Differences in calculated percentage improvement versus patient-reported percentage improvement in pain scores: a review of spinal cord stimulation trials.

INTRODUCTION: Spinal cord stimulation is frequently used for the treatment of intractable chronic pain conditions. Trialing of the spinal cord stimulator device is recommended to assess the patient's response to neurostimulation before permanent implantation. The trial response is often assessed by Numeric Rating Scale changes and patient-reported percentage pain improvement. Using number rating scale changes between prespinal and postspinal cord stimulation trial, a calculated percentage pain improvement can be obtained. The aim of this study was to assess the difference between calculated and patient-reported percentage improvement in pain scale during spinal cord stimulation trials. METHODS: This study was a retrospective single center review of all spinal cord stimulation trials from January 1 2017 to July 1 2019. A total of 174 patients were included. The paired t-test was used to compare numeric pain scores obtained prestimulation versus poststimulation. The mean difference between methods (patient-reported minus calculated) was compared with zero using the 1-sample t-test. Lin's concordance correlation coefficient was computed with a 95% CI, calculated using Fisher z-transformation; and a bootstrapping approach was used to compare the concordance correlation coefficient between groups. In all cases, two-tailed tests were used with p<0.05 considered statistically significant. RESULTS: Based on prestimulation and poststimulation numeric rating scale scores, the mean±SD calculated percentage improvement in pain scale was 54±28. The mean±SD patient-reported percentage improvement in pain scale was 59±25. The overall 95% limits of agreement for the two methods are -30% to +41%. The overall concordance correlation coefficient was 0.76 (95% CI 0.69 to 0.81). CONCLUSION: Although the two methods are highly correlated, there is substantial lack of agreement between patient-reported and calculated percentage improvement in pain scale, suggesting that these measures should not be used interchangeably for spinal cord stimulator trial outcome assessment. This emphasizes the need for improved metrics to better measure patient response to neuromodulation therapies. Additionally, patient-reported percentage improvement in pain was found to be higher than calculated percentage improvement in pain, potentially highlighting the multidimensional experience of pain and the unpredictability of solely using Numeric Rating Scale scores to assess patient outcomes.

A Systematic Review of Intra-Articular Ketamine for Postoperative Analgesia.

BACKGROUND: This systematic review appraises the evidence from human clinical trials comparing postoperative pain scores and opioid consumption in patients receiving intra-articular ketamine versus other modalities of analgesia after orthopedic joint procedures. METHODS: Studies were identified from Embase, Scopus, and OVID Medline databases. Included studies compared patients receiving intra-articular ketamine versus other modalities of analgesia. The primary outcome of interest was postprocedural pain score and total opioid consumption, whereas secondary outcomes included time to rescue analgesic medication request, active range of motion, time to mobilization, and adverse effects. RESULTS: Seventeen studies were included. Dosage of ketamine varied widely from 0.25 to 2 mg/kg. Fifteen of 17 demonstrated decreased overall pain scores and decreased total postoperative opioid consumption in patients receiving intra-articular ketamine versus control groups. Included studies generally demonstrated reduced time to mobilization and increased latency until rescue analgesic medication in the intra-articular ketamine group. CONCLUSIONS: Patients who received intra-articular ketamine generally reported lower pain scores and had lower postoperative opioid consumption after orthopedic joint procedures. This suggests that the intra-articular route of ketamine delivery may be a useful analgesic modality, although future larger-scale trials should explore its pharmacokinetics, optimal dosing, safety, and cost-effectiveness.

Akt: A Therapeutic Target in Hepatic Ischemia-Reperfusion Injury.

BACKGROUND: Liver transplantation is the second most common transplant procedure in the United States. A leading cause of post-transplantation organ dysfunction is I/R injury. During I/R injury, the serine/threonine kinase Akt is activated, stimulating downstream mediators to promote cellular survival. Due to the cellular effects of Akt, therapeutic manipulation of the Akt pathway can help reduce cellular damage during hepatic I/R that occurs during liver transplantation. OBJECTIVE: A full description of therapeutic options available that target Akt to reduce hepatic I/R injury has not been addressed within the literature. The purpose of this review is to illuminate advances in the manipulation of Akt that can be used to therapeutically target I/R injury in the liver. METHODS: An in depth literature review was performed using the Scopus and PubMed databases. A total of 75 published articles were utilized for this manuscript. Terminology searched includes a combination of "hepatic ischemia/reperfusion injury", "Akt/PKB", "preconditioning" and "postconditioning." RESULTS: Four principal methods that reduce I/R injury include hepatic pre- and postconditioning, pharmacological intervention and future miRNA/gene therapy. Discussed therapies used serum alanine aminotransferase levels, liver histology and phosphorylation of downstream mediators to confirm the Akt protective effect. CONCLUSION: The activation of Akt from the reviewed therapies has resulted in predictable reduction in hepatocyte damage using the previously mentioned measurements. In a clinical setting, these therapies could potentially be used in combination to achieve better outcomes in hepatic transplant patients. Evidence supporting reduced I/R injury through Akt activation warrants further studies in human clinical trials.