Safety and Efficacy of Oral Melatonin When Combined with Thoracic Epidural Analgesia in Patients with Bilateral Multiple Fracture Ribs

Pain management for hospitalized patients with rib fractures: A systematic review of randomized clinical trials

STUDY OBJECTIVE

Rib fractures (RF) are common injuries. Multiple analgesia strategies are available for treatment of pain associated with RF. However, the optimal multimodal technique for pain management is not known. The primary aim of this review was to evaluate the status of evidence derived from randomized clinical trials (RCTs) on the effectiveness of pain management modalities for rib fracture pain. Other patient-centered outcomes were secondary objectives.

METHODS

Searches were conducted in MEDLINE, Embase, Scopus, and Cochrane Library. The screening process involved two phases, two researchers independently screened the title and abstract and subsequently screened full text. RCT data were extracted independently by two research team members. Consensus was achieved by comparison and discussion when needed. Risk of bias assessment was performed using the Cochrane Risk of Bias 2 tool.

RESULTS

A total of 1344 citations were identified. Title and abstract screening excluded 1128 citations, and full text review excluded 177 articles. A total of 32 RCTs were included in the full review. Multiple analgesia techniques and medications were identified and their effect on pain score and need for rescue opioid analgesia. None of the included studies were judged to have a high risk of bias, while only 10 studies were assessed as having a low risk of bias.

CONCLUSIONS

This systematic review found that studies are of low quality with diverse methodologies and outcomes. A reduction in pain scores was found for epidural analgesia when compared with other modalities. However, the low quality of the evidence necessitates cautious interpretation of this finding. PROSPERO registration: CRD42022376298 (Nov, 16, 2022).

Perioperative Anxiolysis and Analgesic Effect after Premedication with Melatonin and Pregabalin in Total Hip Arthroplasty under Spinal Anaesthesia: A Prospective Comparative Trial

Background

Preoperative anxiety plays a critical role in post-operative pain response and other outcomes. Melatonin is a naturally secreted hormone which has anxiolytic, sedative, and analgesic properties. Pregabalin, analogue of gabapentin which has property of anxiolytic and analgesic effects.

Materials and Methods

Total 96 patients undergoing total hip arthroplasty, divided into 3 groups of 32 each and were given placebo (group I), melatonin 6 mg (group II), and pregabalin 150 mg (group III). Anxiety level, postoperative pain score, sedation level and duration as well as characteristics of spinal anaesthesia were assessed with other vital parameters.

Results

Group I showed an increment in the anxiety score from baseline whereas in group II and group III, there was a decline in pre-operative anxiety score from baseline at all the periods of observation and more significantly in group III. Visual analogue scale (VAS) score and total dose of rescue analgesia were highest in group I, but group II and group III were comparable to each other. However, the durations of spinal anaesthesia and motor blockade showed a statistically significant difference with maximum duration in group III followed by II and then I. The level of sedation among the three groups were comparable at all the periods of observation.

Conclusions

Pregabalin was found better for perioperative anxiolysis, post-operative analgesia and for prolongation of duration of spinal anaesthesia when compared to melatonin.

Molecular Mechanism of Neuroprotective Effect of Melatonin on Morphine Addiction and Analgesic Tolerance: an Update

Drug addiction is a global health problem and continues to place an enormous financial burden on society. This addiction is characterized by drug dependence sensitization and craving. Morphine has been widely used for pain relief, but chronic administration of morphine causes analgesic tolerance, hyperalgesia, and addiction, all of which limit its clinical usage. Alterations of multiple molecular pathways have been reported to be involved in the development of drug addiction, including mitochondrial dysfunction, excessive oxidative stress and nitric oxide stress, and increased levels of apoptosis, autophagy, and neuroinflammation. Preclinical and clinical studies have shown that the co-administration of melatonin with morphine leads to a reversal of these affected pathways. In addition, murine models have shown that melatonin improves morphine-induced analgesic tolerance and addictive behaviors, such as behavioral sensitization, reward effect, and physical dependence. In this review, we attempt to summarize the recent findings about the beneficial effect and molecular mechanism of melatonin on mitochondrial dysfunction, uncontrolled autophagy, and neuroinflammation in morphine addiction and morphine analgesic tolerance. We propose that melatonin might be a useful supplement in the treatment opiate abuse.