly published on the top journals of anesthesiology, orthopedics and surgery. The topic of these articles is primarily about the clinical issues of rebound pain. Peripheral nerve block, brachial plexus block and femoral nerve block are the activist keywords in the area, while perioperative management, fracture surgery and outcome may become hotpots in the next years.

Conclusion

Our results show that the study of rebound pain after regional anesthesia starts relatively late and is in upward tendency, future studies can focus on the perioperative management and outcomes of fracture patients, and the definition and mechanism of rebound pain after regional anesthesia.

Research priorities in regional anaesthesia: where should we focus?

Using a modified Delphi technique, an international group of regional anaesthetists generated a list of top research priorities in regional anaesthesia. The list of unanswered research questions was created from a questionnaire completed by >500 anaesthetists and distilled into 11 priorities grouped into four themes: clinical practice and efficacy, pain management, technology and equipment, and training and assessment.

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.

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.

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).

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.

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.

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.

Postoperative Pain Management after Full Endoscopic Lumbar Discectomy: An Observational Study

Background: Surgical incision pain, rebound pain, and recurrence can manifest themselves in different forms of postoperative pain after full endoscopic lumbar discectomy (FELD). This study aims to evaluate various postoperative pains after FELD and summarize their characteristics. Methods: Data about the demographic characteristics of patients, pain intensity, and functional assessment results were collected from January 2016 to September 2019. Clinical outcomes including Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, were obtained. Results: A total of 206 patients were enrolled. ODI and VAS of the patients significantly decreased after FELD at 12-month follow-up. A total of 193 (93.7%) patients had mild surgical incision pain after FELD and generally a VAS < 4, and it mostly resolved on its own within 3 days. A total of 12 (5.8%) patients experienced rebound pain, which was typically characterized by pain (mainly leg pain with or without back pain), generally occurring within 2 weeks after FELD and lasting < 3 weeks. The pain levels of rebound pain were equal to or less than those of preoperative pain, and generally scored a VAS of < 6. The recurrence rate was 4.4%. Recurrence often occurs within three months after surgery, with the pain level of the recurrence being greater than or equal to the preoperative pain. Conclusions: Different types of postoperative pain have their own unique characteristics and durations, and treatment options are also distinct. Conservative treatment and analgesia may be indicated for rebound pain and surgical incision pain, but recurrence usually requires surgical treatment.

Peripheral Nerve Blocks Associated With Shorter Length of Stay Without Increasing Readmission Rate for Ankle Open Reduction Internal Fixation in the Outpatient Setting: A Propensity-Matched Analysis

Peripheral nerve blocks (PNB) have become an important modality for pain management in ankle fracture surgery. Previous studies have reported their efficacy, but concerns with rebound pain and readmissions have been cited as possible deterrents. The purpose of this study was to evaluate the effects of PNB on hospital length of stay (LOS), narcotic intake, visual analog scale (VAS) for pain, and associated complications in patients undergoing outpatient ankle open reduction internal fixation (ORIF). Adult patients undergoing ankle ORIF were matched 2:1 (no block:block) using propensity-score matching. Preoperative patient characteristics and postoperative outcomes were compared between cohorts. VAS and total narcotic intake were evaluated for each of the first 3 postoperative 8-hour shifts. Narcotic medication was converted to morphine milligram equivalents (MME). Thirty-two patients who received PNB were matched to 64 patients who did not. The PNB group had lower VAS and MME during each of the 8-hour shifts after surgery: 0 to 8 hours (VAS 1.8 vs 6.3; MME 10.6 vs 77.9; p < .001), 8 to 16 hours (VAS 1.2 vs 5.9; MME 9.2 vs 28.2; p < .001), 16 to 24 hours (VAS 3.7 vs 6.2; MME 13.2 vs 24.2; p = .006 and 0.019). PNB had a shorter LOS (average 16.7 hours vs 26.8 hours; p < .001). There were no differences in rates of ED presentations after discharge, hospital readmissions, or complications between cohorts. Peripheral nerve blocks after ankle ORIF are associated with shorter hospital LOS, lower VAS, and reduced narcotic intake without increasing rates of ED visits, hospital readmissions, or complications.

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.

Development and internal validation of a multivariable risk prediction model for severe rebound pain after foot and ankle surgery involving single-shot popliteal sciatic nerve block

BACKGROUND

Rebound pain occurs after up to 50% of ambulatory surgeries involving regional anaesthesia. To assist with risk stratification, we developed a model to predict severe rebound pain after foot and ankle surgery involving single-shot popliteal sciatic nerve block.

METHODS

After ethics approval, we performed a single-centre retrospective cohort study. Patients undergoing lower limb surgery with popliteal sciatic nerve block from January 2016 to November 2019 were included. Exclusion criteria were uncontrolled pain in the PACU, use of a perineural catheter, or loss to follow-up. We developed and internally validated a multivariable logistic regression model for severe rebound pain, defined as transition from well-controlled pain in the PACU (numerical rating scale [NRS] 3 or less) to severe pain (NRS ≥7) within 48 h. A priori predictors were age, sex, surgery type, planned admission, local anaesthetic type, dexamethasone use, and intraoperative anaesthesia type. Model performance was evaluated using area under the receiver operating characteristic curve (AUROC), Nagelkerke's R², scaled Brier score, and calibration slope.

RESULTS

The cohort included 1365 patients (mean [standard deviation] age: 50 [16] yr). The primary outcome was abstracted in 1311 (96%) patients, with severe rebound pain in 652 (50%). Internal validation revealed poor model performance, with AUROC 0.632 (95% confidence interval [CI]: 0.602-0.661; bootstrap optimisation 0.021), Nagelkerke's R² 0.063, and scaled Brier score 0.047. Calibration slope was 0.832 (95% CI: 0.623-1.041).

CONCLUSIONS

We show that a multivariable risk prediction model developed using routinely collected clinical data had poor predictive performance for severe rebound pain after foot and ankle surgery. Prospective studies involving other patient-related predictors are needed.

CLINICAL TRIAL REGISTRATION

NCT05018104.

Evaluation of intraoperative ketamine on the prevention of severe rebound pain upon cessation of peripheral nerve block: a prospective randomised, double-blind, placebo-controlled study

BACKGROUND

Pain after resolution of peripheral nerve block, known as 'rebound pain' (RP), is a major problem in outpatient surgery. The primary objective was to evaluate the benefit of intraoperative ketamine at an anti-hyperalgesic dose on the incidence of rebound pain after upper limb surgery under axillary plexus block in ambulatory patients. The secondary objective was to better understand the rebound pain phenomenon (individual risk factors).

METHODS

In this prospective, double-blind study, patients were randomised to receive either a single dose of i.v. ketamine (0.3 mg kg^-1) or a placebo. Preoperative mechanical temporal summation and central sensitization inventory were applied to question underlying central sensitisation. Pain catastrophising and Douleur Neuropathique 4 questionnaires were used. Rebound pain was defined as pain intensity score >7 (numeric rating scale, 0-10) after block resolution. Postoperative pain was recorded at Days 1, 4, and 30 after discharge.

RESULTS

A total of 109 subjects completed the study, and 40.4% presented with rebound pain. Ketamine administration did not reduce rebound pain incidence or intensity. Temporal summation and central sensitisation inventory scores did not differ between subjects with and without rebound pain. The predictive risk factors were bone surgery (odds ratio [OR]=5.2; confidence interval [CI], 1.9-14.6), severe preoperative pain (OR=4.2; CI, 1.5-11.7), and high pain catastrophising (OR=4.8; CI, 1.0-22.3). At Day 30, the average daily pain was higher in the rebound pain group involving neuropathic characteristics.

CONCLUSION

Ketamine at an anti-hyperalgesic dose showed no benefit on rebound pain development. Although central sensitisation might not be involved, preoperative pain intensity, and catastrophising stand as risk factors. Because rebound pain remains frequent despite adequate procedure-specific postoperative analgesia, future studies should focus on patient-specific pain management.

Factors associated with low levels of patient satisfaction following peripheral nerve block

Peripheral nerve blocks can provide surgical anaesthesia as well as excellent postoperative analgesia. When questioned postoperatively, however, some patients report low levels of satisfaction with their nerve block experience. At our hospital, patients undergoing regional anaesthesia have their patient characteristics, block characteristics and postoperative feedback routinely recorded in a block registry. We analysed data from 979 consecutive patients undergoing peripheral nerve block for orthopaedic surgery to identify factors associated with low levels of patient satisfaction. The primary outcome was patient satisfaction with their peripheral nerve block (scale 1-5: 4-5 is 'satisfied', 1-3 is 'not satisfied'). Eighty-nine percent (871/979) of patients reported being 'satisfied' with their block. Factors negatively associated with patient satisfaction were rebound pain (adjusted odds ratio (aOR) 0.19, 95% confidence interval (CI) 0.04 to 0.85 for moderate rebound pain; aOR 0.11, 95% CI 0.03 to 0.48 for severe rebound pain), discomfort during the block (aOR 0.37, 95% CI 0.16 to 0.82 for moderate discomfort; aOR 0.19, 95% CI 0.05 to 0.76 for severe discomfort) and pain in the post-anaesthesia care unit (aOR 0.30, 95% CI 0.17 to 0.55 for pain ≥8/10). Only 24% (26/108) of patients who reported being 'not satisfied' stated that they would be unwilling to undergo a hypothetical future nerve block. Rebound pain of at least moderate intensity, procedural discomfort of at least moderate intensity and severe pain in the post-anaesthesia care unit are all negatively associated with patient satisfaction. Of these factors, rebound pain occurs most frequently, being present in 52% (403/777) of our respondents.

Peripheral nerve block anaesthesia and postoperative pain in acute ankle fracture surgery: the AnAnkle randomised trial

BACKGROUND

Peripheral nerve blocks (PNBs) are increasingly popular in acute ankle fracture surgery but rebound pain may outweigh the benefits. The AnAnkle Trial was designed to assess the postoperative pain profile of PNB anaesthesia compared with spinal anaesthesia (SA).

METHODS

The AnAnkle Trial was a randomised, two-centre, blinded outcome analysis trial. Eligible adults booked for primary ankle fracture surgery were randomised to PNB or SA. The PNBs were ultrasound-guided popliteal sciatic and saphenous blocks with ropivacaine and SAs were with hyperbaric bupivacaine. Postoperatively, all subjects received paracetamol, ibuprofen, and patient-controlled i.v. morphine for pain. The primary endpoint was 27 h Pain Intensity and Opioid Consumption (PIOC) score. Secondary endpoints included longitudinal pain scores and morphine consumption separately, and questionnaires on quality of recovery.

RESULTS

This study enrolled 150 subjects, and the PNB success rate was >94%. PIOC was lower with PNB anaesthesia (median, -26.5% vs +54.3%; P<0.001) and the probability of a better PIOC score with PNB than with SA was 74.8% (95% confidence interval, 67.0-82.6). Pain scores and morphine consumption analysed separately also yielded a clear benefit with PNB, despite substantial rebound pain when PNBs subsided. Quality of recovery scores were similar between groups, but 99% having PNB vs 90% having SA would choose the same anaesthesia form again (P=0.03).

CONCLUSIONS

PNB anaesthesia was efficient and provided a superior postoperative pain profile compared with SA for acute ankle fracture surgery, despite potentially intense rebound pain after PNB.

CLINICAL TRIAL REGISTRATION

Clinicaltrialsregister.eu, EudraCT number: 2015-001108-76.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Dexamethasone added to levobupivacaine prolongs the duration of interscalene brachial plexus block and decreases rebound pain after arthroscopic rotator cuff repair

BACKGROUND

It has been reported that the addition of dexamethasone to interscalene brachial plexus block (ISBPB) prolongs the duration of the block effect. However, there have been no studies focusing on the effects of dexamethasone on rebound pain after the block effect has worn off. The aim of this study was to investigate the effect on postoperative pain when dexamethasone was added to ISBPB for arthroscopic rotator cuff repair (ARCR).

METHODS

In this multicenter, single-blinded, and randomized controlled study, 54 patients (33 males, 21 females) who received ARCR were randomly assigned to group L (ISBPB with 20 cc of 0.25% levobupivacaine; 21 patients) or group LD (ISBPB with 20 cc of 0.25% levobupivacaine + 3.3 mg dexamethasone; 33 patients). The primary outcome was the visual analog scale (VAS) for pain after the block effect had worn off. Secondary outcomes were the duration of analgesia, the time to the first request for additional analgesic, the number of additional doses of analgesic, and complications.

RESULTS

The VAS scores on postoperative days 0 and 1 were significantly lower in group LD than group L (P = .005, .035). This indicated that the rebound pain was relieved in group LD. After postoperative day 1, there was no significant difference in VAS score (P = .43 and .19 for days 2 and 3, respectively). The duration of analgesia was significantly longer in group LD than group L (P < .001). The time to the first request for additional analgesic was significantly longer in group LD than group L (P < .001). The number of additional doses of analgesic was significantly lower in group LD (P < .001).

CONCLUSION

In ARCR, the addition of dexamethasone to levobupivacaine not only prolongs the duration of ISBPB but also relieves rebound pain after the block effect wears off.

Does Rebound Pain after Peripheral Nerve Block for Orthopedic Surgery Impact Postoperative Analgesia and Opioid Consumption? A Narrative Review

Regional anesthesia has been considered a great tool for maximizing post-operative pain control while minimizing opioid consumption. Post-operative rebound pain, characterized by hyperalgesia after the peripheral nerve block, can however diminish or negate the overall benefit of this modality due to a counter-productive increase in opioid consumption once the block wears off. We reviewed published literature describing pathophysiology and occurrence of rebound pain after peripheral nerve blocks in patients undergoing orthopedic procedures. A search of relevant keywords was performed using PubMed, EMBASE, and Web of Science. Twenty-eight articles (n = 28) were included in our review. Perioperative considerations for peripheral nerve blocks and other alternatives used for postoperative pain management in patients undergoing orthopedic surgeries were discussed. Multimodal strategies including preemptive analgesia before the block wears off, intra-articular or intravenous anti-inflammatory medications, and use of adjuvants in nerve block solutions may reduce the burden of rebound pain. Additionally, patient education regarding the possibility of rebound pain is paramount to ensure appropriate use of prescribed pre-emptive analgesics and establish appropriate expectations of minimized opioid requirements. Understanding the impact of rebound pain and strategies to prevent it is integral to effective utilization of regional anesthesia to reduce negative consequences associated with long-term opioid consumption.

AnAnkle Trial study protocol: a randomised trial comparing pain profiles after peripheral nerve block or spinal anaesthesia for ankle fracture surgery

INTRODUCTION

Ankle fracture surgery is a common procedure, but the influence of anaesthesia choice on postoperative pain and quality of recovery is poorly understood. Some authors suggest a benefit of peripheral nerve block (PNB) in elective procedures, but the different pain profile following acute fracture surgery and the rebound pain on cessation of the PNB both remain unexplored. We present an ongoing randomised study aiming to compare primary PNB anaesthesia with spinal anaesthesia for ankle fracture surgery regarding postoperative pain profiles and quality of recovery.

METHODS AND ANALYSIS

AnAnkle Trial is a randomised, dual-centre, open-label, blinded analysis trial of 150 adult patients undergoing primary internal fixation of an ankle fracture. Main exclusion criteria are habitual opioid use, impaired pain sensation, other painful injuries or cognitive impairment. The intervention is ultrasound-guided popliteal sciatic (20 mL) and saphenal nerve (8 mL) PNB with ropivacaine 7.5 mg/mL, and controls receive spinal anaesthesia (2 mL) with hyperbaric bupivacaine 5 mg/mL. Postoperatively all receive paracetamol, ibuprofen and patient-controlled intravenous morphine on demand. Morphine consumption and pain scores are registered in the first 27 hours and reported as an integrated pain score as the primary endpoint. Pain score intervals are 3 hours and we will use the area under curve to get a longitudinal measure of pain. Secondary outcomes include rebound pain on cessation of anaesthesia, opioid side effects (Opioid-Related Symptom Distress Scale), quality of recovery (Danish Quality of Recovery-15 score) and pain scores and medication days 1-7 (diary).

ETHICS AND DISSEMINATION

The study has been approved by the Regional Ethics Committees in the Capital Region of Denmark, the Danish Data Protection Agency and the Danish Health and Medical Authority. We will publish the results in international peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

AnAnkle Trial is registered in the European Clinical Trials Database (EudraCT 2015-001108-76).

Preemptive Femoral Nerve Block Could Reduce the Rebound Pain After Periarticular Injection in Total Knee Arthroplasty

BACKGROUND

We evaluated the effectiveness of postoperative pain management using intraoperative periarticular injection (PAI) and/or electromyography-guided preoperative femoral nerve block (FNB) in knees undergoing total knee arthroplasty (TKA).

METHODS

This study included 90 patients (90 knees) who underwent primary TKA. Thirty patients received a single injection of electromyography-guided FNB, 30 received intraoperative PAI, and 30 received both. Pain at rest and while moving was evaluated by a visual analog scale (VAS) at 0, 4, 8, 24, and 48 hours. Postoperative range of motion, time to walking, amount of opioid consumption, and complications were analyzed.

RESULTS

VAS immediately after surgery was significantly higher in the FNB group than in the PAI and combined groups, but did not differ significantly in the latter 2 groups. VAS after 4 and 8 hours showed similar results. VAS after 24 hours was significantly higher in the PAI than in the FNB and combined groups. After 48 hours, there were no differences among the 3 groups. Total opioid consumption was lower in the combined than in the FNB and PAI groups. Postoperative range of motion and time to walking were similar in the 3 groups.

CONCLUSION

PAI was more effective than FNB during the early (0-8 hours) postoperative period after TKA. Patients treated with PAI, however, experienced rebound pain at 24 hours. The combination of PAI and FNB may provide greater postoperative pain management than either alone for the first 24 hours after TKA.