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Background: Intravenous (IV) ketamine is used for chronic neuropathic pain refractory to other treatments. Administration of such a medication requires high-cost services while the result is not always satisfactory with a significant percentage of failure. Success and failure are related to some factors. Method: In this study, we aim to point the most responsive disease category to IV ketamine and the predictive factors for successful and failed treatment. Two hundred and sixty-nine patients out of 371 were included. Demographic, clinical, and therapy-related variables were retrospectively collected and then statistically analyzed using various descriptive and inferential methods. A few descriptive statistics are obtained for the variables depending on their nature (e.g., percentages for qualitative variables and means for quantitative variables). Furthermore, several inferential methods are considered to address some statistical points of interest, including, but not limited to, odds ratio interpretations via logistic regression as well as association and correlation analyses. Results: A significant association was found between the presence of intermittent pain pattern as well as the pain of chronic primary category and favorable response to IV ketamine while the history of previous analgesic interventions was significantly associated with a negative response. Conclusion: The identified factors can be used to prospectively study the efficacy of ketamine using selection criteria based on the observed results in our study to re-evaluate the percentage of responsiveness according to these new parameters.
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INTRODUCTION: At present, the diagnosis of ulcerative colitis (UC) requires the histologic demonstration of characteristic mucosal inflammatory changes. A rapid and noninvasive diagnosis would be of value, especially if it could be adapted to a simple rectal probe. Raman spectroscopy creates a molecular fingerprint of substances by detecting laser light scattered from asymmetric, vibrating, and chemical bonds. We hypothesize that Raman spectroscopy can distinguish UC from non-UC colon tissue rapidly and accurately. MATERIALS AND METHODS: Colon tissue specimens were obtained from patients operated at the Children's Hospital of Michigan, United States, including UC colon and non-UC colon. The samples were examined with a Renishaw inVia Raman microscope (Gloucestershire, United Kingdom) with a 785 nm laser. Principal component analysis and discriminant function analysis were used to classify groups. Final classification was evaluated against histologic diagnoses using leave-one-out cross-validation at a spectral level. RESULTS: We compared Raman spectroscopy examination of colon specimens from four patients with UC and four patients without UC. A total of 801 spectra were recorded from colon specimens. We evaluated 100 spectra each from the mucosal and serosal surfaces of patients with UC and 260 spectra from the mucosal surface and 341 spectra from the serosal surface of the patients who did not have UC. For samples from the mucosal surface, the Raman analysis had a sensitivity of 82% and a specificity of 89%. For samples from the serosal surface, Raman spectroscopy had a sensitivity of 87% and a specificity of 93%. When considering each tissue sample and deciding the diagnosis based on the majority of spectra from that sample, there were no errors in the diagnosis. CONCLUSIONS: Raman spectroscopy can distinguish UC from normal colon tissue rapidly and accurately. This technology offers the possibility of real-time diagnosis as well as the ability to study changes in UC-afflicted colon tissue that do not appear histologically.
