Pain in critically ill COVID-19 patients: An Italian retrospective study

A systematic review and meta-analysis comparing the efficacy and safety of ketamine versus morphine for the treatment of acute pain

INTRODUCTION

Ketamine is reported as a potent opioid alternative that provides significant reduction in pain with no severe adverse events. However, some studies didn't find its use satisfactory and reported less reduction in pain score with ketamine. The purpose of this study is to compare the efficacy and safety of ketamine versus morphine for the treatment of acute pain in emergency situations.

EVIDENCE ACQUISITION

The PubMed, MEDLINE, PsycINFO EMBASE, Cochrane Library, PROSPERO registry platform, and ClinicalTrials.gov websites were queried in accordance with the PRISMA guidelines in order to locate relevant studies. According to the predefined PICOS criteria, articles were included and event data pertaining to changes in Visual Analog Scale or Numeric Rating Scale pain scales were extracted. Using RevMan and MedCalc, a meta-analysis was conducted to compare the effects of ketamine and morphine for the treatment of acute pain.

EVIDENCE SYNTHESIS

Twelve studies met the criteria for inclusion in this meta-analysis. Ketamine was found to be more effective than morphine at reducing pain scores, with an odds ratio of 0.60 (95% CI 0.48 to 0.76). Similarly, no severe adverse events related to ketamine were reported in any study, and it has a low-risk ratio of 0.78 (95% CI 0.70 to 0.87). Egger's Test P values (0.3052) and Begg's Test P values (0.3869) indicate a low risk of bias, and the Bland-Altman plot demonstrates a high degree of concordance.

CONCLUSIONS

Ketamine is a potent and effective alternative to morphine for the management of acute pain, and it reduces pain score significantly with minimal side effects.

COVID-19 and musculoskeletal pain: an overview of the current knowledge

The Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) has provoked billions of infections worldwide. Several meta-analyses have observed that up to 50% of individuals who had survived to a SARS-CoV-2 acute infection suffer from post-COVID symptoms lasting for weeks or months and up to one year after infection. The prevalence of post-COVID pain ranges between 10% to 20% when assessed with other overall post-COVID symptoms and can reach up to 50% to 60% when investigated specifically. The most common musculoskeletal manifestations of post-COVID-19 condition include fatigue, myalgia, arthralgia or back pain. Despite pain of musculoskeletal origin is one of the most prevalent post-COVID pain symptoms, the exact pathophysiological mechanisms of musculoskeletal post-COVID pain are not completely understood. Studies have reported the complexity of post-COVID pain including immune, biological, and psychological factors, and more recently, they have suggested that genetic and epigenetic factors may also play a potential role, highlighting the need for further investigation into these mechanisms. Its management is still controversial, as no specific guideline for treating musculoskeletal post-COVID pain has been proposed with only general consideration about the relevance of multidisciplinary and multimodal treatment approaches. In this paper we will highlight the clinical features, the mechanism, and the management possibilities of musculoskeletal post-COVID pain.

Application of Ketamine in Pain Management and the Underlying Mechanism

Since ketamine was approved by the FDA as an intravenous anesthetic, it has been in clinical use for more than 50 years. Apart from its anesthetic effects, ketamine is one of the few intravenous anesthetics with potent analgesic properties. As part of the effort to develop pain management, renewed interest has focused on the use of ketamine for the treatment of acute and chronic pain. Ketamine is commonly used to treat various kinds of chronic pain syndromes and is also applied to control perioperative pain and reduce the consumption of postoperative analgesics. However, its precise mechanisms of action remain mysterious for a large part. Despite extensive research in the field, the mechanism of ketamine is still unclear. Its analgesic effect appears to be largely mediated by blockade of NMDARs, but opioid, GABA, and monoaminergic system seem to partly participate in the pain transmission procedure. Its metabolites also have an analgesic effect, which may prolong pain relief. More recently, the antidepressant effect of ketamine has been considered to reduce pain-related aversion to relieve chronic pain. Overall, the analgesic mechanism of ketamine seems to be a complex combination of multiple factors. Due to its potent analgesic properties, ketamine is an analgesic with great clinical application prospects. Exploring the precise mechanism of action of ketamine will help guide clinical medication and confirm indications for ketamine analgesia. This review aims to list the application of ketamine in pain management and discuss its analgesic mechanism.

Advances and challenges in neuropathic pain: a narrative review and future directions

Over the past few decades, substantial advances have been made in neuropathic pain clinical research. An updated definition and classification have been agreed. Validated questionnaires have improved the detection and assessment of acute and chronic neuropathic pain; and newer neuropathic pain syndromes associated with COVID-19 have been described. The management of neuropathic pain has moved from empirical to evidence-based medicine. However, appropriately targeting current medications and the successful clinical development of drugs acting on new targets remain challenging. Innovative approaches to improving therapeutic strategies are required. These mainly encompass rational combination therapy, drug repurposing, non-pharmacological approaches (such as neurostimulation techniques), and personalised therapeutic management. This narrative review reports historical and current perspectives regarding the definitions, classification, assessment, and management of neuropathic pain and explores potential avenues for future research.