Validation of ICD-9 Codes for Identification of Chronic Overlapping Pain Conditions.

Chronic overlapping pain conditions (COPCs) are a collection of chronic pain syndromes that often co-occur and are thought to share underlying nociplastic pathophysiology. Since they can manifest as seemingly unrelated syndromes they have historically been studied in isolation. Use of International Classification of Diseases (ICD) codes in medical records has been proposed as a means to identify and study trends in COPCs at the population level, however validated code sets are needed. Recently, a code set comprising ICD-10 codes as proxies for 11 COPCs was validated. The goal of this project was to validate a code set composed of ICD-9 codes for the identification of COPCs in administrative datasets. Data was extracted using the Electronic Medical Record Search Engine at the University of Michigan Health System from January 1st, 2011 to January 1st, 2015. The source population were patients with one of the candidate ICD-9 codes corresponding to various COPCs. Natural language searches were used as a reference standard. If code sets met a pre-specified threshold of agreement between ICD-9 codes and natural language searches (≥ 70%), they were retained and diagnostic accuracy statistics were calculated for each code set. Validated ICD-9 code sets were generated for 10 of the 11 COPCs evaluated. The majority had high levels of diagnostic accuracy, with all but one code set achieving ≥ 80% specificity, sensitivity, and predictive values. This code set may be used by pain researchers to identify COPCs using ICD-9 codes in administrative datasets.

COPCs share underlying nociplastic etiology; it is important to distinguish these from other pain etiologies to better understand their prevalence, identify comorbid conditions, and understand trends in their pharmacologic management.COPCs have historically been under-recognized and -studied due to challenges with identifying them in administrative datasets.A validated code set for identifying COPCs in administrative datasets using ICD-10 codes exists, however this limits any longitudinal studies as ICD-10 coding was not fully implemented until 2015.This study used natural language searches to validate a set of ICD-9 codes for identifying COPCs.Code sets were able to be validated for 10 of 11 COPCs with high specificity, sensitivity, and predictive values.

Warfarin Dose Requirements in Adults Hospitalized With COVID-19 Infection: A Retrospective Case Series.

PURPOSE: To describe the impact of hospitalization with COVID-19 infection on warfarin dose requirements in adult inpatients. SUMMARY: A retrospective chart review of 8 adults on warfarin admitted to Michigan Medicine with COVID-19 infection was conducted and reported as a case series. Outcomes of interest were difference in average daily dose of warfarin prior to admission (PTA) and while inpatient (IP), warfarin sensitivity, time in therapeutic range (TTR), confirmed or suspected thromboembolic event, any major or clinically significant bleeding episodes, and in-hospital mortality. IP average daily warfarin doses were lower when compared to PTA average daily doses [1.3 mg (1.3) vs. 6.2 mg (4.1)]. The mean percentage decrease in dose was 68.8% (23) and the mean absolute dose difference was 4.8 mg (4.3). Mean IP percentage tests in range was 30.8% (24.6) and mean IP warfarin sensitivity was 4.2 (3.8), both of which differed from PTA TTR and warfarin sensitivity for those with data available (n = 3, n = 6, respectively). One patient was treated for suspected acute pulmonary embolism while on warfarin and one patient experienced clinically relevant bleeding. In-hospital mortality was zero, mean length of stay (LOS) was 17 days (14.4), and mean intensive care unit (ICU) LOS for the 3 patients requiring ICU level care was 14.3 days (4.5). CONCLUSION: Decreased warfarin dose requirements were evident in this group of adults hospitalized with COVID-19 infection. These findings suggest lower doses of warfarin may be needed to achieve therapeutic anticoagulation while inpatient.

Retracing our steps to understand ketamine in depression: A focused review of hypothesized mechanisms of action.

INTRODUCTION: MDD represents a significant burden worldwide, and while a number of approved treatments exist, there are high rates of treatment resistance and refractoriness. Ketamine, an N-methyl-d-aspartate receptor (NMDAR) antagonist, is a novel, rapid-acting antidepressant, however the mechanisms underlying the efficacy of ketamine are not well understood and many other mechanisms outside of NMDAR antagonism have been postulated based on preclinical data. This focused review aims to present a summary of the proposed mechanisms of action by which ketamine functions in depressive disorders supported by preclinical data and clinical studies in humans. METHODS: A literature search was completed using the PubMed and Google Scholar databases. Results were limited to clinical trials and case studies in humans that were published in English. The findings were used to compile this article. RESULTS: The antidepressant effects associated with ketamine are mediated via a complex interplay of mechanisms; key steps include NMDAR blockade on γ-aminobutyric acid interneurons, glutamate surge, and subsequent activation and upregulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor. DISCUSSION: Coadministration of ketamine for MDD with other psychotropic agents, for example benzodiazepines, may attenuate antidepressant effects. Limited evidence exists for these effects and should be evaluated on a case-by-case basis.

Strategies for Rotation between Gabapentinoids in the Inpatient Setting.

Guidance and evidence to support best practices in rotating between gabapentinoids is lacking. This retrospective cohort study was performed to describe and evaluate strategies for rotation. Patients rotated while admitted from June 1st, 2014 to April 25th, 2020 at a large, academic medical center were included. The primary outcome was the proportion of rotations using a direct switch strategy compared to a cross-taper strategy. Secondary outcomes were successful rotation, defined as stable or improved pain scores pre- to post-rotation, dose ratios, and adverse effects. A total of 67 patients were included. Median age was 50 years (35 - 59) and 58% (38) were male. The majority used a direct switch strategy (87%). Ninety-five percent of patients using the direct switch strategy and 78% of patients using the cross-taper strategy were successful. There was no difference in strategies between those who were successful and those who were not. Post hoc analysis of patients with normal renal function (eGFR ≥ 50 mL/min/1.73 m2) found that those who were successful were more likely to have used a direct switch strategy (p = 0.048). There were no differences in adverse effects. These findings suggest that either strategy is reasonable for gabapentinoid rotation in the inpatient setting.