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

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.

Esketamine opioid-free intravenous anesthesia versus opioid intravenous anesthesia in spontaneous ventilation video-assisted thoracic surgery: a randomized controlled trial

Background

Opioid-free anesthesia (OFA) provides adequate analgesia and can reduce postoperative opioid consumption, but its efficacy in spontaneous ventilation video-assisted thoracic surgery (SV-VATS) has not been demonstrated. We aimed to investigate the hypothesis that OFA could provide the same perioperative pain control as opioid anesthesia (OA), maintain safe and stable respiration and hemodynamics during surgery, and improve postoperative recovery.

Methods

Sixty eligible patients (OFA group: n=30; OA group: n=30) treated between September 15, 2022, and December 15, 2022, at The First Hospital of Guangzhou Medical University were included. They were randomized to receive standard balanced OFA with esketamine or OA with remifentanil combined with sufentanil. The primary outcome was the pain numeric rating score (NRS) at postoperative 24 h, and the secondary outcomes were intraoperative respiratory and hemodynamic data, opioid consumption, vasoactive drug dosage, and recovery in the post-anesthesia care unit and ward.

Results

There was no significant difference in the postoperative pain scores and recovery quality between the two groups. The OFA group had a significantly lower dose of phenylephrine (P=0.001) and a lower incidence of hypotension (P=0.004) during surgery. The OFA group resumed spontaneous respiration faster (P<0.001) and had a higher quality of lung collapse (P=0.02). However, the total doses of propofol and dexmetomidine were higher (P=0.03 and P=0.02), and the time to consciousness was longer (P=0.039) in the OFA group.

Conclusions

OFA provides the same level of postoperative pain control as OA, but it is more advantageous in maintaining circulatory and respiratory stability and improving the quality of pulmonary collapse in SV-VATS.

Pre-incisional infiltration with ropivacaine plus dexamethasone palmitate emulsion for postoperative pain in patients undergoing craniotomy: study protocol for a prospective, randomized controlled trial

BACKGROUND

Post-craniotomy pain is a common occurrence which is associated with poor outcomes. Pre-emptive scalp infiltration with dexamethasone and ropivacaine has been proven effective in previous studies but with limited clinical significance. Dexamethasone palmitate emulsion (D-PAL) is a pro-drug incorporating dexamethasone into lipid microspheres with greater anti-inflammatory activity and fewer side effects than free dexamethasone. However, its effects in post-craniotomy pain management remain unknown. This study hypothesizes that pre-emptive scalp infiltration with ropivacaine plus D-PAL emulsion can achieve superior analgesic effects to ropivacaine alone in adult patients undergoing craniotomy.

METHODS/DESIGN

This is a single center, randomized controlled trial enrolling 130 patients scheduled for supratentorial craniotomy, which is expected to last longer than 4 h. We compare the efficacy and safety for postoperative pain relief of ropivacaine plus D-PAL group and ropivacaine alone group following pre-emptive scalp infiltration. Primary outcome will be pain Numerical Rating Scale at 24 h postoperatively. Secondary outcomes will include further analgesia evaluations and drug-related complications within a follow-up period of 3 months.

DISCUSSION

This is the first randomized controlled trial aiming to assess the possible benefits or disadvantages of D-PAL emulsion for incisional pain in craniotomy. It may provide an alternative to optimize pain outcome for neurosurgical patients.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04488315). Registered on 19 July 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.

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.

Epidural corticosteroid injections for lumbosacral radicular pain

BACKGROUND

Lumbosacral radicular pain (commonly called sciatica) is a syndrome involving patients who report radiating leg pain. Epidural corticosteroid injections deliver a corticosteroid dose into the epidural space, with the aim of reducing the local inflammatory process and, consequently, relieving the symptoms of lumbosacral radicular pain. This Cochrane Review is an update of a review published in Annals of Internal Medicine in 2012. Some placebo-controlled trials have been published recently, which highlights the importance of updating the previous review.

OBJECTIVES

To investigate the efficacy and safety of epidural corticosteroid injections compared with placebo injection on pain and disability in patients with lumbosacral radicular pain.

SEARCH METHODS

We searched the following databases without language limitations up to 25 September 2019: Cochrane Back and Neck group trial register, CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, International Pharmaceutical Abstracts, and two trial registers. We also performed citation tracking of included studies and relevant systematic reviews in the field.

SELECTION CRITERIA

We included studies that compared epidural corticosteroid injections of any corticosteroid drug to placebo injections in patients with lumbosacral radicular pain. We accepted all three anatomical approaches (caudal, interlaminar, and transforaminal) to delivering corticosteroids into the epidural space. We considered trials that included a placebo treatment as delivery of an inert substance (i.e. one with no pharmacologic activity), an innocuous substance (e.g. normal saline solution), or a pharmacologically active substance but not one considered to provide sustained benefit (e.g. local anaesthetic), either into the epidural space (i.e. to mimic epidural corticosteroid injection) or adjacent spinal tissue (i.e. subcutaneous, intramuscular, or interspinous tissue). We also included trials in which a local anaesthetic with a short duration of action was used as a placebo and injected together with corticosteroid in the intervention group.

DATA COLLECTION AND ANALYSIS

Two authors independently performed the screening, data extraction, and 'Risk of bias' assessments. In case of insufficient information, we contacted the authors of the original studies or estimated the data. We grouped the outcome data into four time points of assessment: immediate (≤ 2 weeks), short term (> 2 weeks but ≤ 3 months), intermediate term (> 3 months but < 12 months), and long term (≥ 12 months). We assessed the overall quality of evidence for each outcome and time point using the GRADE approach.

MAIN RESULTS

We included 25 clinical trials (from 29 publications) investigating the effects of epidural corticosteroid injections compared to placebo in patients with lumbosacral radicular pain. The included studies provided data for a total of 2470 participants with a mean age ranging from 37.3 to 52.8 years. Seventeen studies included participants with lumbosacral radicular pain with a diagnosis based on clinical assessment and 15 studies included participants with mixed duration of symptoms. The included studies were conducted mainly in North America and Europe. Fifteen studies did not report funding sources, five studies reported not receiving funding, and five reported receiving funding from a non-profit or government source. Eight trials reported data on pain intensity, 12 reported data on disability, and eight studies reported data on adverse events. The duration of the follow-up assessments ranged from 12 hours to 1 year. We considered eight trials to be of high quality because we judged them as having low risk of bias in four out of the five bias domains. We identified one ongoing trial in a trial registry. Epidural corticosteroid injections were probably slightly more effective compared to placebo in reducing leg pain at short-term follow-up (mean difference (MD) -4.93, 95% confidence interval (CI) -8.77 to -1.09 on a 0 to 100 scale; 8 trials, n = 949; moderate-quality evidence (downgraded for risk of bias)). For disability, epidural corticosteroid injections were probably slightly more effective compared to placebo in reducing disability at short-term follow-up (MD -4.18, 95% CI -6.04 to -2.17, on a 0 to 100 scale; 12 trials, n = 1367; moderate-quality evidence (downgraded for risk of bias)). The treatment effects are small, however, and may not be considered clinically important by patients and clinicians (i.e. MD lower than 10%). Most trials provided insufficient information on how or when adverse events were assessed (immediate or short-term follow-up) and only reported adverse drug reactions - that is, adverse events that the trialists attributed to the study treatment. We are very uncertain that epidural corticosteroid injections make no difference compared to placebo injection in the frequency of minor adverse events (risk ratio (RR) 1.14, 95% CI 0.91 to 1.42; 8 trials, n = 877; very low quality evidence (downgraded for risk of bias, inconsistency and imprecision)). Minor adverse events included increased pain during or after the injection, non-specific headache, post-dural puncture headache, irregular periods, accidental dural puncture, thoracic pain, non-local rash, sinusitis, vasovagal response, hypotension, nausea, and tinnitus. One study reported a major drug reaction for one patient on anticoagulant therapy who had a retroperitoneal haematoma as a complication of the corticosteroid injection.

AUTHORS' CONCLUSIONS

This study found that epidural corticosteroid injections probably slightly reduced leg pain and disability at short-term follow-up in people with lumbosacral radicular pain. In addition, no minor or major adverse events were reported at short-term follow-up after epidural corticosteroid injections or placebo injection. Although the current review identified additional clinical trials, the available evidence still provides only limited support for the use of epidural corticosteroid injections in people with lumbosacral radicular pain as the treatment effects are small, mainly evident at short-term follow-up and may not be considered clinically important by patients and clinicians (i.e. mean difference lower than 10%). According to GRADE, the quality of the evidence ranged from very low to moderate, suggesting that further studies are likely to play an important role in clarifying the efficacy and tolerability of this treatment. We recommend that further trials should attend to methodological features such as appropriate allocation concealment and blinding of care providers to minimise the potential for biased estimates of treatment and harmful effects.

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.

Pre-emptive scalp infiltration with dexamethasone plus ropivacaine for postoperative pain after craniotomy: a protocol for a prospective, randomized controlled trial

Background: Approximately 55–87% of the patients undergoing craniotomy experience moderate to severe pain during the first 48 hrs after surgery, which negatively influences patients’ postoperative rehabilitation. Recently, local infiltration of analgesia (LIA) has been widely performed clinically as a promising analgesic method that could avoid the side effects of analgesics but only has a short pain-free duration; researchers have clarified that the addition of dexamethasone to LIA could provide significant analgesic effects and significantly prolong the duration of analgesic effects without obvious complications for various types of surgeries. To date, no studies have evaluated the addition of dexamethasone to LIA for patients receiving craniotomy. The aim of the study was to test the hypothesis that pre-emptive scalp infiltration with a steroid (dexamethasone) plus a local anesthetic (ropivacaine) could achieve superior postoperative analgesic effects to a local anesthetic (ropivacaine) alone in adult patients undergoing a craniotomy.

Study design and methods: This study is a randomized controlled trial that will include one intervention and one control group involving a total of 140 adults scheduled for elective craniotomy for resection of supratentorial tumors under general anesthesia and with an anticipated full recovery within 2 hrs postoperatively. The intervention will involve pre-emptive scalp infiltration with ropivacaine plus dexamethasone (the dexamethasone group) or ropivacaine alone (the control group), and the participants in both groups will complete a 6-month follow-up. The primary outcome will be the cumulative sufentanil consumption within 48 hrs postoperatively.

Discussion: The intervention, if effective, this study will provide clinically important information on the role of dexamethasone in scalp infiltration for post-craniotomy pain management.