Efficacy of Dexmedetomidine as an Adjuvant to Local Anesthetic Agent in Scalp Block and Scalp Infiltration to Control Postcraniotomy Pain: A Double-Blind Randomized Trial

Posterior scalp block with bupivacaine and dexmedetomidine for pain management in posterior fossa surgeries: a prospective, double blind randomized controlled trial

BACKGROUND

Pain management in posterior fossa surgeries poses significant challenges, with opioid-based approaches causing unwanted side effects. This study evaluates the efficacy of posterior scalp block using bupivacaine and dexmedetomidine compared to skin infiltration for managing perioperative pain.

METHODS

In this prospective, double-blind, randomized controlled trial, 34 adult patients undergoing elective posterior fossa surgeries were equally assigned to either posterior scalp block or skin infiltration groups. Outcomes measured included hemodynamic parameters, pain scores, opioid consumption, time to first analgesic, and sedation levels.

RESULTS

The posterior scalp block group showed significantly lower opioid consumption (211.47 ± 101.95 mcg vs 305.88 ± 117.10 mcg; p < 0.01) and pain scores (VAS 2.29 ± 0.9 vs 5.06 ± 1.3; p < 0.001) at 24 hours post-surgery. This group also demonstrated better hemodynamic stability and fewer rescue opioid requirements (9 vs 15 patients; p < 0.009).

CONCLUSIONS

Posterior scalp block with bupivacaine and dexmedetomidine significantly improves pain management, reduces opioid use, and provides better hemodynamic stability compared to skin infiltration in posterior fossa surgeries.

CLINICAL TRIAL REGISTRATION

CTRI/2023/07/0554959.

Progress on the Mechanisms and Neuroprotective Benefits of Dexmedetomidine in Brain Diseases

INTRODUCTION

Dexmedetomidine, a highly specific α2 agonist, has been extensively utilized in clinical sedation and surgical anesthesia since its introduction in 2000 due to its excellent sympatholytic, sedative, and analgesic effects. This review aimed to identify new approaches for the treatment of patients with brain disorders by thoroughly describing the mechanism of action of dexmedetomidine and examining its neuroprotective effects from the standpoints of basic and clinical research.

METHODS

The PubMed and Web of Science databases were searched using the keywords dexmedetomidine and related brain diseases, although relevant articles from the last decade were included for detailed summarization and analysis.

RESULTS

Dexmedetomidine has shown strong neuroprotective effects, such as protection of the blood-brain barrier, decreased neuronal death, maintained hemodynamic stability, and reduced postoperative agitation and cognitive dysfunction. Furthermore, dexmedetomidine has been shown to exert various neuroprotective effects, including anti-inflammatory and antioxidative stress effects, modulation of autophagy, and reduction of apoptosis in cerebral diseases.

CONCLUSIONS

Dexmedetomidine acts as a neuroprotective agent against brain diseases during all phases of treatment. However, clinical trials with larger sample sizes are required to optimize dosage and dosing strategies.

An update on the perioperative management of postcraniotomy pain

PURPOSE OF REVIEW

Pain after craniotomy is often severe and undertreated. Providing adequate analgesia while avoiding medication adverse effects and physiological complications of pain remains a perioperative challenge.

RECENT FINDINGS

Multimodal pain management includes regional anesthesia and analgesic adjuncts. Strategies aim to reduce or eliminate opioids and the associated side effects. Many individual pharmacologic interventions have been studied with beneficial effects on acute pain following craniotomy. Evidence has been accumulating in support of scalp blockade, nonsteroidal anti-inflammatory drugs (NSAIDs), dexmedetomidine, paracetamol, and gabapentinoids. The strongest evidence supports scalp block in reducing postcraniotomy pain and opioid requirements.

SUMMARY

Improving analgesia following craniotomy continues to be a challenge that should be managed with multimodal medications and regional techniques. Additional studies are needed to identify the most effective regimen, balancing efficacy and adverse drug effects.

The analgetic effect of adjuvants in local infiltration analgesia - a systematic review with network meta-analysis of randomized trials

BACKGROUND

Local infiltration analgesia is commonly used for postoperative pain control after several surgical procedures including intra- and peri-articular as well as wound infiltration. Even though, various adjuvants injected with the local anesthetic have been studied in pairwise comparison or compared to peripheral nerve blocks, the question which adjuvant or combination of adjuvants is the most effective in prolonging the duration of different types of local infiltration analgesia (LIA) has not been answered conclusively.

OBJECTIVE

The objective of this network meta-analysis was to determine the analgesic effectiveness and safety of adjuvants in local infiltration analgesia.

DESIGN

Systematic review of randomized controlled trials with network meta-analyses.

DATA SOURCES

A comprehensive literature search in Embase, CENTRAL, MEDLINE and Web of Science was performed up to March 2023.

RESULTS

The best interventions to prolong the duration of analgesia were dexamethasone (Ratio of Means (ROM) 3.33) followed by the combinations of clonidine + morphine (ROM 3.35) and morphine + magnesium sulfate (ROM 2.92), fentanyl (ROM 2.27), ketorolac (ROM 2.26), buprenorphine (ROM 2.04), morphine (ROM 1.93), magnesium sulfate (ROM 1.91), clonidine (ROM 1.89), dexmedetomidine (ROM 1.74) and tramadol (ROM 1.58). Serious adverse events were not reported with either investigated adjuvant.

CONCLUSION

There is moderate evidence that dexamethasone is the most effective adjuvant to prolong the duration of analgesia in LIA. The evidence for the alpha-2 agonists dexmedetomidine and clonidine is also moderate, but their effectivity to prolong analgesia stays behind dexamethasone. Clonidine and dexmedetomidine had a small detectable effect on pain scores, yet below clinical relevance, but the largest effect on MEQ consumption. The effects of different opioids were homogenous for all endpoints. The prespecified subgroup analysis of LIA of the knee did not show significantly different results than the pooled analysis.

STUDY REGISTRATION

PROSPERO 2020 CRD42020176154 (28.04.2020).

Comparison of the Effect of Scalp Block With Ropivacaine vs. Ropivacaine and Clonidine on Postoperative Pain in Patients Undergoing Craniotomy Surgery Under General Anesthesia

Introduction Clonidine, an α2 agonist known for its hypotensive and analgesic effects, has proven beneficial in various routes of administration such as oral, intravenous, and local infiltration. Scalp blocks enhance hemodynamic stability during surgery and reduce intraoperative opioid requirements compared to controls in numerous studies. Additionally, they are effective in managing postoperative pain, resulting in reduced opioid consumption. Research has shown that clonidine can enhance and prolong the effects of intrathecal, epidural, and peripheral nerve blocks (e.g., brachial plexus, peribulbar). Here, we investigated the impact of adding clonidine at a dose of 1 μg/kg to scalp blocks performed with 0.5% ropivacaine for supra-tentorial craniotomy Material and methods This study was conducted on 60 patients under the American Society of Anesthesiologists (ASA) grade I and II who were scheduled for elective supratentorial craniotomy. Patients were divided into two equal groups of 30 and received a scalp block following general anesthesia. Patients in Group A (n=30) received a scalp block of 0.5% ropivacaine plus 1 ml of normal saline (total 21 cc). Patients in Group B (n=30) received a scalp block of 0.5% ropivacaine and clonidine (1 μg/kg) combined with 0.5 ml of normal saline (total 21 cc). Blood pressure, heart rate, peripheral oxygen saturation (SpO2), visual analog score, Ramsay sedation score, duration of analgesia, and analgesia requirement in the first 24 hours were recorded from baseline and postoperatively. Results The duration of first rescue analgesia for Group A was 4.30 ± 1.5 hours and that of Group B was 9.10 ± 1.4 hours. Duration of analgesia was significantly prolonged in patients receiving ropivacaine with clonidine for scalp nerve block. The amount of tramadol given in the first 24 hours in Group A, 62.50 ± 25.00 mg, was high compared to Group B, 57.14 ± 18.89 mg. The mean arterial blood pressure differed significantly in both groups at 30 minutes, 1 hour, 3 hours, and 12 hours after scalp block postoperatively and lower in Group B. Although changes in pulse rate, and SpO2 were not statistically significant in both groups, patients were hemodynamically stable and did not require any ionotropic support. Ramsay sedation score and visual analog score postoperatively were not significant. There were no significant adverse effects noted in any groups. Conclusion Our study concluded that administering clonidine at a dosage of 1 μg/kg, in combination with 0.5% ropivacaine for scalp nerve block procedures, significantly extends the duration of analgesia and enhances its quality, all while maintaining stable hemodynamic parameters.

Dexmedetomidine Prevents Chronic Incisional Pain After Brain Tumor Resection: A Secondary Analysis of the Randomized Control Trial

BACKGROUND

Dexmedetomidine was reported to reduce postoperative acute pain after neurosurgery. However, the efficacy of dexmedetomidine for preventing chronic incisional pain is uncertain.

METHODS

This article is a secondary analysis of a randomized, double-blind, placebo-controlled trial. Eligible patients were randomly allocated to either the dexmedetomidine group or the placebo group. Patients assigned to the dexmedetomidine group were given a 0.6 μg kg -1 dexmedetomidine bolus followed by a 0.4 μg kg -1 h -1 maintenance dose until dural closure; placebo patients were given comparable amounts of normal saline. The primary end point was the incidence of incisional pain at 3 months after craniotomy evaluated by numerical rating scale scores and defined as any score >0. The secondary end points were postoperative acute pain scores, sleep quality, and Short-Form McGill Pain Questionnaire (SF-MPQ-2) at 3 months after craniotomy.

RESULTS

From January 2021 to December 2021, a total of 252 patients were included in the final analysis: the dexmedetomidine group (n = 128) and the placebo group (n = 124). The incidence of chronic incisional pain was 23.4% (30 of 128) in the dexmedetomidine group versus 42.7% (53 of 124) in the placebo group (risk ratio, 0.55; 95% confidence interval, 0.38-0.80; P = .001). The overall severity of chronic incisional pain was mild in both groups. Patients in the dexmedetomidine group had lower acute pain severity on movement than those in the placebo group for the first 3 days after surgery (all adjusted P < .01). Sleep quality did not differ between groups. However, the SF-MPQ-2 total sensory ( P = .01) and neuropathic pain descriptor ( P = .023) scores in the dexmedetomidine group were lower than those in the placebo group.

CONCLUSIONS

Prophylactic intraoperative dexmedetomidine infusion reduces the incidence of chronic incisional pain as well as acute pain score after elective brain tumor resections.

Dexamethasone and dexmedetomidine as adjuvants to ropivacaine do not prolong analgesia in wound infiltration for lumbar spinal fusion: a prospective randomized controlled study

BACKGROUND AND OBJECTIVES

Local anesthetics (LAs) are widely used to infiltrate into surgical wounds for postoperative analgesia. Different adjuvants like dexamethasone and dexmedetomidine, when added to LA agents, could improve and prolong analgesia. The aim of this trial was to evaluate the analgesic efficacy and opioid-sparing properties of dexamethasone and dexmedetomidine when added to ropivacaine for wound infiltration in transforaminal lumbar interbody fusion (TLIF).

METHODS

We conducted a controlled study among 68 adult patients undergoing TLIF, which was prospective, randomized and double-blind in nature. The participants were divided into four equal groups at random. Group R was given 150 mg of 1% ropivacaine (15 mL) and 15 mL of normal saline. Group R + DXM received 150 mg of 1% ropivacaine (15 mL) and 10 mg of dexamethasone (15 mL). Group R + DEX received 150 mg of 1% ropivacaine (15 mL) and 1 µg/kg of dexmedetomidine (15 mL). Lastly, group R + DXM + DEX was given 150 mg of 1% ropivacaine (15 mL), 10 mg of dexamethasone and 1 µg/kg of dexmedetomidine (15 mL). The primary focus was on the length of pain relief provided. Additionally, secondary evaluations included the amount of hydromorphone taken after surgery, the numerical rating scale and safety assessments within 48 h after the operation.

RESULTS

Based on the p value (P > 0.05), there was no significant variance in the duration of pain relief or the total usage of hydromorphone after surgery across the four groups. Similarly, the numerical rating scale scores at rest and during activity at 6-, 12-, 24- and 48-h post-surgery for all four groups showed no difference (P > 0.05). However, the incidence of delayed anesthesia recovery was slightly higher in group R + DEX and group R + DXM + DEX when compared to group R or group R + DXM. Furthermore, there were no significant differences between the four groups in terms of vomiting, nausea, dizziness or delayed anesthesia recovery.

CONCLUSION

For wound infiltration in TLIF, the addition of dexamethasone and dexmedetomidine to ropivacaine did not result in any clinically significant reduction in pain or opioid consumption and could prompt some side effects.

Ultrasound-guided scalp nerve block in anesthesia of children receiving cranial suture reconstruction

OBJECTIVE

Analgesia is very important for children with craniosynostosis who are undergoing cranial suture reconstruction. This study investigated the effectiveness and safety of an analgesic technique based on scalp nerve block combined with general anesthesia versus general anesthesia alone.

METHODS

This was a single-center, prospective, randomized, controlled study. A total of 60 children aged 6-24 months who underwent cranial suture reconstruction were randomly divided into two groups: Group A (general anesthesia combined with scalp nerve block) and Group N (general anesthesia). The hemodynamics were recorded preoperatively, at 5 min after incision and at 1, 6 and 12 h after surgery; the pain was scored at 1, 6 and 12 h after surgery, and blood glucose was detected at 1 h after surgery.

RESULTS

The mean arterial pressure and heart rate at 5 min after incision and 1 h after surgery in Group N were higher than those in Group A; the blood glucose and FLACC score in Group N were higher than those in Group A; and the number of postoperative analgesic pump presses were also significantly increased in Group N.

CONCLUSION

Preoperative scalp nerve block can reduce hemodynamic fluctuation and postoperative pain in children undergoing cranial suture reconstruction for craniosynostosis. Thus, it can be safely and effectively applied in the anesthesia of these children.

Systematic Review and Meta-Analysis of Randomized Controlled Trials for Scalp Block in Craniotomy

BACKGROUND

Scalp block is regional anesthetic injection along nerves innervating the cranium. Scalp blocks for craniotomy may decrease postoperative pain and opioid consumption. Benefits may extend beyond the anesthetic period.

OBJECTIVE

To analyze evidence for scalp block on postoperative pain and opioid use.

METHODS

This systematic review and meta-analysis, Prospective Register of Systematic Reviews registration (CRD42022308048), included Ovid Medical Literature Analysis and Retrieval System Online, Embase, and Cochrane Central Register of Controlled Trials inception through February 9, 2022. Only randomized controlled trials were included. We excluded studies not reporting either main outcome. Duplicate reviewers performed study selection, risk of bias assessment, data extraction, and evidence certainty Grading of Recommendations Assessment, Development, and Evaluation appraisal. Main outcomes were postoperative pain by visual analog scale within 72 hours and opioid consumption as morphine milligram equivalent (MME) within 48 hours.

RESULTS

Screening filtered 955 studies to 23 trials containing 1532 patients. Risk of bias was overall low. Scalp block reduced postoperative pain at 2 through 72 hours, visual analog scale mean differences of 0.79 to 1.40. Opioid requirements were reduced at 24 hours by 16.52 MME and 48 hours by 15.63 MME.

CONCLUSION

Scalp block reduces postoperative pain at 2 through 48 hours and may reduce pain at 72 hours. Scalp block likely reduces opioid consumption within 24 hours and may reduce opioid consumption to 48 hours. The clinical utility of these differences should be interpreted within the context of modest absolute reductions, overall care optimization, and patient populations. This is the first level 1A evidence to evaluate scalp block efficacy in craniotomy.

Anesthesia and analgesia for experimental craniotomy in mice and rats: a systematic scoping review comparing the years 2009 and 2019

Experimental craniotomies are a common surgical procedure in neuroscience. Because inadequate analgesia appears to be a problem in animal-based research, we conducted this review and collected information on management of craniotomy-associated pain in laboratory mice and rats. A comprehensive search and screening resulted in the identification of 2235 studies, published in 2009 and 2019, describing craniotomy in mice and/or rats. While key features were extracted from all studies, detailed information was extracted from a random subset of 100 studies/year. Reporting of perioperative analgesia increased from 2009 to 2019. However, the majority of studies from both years did not report pharmacologic pain management. Moreover, reporting of multimodal treatments remained at a low level, and monotherapeutic approaches were more common. Among drug groups, reporting of pre- and postoperative administration of non-steroidal anti-inflammatory drugs, opioids, and local anesthetics in 2019 exceeded that of 2009. In summary, these results suggest that inadequate analgesia and oligoanalgesia are persistent issues associated with experimental intracranial surgery. This underscores the need for intensified training of those working with laboratory rodents subjected to craniotomies.

Systematic review registration

https://osf.io/7d4qe.

Prevention of Post-Operative Pain after Elective Brain Surgery: A Meta-Analysis of Randomized Controlled Trials

Background and Objective: To analyze the effects of several drug for pain prevention in adults undergoing craniotomy for elective brain surgery. Material and Methods: A systematic review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The inclusion criteria were limited to randomized controlled trials (RCTs) that evaluated the effectiveness of pharmacological treatments for preventing post-operative pain in adults (aged 18 years or older) undergoing craniotomies. The main outcome measures were represented by the mean differences in validated pain intensity scales administered at 6 h, 12 h, 24 h and 48 h post-operatively. The pooled estimates were calculated using random forest models. The risk of bias was evaluated using the RoB2 revised tool, and the certainty of evidence was assessed according to the GRADE guidelines. Results: In total, 3359 records were identified through databases and registers' searching. After study selection, 29 studies and 2376 patients were included in the meta-analysis. The overall risk of bias was low in 78.5% of the studies included. The pooled estimates of the following drug classes were provided: NSAIDs, acetaminophen, local anesthetics and steroids for scalp infiltration and scalp block, gabapentinoids and agonists of adrenal receptors. Conclusions: High-certainty evidence suggests that NSAIDs and acetaminophen may have a moderate effect on reducing post-craniotomy pain 24 h after surgery compared to control and that ropivacaine scalp block may have a bigger impact on reducing post-craniotomy pain 6 h after surgery compared to control. Moderate-certainty evidence indicates that NSAIDs may have a more remarkable effect on reducing post-craniotomy pain 12 h after surgery compared to control. No moderate-to-high-certainty evidence indicates effective treatments for post-craniotomy pain prevention 48 h after surgery.

Dexmedetomidine as an adjuvant to scalp block in patients undergoing elective craniotomy: A prospective randomized controlled trial

OBJECTIVE

Regional techniques minimize anesthetic requirements and their effects may be beneficial. There is a lack of consensus and evidence concerning alternative analgesia strategies for cranial neurosurgery. This study was designed to evaluate the effect of scalp block with or without dexmedetomidine combined with general anesthesia on hemodynamic stability, opioid consumption and postoperative pain in patients undergoing elective craniotomy.

METHODS

One hundred five patients undergoing elective craniotomy for tumor dissection were randomly divided into three groups to receive scalp block as an adjuvant to general anesthesia: with either 40 ml ropivacaine 0.5 % (Group R), 40 ml ropivacaine 0.5 % plus dexmedetomidine 1 μg/kg (Group RD) or 40 ml saline as a placebo (Group C). After a standard induction sequence using propofol, fentanyl and a single dose of rocuronium, patients were intubated. Bilateral scalp block was given immediately after induction. Anesthesia was maintained with propofol and remifentanil infusion. Five minutes before head pinning scalp block was performed by blocking the supraorbital, supratrochlear, auriculotemporal, occipital, and postauricular branches of the greater auricular nerves. All patients were monitored with electrocardiogram, invasive blood pressure, pulse oximetry and BIS monitoring. Primary outcomes measures were overall hemodynamic variables during surgery and intravenous fentanyl and remifentanil consumption. Mean arterial pressure (MAP) and heart rate (HR) were recorded at seven time-points: scalp block (T1-baseline), pin fixation (T2), skin incision (T3), drilling (T4), dura matter incision (T5), dura matter closure (T6) and skin closure (T7). For all time points it was recorded the mean value after 3 consecutive measures with 5 min interval. Secondary outcome was postoperative pain intensity using visual analog scale 24 and 48 h after surgery. VAS scores, fentanyl and remifentanil were evaluated using Kruskal-Wallis test. MAP and HR were compared by One-Way repeated measures Anova (GLMM) using time as random efect and by One-Way Anova using time as fxed efect.

RESULTS

Mean arterial pressure was significant lower at skin closure compared to baseline in group R (p < 0,001) and in group RD (p < 0,001). Patients in group RD showed significant lower heart rate at dura matter incision, dura matter closure and skin closure compared to baseline, pin fixation and skin incision time points (p < 0,001) and reported significantly less heart rate than group C (p < 0,001) and group R (p < 0,001) during dura matter incision, dura matter closure and skin closure time points. Patients in group RD receive significant lower fentanyl than group R (p < 0,01). The intraoperative consumption of remifentanil was significant higher in control group compared to group R (p < 0,01) and to group RD (p < 0,001). Additionally, remifentanil consumption was significant lower in group RD as compared to group R (p < 0,001). Postoperative pain had no statistically differences between the three groups at 24 h and 48 h after craniotomy (Preop VAS: p = 0,915, VAS 24: p = 0,284, VAS 48, p = 0,385). No adverse effects were noted.

CONCLUSION

Our study indicated that addition of dexmedetomidine to scalp block with ropivacaine 0.5% provided significantly better perioperative hemodynamic stability during elective craniotomy. Moreover, scalp block with or without dexmedetomidine reduced fentanyl and remifentanil consumption, but it didn't significantly prolonged analgesia in patients undergoing elective craniotomy.

Impact of Bilateral Quadratus Lumborum Block Using Different Doses of Dexmedetomidine for Postoperative Analgesia in Laparoscopic Myomectomy: A Randomized Controlled Trial

OBJECTIVES

The optimal dosage of dexmedetomidine (DEX) for postoperative analgesia of quadratus lumborum block (QLB) after laparoscopic myomectomy is not clear. Our study evaluated the analgesic and adverse effects of different doses of locally administered DEX.

MATERIALS AND METHODS

Patients underwent laparoscopic myomectomy were enrolled in this randomized controlled trial. Transmuscular bilateral QLB was conducted postoperatively using local anesthetic plus different doses of DEX, as an adjuvant, per side. Numeric rating scales (NRS) of pain score and heart rate (HR) were assessed after performing QLB. Additional analgesics through patient-controlled analgesia pump, recovery time to first flatus, hospital stay, and other outcomes were also compared.

RESULTS

A total of 150 participants were randomly divided into 3 groups (DEX1 group: 0.1 μg/kg; DEX2 group: 0.3 μg/kg; DEX3 group: 0.5 μg/kg), 50 for each group. Compared with the DEX1 group, NRS pain scores were lower in groups DEX2 and DEX3 ( P <0.017) 20 minutes after QLB and the significance lasted for 24 hours. Patients in groups DEX2 and DEX3 needed fewer additional analgesics than the group DEX1 ( P <0.017). HR in groups DEX2 and DEX3 was lower than the group DEX1 10 minutes and 20 minutes after QLB, respectively ( P <0.017). Sixty minutes after QLB, HR in the DEX3 group was still lower than the other groups. More patients in the DEX3 group were found bradycardia. Satisfaction score of postoperative analgesia was higher in groups DEX2 and DEX3 than the DEX1 group ( P <0.017).

DISCUSSION

The results suggest that solution of DEX 0.3 μg/kg in ropivacaine 0.25% for QLB is recommended to relieve postoperative pain after laparoscopic myomectomy effectively and safely.

Opioid-Sparing Effects of Flurbiprofen Axetil as an Adjuvant to Ropivacaine in Pre-Emptive Scalp Infiltration for Post-Craniotomy Pain: Study Protocol for a Multicenter, Randomized Controlled Trial

Background

Pain after craniotomy remains a poorly controlled problem that is mainly caused by the inflammatory reaction at the incision site. Nowadays, systemic opioids use, as first-line analgesics, is often limited because of adverse effects. Flurbiprofen axetil (FA) is a non-steroidal anti-inflammatory drug merged into emulsified lipid microspheres, which represent a strong affinity to inflammatory lesions. Local administration of flurbiprofen into a surgical wound has induced enhanced analgesic efficacy and few systemic or local adverse effects after oral surgery. However, the impact of local FA, as a non-opioid pharmacologic alternative, remains elusive on postoperative pain in craniotomy. In this study, we presume that pre-emptive infiltration of scalp with FA as an adjuvant to ropivacaine can lead to less sufentanil consumption postoperatively in patient controlled intravenous analgesia (PCIA) compared with ropivacaine alone.

Methods/Design

We design a multicenter, randomized controlled study that will enroll 216 subjects who are planned to receive supratentorial craniotomy. Patients will receive pre-emptive infiltration of scalp either with 50 mg FA and 0.5% ropivacaine, or with 0.5% ropivacaine alone. Primary outcome is total consumption of sufentanil with PCIA device at 48 h postoperatively.

Discussion

This is the first study attempting to explore the analgesic and safety profile of local FA as an adjuvant to ropivacaine for incisional pain in patients undergoing craniotomy. It will provide additional insights into the opioid-sparing analgesia pathways by local administration of NSAIDs for neurosurgery.

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.

Comparative Analysis of Anaesthetic Efficacy of 2% Lignocaine With Dexmedetomidine as an Adjunct in Nerve Blocks for Dental Extractions: A Randomised Controlled Study

Introduction

Adequate perioperative pain control through peripheral nerve blocks is a time-honored practice. Local anesthetic (LA) alone may fail to provide desirable pain control operatively. Dexmedetomidine (DEXMED), is a relatively latest addition to the class of α agonists. The present study was deliberated with the hypothesis that addition of DEXMED to LA does not alter the potency and efficacy of lignocaine. The primary outcome variable measured was pain. Onset, depth of anesthesia, and vital parameters duration of postoperative analgesia following administration of nerve blocks with the two solutions were also measured.

Method

A prospective, randomized, crossover, double-blind study was conducted on 60 systemically healthy subjects for extraction of premolars in all four quadrants. Subjects were randomly assigned to receive lignocaine mixed with epinephrine (2% lignocaine in 1:2,00,000 epinephrine) or lignocaine plus DEXMED (1μcg/ml lignocaine). On the second appointment of the study, the subjects received the other solution. Pulse rate, blood pressure, arterial oxygen saturation (SPo2), and respiratory rate were recorded as a baseline before performing, during, and two hours later.

Results

It showed the comparison of onset of anesthesia, and duration of anesthesia in between the two groups was found to be significant (p=0.00) in Group D and Group L. Number of subjects who consumed analgesics in Group L was 34 and in Group D was 14. The hemodynamic parameters displayed no statistically significant difference from their baseline values in the two groups.

Conclusion

The study concluded that dexmedetomidine when administered with lignocaine in nerve blocks provides greater hemodynamic stability and increases its anesthetic and analgesic potency making it a suitable addition to the existing list of additives for local anesthetic agents.

Analgesia in the Neurosurgical Intensive Care Unit

Acute pain in neurosurgical patients is an important issue. Opioids are the most used for pain treatment in the neurosurgical ICU. Potential side effects of opioid use such as oversedation, respiratory depression, hypercapnia, worsening intracranial pressure, nausea, and vomiting may be problems and could interfere with neurologic assessment. Consequently, reducing opioids and use of non-opioid analgesics and adjuvants (N-methyl-D-aspartate antagonists, α2 -adrenergic agonists, anticonvulsants, corticosteroids), as well as non-pharmacological therapies were introduced as a part of a multimodal regimen. Local and regional anesthesia is effective in opioid reduction during the early postoperative period. Among non-opioid agents, acetaminophen and non-steroidal anti-inflammatory drugs are used frequently. Adverse events associated with opioid use in neurosurgical patients are discussed. Larger controlled studies are needed to find optimal pain management tailored to neurologically impaired neurosurgical patients.

Multimodal analgesia in neurosurgery: a narrative review

Pain following brain surgery can compromise the result of surgery. Several pharmacological interventions have been used to prevent postoperative pain in adults undergoing brain surgery. Pain following craniotomy is considered to be moderate to severe during the first two post-operative days. Opioids have been historically the mainstay and are the current prominent strategy for pain treatment. They produce analgesia but may alter respiratory, cardiovascular, gastrointestinal, and neuroendocrine functions. All these side effects may affect the normal postoperative course of craniotomy by affecting neurological function and increasing intracranial pressure. Therefore, their use in neurosurgery is limited, and opioids are used in case of strict necessity or as rescue medication. In addition to opioids, drugs with differing mechanisms of actions target pain pathways, resulting in additive and/or synergistic effects. Some of these agents include acetaminophen/non-steroidal anti-inflammatory drugs (NSAIDs), alpha-2 agonists, NMDA receptor antagonists, gabapentinoids, and local anesthesia techniques. Multimodal analgesia should be a balance between adequate analgesia and less drug-induced sedation, respiratory depression, hypercapnia, nausea, and vomiting, which may increase intracranial pressure. Non-opioid analgesics can be an useful pharmacological alternative in multimodal regimes to manage post-craniotomy pain. This narrative review aims to outline the current clinical evidence of multimodal analgesia for post craniotomy pain control.

Anesthetic Management of Asleep and Awake Craniotomy for Supratentorial Tumor Resection

Understanding how anesthetics impact cerebral physiology, cerebral blood flow, brain metabolism, brain relaxation, and neurologic recovery is crucial for optimizing anesthesia during supratentorial craniotomies. Intraoperative goals for supratentorial tumor resection include maintaining cerebral perfusion pressure and cerebral autoregulation, optimizing surgical access and neuromonitoring, and facilitating rapid, cooperative emergence. Evidence-based studies increasingly expand the impact of anesthetic care beyond immediate perioperative care into both preoperative optimization and minimizing postoperative consequences. New evidence is needed for neuroanesthesia's role in neurooncology, in preventing conversion from acute to chronic pain, and in decreasing risk of intraoperative ischemia and postoperative delirium.

Efficacy and safety of dexmedetomidine as an adjuvant to local wound infiltration anaesthesia: A meta-analysis with trial sequential analysis of 23 randomised controlled trials

To further identify the real efficacy and safety of dexmedetomidine as an adjuvant to local wound infiltration anaesthesia, we conducted this meta-analysis. The systematic search strategy was performed using PubMed, Embase, Cochrane Library, and Chinese databases. As a result, a total of 23 RCTs (1445 patients) were included. Patients receiving dexmedetomidine combined with local anaesthetics had a lower rescue analgesia rate [risk ratio (RR): 0.48; 95% confidence interval (CI): 0.36-0.65] and lower rescue analgesic consumption [weighted mean difference (WMD): -10.80 mg; 95%CI: -13.28 to -8.31 mg] than patients receiving local anaesthetics alone. The dexmedetomidine-related adverse reactions included bradycardia (RR: 1.33; 95%CI: 0.32-5.56) and hypotension (RR: 3.00; 95%CI: 0.49-18.42). In addition, the time to first analgesic request (WMD: 296.16 minutes; 95%CI: 165.69 minutes ~ 426.63 minutes), incidence of postoperative nausea and vomiting (PONV) and pain scores at 4 hours postoperatively were also significantly lower in patients receiving dexmedetomidine combined with local anaesthetics. This meta-analysis demonstrated that the use of dexmedetomidine as an adjuvant to wound infiltration is effective for reducing the rescue analgesia rate, rescue analgesic consumption and PONV. In addition, limited evidence shows that dexmedetomidine can prolong postoperative analgesia for approximately 5 hours. Further investigations on dexmedetomidine-related adverse reactions and the dose-response effect of dexmedetomidine in wound infiltration are warranted.

Postoperative analgesia of scalp nerve block with ropivacaine in pediatric craniotomy patients: a protocol for a prospective, randomized, placebo-controlled, double-blinded trial

Background

Moderate-to-severe postoperative pain following craniotomy has a high incidence in pediatric patients. Such pain may cause agitation, intracranial hypertension, epileptic seizures, and postoperative hematoma, which affect morbidity and mortality. Although scalp nerve block (SNB) achieves satisfactory pain relief except for suboccipital mid-craniotomy in adults and ropivacaine is widely used as a long-acting peripheral nerve block agent in children, there are few studies of SNB with ropivacaine in pediatric patients undergoing craniotomy. In addition, the neurosurgery operation time is relatively long, but the duration of action of SNB is limited. It is generally believed that postoperative SNB is better than preoperative SNB for postoperative analgesia. However, considering the concept of preemptive analgesia, we believe that preoperative SNB may achieve a longer postoperative analgesia effect than we expected.

Methods

This trial is a single-institution, prospective, randomized, controlled, double-blind study. A total of 180 children aged between 1 and 12 years who are undergoing elective craniotomy will be randomly allocated in a 1:1:1 ratio to three groups: group B (preoperative ropivacaine block group), group A (postoperative ropivacaine block group), and group N (nonblocking control group). This randomization will be stratified by age in two strata (1–6 years and 7–12 years). The primary outcome is the total consumption of sufentanil within 24 h after surgery. The secondary outcomes include assessment of pain scores, total consumption of sufentanil and emergency-remedy medicine consumption at observation points, the occurrence of postoperative complications, and the length of hospitalization after surgery.

Discussion

This study is designed to explore the effect and feasibility of SNB with ropivacaine for postoperative analgesia in pediatric patients undergoing craniotomy. Further aims are to compare the effects of preoperative and postoperative SNB on postoperative analgesia in order to identify whether there is a preemptive analgesic effect and determine the better time to implement SNB in pediatric patients during craniotomy.

Trial registration

Chinese Clinical Trial Registry ChiCTR1800017386. Registered on 27 July 2018.

Adjuncts to local anesthetic wound infiltration for postoperative analgesia: a systematic review

Local anesthetics (LAs) are commonly infiltrated into surgical wounds for postsurgical analgesia. While many adjuncts to LA agents have been studied, it is unclear which adjuncts are most effective for co-infiltration to improve and prolong analgesia. We performed a systematic review on adjuncts (excluding epinephrine) to local infiltrative anesthesia to determine their analgesic efficacy and opioid-sparing properties. Multiple databases were searched up to December 2019 for randomized controlled trials (RCTs) and two reviewers independently performed title/abstract screening and full-text review. Inclusion criteria were (1) adult surgical patients and (2) adjunct and LA agents infiltration into the surgical wound or subcutaneous tissue for postoperative analgesia. To focus on wound infiltration, studies on intra-articular, peri-tonsillar, or fascial plane infiltration were excluded. The primary outcome was reduction in postoperative opioid requirement. Secondary outcomes were time-to-first analgesic use, postoperative pain score, and any reported adverse effects. We screened 6670 citations, reviewed 126 full-text articles, and included 89 RCTs. Adjuncts included opioids, non-steroidal anti-inflammatory drugs, steroids, alpha-2 agonists, ketamine, magnesium, neosaxitoxin, and methylene blue. Alpha-2 agonists have the most evidence to support their use as adjuncts to LA infiltration. Fentanyl, ketorolac, dexamethasone, magnesium and several other agents show potential as adjuncts but require more evidence. Most studies support the safety of these agents. Our findings suggest benefits of several adjuncts to local infiltrative anesthesia for postoperative analgesia. Further well-powered RCTs are needed to compare various infiltration regimens and agents.

Protocol registration

PROSPERO (CRD42018103851) (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=103851)

Pharmacological interventions for the prevention of acute postoperative pain in adults following brain surgery

BACKGROUND

Pain following brain surgery can compromise recovery. Several pharmacological interventions have been used to prevent pain after craniotomy; however, there is currently a lack of evidence regarding which interventions are most effective.

OBJECTIVES

The objectives are to assess the effectiveness of pharmacological interventions for prevention of acute postoperative pain in adults undergoing brain surgery; compare them in terms of additional analgesic requirements, incidence of chronic headache, sedative effects, length of hospital stay and adverse events; and determine whether these characteristics are different for certain subgroups.

SEARCH METHODS

We searched MEDLINE, Embase, CINAHL, CENTRAL, Web of Science and two trial registries together with reference checking and citation searching on 28th of November 2018.

SELECTION CRITERIA

We included blinded and non-blinded, randomized controlled trials evaluating pharmacological interventions for the prevention of acute postoperative pain in adults undergoing neurosurgery, which had at least one validated pain score outcome measure.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We calculated mean differences for the primary outcome of pain intensity; any pain scores reported on a 0 to 100 scale were converted to a 0 to 10 scale.

MAIN RESULTS

We included 42 completed studies (3548 participants) and identified one ongoing study. Nonsteroidal anti-inflammatories (NSAIDs) Nonsteroidal anti-inflammatories (NSAIDs) reduce pain up to 24 hours (0 to 6 hours, MD -1.16, 95% CI -1.57 to -0.76; 12 hours, MD -0.62, 95% CI -1.11 to -0.14; 24 hours, MD -0.66, 95% CI -1.18 to -0.13; 6 studies, 742 participants; all high-quality evidence). Results for other outcomes were imprecise (additional analgesic requirements: MD 1.29 mg, 95% CI -5.0 to 2.46, 4 studies, 265 participants; nausea and vomiting RR 1.34, 95% CI 0.30 to 5.94, 2 studies, 345 participants; both low-quality evidence). Dexmedetomidine reduces pain up to 12 hours (0 to 6 hours, MD -0.89, 95% CI -1.27 to -0.51, moderate-quality evidence; 12 hours, MD -0.81, 95% CI -1.21 to -0.42, low-quality evidence). It did not show efficacy at 24 hours (MD -0.08, 95% CI -0.32 to 0.16; 2 studies, 128 participants; low-quality evidence). Dexmedetomidine may decrease additional analgesic requirements (MD -21.36 mg, 95% CI -34.63 to -8.1 mg, 2 studies, 128 participants, low-quality evidence). Results for other outcomes were imprecise (nausea and vomiting RR -0.43, 95% CI 0.06 to 3.08, 3 studies, 261 participants; hypotension RR 0.5, 95% CI 0.05 to 5.28, 3 studies, 184 participants; both low-quality evidence). Scalp blocks may reduce pain up to 48 hours (0 to 6 hours, MD -0.98, 95% CI -1.66 to -0.3, 10 studies, 414 participants; 12 hours, MD -0.95, 95% CI -1.53 to -0.37, 8 studies, 294 participants; 24 hours, MD -0.78, 95% CI -1.52 to -0.05, 9 studies, 433 participants, all low-quality evidence; 48 hours, MD -1.34, 95% CI -2.57 to -0.11, 4 studies, 135 participants, very low-quality evidence. When studies with high risk of bias were excluded, significance remained at 12 hours only. Scalp blocks may decrease additional analgesia requirements (SMD -1.11, 95% CI -1.97 to -0.25, 7 studies, 314 participants). Results for other outcomes were imprecise (nausea and vomiting RR 0.66, 95% CI 0.33 to 1.32, 4 studies, 165 participants, very low-quality evidence). Scalp Infiltration may reduce pain postoperatively but efficacy was inconsistent, with a significant effect at 12 and 48 hours only (12 hours, MD -0.71, 95% CI -1.34 to -0.08, 7 studies, 309 participants, low-quality evidence; 48 hours, MD - 1.09, 95% CI -2.13 to - 0.06, 3 studies, 128 participants, moderate-quality evidence). No benefit was observed at other times (0 to 6 hours, MD -0.64, 95% CI -1.28 to -0.00, 9 studies, 475 participants, moderate-quality evidence; 24 hours, MD -0.39, 95% CI -1.06 to 0.27,6 studies, 260 participants, low-quality evidence. Scalp infiltration may reduce additional analgesia requirements MD -9.56 mg, 95% CI -15.64 to -3.49, 6 studies, 345 participants, very low-quality evidence). When studies with high risk of bias were excluded, scalp infiltration lost the pain benefit at 12 hours and effects on additional analgesia requirements, but retained the pain-reducing benefit at 48 hours (MD -0.56, 95% CI -1.20 to -0.32, 2 studies, 100 participants, very low-quality evidence). Results for other outcomes were imprecise (nausea and vomiting, RR 0.74, 95% CI 0.48 to 1.41, 4 studies, 318 participants, low-quality evidence). Pregabalin or gabapentin may reduce pain up to 6 hours (2 studies, 202 participants), MD -1.15,95% CI -1.66 to -0.6, 2 studies, 202 participants, low-quality evidence). One study examined analgesic efficacy at 12 hours showing significant benefit. No analgesia efficacy was shown at later times (24 hours, MD -0.29, 95% CI -0.78 to -0.19; 48 hours, MD - 0.06, 95% CI -0.86 to 0.77, 2 studies, 202 participants, low-quality evidence). Additional analgesia requirements were not significantly less (MD -0.37 (95% CI -1.10 to 0.35, 3 studies, 234 participants, low-quality evidence). Risk of nausea and vomiting was significantly reduced (RR 0.51, 95% CI 0.29 to 0.89, 3 studies, 273 participants, low-quality evidence). Results for other outcomes were imprecise (additional analgesia requirements: MD -0.37, 95% CI -1.10 to 0.35, 3 studies, 234 participants, low-quality evidence). Acetaminophen did not show analgesic benefit (0 to 6 hours, MD -0.35, 95% CI -1.00 to 0.30; 12 hours, MD -0.51, 95% CI -1.04 to 0.03, 3 studies, 332 participants, moderate-quality evidence; 24 hours, MD -0.34, 95% CI -1.20 to 0.52, 4 studies, 439 participants, high-quality evidence). Results for other outcomes remained imprecise (additional analgesia requirements, MD 0.07, 95% CI -0.86 to 0.99, 4 studies, 459 participants, high-quality evidence; length of hospitalizations, MD -3.71, 95% CI -14.12 to 6.7, 2 studies, 335 participants, moderate-quality evidence).

AUTHORS' CONCLUSIONS

There is high-quality evidence that NSAIDs reduce pain up to 24 hours postoperatively. The evidence for reductions in pain with dexmedetomidine, pregabalin or gabapentin, scalp blocks, and scalp infiltration is less certain and of very low to moderate quality. There is low-quality evidence that scalp blocks and dexmedetomidine may reduce additional analgesics requirements. There is low-quality evidence that gabapentin or pregabalin may decrease nausea and vomiting, with the caveat that the total number of events for this comparison was low.

Dexmedetomidine as an Additive to Local Anesthesia: A Step to Development in Dentistry

PURPOSE

The study aimed to compare the effect of dexmedetomidine added to lidocaine against epinephrine added to lidocaine on local anesthetic potency and to look for future prospects of dexmedetomidine as an additive to local anesthesia in dentistry.

MATERIALS AND METHODS

The study included 25 healthy volunteers in whom extraction of all first premolars was scheduled as part of their orthodontic treatment plan. In this split-mouth, double-blind, crossover, randomized controlled trial, patients were randomized into 2 groups: Group 1 received injection lidocaine plus dexmedetomidine, and group 2 was administered lidocaine plus epinephrine. Patients were assessed for the onset of action of anesthesia, duration of analgesia, pain perception, and vital signs.

RESULTS

The mean values (±standard deviations) for the onset of anesthetic action in groups 1 and 2 were 113 ± 24.9 and 141 ± 34.8 seconds, respectively, for the mandible. For the maxilla, the mean values were 113 ± 24.9 seconds for group 1 and 165 ± 43.8 seconds for group 2. The duration of anesthesia was longer in group 1 (lidocaine plus dexmedetomidine), in which the requirement for the first analgesic on request was seen after a longer time interval, when compared with group 2 (lidocaine plus epinephrine). Pain perception elicited statistically significant results with less perception of pain in group 1 (lidocaine plus dexmedetomidine). The vital parameters remained stable, and the results were not statistically significant.

CONCLUSIONS

In this study, we observed that the addition of dexmedetomidine to lidocaine for maxillary and mandibular nerve blocks significantly prolonged the block duration and shortened the onset of action, as well as improved postoperative analgesia in terms of the need for fewer analgesics in the postoperative period. Furthermore, the vital parameters remained stable and no complications were encountered. The findings were supportive of the use of dexmedetomidine as an adjunct to local anesthetics in dental procedures.