Femoral nerve blockade using various concentrations of local anesthetic for knee arthroscopy in the pediatric population

Minimum effective concentration 90 (EC90) of ropivacaine for Femoral nerve block: A biased-coin up-and-down sequential method study

Background and Aims

The femoral nerve (FN) is commonly blocked using ropivacaine to provide postoperative analgesia after knee surgery. However, the minimal required concentration has not yet been defined. The aim of this study was to estimate the minimal ropivacaine concentration required to achieve adequate analgesic FN block in 90% of cases (EC90).

Methods

This study included 50 patients who were scheduled for knee ligament reconstruction under combined nerve block and general anaesthesia. The FN block was performed using 15 mL of ropivacaine with varying concentrations and considered adequate when associated with pain-free recovery. The sciatic, obturator, and lateral femoral cutaneous nerves were blocked to negate other knee pain generators, and their block success was confirmed. We used the biased-coin design up-down sequential method where the adequacy of an FN block altered the ropivacaine concentration used for the next block. The adequacy of the analgesic block or lack of it was analysed to calculate the analgesic EC90. The quadriceps motor power and morphine requirement were also recorded.

Results

The recommended analgesic ropivacaine EC90 was 0.05% w/v. The associated quadriceps weakness and morphine requirement were minimal.

Conclusion

FN block using ropivacaine 0.05% w/v may provide adequate analgesia in 90% of patients.

Effect of bupivacaine concentration on ultrasound-guided pericapsular group nerve block efficacy in hip surgery patients: comparative, randomized, double-blinded clinical trial

Background

The pericapsular nerve group (PENG) block offers effective postoperative pain relief following hip fracture surgery. This research investigated three doses of bupivacaine, all administered in the same total volume, for performing ultrasound-guided PENG blocks during hip fracture procedures.

Methods

This randomized, double-blinded clinical trial was conducted on 135 patients aged between 18 and 70 years of both sexes who underwent hip fracture surgeries. Participants were randomized into three groups (n = 45). Ultrasound-guided PENG block was applied, the groups received 20 mL of local anesthetics. The first group received 0.5% bupivacaine, the second group received 0.375% bupivacaine, and the third group received 0.25% bupivacaine. The following parameters were recorded: onset of sensory block, resting NRS after passively raising the limb by 15° half an hour post-procedure, quality of recovery score (QoR-15) at 24 h postoperative.

Results

The 0.25% bupivacaine group exhibited a longer sensory block onset than the other groups (p ≤ .05). Significant differences were demonstrated between the groups regarding the time to 1st analgesia (p = .033) and total morphine consumption (p = .025). NRS at baseline and T30 post-block did not show significant differences between the studied groups. No significant differences were detected postoperatively in rest and dynamic NRS (p ≤ .05). Patient satisfaction, QoR-15 score, and ease of spinal positioning did not differ between the groups.

Conclusion

Compared to 0.25% bupivacaine, PENG block with 0.5% and 0.375% bupivacaine provided a rapid onset sensory block, delayed first analgesic requirements, and reduced total morphine consumption after hip surgeries.

Protocol Registration

The trial was registered at the clinicaltrials.gov with study number (Trial ID: NCT05788458).

Local anesthetic delivery systems for the management of postoperative pain

Postoperative pain (POP) is a major clinical challenge. Local anesthetics (LAs), including amide-type LAs, ester-type LAs, and other potential ion-channel blockers, are emerging as drugs for POP management because of their effectiveness and affordability. However, LAs typically exhibit short durations of action and prolonging the duration by increasing their dosage or concentration may increase the risk of motor block or systemic local anesthetic toxicity. In addition, techniques using LAs, such as intrathecal infusion, require professional operation and are prone to catheter displacement, dislodgement, infection, and nerve damage. With the development of materials science and nanotechnology, various LAs delivery systems have been developed to compensate for these disadvantages. Numerous delivery systems have been designed to continuously release a safe dose in a single administration to ensure minimal systemic toxicity and prolong pain relief. LAs delivery systems can also be designed to control the duration and intensity of analgesia according to changes in the external trigger conditions, achieve on-demand analgesia, and significantly improve pain relief and patient satisfaction. In this review, we summarize POP pathways, animal models and methods for POP testing, and highlight LAs delivery systems for POP management. STATEMENT OF SIGNIFICANCE: Postoperative pain (POP) is a major clinical challenge. Local anesthetics (LAs) are emerging as drugs for POP management because of their effectiveness and affordability. However, they exhibit short durations and toxicity. Various LAs delivery systems have been developed to compensate for these disadvantages. They have been designed to continuously release a safe dose in a single administration to ensure minimal toxicity and prolong pain relief. LAs delivery systems can also be designed to control the duration and intensity of analgesia to achieve on-demand analgesia, and significantly improve pain relief and patient satisfaction. In this paper, we summarize POP pathways, animal models, and methods for POP testing and highlight LAs delivery systems for POP management.

A reduced concentration femoral nerve block is effective for perioperative pain control following ACL reconstruction: a retrospective review

INTRODUCTION

Femoral nerve block (FNB) is a routinely used regional analgesic technique for anterior cruciate ligament (ACL) reconstruction. One method to balance the analgesic effect and functional impairment of FNBs may be to control the concentration of local anesthetics utilized for the block.

MATERIALS AND METHODS

Retrospective chart review was performed on 390 consecutive patients who underwent ACL reconstruction between June 2014 and May 2017. Patients were divided into those who received a standard (0.5%-bupivacaine) or low (0.1-0.125%-bupivacaine) concentration single-shot FNB performed with ultrasound guidance. Maximum postoperative VAS, Post-Anaesthesia Care Unit (PACU) time prior to discharge, need for additional 'rescue' block, and intravenous postoperative narcotic requirements were recorded.

RESULTS

A total of 268 patients (28.4 ± 11.9 years) were included for final analysis, with 72 patients in the low-concentration FNB group and 196 patients receiving the standard concentration. There were no differences in the maximum postoperative VAS between the low (6.4 ± 2.5) and standard (5.7 ± 2.9) concentration groups (P = 0.08). Similarly, the time from PACU arrival to discharge was not different between groups (P = 0.64). A sciatic rescue block was needed in 22% of patients with standard-dose FNB compared to 30% of patients receiving the low-concentration FNB (P = 0.20). Patients with a hamstring autograft harvest were more likely to undergo a postoperative sciatic rescue block compared to a bone-patellar tendon autograft (P = 0.005), regardless of preoperative block concentration. Quadriceps activation was preserved with low-concentration blocks.

CONCLUSIONS

Using 1/5th to 1/4th the standard local anesthetic concentration for preoperative femoral nerve block in ACL reconstruction did not significantly differ in peri-operative outcomes, PACU time, need for rescue blockade, or additional immediate opioid requirements.

LEVEL OF EVIDENCE

III.

Safety and efficacy concerns of modern strategies of local anesthetics delivery

In the last few decades, several formulations have evolved to realize better efficacy of administered anesthesia. These innovative formulations have facilitated surgeons to perform operations under purely local anesthesia, which provides extra protection and comfort to patients. Ease of delivery of local anesthesia is the need of the current generation, because some of the standard procedures are performed without the use of any sedative agent. Therefore, we are presenting here the various approaches of administration of local anesthetics by the surgeons. To construct a comprehensive report on various methods of anesthesia, we followed a systematic literature search of bibliographic databases of published articles recently in the international journals and publishers of repute. A comprehensive study of several reports of the field indicates that there are significant progresses towards developing novel formulations of anesthesia drugs as well as strategies of delivery. Among formulations, nanoparticle-based delivery approaches, including polymeric, liposomal, and micellar structures, have offered the much needed efficacy with low toxicity. Therefore, several of such techniques are at various stages of clinical trials. Nanotechnology-based delivery approaches have significantly emerged in recent past due to the low systemic toxicity and better efficacy of the nonconventional local anesthetics. The other methods of local anesthesia delivery such as transdermal, magnetophoresis, electrophoresis, and iontophoresis are frequently used due to them being minimally invasive and locally effective. Therefore, the combination of the nanotechnological methods with above mentioned techniques would significantly enhance the overall process of local anesthesia delivery and efficacy.

The efficacy of dexamethasone on pain management for knee arthroscopy: A meta-analysis of randomized controlled trials

INTRODUCTION

The impact of dexamethasone on pain management for knee arthroscopy remains controversial. We conduct a systematic review and meta-analysis to explore the influence of dexamethasone for knee arthroscopy.

METHODS

We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through October 2018 for randomized controlled trials (RCTs) assessing the effect of dexamethasone on pain intensity for patients with dental implant. This meta-analysis is performed using the random-effect model.

RESULTS

Four RCTs involving 228 patients are included in the meta-analysis. Overall, compared with control group for knee arthroscopy, dexamethasone supplementation has no notable effect on pain scores at 4 to 6 hours (Std. MD = 0.99; 95% CI = -2.97 to 4.95; P = .62), but exerts significantly favorable promotion to pain scores at 12 hours (Std. MD = -1.06; 95% CI = -1.43 to -0.69; P < .00001), duration of block (Std. MD = 1.87; 95% CI = 0.65 to 3.10; P = .003), time to first analgesic requirement (Std. MD = 0.90; 95% CI = 0.51 to 1.29; P < .00001), analgesic consumption (Std. MD = -1.62; 95% CI = -2.31 to -0.93; P < .00001), and patient satisfaction (Std. MD = 1.15; 95% CI = 0.73 to 1.58; P < .00001).

CONCLUSIONS

Dexamethasone supplementation has importantly positive influence on pain control for knee arthroscopy.

Short-term Outcomes in Pediatric Patients Managed with Peripheral Nerve Blockade for Arthroscopic Anterior Cruciate Ligament Reconstruction and/or Meniscus Surgeries

Introduction

Peripheral nerve blockade (PNB) can be a useful component of a multimodal analgesia approach in managing pain after knee arthroscopy. However, the impact of PNB and short-term recovery in pediatric patients, particularly adolescents, who underwent knee arthroscopy for anterior cruciate ligament (ACL) reconstruction and/or meniscus surgery (repair or resection) has not been well characterized. This prospective study presents observational data on short-term patient outcomes and side effects for 72 hours following discharging home of pediatric patients who underwent arthroscopic ACL and/or meniscus procedures with PNB.

Methods

This is a single-center, single-surgeon prospective observational study conducted over a three-year period. We characterized 72-hour postoperative outcomes including pain scores, return of sensation to the affected limb, analgesic use [nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids], readmission rate, and activities of daily living (ADL) via telephone survey. In addition, retrospective chart review was conducted to obtain perioperative and anesthesia details. Results for surgery groups were analyzed using descriptive and Pearson correlations using the SPSS version 24 (IBM Corp. Released 2016. IBM SPSS Statistics for Mac, Version 24.0. Armonk, NY, USA).

Results

We collected data on 47 patients undergoing ACL reconstruction with or without meniscus surgery (18/47, 38.3%) or meniscus surgery only (29/47, 61.7%). At 72 hours postsurgery, there were no readmissions or complications related to pain. Median-reported pain scores were 2.5 and 5.0 for the ACL and meniscus groups, respectively. A majority of patients continued to require opioids (45/47, 95.7%) and NSAIDs (46/47, 97.9%) at 72 hours postsurgery, but the number of daily opioid doses taken decreased with each day postoperatively. Over 93% of the patients could ambulate and shower at 72 hours postsurgery.

Conclusions

Regional nerve block appears to be an effective and safe analgesic strategy for pediatric arthroscopic ACL and meniscus procedures, with no short-term complications or readmissions related to pain in our cohort. Future prospective investigation is needed to characterize long-term pain outcomes in this surgical population.

Postoperative pain management in the postanesthesia care unit: an update

Acute postoperative pain remains a major problem, resulting in multiple undesirable outcomes if inadequately controlled. Most surgical patients spend their immediate postoperative period in the postanesthesia care unit (PACU), where pain management, being unsatisfactory and requiring improvements, affects further recovery. Recent studies on postoperative pain management in the PACU were reviewed for the advances in assessments and treatments. More objective assessments of pain being independent of patients' participation may be potentially appropriate in the PACU, including photoplethysmography-derived parameters, analgesia nociception index, skin conductance, and pupillometry, although further studies are needed to confirm their utilities. Multimodal analgesia with different analgesics and techniques has been widely used. With theoretical basis of preventing central sensitization, preventive analgesia is increasingly common. New opioids are being developed with minimization of adverse effects of traditional opioids. More intravenous nonopioid analgesics and adjuncts (such as dexmedetomidine and dexamethasone) are introduced for their opioid-sparing effects. Current evidence suggests that regional analgesic techniques are effective in the reduction of pain and stay in the PACU. Being available alternatives to epidural analgesia, perineural techniques and infiltrative techniques including wound infiltration, transversus abdominis plane block, local infiltration analgesia, and intraperitoneal administration have played a more important role for their effectiveness and safety.

Evaluation of analgesic regimens in total knee arthroplasty, retrospective study

OBJECTIVE:

Analgesic therapies have an immense role in early rehabilitation period after total knee arthroplasty (TKA) and multimodal approaches should be considered as the first choice of treatment. In this retrospective study, the aim was to evaluate the effectiveness of multimodal analgesic therapies for TKA, including femoral nerve block (FNB) and patient controlled analgesia (PCA).

METHODS:

The data of 79 patients who underwent TKA between January and December 2016 were retrospectively evaluated. In all, 63 patients met the inclusion criteria. Hemodynamic records and Visual Analogue Scale (VAS) pain scores for postoperative 0, 2, 4, 6, 9, and 12 hours were evaluated and patients were separated into 3 groups. Group 1: FNB with 0.25% bupivacaine, Group 2: FNB with 0.166% bupivacaine, and Group 3: No FNB.

RESULTS:

The average age of the patients was 64.3±14.9 years and average body mass index (BMI) was 32.5±5.3 kg/m². There was no statistical difference between groups in age, gender, American Society of Anesthesiologists (ASA) classification of physical health scores, BMI, or anesthesia type (p<0.05). When VAS scores at postoperative time intervals were compared, there was a statistically significant difference between Group 1 and Group 2 (p>0.05). When difference between Groups 1 and 3 and Groups 2 and 3 were compared, the difference was statistically significant for VAS 0 (p>0.05). Additional analgesic use was highest in Group 3.

CONCLUSION:

This study demonstrated that FNB significantly decreases postoperative pain intensity and additional analgesia requirement in patients undergoing TKA. A concentration of 0.166% bupivacaine is as effective as a concentration of 0.25% when used as part of a multimodal analgesia regimen in TKA.