Comparative study between transdermal fentanyl and melatonin patches on postoperative pain relief after lumber laminectomy, a double-blind, placebo-controlled trial

Experimental Data on the Role of Melatonin in the Pathogenesis of Nonalcoholic Fatty Liver Disease

Despite the increasing prevalence of nonalcoholic fatty liver disease (NAFLD) worldwide, its complex pathogenesis remains incompletely understood. The currently stated hypotheses cannot fully clarify the interrelationships between individual pathogenetic mechanisms of the disease. No appropriate health strategies have been developed for treating NAFLD. NAFLD is characterized by an accumulation of triglycerides in hepatic cells (steatosis), with the advanced form known as nonalcoholic steatohepatitis. In the latter, superimposed inflammation can lead to fibrosis. There are scientific data on NAFLD's association with components of metabolic syndrome. Hormonal factors are thought to play a role in the development of metabolic syndrome. Endogenous melatonin, an indoleamine hormone synthesized by the pineal gland mainly at night, is a powerful chronobiotic that probably regulates metabolic processes and has antioxidant, anti-inflammatory, and genomic effects. Extrapineal melatonin has been found in various tissues and organs, including the liver, pancreas, and gastrointestinal tract, where it likely maintains cellular homeostasis. Melatonin exerts its effects on NAFLD at the cellular, subcellular, and molecular levels, affecting numerous signaling pathways. In this review article, we discuss the experimental scientific data accumulated on the involvement of melatonin in the intimate processes of the pathogenesis of NAFLD.

Pain management after laminectomy: a systematic review and procedure-specific post-operative pain management (prospect) recommendations

PURPOSE

With lumbar laminectomy increasingly being performed on an outpatient basis, optimal pain management is critical to avoid post-operative delay in discharge and readmission. The aim of this review was to evaluate the available literature and develop recommendations for optimal pain management after one- or two-level lumbar laminectomy.

METHODS

A systematic review utilizing the PROcedure-SPECific Post-operative Pain ManagemenT (PROSPECT) methodology was undertaken. Randomised controlled trials (RCTs) published in the English language from 1 January 2008 until 31 March 2020-assessing post-operative pain using analgesic, anaesthetic and surgical interventions-were identified from MEDLINE, EMBASE and Cochrane Databases.

RESULTS

Out of 65 eligible studies identified, 39 RCTs met the inclusion criteria. The analgesic regimen for lumbar laminectomy should include paracetamol and a non-steroidal anti-inflammatory drug (NSAID) or cyclooxygenase (COX)-2 selective inhibitor administered preoperatively or intraoperatively and continued post-operatively, with post-operative opioids for rescue analgesia. In addition, surgical wound instillation or infiltration with local anaesthetics prior to wound closure is recommended. Some interventions-gabapentinoids and intrathecal opioid administration-although effective, carry significant risks and consequently were omitted from the recommendations. Other interventions were also not recommended because there was insufficient, inconsistent or lack of evidence.

CONCLUSION

Perioperative pain management for lumbar laminectomy should include paracetamol and NSAID- or COX-2-specific inhibitor, continued into the post-operative period, as well as intraoperative surgical wound instillation or infiltration. Opioids should be used as rescue medication post-operatively. Future studies are necessary to evaluate the efficacy of our recommendations.

Analgesic Efficacy of Melatonin: A Meta-Analysis of Randomized, Double-Blind, Placebo-Controlled Trials

Previous systematic reviews and meta-analyses of randomized controlled trials have reported controversial findings regarding the effects of melatonin on pain reduction. The aim of this study was to evaluate the efficacy of melatonin on pain among adults using a meta-analysis of randomized, double-blind, placebo-controlled trials (RDBPCTs). PubMed, EMBASE, the Cochrane Library, and the bibliographies of relevant articles were searched up to February 2020. Two of the authors independently evaluated eligibility of the studies based on the pre-determined criteria and extracted data. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) for the pain score change were calculated using a random-effects meta-analysis. Out of 463 that met the initial criteria, a total of 30 trials, which involved 1967 participants with 983 in an intervention group and 984 in a control group, were included in the final analysis. In a random-effects meta-analysis, the use of melatonin reduced chronic pain in all the trials (5 studies, SMD -0.65, 95% CI -0.96 to -0.34, I² = 57.2%) and high-quality trials (4 studies, SMD -0.62, 95% CI -1.01 to -0.23, I² = 49.3%). Moreover, the use of melatonin significantly reduced acute postoperative pain (11 studies, SMD -0.82, 95% CI -1.40 to -0.25, I² = 93.0%). However, the subgroup meta-analysis of high-quality RDBPCTs showed no significant association between them (6 studies, SMD -0.21, 95 % CI -0.66 to 0.24, I² = 82.4%). The current study suggests that melatonin might be used in treatment of chronic pain, while there is no sufficient evidence for acute postoperative or procedural pain. Further trials are warranted to confirm its analgesic effect.

Comparison of Effects of Melatonin and Gabapentin on Post Operative Anxiety and Pain in Lumbar Spine Surgery: A Randomized Clinical Trial

Background

Surgery is one of the stressors that cause physiological and psychological stress. Anxiety and pain and their complications are very important in anesthesiology and many researches have been done to decrease or eliminate them. This training was done to compare the effect of melatonin and gabapentin on pain and anxiety during lumbar surgery.

Methods

This study was a double-blinded clinical trial conducted on 90 patients undergoing lumbar surgery with general anesthesia in Golestan Academic Hospital in 2017. Patients were randomly assigned into 3 groups: 30 patients received 6 mg melatonin, 30 patients received 600 mg gabapentin, and 30 patients were on placebo (control), 100 minutes preoperatively. All patients were given a fixed method of anesthesia. The pain intensity and patients’ satisfaction from analgesia measured at 1, 2, 6, 12, and 24 h after surgery. The anxiety was measured 15 minutes before surgery and 1, 2, 6, 12, and 24 h after surgery.

Results

In our study, there was a significant difference between mean Visual Analog Score between melatonin and gabapentin groups in comparison to placebo (P = 0.02). The intensity of anxiety among the groups was lower in melatonin and gabapentin groups in comparison to placebo (P = 0.01).

Conclusions

The results show that pretreatment with melatonin or gabapentin decreases anxiety and pain in lumbar surgery.