The effects of perineural versus intravenous dexamethasone on sciatic nerve blockade outcomes: a randomized, double-blind, placebo-controlled study

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.

Primary outcomes and anticipated effect sizes in randomised clinical trials assessing adjuncts to peripheral nerve blocks: A scoping review

BACKGROUND

Prolonging effects of adjuncts to local anaesthetics in peripheral nerve blocks have been demonstrated in randomised clinical trials. The chosen primary outcome and anticipated effect size have major impact on the clinical relevance of results in these trials. This scoping review aims to provide an overview of frequently used outcomes and anticipated effect sizes in randomised trials on peripheral nerve block adjuncts.

METHODS

For our scoping review, we searched MEDLINE, Embase and CENTRAL for trials assessing effects of adjuncts for peripheral nerve blocks published in 10 major anaesthesia journals. We included randomised clinical trials assessing adjuncts for single-shot ultrasound-guided peripheral nerve blocks, regardless of the type of interventional adjunct and control group, local anaesthetic used and anatomical localization. Our primary outcome was the choice of primary outcomes and corresponding anticipated effect size used for sample size estimation. Secondary outcomes were assessor of primary outcomes, the reporting of sample size calculations and statistically significant and non-significant results related to the anticipated effect sizes.

RESULTS

Of 11,854 screened trials, we included 59. The most frequent primary outcome was duration of analgesia (35/59 trials, 59%) with absolute and relative median (interquartile range) anticipated effect sizes for adjunct versus placebo/no adjunct: 240 min (180-318) and 30% (25-40) and for adjunct versus active comparator: 210 min (180-308) and 17% (15-28). Adequate sample size calculations were reported in 78% of trials. Statistically significant results were reported for primary outcomes in 45/59 trials (76%), of which 22% did not reach the anticipated effect size.

CONCLUSION

The reported outcomes and associated anticipated effect sizes can be used in future trials on adjuncts for peripheral nerve blocks to increase methodological homogeneity.

Effect of Perineural or Intravenous Betamethasone on Femoral Nerve Block Outcomes in Knee Arthroplasty: A Randomized, Controlled Study

OBJECTIVES

Despite the use of multimodal analgesia, patients undergoing knee arthroplasty still encounter residual moderate pain. The addition of betamethasone to local anesthetic has been shown to improve postoperative pain. However, it remains uncertain whether the positive effects of perineural or intravenous administration of betamethasone on analgesia outcomes lead to better early mobility and postoperative recovery.

METHODS

Between June 2022 and February 2023, a total of 159 patients who were undergoing knee arthroplasty were included in this study. These patients were allocated randomly into three groups: (i) the NS group, received ropivacaine 0.375% and intravenous 3mL 0.9% normal saline; (ii) the PNB group, received ropivacaine 0.375% plus perineural betamethasone (12mg) 3mL and intravenous 3mL 0.9% normal saline; and (iii) the IVB group, received ropivacaine 0.375% and intravenous betamethasone (12mg) 3mL.

RESULTS

Both perineural and intravenous administration of betamethasone led to improved median (IQR) numeric rating scale (NRS) scores on the 6-meter walk test, with a score of 1.0 (1.0-2.0) for both groups, compared with 2.0 (1.0-2.0) for the NS group (p = 0.003). Compared to the NS group, both the PNB and IVB groups showed significant reductions in NRS scores at 24 and 36 h after surgery, along with a significant increase in ROM at 24, 36, and 48 h post-operation. Additionally, it exhibited lower levels of cytokine IL-1β and TNF-α in fluid samples, as well as lower level of HS-CRP in blood samples in the PNB and IVB groups compared to the NS group.

CONCLUSION

The administration of perineural and intravenous betamethasone demonstrated an enhanced analgesic effect following knee arthroplasty. Furthermore, it was associated with reduced levels of IL-1β, TNF-α, and HS-CRP, as well as enhanced knee ROM, which is conducive to early ambulation and postoperative rehabilitation after knee arthroplasty.

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

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

Continuous peripheral nerve blocks for analgesia following painful ambulatory surgery: a review with focus on recent developments in infusion technology

PURPOSE OF REVIEW

Continuous peripheral nerve blocks (cPNB) decrease pain scores and opioid consumption while improving patient satisfaction following ambulatory surgery. This review focuses on the history and evolution of ambulatory cPNBs, recent developments in infusion technology that may prolong the duration of analgesia, optimal choice of cPNB for various surgical procedures, and novel analgesic modalities that may prove to be alternatives or supplements to cPNBs.

RECENT FINDINGS

The primary factor limiting the duration of an ambulatory cPNB is the size of the local anesthetic reservoir. Recent evidence suggests the use of automated boluses, as opposed to continuous infusions, may decrease the rate of consumption of local anesthetic and, thereby, prolong the duration of analgesia. Utilizing a long-acting local anesthetic (e.g. ropivacaine) for initial block placement and an infusion start-delay timer may further increase this duration.

SUMMARY

Patients undergoing painful ambulatory surgery are likely to have less pain and require fewer opioid analgesics when receiving a cPNB for postoperative analgesia. Advances in electronic pumps used for cPNBs may increase the duration of these benefits.

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.

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

Introduction

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

Methods

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

Results

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

Discussion

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

Evaluation of the effects of bupivacaine combined with sugammadex on the duration of the nociceptive blockade in sciatic nerve blocks: a controlled, double-blind animal study

BACKGROUND

Animal and other experimental studies have demonstrated increased block time and quality when α- and β-cyclodextrin drugs are combined with local anesthetics. However, to our knowledge, no study has utilized γ-cyclodextrins in such a combination. In the present study, we used an animal model to evaluate the effects of different doses of the combined administration of γ-cyclodextrin (sugammadex) and bupivacaine on the duration of sciatic nerve blocks in rats.

METHODS

Sciatic nerve blocks were performed with a 0.20 ml mixture in all groups. For the non-experimental groups, this mixture consisted of 0.2 ml saline (Sham group), 0.2 ml sugammadex (Group S), or 0.16 ml bupivacaine 0.5% and 0.04 ml saline (Group B). For the experimental groups, 0.16 ml bupivacaine 0.5% was administered along with 0.01 ml sugammadex and 0.03 ml saline (Group BS1), 0.02 ml sugammadex and 0.02 ml saline (Group BS2), or 0.04 ml sugammadex (Group BS4). Proprioception, nociception, and motor function were evaluated until the sciatic block was completely reversed.

RESULTS

Motor, proprioceptive, and nociceptive blockades occurred within 5 min in all experimental groups. In Group BS4, the duration of the motor, proprioceptive, and nociceptive blockades was significantly increased compared with the other experimental groups. However, in Groups BS1 and BS2, only the duration of the nociceptive blockade was significantly increased.

CONCLUSIONS

The combined administration of sugammadex and bupivacaine for sciatic nerve blocks in rats led to a significant increase in the duration of motor, proprioceptive, and nociceptive blockades.

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.

Elective surgery in ankle and foot disorders-best practices for management of pain: a guideline for clinicians

PURPOSE

Complex elective foot and ankle surgeries are often associated with severe pain pre- and postoperatively. When inadequately managed, chronic postsurgical pain and long-term opioid use can result. As no standards currently exist, we aimed to develop best practice pain management guidelines.

METHODS

A local steering committee (n = 16) surveyed 116 North American foot and ankle surgeons to understand the "current state" of practice. A multidisciplinary expert panel (n = 35) was then formed consisting of orthopedic surgeons, anesthesiologists, chronic pain physicians, primary care physicians, pharmacists, registered nurses, physiotherapists, and clinical psychologists. Each expert provided up to three pain management recommendations for each of the presurgery, intraoperative, inpatient postoperative, and postdischarge periods. These preliminary recommendations were reduced, refined, and sent to the expert panel and "current state" survey respondents to create a consensus document using a Delphi process conducted from September to December 2020.

RESULTS

One thousand four hundred and five preliminary statements were summarized into 51 statements. Strong consensus (≥ 80% respondent agreement) was achieved in 53% of statements including the following: postsurgical opioid use risk should be assessed preoperatively; opioid-naïve patients should not start opioids preoperatively unless non-opioid multimodal analgesia fails; and if opioids are prescribed at discharge, patients should receive education regarding importance of tapering opioid use. There was no consensus regarding opioid weaning preoperatively.

CONCLUSIONS

Using multidisciplinary experts and a Delphi process, strong consensus was achieved in many areas, showing considerable agreement despite limited evidence for standardized pain management in patients undergoing complex elective foot and ankle surgery. No consensus on important issues related to opioid prescribing and cessation highlights the need for research to determine best practice.

Adding Dexamethasone to Adductor Canal Block Combined with iPACK Block Improve Postoperative Analgesia of Total Knee Arthroplasty

OBJECTIVE

Both adductor canal block (ACB) and infiltration between the popliteal artery and capsule of knee (iPACK) block are mainly sensory blocks, preserved muscle strength and ability to ambulate. This study was designed to evaluate whether adding dexamethasone to ropivacaine could improve postoperative analgesia after total knee arthroplasty (TKA).

METHODS

This prospective double-blind randomized controlled trial included 60 patients who underwent unilateral TKA under general anesthesia. All patients who received ACB and iPACK block were randomly divided into a dexamethasone group (Group D, ropivacaine combined with dexamethasone) and a control group (Group C, ropivacaine only). The primary outcome was the time to first administration of rescue analgesic drugs. Secondary outcomes included the total amount of rescue analgesic drugs and the pain scores at different time points within 72 hours postoperatively; the time to first getting out of bed, quality of recovery scale (QOR-15 score), and the levels of plasma inflammatory markers (IL-6 and CRP) on postoperative day 1.

RESULTS

Compared with Group C, the time to first administration of rescue analgesic drugs of Group D was significantly extended by approximately 10.5 hours. Patients in Group D had significantly lower pain scores at postoperative different time points and consumed significantly smaller total morphine within 72 hours postoperatively. In addition, patients in group D reported significantly higher QoR-15 scores on postoperative days 1 and 3, earlier first time of getting out of bed, and significantly lower levels of CRP and IL-6 on postoperative day 1.

CONCLUSIONS

Compared with using ropivacaine alone, ultrasonic guided ACB combined with iPACK using ropivacaine and dexamethasone could prolong the duration of postoperative analgesia and strength analgesic intensity and promote the early rehabilitation exercise of patients undergoing TKA.

Comparison of the effects of perineural or intravenous dexamethasone on thoracic paravertebral block in Ivor‐Lewis esophagectomy: A double‐blind randomized trial

Efforts to prolong thoracic paravertebral block (TPVB) analgesia include local anesthetic adjuvants, such as dexamethasone (Dex). Previous studies showed that both perineural (PN) and intravenous (i.v.) routes could prolong analgesia. As PN Dex is an off‐label use, anesthesiologists should be fully informed of the clinical differences, if any, on block duration. This study was designed to evaluate the two administration routes of Dex for duration of analgesia in TPVB. Ninety‐five patients scheduled for Ivor‐Lewis esophagectomy were randomized to receive TPVB (0.5% ropivacaine 15 ml), PN or i.v. Dex 8 mg. The primary end point was the duration of analgesia. The secondary end points included pain scores, analgesic consumption, adverse effects rate, and incidence of chronic pain at 3 months postoperatively. The PN‐Dex group showed better analgesic effects than the i.v.‐Dex group (p < 0.05). Similarly, the visual analogue scale scores in patients at 2, 4, 8, and 12 h postoperatively were lower in the PN‐Dex group than the i.v.‐Dex group (p < 0.05). The analgesic consumption in both the PN‐Dex and i.v.‐Dex groups was significantly lower than that in the control group (p < 0.05). Regarding the incidence of chronic pain, regardless of route, Dex decreased the incidence of chronic postsurgical pain and neuropathic pain at 3 months after surgery (p < 0.05), but there were no clinical differences between the i.v.‐Dex and PN‐Dex groups. Perineural dexamethasone improved the magnitude and duration of analgesia compared to that of the i.v.‐Dex group in TPVB in Ivor‐Lewis esophagectomy. However, there were no clinically significant differences between the two groups in the incidence of chronic pain.

Epinephrine and Dexamethasone as Adjuvants in Upper Extremity Peripheral Nerve Blocks in Pediatric Patients

Introduction: Regional anesthesia in children in recent years has been accepted worldwide. The increased interest in it is partly due to the use of ultrasonography which provides confidence and accuracy to the anesthesiologic team. Adjuvants are used to extend the duration of the sensory and motor blocking, limiting the cumulative dose of local anesthetics. The use of adjuvants in peripheral nerve blocks in the pediatric population is still under research. Aim: To observe the effect of epinephrine and dexamethasone as adjuvants to local anesthetics in peripheral upper extremity nerve blocks in pediatric patients. Materials and methods: The study included 63 patients, aged group 4-14 years, admitted to the University Clinic of Pediatric Surgery for surgical treatment of upper limb fractures in the period of January 2020 until March 2021. Patients were randomized into three groups, and all patients in the groups received analgo-sedation prior to peripheral nerve block. Patients in group 1 (21 patients) received supraclavicular, or interscalene block with 2 ml lidocaine 2% and bupivacaine 0.25% (max 2mg/kg) with a total volume of 0.5ml/kg. In group 2, the patients (21) received 25 μg of epinephrine in 2 ml of 2% solution of lidocaine and 0.25% bupivacaine (max 2 mg/kg) with a total volume of 0.5 ml/kg, and in group 3, the patients (21) received 2% lidocaine 2ml and 0.25% bupivacaine (max 2mg/kg) in combination with 2mg dexamethasone with a total volume of 0.5ml/kg. Results: Results showed that in patients in group 1, the average duration of the sensory block was 7 hours, while the duration of the motor block was 5 hours and 30 minutes. In group 2 (epinephrine), the durations of both sensory and motor block were prolonged for about 30 minutes on average compared to the first group. In group 3 (dexamethasone) the duration of the sensory and motor block was significantly longer compared with the first two groups (p<0.0001). Conclusion: Epinephrine and dexamethasone prolong the duration of action of local anesthetics in peripheral nerve blocks of the upper extremity in pediatric patients and thus reduce the need for analgesics in the postoperative period.

Efficacy of perineural dexamethasone in prolonging duration of analgesia with peripheral nerve blocks compared to intravenous dexamethasone: A systematic review and meta-analysis

Background

Perineural dexamethasone has been regarded as a promising adjunct for prolonging the duration of nerve blocks. However, it is uncertain whether its effects are due to local effects on the nerves or from systemic absorption. This systematic review aimed to compare the duration of postoperative analgesia associated with perineural versus intravenous dexamethasone as an adjunct to peripheral nerve blocks.

Methods

A total of 2,216 relevant academic articles were identified after a comprehensive search of PubMed, Embase, Scopus, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from 1967 until 2020. All randomized controlled trials that compared perineural and intravenous dexamethasone as adjuncts to peripheral nerve limb blocks were included.

Results

Fifteen randomized controlled trials (1,467 cases; 738 perineural dexamethasone, 729 intravenous dexamethasone) were eligible. The primary outcome (duration of analgesia) was significantly longer in the perineural than in the intravenous dexamethasone group (mean difference [MD]: 2.72 h, 95% CI [1.42, 4.01], P < 0.001). Perineural dexamethasone was also found to prolong the sensory block (MD: 3.45 h, 95% CI [1.36, 5.54], P = 0.001) and lower 24 h postoperative pain scores (MD: −0.74 h, 95% CI [−1.40, −0.07], P = 0.03).

Conclusions

This review confirms the greater efficacy of perineural compared to intravenous dexamethasone in prolonging the analgesic duration of peripheral nerve blocks. However, the extent of prolongation was small and may not represent a clinically meaningful difference.

Comparison of Perineural and Intravenous Dexamethasone as an Adjuvant to Levobupivacaine in Ultrasound-Guided Infraclavicular Brachial Plexus Block: A prospective Randomized Trial

Background:

The effect of perineural versus intravenous (i.v.) dexamethasone (4 mg) when added to levobupivacaine as an adjuvant has not been well studied.

Aims:

This study was conducted to compare the analgesic efficacy of perineural and i.v. dexamethasone as an adjuvant to levobupivacaine in infraclavicular brachial plexus (ICBP) block.

Settings and Design:

This was a prospective, randomized, double-blind study.

Materials and Methods:

This study was conducted on 68 patients with the ultrasound-guided ICBP block, randomly allocated into two groups (34 each). Four patients had failed block (2 in each group) that was excluded from the study. Group A received 25 mL of levobupivacaine 0.5% and 1 mL of normal saline for the block and i.v. dexamethasone 4 mg. Group B received 25 mL of levobupivacaine 0.5% with 4 mg of perineural dexamethasone for the block. Postoperative vitals and different block characteristics were assessed.

Statistical Analysis Used:

Student's independent sample t-test and Chi-square test were used for statistical analysis.

Results:

The duration of motor block and analgesia in Group A was 1245.94 ± 153.22 min and 1310.16 ± 151.68 min, respectively. However, in Group B, the duration of motor block and analgesia was 1768.13 ± 309.86 min and 1743.59 ± 231.39 min, respectively, which was more when compared to Group A (P < 0.001). The Visual Analog Scale score of ≥3 in Group A was 37% and in Group B was 9% (P = 0.008). Four cases had delayed regression of motor block in the perineural group.

Conclusions:

Perineural dexamethasone significantly prolonged the duration of motor block promoted by levobupivacaine in infraclavicular brachial plexus block, reduced pain intensity and rescue analgesia needs in the postoperative period when compared with the intravenous dexamethasone.

Dexmedetomidine Added to Ropivacaine for Ultrasound-guided Erector Spinae Plane Block Prolongs Analgesia Duration and Reduces Perioperative Opioid Consumption After Thoracotomy: A Randomized, Controlled Clinical Study

OBJECTIVES

Single-injection erector spinae plane block (ESPB) provides good control of pain relief after open thoracotomy surgeries. However, the duration of pain relief does not last long. For this purpose, we hypothesized that adding α2-adrenoceptor agonist, dexmedetomidine, for interfascial nerve blockade may increase the duration of analgesia. There are only few studies using dexmedetomidine for interfasical nerve blocks in humans. In this study, our aim is to investigate whether addition of dexmedetomidine to ropivacaine for ESPB could effectively prolong the duration of postoperative analgesia and reduce opioid consumption after open thoracotomy.

MATERIALS AND METHODS

Sixty patients with esophageal cancer were randomized to receive ESPB using 28 mL of 0.5% ropivacaine, with 2 mL of normal saline (group R) or 0.5 µg/kg dexmedetomidine in 2 mL (group RD) administered interfascially. ESPB was performed at the fifth thoracic level under ultrasound guidance. The primary outcome was the duration of analgesia. The secondary outcomes were total postoperative sufentanil consumption, Numeric Rating Scale pain scores, Ramsay Sedation Scale scores and adverse effects.

RESULTS

The duration of analgesia in group RD (505.1±113.9) was longer than that in group R (323.2±75.4) (P<0.001). The total postoperative sufentanil consumption was lower in group RD (23.3±10.0) than in group R (33.8±13.8) (P=0.001). There was no significant difference in the incidence of adverse effects between the 2 groups.

CONCLUSION

After open thoracotomy, addition of dexmedetomidine to ropivacaine for ESPB effectively prolonged the duration of postoperative analgesia and reduced opioid consumption without increasing additional incidence of adverse effects.

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

Background

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

Methods

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

Results

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

Conclusion

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

Trial registration

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

Effect of Dexamethasone in Peripheral Nerve Blocks on Recovery of Nerve Function

BACKGROUND

Peripheral nerve blocks (PNBs) have revolutionized distal extremity surgery reducing pain and improving hospital efficiency. Perineural dexamethasone has been administered with PNBs to prolong their effects, although the safety of dexamethasone has not been established in the literature. This study aimed to determine if the addition of dexamethasone affected the postoperative neurological sensory status for foot and ankle surgeries and the recovery of nerve injuries. We hypothesized that the rate of persistent nerve injury would be higher in the dexamethasone group.

METHODS

This is a retrospective observational cohort study of prospectively collected data of all patients from a single foot and ankle surgeon's practice. Perineural dexamethasone was routinely used as an adjunct by the regional anesthesia group until a clinical trend of increased paresthesia was found on short-term follow-up, which led to the discontinuation of its use. In this study, the cohort that received dexamethasone with ropivacaine was compared with the cohort that received ropivacaine alone. The primary outcome was a separate sensory nerve status sheet that was completed for every distal nerve territory for every patient at their follow-up visits at 2 weeks, 6 weeks, 3 months, and 6 months. Univariate analysis and a logistic regression model were used to determine the association between dexamethasone and delayed nerve recovery. A total of 250 patients were included in the study, with 117 patients in the dexamethasone group and 133 in the ropivacaine-only group.

RESULTS

The rates of nerve injuries were not different between the groups (72 [62%] in the dexamethasone group vs 79 [59%] in the ropivacaine-only group). However, nerve injury symptoms were more likely to persist and not fully recover in the dexamethasone group (n = 47, 65%) compared with the ropivacaine-only group (n = 32, 41%) (OR, 2.12; P = .006).

CONCLUSION

Perineural dexamethasone added to PNBs may be associated with delayed nerve recovery after foot and ankle surgery. It may be prudent to avoid its use until its full safety profile is established in larger prospective trials.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Protocol of DEXPED trial: efficacy of intravenous dexamethasone, administered at the time of analgesic blocking of the lower limb, on postoperative pain in children: a randomised, placebo-controlled, double-blind trial

INTRODUCTION

Dexamethasone is a drug used to prolong the postoperative analgesia in children after peripheral nerve blockade, although the dose usually used (0.2 mg/kg) has not been studied yet. This study is a monocentric, prospective, randomised, placebo-controlled, double-blinded study in a university hospital in France. The primary objective of the study is to evaluate the efficacy of 0.2 mg/kg intravenous dexamethasone on early postoperative pain in children aged 6-15 years, who require a lower limb peripheral nerve block following general anaesthesia.

METHODS AND ANALYSIS

Eighty children, aged 6-15 years, undergoing surgery for which peripheral nerve lower limb blockade with ropivacaine following general anaesthesia are included. The inclusion criteria are: children aged 6-15 years, with American Society of Anaesthesiologists physical status I or II and scheduled for surgery requiring a peripheral block of the lower limb for analgesic purposes, with a preoperative anaesthetic evaluation between 90 and 2 days before the surgery, with informed consent from legal representatives. General anaesthesia is performed. The patient receives, according to his group, either 0.2 mg/kg of dexamethasone intravenously at the start of anaesthetic induction or the same volume of placebo. Then, the peripheral block of the lower limb is performed with ropivacaine. The primary outcome is the total doses of opioid administered (in mg/kg of morphine equivalent) within 24 hours postoperatively. The secondary objectives are the evaluation of the effect of a single-dose intravenous dexamethasone at the time of anaesthetic induction, on the following parameters: onset of postoperative pain, duration of motor block, postoperative nausea and vomiting within 24 hours.

ETHICS AND DISSEMINATION

This study is conducted according to the principles of the Declaration of Helsinki and has been approved by the French national ethics committee and the National Drug Safety Agency. Findings of this study will be widely disseminated through conference presentations, reports, factsheets and academic publications.

TRIAL REGISTRATION NUMBER

NCT03618173.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Peripheral nerve catheters: A critical review of the efficacy

Continuous peripheral nerve blocks are commonly used for postoperative analgesia after surgery. However, catheter failure may occur due to either primary (incorrect insertion) or secondary reasons (displacement, obstruction, disconnection). Catheter failure results in unanticipated pain, need for opioid use, and risk of readmission or delay in hospital discharge. This review aimed to assess definition and frequency of catheter failure, and discuss the alternatives to prolong duration of single-shot nerve blocks. A literature search was performed on peripheral catheters reporting failure as the main outcome measure. Thirty-three studies met the selection criteria, comprising 2711 catheters. Literature review suggests that peripheral nerve catheters have clinically significant failure rate when the assessment is performed using an objective (imaging) method. Subjective methods of assessment (without imaging) may underestimate the incidence of catheter failure.

A Retrospective Study Evaluating the Effect of Low Doses of Perineural Dexamethasone on Ropivacaine Brachial Plexus Peripheral Nerve Block Analgesic Duration

Objective

Examination of the effectiveness of perineural dexamethasone administered in very low and low doses on ropivacaine brachial plexus block duration.

Design

Retrospective evaluation of brachial plexus block duration in a large cohort of patients receiving peripheral nerve blocks with and without perineural dexamethasone in a prospectively collected quality assurance database.

Setting

A single academic medical center.

Methods

A total of 1,942 brachial plexus blocks placed over a 16-month period were reviewed. Demographics, nerve block location, and perineural dexamethasone utilization and dose were examined in relation to block duration. Perineural dexamethasone was examined as none (0 mg), very low dose (2 mg or less), and low dose (greater than 2 mg to 4 mg). Continuous catheter techniques, local anesthetics other than ropivacaine, and block locations with fewer than 15 subjects were excluded. Associations between block duration and predictors of interest were examined using multivariable regression models. A subgroup analysis of the impact of receiving dexamethasone on block duration within each block type was also conducted using a univariate linear regression approach.

Results

A total of 1,027 subjects were evaluated. More than 90% of brachial plexus blocks contained perineural dexamethasone (≤4 mg), with a median dose of 2 mg. Increased block duration was associated with receiving any dose of perineural dexamethasone (P < 0.0001), female gender (P = 0.022), increased age (P = 0.048), and increased local anesthetic dose (P = 0.01). In a multivariable model, block duration did not differ with very low- or low-dose perineural dexamethasone after controlling for other factors (P = 0.420).

Conclusion

Perineural dexamethasone prolonged block duration compared with ropivacaine alone; however, duration was not greater with low-dose compared with very low-dose perineural dexamethasone.

Perioperative pain management and chronic postsurgical pain after elective foot and ankle surgery: a scoping review

PURPOSE

Chronic postsurgical pain (CPSP) can occur after elective mid/hindfoot and ankle surgery. Effective treatment approaches to prevent the development of CPSP in this population have not been extensively investigated. The impact of multimodal strategies to prevent CPSP following elective mid/hindfoot surgery is unknown because of both the heterogeneity of acute pain management and the lack of a recognized definition particular to this surgery. This review aimed to identify and evaluate current pain management strategies after elective mid/hindfoot and ankle surgery.

SOURCES

Manual and electronic searches (MEDLINE, Embase, and Cochrane Library) were conducted of literature published between 1990 and July 2017. Comparative studies of adults undergoing elective mid/hindfoot and ankle surgery were included. Two reviewers independently reviewed studies and assessed their methodological quality.

PRINCIPAL FINDINGS

We found seven randomized-controlled trials meeting our inclusion criteria. Interventions focused on regional anesthesia techniques such as continuous popliteal sciatic and femoral nerve blockade. Participants were typically followed up to 48 hr postoperatively. Only one study assessed pain six months following elective mid/hindfoot and ankle surgery.

CONCLUSION

There is an overwhelming lack of evidence regarding CPSP and its management for patients undergoing elective mid/hindfoot and ankle surgery. The lack of a recognized and standard definition of CPSP after this group of surgeries precludes accurate and consistent evaluation.

Lower extremity regional anesthesia: essentials of our current understanding

The advent of ultrasound guidance has led to a renewed interest in regional anesthesia of the lower limb. In keeping with the American Society of Regional Anesthesia and Pain Medicine's ongoing commitment to provide intensive evidence-based education, this article presents a complete update of the 2005 comprehensive review on lower extremity peripheral nerve blocks. The current review article strives to (1) summarize the pertinent anatomy of the lumbar and sacral plexuses, (2) discuss the optimal approaches and techniques for lower limb regional anesthesia, (3) present evidence to guide the selection of pharmacological agents and adjuvants, (4) describe potential complications associated with lower extremity nerve blocks, and (5) identify informational gaps pertaining to outcomes, which warrant further investigation.

Perineural Low-Dose Dexamethasone Prolongs Interscalene Block Analgesia With Bupivacaine Compared With Systemic Dexamethasone: A Randomized Trial

BACKGROUND AND OBJECTIVES

Perineural dexamethasone and intravenous (IV) dexamethasone have been shown to prolong peripheral nerve block duration. The effects of perineural and IV dexamethasone have only been compared at doses of 4 mg or greater. This triple-blind, randomized trial examined the effect of 1 mg IV versus perineural dexamethasone on interscalene block (ISB) analgesia duration.

METHODS

Patients undergoing ambulatory shoulder arthroscopy received an ultrasound-guided ISB with 15 mL bupivacaine 0.5% and 1 mg preservative-free dexamethasone that was administered perineurally (PeriD) or IV (IVDex). All patients received IV ketorolac and were discharged on naproxen 500 mg 2 times a day plus oxycodone/acetaminophen as needed. Peripheral nerve block duration, pain, opioid consumption, and block satisfaction were assessed via telephone follow-ups.

RESULTS

There were 63 PeriD patients and 62 IVDex patients who completed the primary outcome follow-up. The median time until analgesia from the ISB completely wore off was 3.5 hours (95% confidence interval, 1.0-6.0 hours) longer in the PeriD versus IVDex groups; P = 0.007). Time until the pain relief from the ISB began to wear off was also longer in the PeriD versus IVDex group (5.5 hours [95% confidence interval, 2.1-9.0 hours]; P = 0.002). Other secondary outcomes, including opioid consumption, satisfaction, and pain scores, were not different between groups.

CONCLUSIONS

In patients undergoing shoulder arthroscopy, low-dose perineural dexamethasone (1 mg) in combination with 15 mL of 0.5% bupivacaine prolonged the median time until pain relief from the ISB completely wore off compared with 1 mg IV dexamethasone. However, the degree of prolongation was smaller than the a priori-defined minimal clinically meaningful difference of 5 hours.

CLINICAL TRIAL REGISTRATION

This study was registered at Clinicaltrials.gov, identifier NCT02506660.

Effect of Perineural and Intravenous Dexamethasone on Duration of Analgesia in Supraclavicular Brachial Plexus Block with Bupivacaine: A Comparative Study

Background:

Perineural dexamethasone has been shown to improve analgesia in single injection supraclavicular block. Systemic mechanism of action of dexamethasone along with safety concerns of perineural route of administration has prompted the investigation of intravenous route as an alternative.

Aims:

We aim to compare the effects of dexamethasone as an additive to local anesthetic when used via perineural and intravenous route in terms of duration of analgesia and onset of motor and sensory block.

Settings and Design:

The study was done as a prospective comparative observational study conducted in a tertiary care hospital in India among 50 patients during a period of 1 year.

Materials and Methods:

Twenty-five patients aged 18–60 years, belonging to the American Society of Anesthesiologists physical status Classes I and II, receiving supraclavicular block with 0.5% bupivacaine and perineural dexamethasone were compared with similar number of patients receiving the block along with intravenous dexamethasone. Duration of analgesia, onset of sensory block, and onset of motor block were studied.

Statistical Analysis:

The results were analyzed using Chi-square test for qualitative variables and unpaired t-test for quantitative variables.

Results:

The duration of analgesia in the group receiving perineural dexamethasone (Group DP) 817.2 ± 88.011 min was comparable to the group receiving intravenous dexamethasone (Group DI) 858.00 ± 86.168, with a P = 0.104. Time to onset of sensory block in Group DP (10.20 ± 1.443 min) was significantly faster than that of Group DI (11.60 ± 1.443) with a P = 0.001. Time to onset of motor block in Group DP (13.92 ± 1.754 min) was significantly earlier than that of Group DI (14.96 ± 1.274 min) with a P = 0.02.

Conclusion:

It is concluded from this study that intravenous and perineural dexamethasone equally prolongs the duration of analgesia in supraclavicular block. However, perineural dexamethasone resulted in a faster onset of motor and sensory blockade.

Prospective Evaluation of Utilization Patterns and Prescribing Guidelines of Opioid Consumption Following Orthopedic Foot and Ankle Surgery

BACKGROUND

Overprescription of narcotic pain medication is a major culprit in the present opioid epidemic plaguing the United States. The current literature on lower extremity opioid usage has limitations and would benefit from additional study. The purpose of our study was to prospectively assess opioid consumption patterns following outpatient orthopedic foot and ankle procedures.

METHODS

Patients undergoing outpatient orthopedic foot and ankle procedures who met inclusion criteria had the following prospective information collected: patient demographics, preoperative health history, patient-reported outcomes, anesthesia type, procedure type, opioid prescription and consumption details. The morphine equivalent dose was calculated for each prescription and then converted to the equivalent of a 5-mg oxycodone "pill." Univariable analyses were performed to identify variables with a statistically robust association with opioid consumption for inclusion in a multivariable linear regression. A stepwise backward regression was then performed to identify independent predictors of opioid consumption. Postoperative opioid utilization was reported for 988 patients (mean age: 49 years).

RESULTS

Overall, patients consumed a median of 20 pills whereas the median number of pills prescribed was 40. This resulted in a utilization rate of 50% and 20 631 pills left unused. Independent factors associated with higher opioid consumption were anesthesia type ( P < .004), age <60 years ( P < .001), preoperative visual analog scale (VAS) pain report of >6 ( P = .008), and bony procedures ( P = .008); residual standard error 16.73 ( F_7,844=14.3, P < .001).

CONCLUSION

Our study found that patients who underwent orthopedic foot and ankle procedures were overprescribed narcotic medication by nearly twice the amount that was actually consumed. Although we identified 4 independent factors associated with opioid consumption, the large residual standard error suggests that there remains a substantial degree of unexplained variance of opioid consumption observed in the patient population. Physicians face a challenging task of setting appropriate protocols when balancing pain relief and generalizable guidelines.

LEVEL OF EVIDENCE

Level II, prospective observational cohort study.

Effect of Perineural Dexamethasone on the Duration of Single Injection Saphenous Nerve Block for Analgesia After Major Ankle Surgery: A Randomized, Controlled Study

BACKGROUND AND OBJECTIVES

Patients undergoing major elective ankle surgery often experience pain from the saphenous nerve territory persisting beyond the duration of a single-injection saphenous nerve block. We hypothesized that perineural dexamethasone as an adjuvant for the saphenous nerve block prolongs the duration of analgesia and postpones as well as reduces opioid-requiring pain.

METHODS

Forty patients were included in this prospective, randomized, controlled study. All patients received a continuous sciatic catheter and were randomized to receive a single-injection saphenous nerve block with 10 mL of 0.5% bupivacaine with 1:200,000 epinephrine with addition of 1 mL of saline or 1 mL of 0.4% (ie, 4 mg) dexamethasone. The primary outcome was duration of saphenous nerve block estimated as the time until the first opioid request. Secondary outcomes were opioid consumption and pain.

RESULTS

The mean (SD) duration of the saphenous nerve block until first opioid request was 29.4 (8.4) hours in the dexamethasone group and 23.2 (10.3) hours in the control group (P = 0.048). The median opioid consumption [interquartile range] during the first 24 hours was 0 mg [0-0] versus 1.5 mg [0-14.2] in the dexamethasone and control groups, respectively. Nonparametric comparison of opioid consumption from 0 to 24 hours was statistically significant. The opioid consumption was similar in the two groups in the time interval 24 to 48 postoperative hours.

CONCLUSION

Perineural dexamethasone as an adjuvant for the single-injection subsartorial saphenous nerve block can prolong analgesia and reduce opioid-requiring pain after major ankle surgery.

Designing the ideal perioperative pain management plan starts with multimodal analgesia

Multimodal analgesia is defined as the use of more than one pharmacological class of analgesic medication targeting different receptors along the pain pathway with the goal of improving analgesia while reducing individual class-related side effects. Evidence today supports the routine use of multimodal analgesia in the perioperative period to eliminate the over-reliance on opioids for pain control and to reduce opioid-related adverse events. A multimodal analgesic protocol should be surgery-specific, functioning more like a checklist than a recipe, with options to tailor to the individual patient. Elements of this protocol may include opioids, non-opioid systemic analgesics like acetaminophen, non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, and local anesthetics administered by infiltration, regional block, or the intravenous route. While implementation of multimodal analgesic protocols perioperatively is recommended as an intervention to decrease the prevalence of long-term opioid use following surgery, the concurrent crisis of drug shortages presents an additional challenge. Anesthesiologists and acute pain medicine specialists will need to advocate locally and nationally to ensure a steady supply of analgesic medications and in-class alternatives for their patients’ perioperative pain management.

Does dexamethasone have a perineural mechanism of action? A paired, blinded, randomized, controlled study in healthy volunteers

BACKGROUND

Dexamethasone prolongs block duration. Whether this is achieved via a peripheral or a central mechanism of action is unknown. We hypothesized that perineural dexamethasone added as an adjuvant to ropivacaine prolongs block duration compared with ropivacaine alone, by a locally mediated effect when controlled for a systemic action.

METHODS

We performed a paired, blinded, randomized trial, including healthy men. All subjects received bilateral blocks of the saphenous nerve with ropivacaine 0.5%, 20 ml mixed with dexamethasone 2 mg in one leg and saline in the other, according to randomization. The primary outcome was the duration of sensory block assessed by temperature discrimination in the saphenous nerve distribution. Secondary outcomes were sensory block assessed by mechanical discrimination, pain response to tonic heat stimulation, and warmth and heat pain detection thresholds.

RESULTS

We included 20 subjects; one had a failed block and was excluded from the paired analysis. Block duration was not statistically significantly longer in the leg receiving dexamethasone when assessed by temperature discrimination (primary outcome, estimated median difference 1.5 h, 95% confidence interval -3.5 to 0, P=0.050). For all other outcomes, the duration was statistically significantly longer in the leg receiving dexamethasone, but the median differences were <2.0 h. Individual subject analysis revealed that only eight subjects had a block prolongation of at least 2 h in the leg receiving dexamethasone perineurally.

CONCLUSION

Perineural administration of dexamethasone 2 mg showed a modest and inconsistent effect of questionable clinical relevance on block duration.

CLINICAL TRIAL REGISTRATION

NCT01981746.

Quality of Recovery After Low-Pressure Laparoscopic Donor Nephrectomy Facilitated by Deep Neuromuscular Blockade: A Randomized Controlled Study

Background

The use of low intra-abdominal pressure (<10 mmHg) reduces postoperative pain scores after laparoscopic surgery.

Objective

To investigate whether low-pressure pneumoperitoneum with deep neuromuscular blockade improves the quality of recovery after laparoscopic donor nephrectomy (LDN).

Design, setting and participants

In a single-center randomized controlled trial, 64 live kidney donors were randomly assigned to 6 or 12 mmHg insufflation pressure. A deep neuromuscular block was used in both groups. Surgical conditions were rated by the five-point Leiden-surgical rating scale (L-SRS), ranging from 5 (optimal) to 1 (extremely poor) conditions. If the L-SRS was insufficient, the pressure was increased stepwise.

Main outcome measure

The primary outcome measure was the overall score on the quality of recovery-40 (QOR-40) questionnaire at postoperative day 1.

Results

The difference in the QOR-40 scores on day 1 between the low- and standard-pressure group was not significant (p = .06). Also the overall pain scores and analgesic consumption did not differ. Eight procedures (24%), initially started with low pressure, were converted to a standard pressure (≥10 mmHg). A L-SRS score of 5 was significantly more prevalent in the standard pressure as compared to the low-pressure group at 30 min after insufflation (p < .01).

Conclusions

Low-pressure pneumoperitoneum facilitated by deep neuromuscular blockade during LDN does not reduce postoperative pain scores nor improve the quality of recovery in the early postoperative phase. The question whether the use of deep neuromuscular blockade during laparoscopic surgery reduces postoperative pain scores independent of the intra-abdominal pressure should be pursued in future studies.

Trial registration

The trial was registered at clinicaltrial.gov before the start of the trial (NCT02146417).

The Combination of IV and Perineural Dexamethasone Prolongs the Analgesic Duration of Intercostal Nerve Blocks Compared with IV Dexamethasone Alone

Objective

The use of multiple-level, single-injection intercostal nerve blocks for pain control following video-assisted thorascopic surgery (VATS) is limited by the analgesic duration of local anesthetics. This study examines whether the combination of perineural and intravenous (IV) dexamethasone will prolong the duration of intraoperatively placed intercostal nerve blocks following VATS compared with IV dexamethasone and a perineural saline placebo.

Design

Prospective, double-blind, randomized placebo-controlled trial.

Setting

Single level-1 academic trauma center.

Subjects

Forty patients undergoing a unilateral VATS under the care of a single surgeon.

Methods

Patients were randomly assigned to two groups and received an intercostal nerve block containing 1) 0.5% bupivacaine with epinephrine and 1 ml of 0.9% saline or 2) 0.5% bupivacaine with epinephrine and 1 ml of a 4 mg/ml dexamethasone solution. All patients received 8 mg of IV dexamethasone.

Results

Group 2 had lower NRS-11 scores at post-operative hours 8 (5.05, SD = 2.13 vs 3.50, SD = 2.50; p  = 0.04), 20 (4.30, SD = 2.96 vs 2.26, SD = 2.31; p  = 0.02), and 24 (4.53, SD = 1.95 vs 2.26, SD = 2.31; p  = 0.02). Equianalgesic opioid requirement was decreased in group 2 at 32 hours (5.78 mg, SD = 5.77 vs 1.67 mg, SD = 3.49; p  = 0.02). Group 2 also had greater FEV1 measured at 8, 12, 24, and 44 hours; greater FVC at 24 hours; greater PEF at 28 through 48 hours; and greater FEV1/FVC at 8 and 36 hours.

Conclusions

The combination of IV and perineural dexamethasone prolonged the duration of a single-injection bupivacaine intercostal nerve block as measured by NRS-11 compared with IV dexamethasone alone at 24 hours. Reduced NRS-11 at other times, reduced opioid requirements, and increased PFTs were observed in group 2.

The effect of perineural dexamethasone on duration of sciatic nerve blockade: a randomized, double-blind study

BACKGROUND

Major hindfoot and ankle surgery is associated with severe postoperative pain, which is effectively alleviated by combined sciatic and saphenous nerve blockade. Local anaesthetics with added dexamethasone consistently prolongs the duration of pain relief compared to local anaesthetics alone. However, whether the extended duration of pain relief is due to an effect on duration of sensorimotor block per se vs. systemic absorption of the dexamethasone is still not fully elucidated. We aimed to investigate the postoperative duration of sensorimotor blockade with either dexamethasone or saline added to bupivacaine-epinephrine.

METHODS

Fifty six patients scheduled for surgery were randomly assigned to a popliteal sciatic nerve block of 18 ml 0.5% bupivacaine-epinephrine with either 2 ml of 0.4% dexamethasone or 2 ml 0.9% normal saline added. Sensory and motor functions were tested every 30 min until normalized nerve functions. Primary outcome was time until complete return of sensorimotor functions.

RESULTS

Mean (SD) time until return of normal sensory and motor functions was 26 (6) vs. 16 (4) hours, P < 0.001, postponing block remission by 10 (95% CI: 8-13) hours. Mean (SD) time until first opioid request was 34 (11) vs. 15 (7) hours, P < 0.001, extending first opioid request by 19 (95% CI: 13-25) hours. Total oral morphine equivalents administered 0-48 h differed significantly between the two groups by 39 (95% CI: 23-55) mg.

CONCLUSIONS

Addition of 8 mg dexamethasone to 0.5% bupivacaine-epinephrine significantly prolongs the duration of sensorimotor popliteal sciatic nerve blockade, and reduces pain and opioid consumption in patients after major hind foot and ankle surgery.

Dexamethasone Compared to Dexmedetomidine as an Adjuvant to Local Anesthetic Mixture in Peribulbar Block for Vitreoretinal Surgery. A Prospective Randomized Study

BACKGROUND

Dexamethasone or dexmedetomidine may improve the quality of peribulbar block.

AIM

The aim of this study is to compare the effects of adding either dexamethasone or dexmedetomidine to peribulbar block on the efficacy, intraocular pressure (IOP), time to first analgesic request, total analgesic requirement, and side effects in patients undergoing vitreoretinal surgery.

DESIGN

This was a clinical prospective randomized study.

PATIENTS AND METHODS

One hundred and fifty adult patients scheduled for vitreoretinal surgery with peribulbar block were randomized into three groups (50 patients each). Group I received 3.5 ml of 0.5% bupivacaine and 3.5 ml of 2% lidocaine + 1 ml normal Saline. 4 mg dexamethasone and 25 μg dexmedetomidine in 1 ml were added to the local anesthetic mixture in Groups II and III respectively. Onset and duration of sensory and motor blocks, adequate time to start surgery, IOP, time to first request of rescue analgesia, total analgesic consumption, and side effects were recorded. The statistical software SPSS 16 was utilized for statistical analysis.

RESULTS

Dexamethasone and dexmedetomidine groups showed significantly prolonged duration of corneal anesthesia (234.07 ± 1.37 and 233.54.1.97 min respectively), prolonged lid and globe akinesia (194.27 ± 1.63 and 194.73 ± 2.35 min respectively) with prolonged time to first request of analgesia and less consumption of rescue analgesia as compared to control group (P < 0.05) with non significant differences between both groups (P > 0.05). The onset of corneal anesthesia as well as lid and globe akinesia were enhanced in dexmedetomidine group compared to the other two groups (P < 0.05). In addition, the measurement of IOP was significantly less in the dexmedetomidine group after 10 min. All the patients were hemodynamically stable with no side effects observed.

CONCLUSION

The addition of dexamethasone and dexmedetomidine to local anesthetic mixture in peribulbar block for vitreoretinal surgeries provided safe and effective block with prolonged duration and decreased requirements of postoperative analgesia with better quality for dexmedetomidine group regarding the fast onset of the block and reduced IOP.

A Randomized Non-Inferiority Trial of Adductor Canal Block for Analgesia After Total Knee Arthroplasty: Single Injection Versus Catheter Technique

BACKGROUND

Adductor canal blocks (ACBs) provide effective analgesia following total knee arthroplasty. We hypothesized that ACB single injection plus intravenous (IV) dexamethasone (Dex) shows non-inferiority to catheter, while ACB single injection does not.

METHODS

One hundred eighty patients were randomized and 177 analyzed from among 1 of 3 ACB interventions: (1) 0.5% ropivacaine 20 mL; (2) 0.5% ropivacaine 20 mL plus IV Dex 8 mg; (3) 0.5% ropivacaine 20 mL followed by continuous infusion of 0.2% ropivacaine at 5 mL/h for 48 hours. The primary endpoint was cumulative opioid consumption at 24 hours in oral morphine equivalents, with a non-inferiority limit of 30 mg. Secondary endpoints included opioid consumption at 12 and 48 hours, rest pain scores, quality of recovery survey, length of stay, and anti-emetic usage.

RESULTS

For 24-hour opioid consumption, single injection ACB with and without IV Dex had a mean difference of -24.2 mg (confidence interval [CI] 0.5 to -48.9, P < .001) and -21 mg (CI 3.2 to -45.1, P < .001) relative to catheter, demonstrating non-inferiority. Non-inferiority was also shown at 12 hours by Dex and single injection over catheter with mean difference of -20.4 mg (CI -6.8 to -33.9, P < .001) and -15.1 mg (CI -2.1 to -28.2, P < .001), respectively. No intergroup difference was found for 48-hour opioid consumption. No differences in other secondary outcomes were observed across the 3 groups.

CONCLUSION

Single injection ACB, with and without IV Dex, is non-inferior to ACB catheters in 24-hour opioid consumption, and may be attractive options for early-discharge, fast-track total knee arthroplasty.

Advances in regional anaesthesia: A review of current practice, newer techniques and outcomes

Advances in ultrasound guided regional anaesthesia and introduction of newer long acting local anaesthetics have given clinicians an opportunity to apply novel approaches to block peripheral nerves with ease. Consequently, improvements in outcomes such as quality of analgesia, early rehabilitation and patient satisfaction have been observed. In this article we will review some of the newer regional anaesthetic techniques, long acting local anaesthetics and adjuvants, and discuss evidence for key outcomes such as cancer recurrence and safety with ultrasound guidance.

Dexamethasone as an adjuvant to peripheral nerve block

BACKGROUND

Peripheral nerve block (infiltration of local anaesthetic around a nerve) is used for anaesthesia or analgesia. A limitation to its use for postoperative analgesia is that the analgesic effect lasts only a few hours, after which moderate to severe pain at the surgical site may result in the need for alternative analgesic therapy. Several adjuvants have been used to prolong the analgesic duration of peripheral nerve block, including perineural or intravenous dexamethasone.

OBJECTIVES

To evaluate the comparative efficacy and safety of perineural dexamethasone versus placebo, intravenous dexamethasone versus placebo, and perineural dexamethasone versus intravenous dexamethasone when added to peripheral nerve block for postoperative pain control in people undergoing surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, DARE, Web of Science and Scopus from inception to 25 April 2017. We also searched trial registry databases, Google Scholar and meeting abstracts from the American Society of Anesthesiologists, the Canadian Anesthesiologists' Society, the American Society of Regional Anesthesia, and the European Society of Regional Anaesthesia.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) comparing perineural dexamethasone with placebo, intravenous dexamethasone with placebo, or perineural dexamethasone with intravenous dexamethasone in participants receiving peripheral nerve block for upper or lower limb surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 35 trials of 2702 participants aged 15 to 78 years; 33 studies enrolled participants undergoing upper limb surgery and two undergoing lower limb surgery. Risk of bias was low in 13 studies and high/unclear in 22. Perineural dexamethasone versus placeboDuration of sensory block was significantly longer in the perineural dexamethasone group compared with placebo (mean difference (MD) 6.70 hours, 95% confidence interval (CI) 5.54 to 7.85; participants1625; studies 27). Postoperative pain intensity at 12 and 24 hours was significantly lower in the perineural dexamethasone group compared with control (MD -2.08, 95% CI -2.63 to -1.53; participants 257; studies 5) and (MD -1.63, 95% CI -2.34 to -0.93; participants 469; studies 9), respectively. There was no significant difference at 48 hours (MD -0.61, 95% CI -1.24 to 0.03; participants 296; studies 4). The quality of evidence is very low for postoperative pain intensity at 12 hours and low for the remaining outcomes. Cumulative 24-hour postoperative opioid consumption was significantly lower in the perineural dexamethasone group compared with placebo (MD 19.25 mg, 95% CI 5.99 to 32.51; participants 380; studies 6). Intravenous dexamethasone versus placeboDuration of sensory block was significantly longer in the intravenous dexamethasone group compared with placebo (MD 6.21, 95% CI 3.53 to 8.88; participants 499; studies 8). Postoperative pain intensity at 12 and 24 hours was significantly lower in the intravenous dexamethasone group compared with placebo (MD -1.24, 95% CI -2.44 to -0.04; participants 162; studies 3) and (MD -1.26, 95% CI -2.23 to -0.29; participants 257; studies 5), respectively. There was no significant difference at 48 hours (MD -0.21, 95% CI -0.83 to 0.41; participants 172; studies 3). The quality of evidence is moderate for duration of sensory block and postoperative pain intensity at 24 hours, and low for the remaining outcomes. Cumulative 24-hour postoperative opioid consumption was significantly lower in the intravenous dexamethasone group compared with placebo (MD -6.58 mg, 95% CI -10.56 to -2.60; participants 287; studies 5). Perinerual versus intravenous dexamethasoneDuration of sensory block was significantly longer in the perineural dexamethasone group compared with intravenous by three hours (MD 3.14 hours, 95% CI 1.68 to 4.59; participants 720; studies 9). We found that postoperative pain intensity at 12 hours and 24 hours was significantly lower in the perineural dexamethasone group compared with intravenous, however, the MD did not surpass our pre-determined minimally important difference of 1.2 on the Visual Analgue Scale/Numerical Rating Scale, therefore the results are not clinically significant (MD -1.01, 95% CI -1.51 to -0.50; participants 217; studies 3) and (MD -0.77, 95% CI -1.47 to -0.08; participants 309; studies 5), respectively. There was no significant difference in severity of postoperative pain at 48 hours (MD 0.13, 95% CI -0.35 to 0.61; participants 227; studies 3). The quality of evidence is moderate for duration of sensory block and postoperative pain intensity at 24 hours, and low for the remaining outcomes. There was no difference in cumulative postoperative 24-hour opioid consumption (MD -3.87 mg, 95% CI -9.93 to 2.19; participants 242; studies 4). Incidence of severe adverse eventsFive serious adverse events were reported. One block-related event (pneumothorax) occurred in one participant in a trial comparing perineural dexamethasone and placebo; however group allocation was not reported. Four non-block-related events occurred in two trials comparing perineural dexamethasone, intravenous dexamethasone and placebo. Two participants in the placebo group required hospitalization within one week of surgery; one for a fall and one for a bowel infection. One participant in the placebo group developed Complex Regional Pain Syndrome Type I and one in the intravenous dexamethasone group developed pneumonia. The quality of evidence is very low due to the sparse number of events.

AUTHORS' CONCLUSIONS

Low- to moderate-quality evidence suggests that when used as an adjuvant to peripheral nerve block in upper limb surgery, both perineural and intravenous dexamethasone may prolong duration of sensory block and are effective in reducing postoperative pain intensity and opioid consumption. There is not enough evidence to determine the effectiveness of dexamethasone as an adjuvant to peripheral nerve block in lower limb surgeries and there is no evidence in children. The results of our review may not apply to participants at risk of dexamethasone-related adverse events for whom clinical trials would probably be unsafe.There is not enough evidence to determine the effectiveness of dexamethasone as an adjuvant to peripheral nerve block in lower limb surgeries and there is no evidence in children. The results of our review may not be apply to participants who at risk of dexamethasone-related adverse events for whom clinical trials would probably be unsafe. The nine ongoing trials registered at ClinicalTrials.gov may change the results of this review.

Adjuvants to local anesthetics: Current understanding and future trends

Although beneficial in acute and chronic pain management, the use of local anaesthetics is limited by its duration of action and the dose dependent adverse effects on the cardiac and central nervous system. Adjuvants or additives are often used with local anaesthetics for its synergistic effect by prolonging the duration of sensory-motor block and limiting the cumulative dose requirement of local anaesthetics. The armamentarium of local anesthetic adjuvants have evolved over time from classical opioids to a wide array of drugs spanning several groups and varying mechanisms of action. A large array of opioids ranging from morphine, fentanyl and sufentanyl to hydromorphone, buprenorphine and tramadol has been used with varying success. However, their use has been limited by their adverse effect like respiratory depression, nausea, vomiting and pruritus, especially with its neuraxial use. Epinephrine potentiates the local anesthetics by its antinociceptive properties mediated by alpha-2 adrenoreceptor activation along with its vasoconstrictive properties limiting the systemic absorption of local anesthetics. Alpha 2 adrenoreceptor antagonists like clonidine and dexmedetomidine are one of the most widely used class of local anesthetic adjuvants. Other drugs like steroids (dexamethasone), anti-inflammatory agents (parecoxib and lornoxicam), midazolam, ketamine, magnesium sulfate and neostigmine have also been used with mixed success. The concern regarding the safety profile of these adjuvants is due to its potential neurotoxicity and neurological complications which necessitate further research in this direction. Current research is directed towards a search for agents and techniques which would prolong local anaesthetic action without its deleterious effects. This includes novel approaches like use of charged molecules to produce local anaesthetic action (tonicaine and n butyl tetracaine), new age delivery mechanisms for prolonged bioavailability (liposomal, microspheres and cyclodextrin systems) and further studies with other drugs (adenosine, neuromuscular blockers, dextrans).