Rebound pain after regional anesthesia in the ambulatory patient

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.

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

Background

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

Methods

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

Results

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

Conclusions and recommendation

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

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).

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.

0.25% bupivacaine-1% lidocaine vs 0.5% bupivacaine for ultrasound-guided infraclavicular brachial plexus block: a randomized controlled trial

INTRODUCTION

In an effort to shorten onset time, a common practice is to add lidocaine to bupivacaine. In the setting of infraclavicular block, it is unclear what the block characteristics of this practice are compared with bupivacaine alone. We hypothesized that bupivacaine alone increases the duration of motor block, sensory block, and postoperative analgesia while resulting in a slower onset time compared with a bupivacaine and lidocaine mixture.

METHODS

40 patients receiving ultrasound-guided infraclavicular brachial plexus block were randomly assigned to receive either 35 mL of 0.25% bupivacaine and 1% lidocaine or 0.5% bupivacaine, both associated with perineural adjuvants (epinephrine 5 µg/mL and dexamethasone 4 mg). After the block was performed, a blinded observer evaluated the success of the block, the onset time, and the incidence of surgical anesthesia. Postoperatively, a blinded observer contacted patients who had successful blocks to inquire about the duration of motor block, sensory block, postoperative analgesia, and the presence of rebound pain.

RESULTS

When comparing patients having bupivacaine alone versus bupivacaine and lidocaine, the mean (SD) motor block duration was 28.4 (5.2) vs 18.9 (3.1) hours, respectively; the mean difference 9.5 hours (95% CI 6.5 to 12.4; p<0.001); the mean (SD) sensory block duration was 29.3 (5.8) vs 18.7 (4.0) hours, respectively; the mean difference 10.6 hours (95% CI 7.1 to 14.0; p<0.001); the mean (SD) postoperative analgesia duration was 38.3 (7.4) vs 24.3 (6.6) hours, respectively; the mean difference 14 hours (95% CI 9.2 to 18.8; p<0.001); and the median (IQR) onset time was 35 (15) vs 20 (10) min, respectively; p<0.001. No other significant differences were detected.

CONCLUSIONS

Compared with mixed bupivacaine-lidocaine, 0.5% bupivacaine significantly prolongs sensorimotor block and postoperative analgesia at the expense of a delayed onset time.

TRIAL REGISTRATION NUMBER

NCT05834023.

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: 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.

Advancing pain management for extremity trauma: the evolution of ultrasound-guided nerve blocks for patients in the supine position in trauma centers

PURPOSE

Trauma, particularly extremity trauma, poses a considerable challenge in healthcare, especially among young adults. Given the severity of patient pain and the risks associated with excessive opioid use, managing acute pain in trauma centers is inherently complex. This study aims to investigate the application and benefits of ultrasound-guided nerve blocks for early pain management in patients with extremity trauma positioned supine.

METHODS

A comprehensive literature review was conducted to assess the effectiveness and advantages of ultrasound-guided peripheral nerve blocks in the acute pain management of extremity trauma patients in the supine position. Special emphasis was placed on evaluating the selection criteria, indications, contraindications, adverse reactions, and potential complications associated with these nerve block techniques.

RESULTS

Ultrasound-guided nerve blocks represent a safer and more precise option for managing pain in extremity trauma patients placed in the supine position. These techniques offer significant advantages in terms of reducing healthcare expenses, diminishing reliance on opioid medications, and mitigating opioid-related complications. Nonetheless, challenges may arise due to the necessity for patient cooperation during specific nerve block procedures.

CONCLUSION

Ultrasound-guided nerve blocks present a promising avenue for early pain management in extremity trauma patients positioned supinely. Their implementation can lead to improved patient outcomes by alleviating pain severity, reducing opioid consumption, and cutting down healthcare costs. Further research and clinical integration of these techniques is imperative to enhance pain management protocols in trauma centers.

Comparison of intrathecal low-dose bupivacaine and morphine with intravenous patient control analgesia for postoperative analgesia for video-assisted thoracoscopic surgery

BACKGROUND

Thoracoscopic surgical techniques continue to advance, yet the intensity of postoperative pain remains significant, impeding swift patient recovery. This study aimed to evaluate the differences in postoperative pain and recuperation between patients receiving intrathecal morphine paired with low-dose bupivacaine and those administered general anesthesia exclusively.

METHODS

This randomized controlled trial enrolled 100 patients, who were allocated into three groups: Group M (5 μg/kg morphine intrathecal injection), Group B (5 μg/kg morphine combined with bupivacaine 3 mg intrathecal injection) and Group C (intrathecal sham injection). The primary outcome was the assessment of pain relief using the Numeric Rating Scale (NRS). Additionally, intraoperative remifentanil consumption was quantified at the end of the surgery, and postoperative opioid use was determined by the number of patient-controlled analgesia (PCIA) compressions at 48 h post-surgery. Both the efficacy of the treatments and any complications were meticulously recorded.

RESULTS

Postoperative NRS scores for both rest and exercise at 6, 12, 24, and 48 h were significantly lower in groups M and B than in group C (P<0.05). The intraoperative remifentanil dosage was significantly greater in groups M and C than in group B (P<0.05), while there was no significant difference between groups M and C (P>0.05). There was no significant difference in intraoperative propofol dosage across all three groups (P>0.05). Postoperative dosages of both sufentanil and Nonsteroidal anti-inflammatory drugs (NSAIDs) were significantly less in groups M and B compared to group C (P<0.05). The time of first analgesic request was later in both groups M and B than in group C (P<0.05). Specific and total scores were elevated at 2 days postoperative when compared to scores at 1 day for all groups (P<0.05). Furthermore, at 1 day and 2 days postoperatively, both specific scores and total scores were higher in groups M and B compared to group C (P<0.05).

CONCLUSION

Intrathecal administration of morphine combined with bupivacaine has been shown to effectively ameliorate acute pain in patients undergoing thoracoscopic surgery.

TRIAL REGISTRATION

The trial was registered on ClinicalTrials.gov: ChiCTR2200058544, registered 10/04/2022.

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 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.

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).

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

INTRODUCTION

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

METHODS

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

RESULTS

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

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.

Regional anaesthesia for ambulatory surgery

Regional anaesthesia (RA) has an important and ever-expanding role in ambulatory surgery. Specific practices vary depending on the preferences and resources of the anaesthesia team and hospital setting. It is used for various purposes, including as primary anaesthetic technique for surgery but also as postoperative analgesic modality. The limited duration of action of currently available local anaesthetics limits their application in postoperative pain control and enhanced recovery. The search for the holy grail of regional anaesthetics continues. Current evidence suggests that a peripheral nerve block performed with long-acting local anaesthetics in combination with intravenous or perineural dexamethasone gives the longest and most optimal sensory block. In this review, we outline some possible blocks for ambulatory surgery and additives to perform RA. Moreover, we give an update on local anaesthesia drugs and adjuvants, paediatric RA in ambulatory care and discuss the impact of RA by COVID-19.

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.

The Effects of Intraoperative Remifentanil Infusion on Postoperative Opioid Consumption in Patients Who Underwent Total Knee Arthroplasty with Femoral Nerve Block

(1) Background: Remifentanil is used for intraoperative pain control; however, it has several side effects, such as hypotension and opioid-induced hyperalgesia. We aimed to determine whether an intraoperative remifentanil infusion may increase postoperative opioid consumption in patients undergoing total knee arthroscopy (TKA) under femoral nerve block (FNB) in addition to general anesthesia. (2) Methods: We randomly assigned 66 patients who underwent total knee arthroplasty to the remifentanil (R) and control (C) groups. All patients underwent FNB and popliteal artery and posterior capsule of the knee (iPACK) block in addition to sevoflurane-based general anesthesia. Postoperative pain control was achieved using intravenous patient-controlled analgesia (IV-PCA) fentanyl. We recorded IV-PCA fentanyl consumption at various postoperative timepoints, numerical rating scale (NRS) scores, intraoperative changes in vital signs and index of nociception (qNOX), ephedrine consumption, postoperative side effects, satisfaction, and sleep quality. (3) Results: The primary outcome (the cumulative IV-PCA fentanyl usage within 48 h postoperatively) was significantly lower in the C group (541.1 ± 294.5 µg) than in the R group (717.5 ± 224.0 µg) (p < 0.001). The secondary outcome (the cumulative IV-PCA fentanyl usage within 12, 24, and 72 h) was lower in the C group than in the R group and the mean arterial pressure was lower in the R group than in the C group from immediately after tourniquet on to immediately after tourniquet off. The heart rate was lower in the R group from immediately after incision to immediately after irrigation. There was no significant between-group difference in the perioperative qNOX and NRS scores at rest and activity except for NRS scores at 72 h postoperatively. Ephedrine use was higher in the R group than in the C group (p = 0.003). There was no significant between-group difference in the incidence of postoperative nausea and vomiting, nor in the postoperative satisfaction and sleep quality. (4) Conclusions: Avoiding intraoperative remifentanil infusion may reduce total opioid consumption in patients undergoing FNB before TKA.

Effect of Supplemental Regional Anesthesia on the Complication and Readmission Rate of Patients After Elective Foot and Ankle Surgery

BACKGROUND

The purpose of this study is to define the effect of facility type (inpatient vs outpatient) for the use of supplemental regional anesthesia (SRA), and SRA's effect on complications, readmissions, operation time, and length of hospital stay after elective foot and ankle surgery.

METHODS

We performed a retrospective review to identify a large cohort of adult patients who underwent elective foot and ankle surgery between 2006 and 2020 from the American College of Surgeons National Surgical Quality Improvement Program database. We fit log-binomial generalized linear models to estimate risk ratios for general anesthesia (GA) with SRA versus GA alone, and linear regression models to estimate the effect of GA with SRA on the average total hospital length of stay (in days) and operation time (in minutes); we also performed inverse propensity scores.

RESULTS

We found that there is no statistical difference in the rate of readmissions (P = .081) between patients under GA alone versus GA with SRA. In the propensity score analysis, patients who underwent midfoot/forefoot surgery had 3.85 times the risk of complications under GA with SRA compared with GA alone (P = .045). Also, patients who received GA with SRA had a longer unadjusted operative duration (102.22 minutes) when compared with patients who received GA alone (93.84 minutes) (P < .001). However, patients who received GA alone had a longer unadjusted hospital length of stay (0.88 days) when compared with patients who received GA with SRA (0.70 days) (P = .006).

CONCLUSION

This study found that, when compared with GA alone, GA with SRA leads to a statistically significant increased operative time but a shorter hospital stay without significantly increasing readmissions and only increasing the risk of complications for midfoot/forefoot surgery within 30 days postoperatively for elective foot and ankle surgery.

LEVEL OF EVIDENCE

Level III.

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.

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.

Symptom severity trajectories and distresses in patients undergoing video-assisted thoracoscopic lung resection from surgery to the first post-discharge clinic visit

This study aimed to characterize patients' symptom severity trajectories and distresses from video-assisted thoracoscopic lung resection to the first post-discharge clinic visit. Seventy-five patients undergoing thoracoscopic lung resection for diagnosed or suspected pulmonary malignancy prospectively recorded daily symptom severity on a 0-10 numeric scale using the MD Anderson Symptom Inventory until the first post-discharge clinic visit. The causes of postoperative distresses were surveyed, and symptom severity trajectories were analyzed using joinpoint regression. A rebound was defined as a statistically significant positive slope after a statistically significant negative slope. Symptom recovery was defined as symptom severity of ≤3 in two contiguous measurements. The accuracy of pain severity on days 1-5 for predicting pain recovery was determined using area under the receiver operating characteristic curves. We applied Cox proportional hazards models for multivariate analyses of the potential predictors of early pain recovery. The median age was 70 years, and females accounted for 48%. The median interval from surgery to the first post-discharge clinic visit was 20 days. Trajectories of several core symptoms including pain showed a rebound from day 3 or 4. Specifically, pain severity in patients with unrecovered pain had been higher than those with recovered pain since day 4. Pain severity on day 4 showed the highest area under the curve of 0.723 for predicting pain recovery (P = 0.001). Multivariate analysis identified pain severity of ≤1 on day 4 as an independent predictor of early pain recovery (hazard ratio, 2.86; P = 0.0027). Duration of symptom was the leading cause of postoperative distress. Several core symptoms after thoracoscopic lung resection showed a rebound in the trajectory. Specifically, a rebound in pain trajectory may be associated with unrecovered pain; pain severity on day 4 may predict early pain recovery. Further clarification of symptom severity trajectories is essential for patient-centered care.

Regional anesthesia provides limited decreases in opioid use following distal tibia and ankle fracture surgery

PURPOSE

Regional anesthesia (RA) is used for pain control, but its impacts on the orthopedic trauma population are not well known. This study evaluated the impact of peripheral nerve blocks after distal tibia and ankle fracture repair on opioid use and pain scores and quantified the magnitude and duration of any changes.

METHODS

This retrospective cohort study included patients treated operatively for distal tibia and ankle fractures over a 5-year period, both with and without peripheral nerve blocks. Total inpatient 5 mg oxycodone equivalents (OEs) used in the post-operative period, from 0-24, 24-48, to 48-72 h and maximum visual analog scale (VAS) pain ratings from 0-24, 24-48, to 48-72 h were recorded.

RESULTS

540 non-polytrauma patients and 183 polytrauma patients were included. Patients in the non-polytrauma group who received nerve blocks required fewer opioids on post-operative day (POD) 1 compared to the non-nerve block group (4.8 [95% CI 4.2-5.4] vs. 10.5 [95% CI: 9.2-11.8]; p < 0.001) and had lower VAS scores on POD1 (5.0 [95% CI 4.6-5.4] vs. 7.7 [95% CI: 7.3-8.1]; p < 0.001). However, there were no differences between these groups on POD2 or POD3 and no differences at any timepoints in the polytrauma group.

CONCLUSION

Patients with isolated distal tibia and ankle fractures who receive peripheral nerve blocks demonstrate modest reductions in inpatient opioids and pain scores on POD1. However, there are no clear benefits beyond this point. Furthermore, polytrauma patients do not experience any reductions in opioid consumption or pain scores.

Role of adjuvants in regional anesthesia: A systematic review

The combination of drugs and routes of administration produces a synergistic effect, and one of the most important components of multimodal analgesic strategies are, therefore, nerve blocks for pain management. The effect of a local anaesthetic can be prolonged by administering an adjuvant. In this systematic review, we included studies on adjuvants associated with local anaesthetics in peripheral nerve blocks published in the last 5 years in order to evaluate their effectiveness. The results were reported according to the PRISMA guidelines. The 79 studies selected using our criteria showed a clear prevalence of dexamethasone (n=24) and dexmedetomidine (n=33) over other adjuvants. Different meta-analyses comparing adjuvants suggest that dexamethasone administered perineurally achieves superior blockade with fewer side effects than dexmedetomidine. Based on the studies reviewed, we found moderate evidence to recommend the use of dexamethasone as an adjuvant to peripheral regional anaesthesia in surgeries that can cause moderate to severe pain.

Sciatic Nerve Block Combined with Flurbiprofen Inhibits Spinal Cord Inflammation and Improves Postoperative Pain in Rats with Plantar Incision

Background and Purpose

Peripheral nerve block is often used to relieve postoperative pain. But the effect of nerve block on inflammatory response is not fully understood. Spinal cord is the primary center of pain processing. This study is to investigate the effect of single sciatic nerve block on the inflammatory response of the spinal cord in rats with plantar incision and the combined effect with flurbiprofen.

Methods

The plantar incision was used to establish a postoperative pain model. Single sciatic nerve block, intravenous flurbiprofen or the combination of both were used for intervention. The sensory and motor functions after nerve block and incision were evaluated. The changes of IL-1β, IL-6, TNF-α, microglia and astrocytes in the spinal cord were examined by qPCR and immunofluorescence respectively.

Results

Sciatic nerve block with 0.5% ropivacaine in rats induced sensory block for 2h and motor block for 1.5h. In the rats with plantar incision, the single sciatic nerve block did not alleviate postoperative pain or inhibit the activation of spinal microglia and astrocytes, but the levels of IL-1β and IL-6 in spinal cord were decreased when the nerve block wore off. The combined effect of a single sciatic nerve block and intravenous flurbiprofen not only decreased the levels of IL-1β, IL-6, and TNF-α, but also relieved the pain and alleviated the activation of microglia and astrocytes.

Conclusion

The single sciatic nerve block cannot improve postoperative pain or inhibit the activation of spinal cord glial cells, but can reduce the expression of spinal inflammatory factors. Nerve block combined with flurbiprofen can inhibit spinal cord inflammation and improve postoperative pain. This study provides a reference for rational clinical application of nerve block.

A Case Report on Abdominal Pain Treated With a New Technique of Ultrasound-Guided Transversus Abdominis Plane Hydrodissection Using a Low Concentration of Local Anesthetics

Hydrodissection, a technique for performing morphological dissection between the target tissues via injection, has attracted attention in recent years. However, high-quality evidence is available only for a few entrapment neuropathies, such as carpal tunnel syndrome, and further case studies are needed for other diseases. This case report presents the first case of hydrodissection of the ventral ramus of the spinal nerve, which innervates the abdominal wall, to improve abdominal pain. A 59-year-old Japanese man with a history of cerebral infarction and dyslipidemia presented to the emergency department with the chief complaint of left upper abdominal pain that began two days earlier. The pain radiated to the left side of the back and left axilla. The abdomen was flat and soft with no tenderness on examination, and the pinch test was negative. However, Carnett's sign was observed in the left upper abdomen, and the location of the left upper abdominal pain and that of the radiating pain were consistent with the ninth thoracic vertebra (Th9) dermatome; thus, the cause of the left upper abdominal pain was determined to be the ventral ramus of the spinal nerve of Th9. Two weeks of physical therapy and lifestyle guidance were ineffective; therefore, hydrodissection of the transversus abdominis plane (TAP) between the myofascia of the internal oblique muscle and that of the transversus abdominis at the Th9 level using a 23G 60 mm needle under ultrasound guidance was planned. The abdominal pain immediately improved after hydrodissection, and the patient was able to work without pain. Thus, ultrasound-guided TAP hydrodissection with a low-concentration local anesthetic is effective in the treatment of abdominal pain caused by the entrapment of the ventral ramus of the spinal nerve due to adhesions between the myofascia of the internal oblique muscle and that of the transversus abdominis. This condition should be termed ventral ramus of spinal nerve entrapment syndrome (VERNES), and this concept and TAP hydrodissection must be made known to the public.

Pain treatment and prophylaxis on pain

PURPOSE OF REVIEW

Also in ambulatory surgery, there will usually be a need for analgesic medication to deal with postoperative pain. Even so, a significant proportion of ambulatory surgery patients have unacceptable postoperative pain, and there is a need for better education in how to provide proper prophylaxis and treatment.

RECENT FINDINGS

Postoperative pain should be addressed both pre, intra- and postoperatively. The management should be with a multimodal nonopioid-based procedure specific guideline for the routine cases. In 10-20% of cases, there will be a need to adjust and supplement the basic guideline with extra analgesic measures. This may be because there are contraindications for a drug in the guideline, the procedure is more extensive than usual or the patient has extra risk factors for strong postoperative pain. Opioids should only be used when needed on top of multimodal nonopioid prophylaxis. Opioids should be with nondepot formulations, titrated to effect in the postoperative care unit and eventually continued only when needed for a few days at maximum.

SUMMARY

Multimodal analgesia should start pre or per-operatively and include paracetamol, nonsteroidal anti-inflammatory drug (NSAID), dexamethasone (or alternative glucocorticoid) and local anaesthetic wound infiltration, unless contraindicated in the individual case. Paracetamol and NSAID should be continued postoperatively, supplemented with opioid on top as needed. Extra analgesia may be considered when appropriate and needed. First-line options include nerve blocks or interfascial plane blocks and i.v. lidocaine infusion. In addition, gabapentinnoids, dexmedetomidine, ketamine infusion and clonidine may be used, but adverse effects of sedation, dizziness and hypotension must be carefully considered in the ambulatory setting.

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."

Factors Associated with Rebound Pain After Patient-controlled Epidural Analgesia in Patients Undergoing Major Abdominal Surgery: A Retrospective Study

OBJECTIVES

Although patient-controlled epidural analgesia (PCEA) is an effective form of regional analgesia for abdominal surgery, some patients experience significant rebound pain after the discontinuation of PCEA. However, risk factors for rebound pain associated with PCEA in major abdominal surgery remain unknown. This study evaluated the incidence of rebound pain related to PCEA and explored potential associated risk factors.

METHODS

We performed a retrospective review of 236 patients using PCEA following hepatobiliary and pancreas surgery between 2018 and 2020 in a tertiary hospital in South Korea. Rebound pain was defined as an increase from well-controlled pain (numeric rating scale <4) during epidural analgesia to severe pain (numeric rating scale ≥7) within 24 hours of discontinuation of PCEA. Logistic regression analysis was performed to determine the factors associated with rebound pain.

RESULTS

A total of 236 patients were included in this study. Patients were categorized into the non-rebound pain group (170 patients; 72%) and the rebound pain group (66 patients; 28%). Multivariable logistic regression analysis revealed that preoperative prognostic nutritional index (PNI) below 45 (odds ratio [OR]=2.080, 95% confidential interval [CI]=1.061-4.079, P=0.033) and intraoperative transfusion (OR=4.190, 95% CI=1.436-12.226, P=0.009) were independently associated with rebound pain after PCEA discontinuation.

DISCUSSION

Rebound pain after PCEA occurred in approximately 30% of patients who underwent major abdominal surgery, resulting in insufficient postoperative pain management. Preoperative low PNI and intraoperative transfusion may be associated with rebound pain after PCEA discontinuation.

Group-based trajectory analysis of acute pain after spine surgery and risk factors for rebound pain

Background

This retrospective study was designed to explore the types of postoperative pain trajectories and their associated factors after spine surgery.

Materials and methods

This study was conducted in a single medical center, and patients undergoing spine surgery with intravenous patient-controlled analgesia (IVPCA) for postoperative pain control between 2016 and 2018 were included in the analysis. Maximal pain scores were recorded daily in the first postoperative week, and group-based trajectory analysis was used to classify the variations in pain intensity over time and investigate predictors of rebound pain after the end of IVPCA. The relationships between the postoperative pain trajectories and the amount of morphine consumption or length of hospital stay (LOS) after surgery were also evaluated.

Results

A total of 3761 pain scores among 547 patients were included in the analyses and two major patterns of postoperative pain trajectories were identified: Group 1 with mild pain trajectory (87.39%) and Group 2 with rebound pain trajectory (12.61%). The identified risk factors of the rebound pain trajectory were age less than 65 years (odds ratio [OR]: 1.89; 95% CI: 1.12–3.20), female sex (OR: 2.28; 95% CI: 1.24–4.19), and moderate to severe pain noted immediately after surgery (OR: 3.44; 95% CI: 1.65–7.15). Group 2 also tended to have more morphine consumption (p < 0.001) and a longer length of hospital stay (p < 0.001) than Group 1.

Conclusion

The group-based trajectory analysis of postoperative pain provides insight into the patterns of pain resolution and helps to identify unusual courses. More aggressive pain management should be considered in patients with a higher risk for rebound pain after the end of IVPCA for spine surgery.

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.

Emergency Department Utilization After Administration of Peripheral Nerve Blocks for Upper Extremity Surgery

BACKGROUND

The purpose of this study was to determine the impact of upper extremity peripheral nerve blocks on emergency department (ED) utilization after hand and upper extremity surgery.

METHODS

We reviewed all outpatient upper extremity surgeries performed in a single Midwestern state between January 2009 and June 2019 using the Indiana Network for Patient Care. These encounters were used to develop a database of patient demographics, comorbidities, concurrent procedures, and postoperative ED visit utilization data. We performed univariate, bivariate, and multivariate logistic regression analyses.

RESULTS

Among 108 451 outpatient surgical patients, 9079 (8.4%) received blocks. Within 1 week of surgery, a greater proportion of patients who received peripheral nerve blocks (1.4%) presented to the ED than patients who did not (0.9%) (P < .001). The greatest risk was in the first 2 postoperative days (relative risk, 1.78; P < .001). Pain was the principal reason for ED utilization in the block cohort (53.6%) compared with those who did not undergo a block (35.1%) (P < .001). When controlling for comorbidities and demographics, only peripheral nerve blocks (adjusted odds ratio [OR], 1.71; P = 0.007) and preprocedural opioid use (adjusted OR, 1.43; P = .020) conferred an independently increased risk of ED utilization within the first 2 postoperative days.

CONCLUSIONS

Peripheral nerve blocks used for upper extremity surgery are associated with a higher risk of unplanned ED utilization, most likely related to rebound pain. Through proper patient education and pain management, we can minimize this unnecessary resource utilization.

Effect of remifentanil on post-operative analgesic consumption in patients undergoing shoulder arthroplasty after interscalene brachial plexus block: a randomized controlled trial

PURPOSE

Remifentanil is useful in balanced anesthesia; however, there is concern regarding opioid-induced hyperalgesia. The effect of remifentanil on rebound pain, characterized by hyperalgesia after peripheral nerve block has rarely been studied. This study evaluated whether intraoperative remifentanil infusion may increase postoperative analgesic requirement in patients receiving preoperative interscalene brachial plexus block (IBP).

METHODS

Sixty-eight patients undergoing arthroscopic shoulder surgery under general anesthesia were randomly allocated to remifentanil (R) or control (C) group. Preoperative IBP with 0.5% ropivacaine 15 mL was performed in all patients. Intraoperative remifentanil was administered only in the R group. Postoperative pain was controlled using intravenous patient-controlled analgesia (IV-PCA) and rescue analgesics. The primary outcome was the dosage of fentanyl-nefopam IV-PCA infused over 24 h postoperatively. The secondary outcomes included the numeric rating scale (NRS) score recorded at 4-h intervals over 24 h, amount of rescue analgesics and total postoperative analgesics used over 24 h, occurrence of intraoperative hypotension, postoperative nausea and vomiting (PONV) and delirium.

RESULTS

The dosage of fentanyl-nefopam IV-PCA was significantly less in C group than R group for postoperative 24 h. Fentanyl 101 [63-158] (median [interquartile range]) µg was used in the C group, while fentanyl 161 [103-285] µg was used in the R group (median difference 64 µg, 95% CI 10-121 µg, P = 0.02). Nefopam 8.1 [5.0-12.6] mg was used in the C group, while nefopam 12.9 [8.2-22.8] mg was used in the R group (median difference 5.1 mg, 95% CI 0.8-9.7 mg, P = 0.02). The total analgesic consumption: the sum of PCA consumption and administered rescue analgesic dose, converted to morphine milligram equivalents, was higher in the R group than C group (median difference 10.9 mg, 95% CI 3.0-19.0 mg, P = 0.01). The average NRS score, the incidence of PONV and delirium, were similar in both groups. The incidence of intraoperative hypotension was higher in R group than C group (47.1% vs. 20.6%, P = 0.005).

CONCLUSIONS

Remifentanil administration during arthroscopic shoulder surgery in patients undergoing preoperative IBP increased postoperative analgesic consumption.

[Rebound pain-From definition to treatment]

Hintergrund

Rebound pain als Nebenwirkung einer Regionalanästhesie ist ein übermäßiges Schmerzempfinden nach Abklingen der Wirkung der lokalen Betäubung, welches deutlich über den normalen Wundschmerz nach einer Operation hinausgeht. Dieses Phänomen rückt seit ca. 10 Jahren stärker in den Fokus der Forschung. Die konkreten Ursachen sind bisher unklar, und es existieren auch noch keine zielgerichteten Therapieempfehlungen.

Ziel der Arbeit

Dieser Übersichtsartikel soll der Leserschaft einen Überblick über den aktuellen Stand der Forschung geben. Es werden die Theorien zur Pathophysiologie vorgestellt und Prophylaxe- sowie Behandlungsstrategien erläutert.

Material und Methoden

Für diese Übersichtsarbeit wurden die von 2005 bis Mai 2021 auf PubMed erschienenen Publikationen zum Thema Rebound pain durchgesehen und die Definitionen der Autoren zu Rebound pain sowie die Annahmen zur Pathophysiologie und Therapieempfehlungen zusammengefasst.

Ergebnisse und Diskussion

Insgesamt wurden 22 Originalarbeiten im Hinblick auf die Definition von Rebound pain, die Annahme der Entstehung sowie Therapieoptionen ausgewertet. Dabei zeigt sich, dass keine einheitliche Definition existiert, die Pathophysiologie nicht eindeutig geklärt ist und zum aktuellen Zeitpunkt auch noch keine klaren Empfehlungen zu Prophylaxe sowie Therapie gegeben werden können.

Zusatzmaterial online

Die Online-Version dieses Beitrags (10.1007/s00101-022-01120-z) enthält eine tabellarische Zusammenstellung über Studiendesign sowie Kernaussagen der vorgestellten Studien.

Retrospective evaluation of WALANT in emergency hand surgery in the Bordeaux university hospital

The Wide-Awake Local Anesthesia No Tourniquet (WALANT) technique uses local anesthesia based on lidocaine and adrenaline, enabling surgery without the tourniquet normally used in hand surgery. Only a few studies have been conducted on the use of WALANT for emergency hand surgery in teaching hospitals. We therefore set up the WALANT procedure in our emergency department in the university hospital of Bordeaux, France, to evaluate its feasibility and the satisfaction of patients and operators. Between April and June 2020, we included 58 patients undergoing surgery for acute trauma of the hand/wrist. WALANT was performed following a specific protocol. A tourniquet was systematically available on standby. After the procedure, patients and operators were asked to complete a questionnaire. Patients rated pain on a 0-10 numerical analog scale. Surgeons reported their feelings about bleeding and patient cooperation. All patients underwent a nearly painless operation, with a mean pain score of 0.36/10. The mean pain score during injection was 2.57, and postoperatively 5.2. Bleeding complications were reported to be absent or slight by 43% of operators, moderate but acceptable by 47%, and significant by 10%. Bipolar forceps were used in 76% of cases. No digital necrosis or prolonged ischemia requiring the use of phentolamine was reported. WALANT offers a simple, safe, and effective alternative to traditional anesthesia techniques in an emergency setting. Patients and surgeons reported overall satisfaction, with no increase in the complications rate.

Comparison of Supraclavicular Regional Nerve Block Versus Infraclavicular Regional Nerve Block in Distal Radial Open Reduction and Internal Fixation: A Retrospective Case Series

Background

The management of pain in patients undergoing open reduction and internal fixation (ORIF) of distal radius fractures (DRFs) remains an area of debate for anesthesiologists due to a variety of block options and no definitive superior technique among these modalities. In this retrospective case series, we compare the efficacy of supraclavicular versus infraclavicular regional nerve blocks for surgical patients undergoing distal radial ORIF operations to determine if one approach was superior.

Methodology

This retrospective case series included patients undergoing ORIF of a DRF at a tertiary academic medical center between April 28, 2016, and August 23, 2021. In total, 54 patients undergoing ORIF of a DRF provided written consent for the nerve block(s) on the day of surgery. Of these 54 patients, 54 (100%) underwent primary procedures. Of the 54 primary ORIF patients, 28 (52%) received the supraclavicular block, while 26 (48%) received the infraclavicular nerve block.

Results

The infraclavicular and supraclavicular groups did not significantly differ regarding age, gender, American Society of Anesthesiologists, weight, or body mass index. The primary (intraoperative opioid use) and secondary (postoperative opioid use, postoperative nausea and vomiting in the post-anesthetic care unit, highest and average pain scores, and time to discharge) outcomes data were included in the study. The infraclavicular and supraclavicular groups did not significantly differ in any of the assessed outcomes except for time to discharge.

Conclusions

The supraclavicular block approach for distal radius ORIF offers an effective and non-inferior alternative to the infraclavicular block approach concerning effective analgesia and safety.

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.

Brace versus cast following surgical treatment of distal radial fracture: a prospective randomised study comparing quality of recovery

Background: Immobilisation following surgical treatment of distal radial fractures (DRF) is traditionally performed with a dorsal cast splint. There is an interest in changing the rigid cast to a removable brace. This can reduce the risk for cast-corrections, complications and improve recovery of function.

The aim of the study was to compare quality of recovery (QoR) between brace and traditional cast for immobilisation during the first postoperative week.

Methods: 60 patients with American Society of Anesthesiologists (ASA) physical status 1–3, scheduled for surgical treatment of DRF under a supraclavicular block (SCB) in a day-surgery setting were randomised into two groups of immobilisation post-surgery; brace (n=30) versus traditional cast (n=30). Study objectives were: differences in self-assessed QoR using the QoR-15 questionnaire, postoperative oral oxycodone consumption, perioperative time events and unplanned healthcare contacts one week postoperatively.

Results: 54 patients, 46 females/eight males were included in the analysis; 27 with brace and 27 with traditional cast. QoR-15 median scores improved significantly from baseline/preoperative to day 7 (brace p=0.001, cast p=0.001) with no differences between the two groups. The only difference found was that patients in the brace group had significantly worse pain score 24-hours post-surgery (p=0.022). No significant differences were seen in total median oxycodone consumption the first three postoperative days. No differences were found in perioperative events or unplanned healthcare contacts.

Conclusions: Brace appears to be a feasible option to traditional cast for immobilisation following surgical treatment of DRF. The early QoR was similar in both groups apart from more pain in the brace group the first 24 postoperative hours.

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

Background

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

Methods

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

Results

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

Conclusion

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

Supraclavicular block with Mepivacaine vs Ropivacaine, their impact on postoperative pain: a prospective randomised study

BACKGROUND

Supraclavicular block (SCB) with long-acting local anaesthetic is commonly used for surgical repair of distal radial fractures (DRF). Studies have shown a risk for rebound pain when the block fades. This randomised single-centre study aimed to compare pain and opioid consumption the first three days post-surgery between SCB-mepivacaine vs. SCB-ropivacaine, with general anaesthesia (GA) as control.

METHODS

Patients (n = 90) with ASA physical status 1-3 were prospectively randomised to receive; SCB with mepivacine 1%, 25-30 ml (n = 30), SCB with ropivacaine 0.5%, 25-30 ml (n = 30) or GA (n = 30) with propofol/fentanyl/sevoflurane. Study objectives compared postoperative pain with Numeric Rating Scale (NRS) and sum postoperative Opioid Equivalent Consumption (OEC) during the first 3 days post-surgery between study-groups.

RESULTS

The three groups showed significant differences in postoperative pain-profile. Mean NRS at 24 h was significantly lower for the SCB-mepivacaine group (p = 0.018). Further both median NRS and median OEC day 0 to 3 were significanly lower in the SCB-mepivacaine group as compared to the SCB-ropivacaine group during the first three days after surgery; pain NRS 1 (IQR 0.3-3.3) and 2.7 (IQR 1.3-4.2) (p = 0.017) and OEC 30 mg (IQR 10-80) and 85 mg (IQR 45-125) (p = 0.004), respectively. The GA-group was in between both in pain NRS and median sum OEC. Unplanned healthcare contacts were highest among SCB-ropivacaine patients (39.3%) vs. SCB-mepivacaine patients (0%) and GA-patients (3.4%).

CONCLUSIONS

The potential benefit of longer duration of analgesia, associated to a long-acting local anaesthetic agent, during the early postoperative course must be put in perspective of potential worse pain progression following block resolution.

TRIAL REGISTRATION

NCT03749174 (clinicaltrials.gov, Nov 21, 2018, retrospectively registered).

Multimodal nerve injection provides noninferior analgesic efficacy compared with interscalene nerve block after arthroscopic rotator cuff repair

PURPOSE

This randomized noninferiority trial aimed to evaluate whether combined suprascapular, axillary nerve, and the articular branch of lateral pectoral nerve block (3NB) is noninferior to interscalene nerve block (ISB) for pain control after arthroscopic rotator cuff repair (ASRCR).

MATERIALS AND METHODS

Eighty-five patients undergoing ASRCR were randomized to either 3NB (n = 43) or ISB (n = 42) group. We used 5 and 15 ml of 0.2% ropivacaine for each nerve in the 3NB and ISB groups, respectively. The primary outcome was the visual analog scale (VAS) pain score at 4 h postoperatively measured assessed on an 11-point scale (ranging from 0 = no pain to 10 = worst pain) that was analyzed using noninferiority testing. The secondary outcome was VAS pain scores in the recovery room and at 8, 12, 24, 36, 48, and 72 h postoperatively. Rebound pain, IV-PCA usage during 48 h, dyspnea, muscle weakness, and satisfaction were evaluated.

RESULTS

Regarding the primary outcome, the mean difference in VAS pain scores between the 3NB (2.5 ± 1.6) and ISB (2.2 ± 2.3) groups at 4 h postoperatively was 0.3, with a 95% confidence interval (CI) of -0.56 to 1.11. The upper limit of 95% CI is lower than the noninferiority margin of 1.3 (p < 0.001). At all other time points, except in the recovery room, 3NB showed noninferior to ISB. Rebound pain, IV-PCA usage during the second 24 h, and muscle weakness were lower in the 3NB group (all p < 0.005). The satisfaction was similar in both groups (p = 0.815).

CONCLUSION

Combined 3NB is noninferior to ISB in terms of pain control after ASRCR; and is associated with low levels of rebound pain, IV-PCA usage, and muscle weakness.

LEVEL OF EVIDENCE

Randomized controlled trial, Level I.

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

BACKGROUND AND OBJECTIVES

A single injection interscalene block (ISB) is a common regional analgesic technique in patients undergoing arthroscopic shoulder surgery. However, rebound pain after ISB resolution may reduce its overall benefit. Our primary aim was to assess whether perineural dexamethasone reduces the intensity and incidence of rebound pain in patients undergoing arthroscopic shoulder surgery under general anesthesia combined with a preoperative single injection ISB.

METHODS

The patients were randomly assigned to receive single injection ISB using either 0.5% ropivacaine (control) or 0.5% ropivacaine containing 5 mg of dexamethasone. The primary outcomes were the pain score difference before and after ISB resolution, and the incidence of rebound pain. The secondary outcomes were the onset and duration of rebound pain, the presence of sleep disturbances due to postoperative pain, the first time when an analgesic was requested, and pain scores at various predefined time points.

RESULTS

Pain increase following ISB resolution was lower in the dexamethasone group compared with the control group (4.5±2.4 and 6.9±2.2, respectively, p<0.001). The incidence of rebound pain was significantly lower in the dexamethasone group compared with the control group (37.1% and 82.9%, respectively, p<0.001). The controls experienced greater sleep disturbance during the postoperative period compared with those who received ISB with perineural dexamethasone.

CONCLUSIONS

Perineural dexamethasone added to ISB using ropivacaine led to a much smoother resolution of ISB, reflected in a significantly smaller increase in pain after block resolution, a lower incidence of rebound pain and a lower sleep disturbance during the first postoperative week.

TRIAL REGISTRATION NUMBER

Clinical Trial Registry of Korea (KCT0004418).

Spinal versus general anesthesia for patients undergoing outpatient total knee arthroplasty: a national propensity matched analysis of early postoperative outcomes

BACKGROUND

A comparison of different anesthetic techniques to evaluate short term outcomes has yet to be performed for patients undergoing outpatient knee replacements. The aim of this investigation was to compare short term outcomes of spinal (SA) versus general anesthesia (GA) in patients undergoing outpatient total knee replacements.

METHODS

The ACS NSQIP datasets were queried to extract patients who underwent primary, elective, unilateral total knee arthroplasty (TKA) between 2005 and 2018 performed as an outpatient procedure. The primary outcome was a composite score of serious adverse events (SAE). The primary independent variable was the type of anesthesia (e.g., general vs. spinal).

RESULTS

A total of 353,970 patients who underwent TKA procedures were identified comprising of 6,339 primary, elective outpatient TKA procedures. Of these, 2,034 patients received GA and 3,540 received SA. A cohort of 1,962 patients who underwent outpatient TKA under GA were propensity matched for covariates with patients who underwent outpatient TKA under SA. SAE rates at 72 h after surgery were not greater in patients receiving GA compared to SA (0.92%, 0.66%, P = 0.369). In contrast, minor adverse events were greater in the GA group compared to SA (2.09%, 0.51%), P < 0.001. The rate of postoperative transfusion was greater in the patients receiving GA.

CONCLUSIONS

The type of anesthetic technique, general or spinal anesthesia does not alter short term SAEs, readmissions and failure to rescue in patients undergoing outpatient TKR surgery. Recognizing the benefits of SA tailored to the anesthetic management may maximize the clinical benefits in this patient population.

Comparison of continuous intravenous lidocaine versus transversus abdominis plane block for kidney transplant surgery: a randomized, non-inferiority trial

BACKGROUND AND OBJECTIVES

Transversus abdominis plane (TAP) blocks are associated with an improvement in postoperative analgesia following kidney transplant surgery. However, these blocks carry inherent risk and require a degree of expertise to perform successfully. Continuous intravenous lidocaine may be an effective alternative. In this randomized, non-inferiority study, we hypothesized that a continuous lidocaine infusion provides similar postoperative analgesia to a TAP block.

METHODS

Subjects presenting for kidney transplant surgery were randomized in a 1:1 ratio to either an ultrasound-guided unilateral, single-injection TAP block (TAP group) or a continuous infusion of lidocaine (Lido group). The primary outcome of this non-inferiority study was opioid consumption within the first 24 hours following surgery. Secondary outcomes included pain scores, patient satisfaction, opioid-related adverse events, time to regular diet, and persistent opioid use.

RESULTS

One hundred and twenty subjects, 59 from the TAP group and 61 from the Lido group, completed the study per protocol. Analysis of the primary outcome showed a cumulative geometric mean intravenous morphine equivalent difference between the TAP (14.6±3.2 mg) and Lido (15.9±2.4 mg) groups of 1.27 mg (95% CI -4.25 to 6.79; p<0.001), demonstrating non-inferiority of the continuous lidocaine infusion. No secondary outcomes showed clinically meaningful differences between groups.

CONCLUSIONS

This study demonstrates that a continuous infusion of lidocaine offers non-inferior postoperative analgesia compared with an ultrasound-guided unilateral, single-injection TAP block in the first 24 hours following kidney transplant surgery.

TRIAL REGISTRATION NUMBER

NCT03843879.

Postoperative pain and the gut microbiome

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Poorly controlled postoperative pain remains a major unresolved challenge globally.

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The gut microbiome impacts on inflammatory pain and neuropathic pain.

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Microbiota metabolites can regulate peripheral and central sensitisation.

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Stress is linked to both postoperative pain and an altered gut microbiome.

In excess of 300 million surgical procedures are undertaken worldwide each year. Despite recognition of the prevalence of postoperative pain, and improvements in pain management techniques, poorly controlled postoperative pain remains a major unresolved challenge globally. An estimated 71% and 51% of patients experience moderate to severe pain after surgery in in-patient and outpatient settings, respectively. Inadequately controlled pain after surgery is associated with significant perioperative morbidity including myocardial infarction and pulmonary complications.

As many as 20–56% of patients develop chronic pain after commonly performed procedures such as hernia repair, hysterectomy, and thoracotomy. Traditional analgesics and interventions are often ineffective or partially effective in the treatment of postoperative pain, resulting in a chronic pain condition with related socio-economic impacts and reduced quality of life for the patient. Such chronic pain which occurs after surgery is referred to as Persistent Post-Surgical Pain (PPSP). The complex ecosystem that is the gastrointestinal microbiota (including bacteria, fungi, viruses, phage) plays essential roles in the maintenance of the healthy state of the host. A disruption to the balance of this microbiome has been implicated not only in gastrointestinal disease but also neurological disorders including chronic pain. The influence of the gut microbiome is well documented in the context of visceral pain from the gastrointestinal tract while a greater understanding is emerging of the impact on inflammatory pain and neuropathic pain (both of which can occur during the perioperative period). The gut microbiome is an essential source for driving immune maturation and maintaining appropriate immune response. Given that inflammatory processes have been implicated in postoperative pain, aberrant microbiome profiles may play a role in the development of this type of pain. Furthermore, the microorganisms in our gut produce metabolites, neurotransmitters, and neuromodulators which interact with their receptors to regulate peripheral and central sensitisation associated with chronic pain. Microbiota-derived mediators can also regulate neuroinflammation, which is associated with activation of microglia as well as infiltration by immune cells, known to modulate the development and maintenance of central sensitisation. Moreover, risk factors for developing postoperative pain include anxiety, depression, and increased stress response. These central nervous system-related disorders have been associated with an altered gut microbiome and microbiome targeted intervention studies indicate improvements. Females are more likely to suffer from postoperative pain. As gonadal hormones are associated with a differential microbiome and pre-clinical studies show that male microbiome confers protection from inflammatory pain, it is possible that the composition of the microbiome and its by-products contribute to the increased risk for the development of postoperative pain. Very little evidence exists relating the microbiome to somatic pain. Here we discuss the potential role of the gut microbiome in the aetiology and pathophysiology of postoperative pain in the context of other somatic pain syndromes and what is known about microbe-neuron interactions. Investigations are needed to determine the specific role of the gut microbiome in this type of pain which may help inform the development of preventative interventions as well as management strategies to improve patient outcome.

Is supplemental regional anesthesia associated with more complications and readmissions after ankle fracture surgery in the inpatient and outpatient setting?

BACKGROUND

There is concern that regional anesthesia is associated with increased risk of complications, including return to the hospital for uncontrolled pain once the regional anesthetic wears off.

METHODS

Retrospective database review of patients who underwent open reduction and internal fixation of a closed ankle fracture from 2014-16 who received general anesthesia alone (GA) or general anesthesia plus regional anesthesia (RA).

RESULTS

9459 patients met inclusion criteria. Patients in the RA group had significantly longer operative duration in both inpatient (GAI=71min vs RAI=79min, p=0.002) and outpatient setting (GAO=66min vs RAI=72min, p<0.001), lower overall LOS (GA=1.7 days vs RA=1.1 days, p<0.001), and higher readmission rate for pain (RAO=4 [0.3%] vs GAO=1 [0.0%], p=0.007).

CONCLUSIONS

Patients who received supplemental regional anesthesia had shorter hospital LOS, increased operative time, and increased readmission rates for rebound pain. However, the small number of patients needing readmission are not clinically significant demonstrating that regional anesthesia is safe, effective and readmission for rebound pain should not be a concern.

LEVEL OF EVIDENCE

III.

Infiltration between the popliteal artery and the capsule of the knee (IPACK) block in knee surgery: a narrative review

BACKGROUND

The infiltration between the popliteal artery and the capsule of the knee (IPACK) block has been described as an alternative analgesic strategy for knee pain.

OBJECTIVE

Our aim was to perform a narrative review to examine the place and value that the IPACK block has in comparison to and in conjunction with other regional anesthesia modalities.

EVIDENCE REVIEW

Following an extensive search of electronic databases, we included anatomical studies, letters, comparative observational studies, and non-randomized and randomized controlled trials that examined the IPACK block in relation to surgery on the knee under general or neuraxial anesthesia.

FINDINGS

In all, 35 articles were included. Cadaveric studies demonstrated the potential for injected dye to spread to the nerves responsible for the innervation of the posterior as well as anteromedial and anterolateral aspects of the knee. Of the comparative observational studies (n=15) and non-randomized (n=1) and randomized controlled trials (n=13), 2 and 27 were conducted in the context of anterior cruciate ligament reconstruction and knee replacement surgery, respectively. The role of the IPACK block with each different permutation of regional anesthesia techniques was investigated by a small number of studies. Clinical studies, in the setting of knee replacement surgery, revealed variation in the manner in which the IPACK block was performed, and indicated the possible superiority of distal injection at the level of the femoral condyles for the management of posterior knee pain. Evidence suggested the following: the IPACK block in combination with single shot adductor canal block (ACB) may be beneficial for analgesic and functional outcomes; in conjunction with single shot or continuous ACB, the IPACK block might be superior to local infiltration analgesia (LIA); and functional outcomes may be improved with the supplementation of continuous ACB and LIA with the IPACK block. The IPACK block did not commonly result in the occurrence of foot drop. Relative to tibial nerve block (TNB), the IPACK block reduced the occurrence of foot drop and increased the proportion of patients who were able to be discharged on the third postoperative day.

CONCLUSIONS

The IPACK block was potentially complementary to the ACB and might be preferable to the TNB as a motor-sparing regional anesthesia technique in knee surgery. Definitive recommendations were not reached in the presence of the heterogeneous and limited evidence base.

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.