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

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.

Nerve Blocks for Post-Surgical Pain Management: A Narrative Review of Current Research

Opioids remain the mainstay of post-surgical pain management; however, concerns regarding addiction and side effects necessitate the exploration of alternatives. This narrative review highlights the potential of nerve blocks as a safe and effective strategy for post-surgical pain control. This review explores the use of various nerve block techniques tailored to specific surgical procedures. These include nerve blocks for abdominal surgeries; fascial plane blocks for chest surgeries; nerve blocks for arm surgeries; and nerve blocks for lower limb surgery including; femoral, hip, and knee surgeries. By targeting specific nerves, these blocks can provide targeted pain relief without the negative side effects associated with opioids. Emerging evidence suggests that nerve blocks can be as effective as opioids in managing pain, while potentially offering additional benefits such as faster recovery, improved patient satisfaction, and reduced reliance on opioids. However, the effectiveness of nerve blocks varies depending on type of surgery, and in individual patients. Rebound pain, which temporary increase in pain after a block wears off, can occur. In addition, some techniques require specialized guidance for accurate placement. In conclusion, nerve blocks show great promise as effective alternatives for managing post-surgical pain. They can reduce the need for opioids and their side effects, leading to better patient outcomes and satisfaction. Future studies should assess the long-term impacts of specific nerve blocks on mortality rates, cost-effectiveness, and their incorporation into multimodal pain management approaches to further enhance post-surgical care.

Anterior quadratus lumborum catheters for elective cesarean section: A double-blind, randomized, placebo-controlled trial

BACKGROUND

Optimizing pain management following cesarean section is crucial for the well-being of both mother and infant. Various types of quadratus lumborum blocks have exhibited reduced opioid consumption and pain scores after cesarean section. However, duration of block effect is relatively short. The aim of this study was to investigate the analgesic efficacy of the anterior quadratus lumborum catheters for cesarean section.

METHODS

All 32 enrolled participants were allocated to postoperative bilateral ultrasound-guided anterior quadratus lumborum catheter placement with injection of 60 mL ropivacaine 0.375% after cesarean section. Randomization at 2 h resulted in either 60 mL ropivacaine 0.2% or 60 mL isotonic saline injected through the catheters, with subsequent 22-h infusion of either ropivacaine 0.2% or isotonic saline with an infusion rate of 4 mL h-1 per catheter. Participants in the active group received a total of 697 mg ropivacaine during the first 24 h. All participants received the standard postoperative multimodal pain regimen, and a final bilateral injection at 24-h post-catheter placement of 60 mL ropivacaine 0.375% in total. The primary outcome was time to first opioid administration. Secondary outcomes were pain scores, time to first ambulation, nausea and vomiting, accumulated opioid consumption, and catheter displacement rates.

RESULTS

No significant intergroup differences were observed following the randomized intervention. Median time to first opioid (IQR) was (active vs. placebo) 414 (283, 597) vs. 428 (245, 552) minutes, with a median difference (CI) of -14 (-184 to 262) min, p = .32.

CONCLUSION

Bilateral anterior quadratus lumborum catheters with continuous infusion did not prolong time to first opioid after elective cesarean section.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Multimodal Analgesia in the Aesthetic Plastic Surgery: Concepts and Strategies

Postoperative pain management is crucial for aesthetic plastic surgery procedures. Poorly controlled postoperative pain results in negative physiologic effects and can affect length of stay and patient satisfaction. In light of the growing opioid epidemic, plastic surgeons must be keenly familiar with opioid-sparing multimodal analgesia regimens to optimize postoperative pain control.

Methods

A review study based on multimodal analgesia was conducted.

Results

We present an overview of pain management strategies pertaining to aesthetic plastic surgery and offer a multimodal analgesia model for outpatient aesthetic surgery practices.

Conclusion

This review article presents an evidence-based approach to multimodal pain management for aesthetic plastic surgery.

Programmed, intermittent boluses versus continuous infusion to the sciatic nerve - a non-inferiority randomized, controlled trial

BACKGROUND

Trials comparing programmed, intermittent boluses (PIB) and continuous infusion in catheter-based nerve blocks found no analgesic differences. However, as these trials used equal doses of local anesthetic (LA), the time of action of each bolus was not accounted for. Therefore, the dose-sparing benefits of PIB may have been overlooked. We compared the analgesic effect of boluses administered in intervals resembling the time of action of each bolus with continuous infusion. We hypothesized that PIB provided non-inferior analgesia despite consuming less LA.

METHODS

Eighty-one patients undergoing fore- and midfoot surgery receiving a catheter-based sciatic nerve block were randomized to ropivacaine 0.2% as PIB of 10 ml every 8th hour or as continuous infusion, 6 ml h^-1 . All participants could also receive boluses of 10 ml every 4th hour as needed. A non-inferiority randomized controlled design was used. Primary outcome was pain (VAS, 0-100 mm) for 72 h using area under curve (AUC) calculation. We assumed a linear relationship between mean VAS and AUC-VAS and used a non-inferiority margin of VAS = 20 mm, corresponding to AUC-VAS = 1440 mm h.

RESULTS

Mean difference in AUC-VAS was -416 mm h (95% CI -1076 to 244; p = .217) between continuous infusion (mean AUC-VAS 1206 mm h) and PIB (mean AUC-VAS 1621 mm h), establishing non-inferiority. Mean total LA consumption was significantly larger for continuous infusion compared to PIB ((468 ml (95% CI 458 to 478) vs. 136 ml (95% CI 123 to 148); p < 0.0001)).

CONCLUSIONS

PIB provided non-inferior analgesia compared to continuous infusion for 72 postoperative hours despite using significantly less LA.

REDUCE trial: the effects of perineural dexamethasone on scalp nerve blocks for relief of postcraniotomy pain-a study protocol for a randomized controlled trial

BACKGROUND

Pain is common in the first 2 days after major craniotomy. Inadequate analgesia may lead to an increased risk of postoperative complications. Most pain following craniotomy arises from the pericranial muscles and soft tissues of the scalp. Scalp nerve blocks with local anesthesia seem to provide effective, safe, however, transient postoperative analgesia which does not seem to meet the requirements of craniotomy. Currently, peripheral dexamethasone has been observed to significantly prolong the duration of analgesia of nerve blocks (e.g., saphenous nerve block, adductor canal block, thoracic paravertebral block, brachial plexus nerve block). On the contrary, a study reported that perineural dexamethasone did not appear to prolong the analgesic time after supratentorial craniotomy. However, all patients in this study were given 24 mg of oral or intravenous dexamethasone regularly for at least 7 days during the perioperative period, which possibly masked the role of single local low doses of perineural dexamethasone. Therefore, the analgesic effect of single dexamethasone for scalp nerve blocks without the background of perioperative glucocorticoid deserves further clarification.

METHODS

The REDUCE trial is a prospective, single-center, parallel-group randomized controlled trial involving a total of 156 adults scheduled for elective craniotomy with general anesthesia. Patients will be randomly divided among two groups: the control group (n = 78) will receive scalp nerve blocks with 0.5% bupivacaine, plus normal saline with epinephrine at 1:200,000; the DEX_4mg group (n = 78) will receive scalp nerve blocks with 0.5% bupivacaine, plus 4 mg dexamethasone with epinephrine at 1:200,000. The primary outcome will be the duration of analgesia, defined as the time between the performance of the block and the first analgesic request.

DISCUSSION

The REDUCE trial aims to further assess the analgesic effect of single dexamethasone as an adjuvant to scalp nerve blocks for relief of postcraniotomy pain without the background of perioperative glucocorticoid.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04648358 . Registered on November 30, 2020.

Dexamethasone Addition to Popliteal Nerve Blocks: Effects on Duration of Analgesia and Incidence of Postoperative Nerve Complication

Background. The purpose of this prospective, double-blinded randomized control pilot study was to evaluate the effect of adjunctive dexamethasone on analgesia duration and the incidence of postoperative neuropathic complication. Peripheral nerve blocks are an effective adjunct to decrease postoperative pain in foot and ankle surgery, and any possible modalities to augment their efficacy is of clinical utility. Methods. Patients were randomly assigned to a control group (n = 25) receiving nerve blocks of bupivacaine and epinephrine or an experimental group (n = 24) with an adjunctive 8 mg dexamethasone. The patients, surgeons, and anesthesiologists were all blinded to allocation. Patients had a minimum 1 year postoperative follow-up. Results. Forty-nine patients completed the protocol. There was no statistically significant difference in analgesia duration (P = .38) or postoperative neuropathic complication incidence (P = .67) between the 2 groups. Conclusions. The addition of dexamethasone to popliteal nerve blocks does not appear to affect analgesia duration or incidence of postoperative neuropathic complications. However, our study was underpowered, and we recommend a larger scale prospective study for validation.Levels of Evidence: Level II: Prospective, randomized control pilot study.

Comparison of postoperative analgesic effects in response to either dexamethasone or dexmedetomidine as local anesthetic adjuvants: a systematic review and meta-analysis of randomized controlled trials

This review compares the effects of peripheral dexamethasone and dexmedetomidine on postoperative analgesia. We included six randomized controlled trials (354 patients) through a systematic literature search. We found that analgesia duration was comparable between dexamethasone and dexmedetomidine (58.59 min, 95% CI (confidence interval), -  66.13, 183.31 min) with extreme heterogeneity. Secondary outcome was also compared and no significant difference was observed in sensory block onset and duration and motor block duration and also for postoperative nausea and vomiting. It is noteworthy that dexamethasone reduced analgesic consumption (fentanyl) by 29.12 mcg compared with dexmedetomidine. We performed subgroup analyses and found no significant difference between the following: (1) lidocaine vs ropivacaine (P = 0.28), (2) nerve block vs nerve block + general anesthesia (P = 0.47), and (3) upper limb surgery vs thoracoscopic pneumonectomy (P = 0.27). We applied trial sequential analysis to assess the risks of type I and II errors and concluded that the meta-analysis was insufficiently powered to answer the clinical question, and further analysis is needed to establish which adjuvant is better. In conclusion, we believe that existing research indicates that dexamethasone and dexmedetomidine have equivalent analgesic effects in peripheral nerve blocks.

Use of Dexmedetomidine With Dexamethasone for Extended Pain Relief in Adductor Canal/Popliteal Nerve Block During Achilles Tendon Repair

The use of regional anesthetic techniques in the peri-operative period has increased as a means to improve analgesia and patient outcomes. Traditionally, various local anesthetics are used and addition of adjuncts such as epinephrine, clonidine, and dexamethasone has shown to prolong the block effect. There has been ongoing research to support the prolongation of a regional block with the addition of dexamethasone and dexmedetomidine (Dex-Dex), providing analgesia for multiple days. We present a case of a 35-year-old female who underwent an Achilles tendon repair with an adductor/popliteal nerve block. Both dexmedetomidine and dexamethasone were added to the local anesthetic mixture with substantial postoperative analgesic control. The patient also did not require any supplemental opioid medication. This case emphasizes the proposed synergistic effect of dexmedetomidine and dexamethasone when added to the local anesthesia injectate for lower extremity peripheral nerve blocks.

Dual adjunct therapy with dexamethasone and dexmedetomidine in transversus abdominis plane blocks reduces postoperative opioid use in colorectal surgery

BACKGROUND

The objective of this study is to determine if the addition of dexmedetomidine to dexamethasone in transversus abdominis plane (TAP) blocks lowers postoperative opioid use following colorectal surgery.

METHODS

Retrospective review of patients undergoing minimally invasive colorectal surgery and perioperative TAP block with either 1) local anesthetic and dexamethasone or 2) local anesthetic, dexamethasone, and dexmedetomidine. Post-operative opioid use was converted to morphine milligram equivalents (MME).

RESULTS

55 patients were identified: 38 (69%) receiving dexamethasone only and 17 (31%) receiving dexamethasone and dexmedetomidine. The dexamethasone and dexmedetomidine group had significantly lower median MME use at 12-h (2 vs. 13 mg), 24-h (4 vs. 28 mg), 36-h (8 vs. 38 mg), and 48-h (17 vs. 53 mg) (all p < 0.05). There was no difference at 72-h.

CONCLUSION

Perioperative TAP blocks with dexamethasone and dexmedetomidine following colorectal surgery results in significantly less postoperative opioid use up to 48 h after surgery.

Dexamethasone and dexmedetomidine as adjuvants to local anesthetic mixture in intercostal nerve block for thoracoscopic pneumonectomy: a prospective randomized study

BACKGROUND AND OBJECTIVES

Perineural dexamethasone or dexmedetomidine prolongs the duration of single-injection peripheral nerve block when added to the local anesthetic solution. In a randomized, controlled, double-blinded study in patients undergoing thoracoscopic pneumonectomy, we tested the hypothesis that combined perineural dexamethasone and dexmedetomidine prolonged the duration of analgesia as compared with either perineural dexamethasone or perineural dexmedetomidine after intercostal nerve block (INB).

METHODS

Eighty patients were randomized to receive INB using 28 mL 0.5% ropivacaine, with 2 mL normal saline (R group), with 10 mg dexamethasone in 2 mL (RS group) or 1 µg/kg dexmedetomidine in 2 mL (RM group), or with 1 µg/kg dexmedetomidine and 10 mg dexamethasone in 2 mL (RSM group) administrated perineurally. The INB was performed by the surgeon under thoracoscopic direct vision; a total of six intercostal spaces were involved, each with an injection of 5 mL. The primary outcome was the duration of analgesia. Secondary outcomes included total postoperative fentanyl consumption, visual analog scale pain score and safety assessment (adverse effects).

RESULTS

The duration of analgesia in RSM (824.2±105.1 min) was longer than that in RS (611.5±133.0 min), RM (602.5±108.5 min) and R (440.0±109.6 min) (p<0.001). Total postoperative fentanyl consumption was lower in RSM (106.0±84.0 µg) compared with RS (243.0±175.2 µg), RM (237.0±98.7 µg) and R (369.0±134.2 µg) (p<0.001). No significant difference was observed in the incidences of adverse effects between the four groups.

CONCLUSION

The addition of combined perineural dexmedetomidine and dexamethasone to ropivacaine for INB seemed to be an attractive method for prolonged analgesia with almost no adverse effects.

TRIAL REGISTRATION NUMBER

ChiCTR-IOR-17012183.

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.

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.

The Importance of the Saphenous Nerve Block for Analgesia Following Major Ankle Surgery: A Randomized, Controlled, Double-Blind Study

BACKGROUND AND OBJECTIVES

Major ankle surgery causes intense postoperative pain, and whereas the importance of a sciatic nerve block is well established, the clinical significance of a supplemental saphenous nerve block has never been determined in a prospective, randomized, double-blind, placebo-controlled trial. We hypothesized that a saphenous nerve block reduces the proportion of patients experiencing significant clinical pain after major ankle surgery.

METHODS

Eighteen patients were enrolled and received a popliteal sciatic nerve block. Patients were randomized to single-injection saphenous nerve block with 10 mL 0.5% bupivacaine with 1:200,000 epinephrine or 10 mL saline (Fig. 1). Primary outcome was the proportion of patients reporting significant clinical pain, defined as a score greater than 3 on the numerical rating scale. Secondary outcomes were maximal pain and analgesia of the cutaneous territory of the infrapatellar branch of the saphenous nerve.

RESULTS

Eight of 9 patients in the placebo group reported significant clinical pain versus 1 of 9 patients in the bupivacaine-epinephrine group (P = 0.003). Maximal pain was significantly lower in the active compared with the placebo group (median, 0 [0-0] vs 5 [4-6]; P = 0.001). Breakthrough pain from the saphenous territory began within 30 minutes after surgery in all cases. Sensory testing of the cutaneous territory of the infrapatellar branch of the saphenous nerve showed correlation between pain reported in the anteromedial ankle region and the intensity of cutaneous sensory block in the anteromedial knee region.

CONCLUSIONS

The saphenous nerve is an important contributor to postoperative pain after major ankle surgery, with significant clinical pain appearing within 30 minutes after surgery.

CLINICAL TRIALS REGISTRATION

This study has been registered at ClinicalTrials.gov, identifier NCT02697955.

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.