A Machine Learning Model for Prediction of Amputation in Diabetics.

BACKGROUND: Diabetic foot ulcer (DFU) and the resulting lower extremity amputation are associated with a poor survival prognosis. The objective of this study is to generate a model for predicting the probability of major amputation in hospitalized patients with DFU. METHODS: The National Inpatient Sample (NIS) database from 2008 to 2014 was used to select patients with DFU, who were then further divided by major amputation status. International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) and Agency for Healthcare Research and Quality (AHRQ) comorbidity codes were used to compare patient characteristics. For the descriptive statistics, the Student t test, the χ2 test, and the Spearman correlation were utilized. The five most predictive variables were identified. A decision tree model (CTREE) based on conditional inference framework algorithm and a random forest model were used to develop the algorithm. RESULTS: A total of 326 853 inpatients with DFU were identified, and 5.9% underwent major amputation. The top five contributory variables (all with P < .001) were gangrene (odds ratio [OR] = 11.8, 95% confidence interval [CI] = 11.5-12.2), peripheral vascular disease (OR = 2.9, 95% CI = 2.8-3.0), weight loss (OR = 2.6, 95% CI = 2.5-2.8), systemic infection (OR = 2.5, 95% CI = 2.4-2.53), and osteomyelitis (OR = 1.7, 95% CI = 1.6-1.73). The model performance of the training data was 77.7% (76.1% sensitivity and 79.3% specificity) and of the testing data was 77.8% (76.2% sensitivity and 79.4% specificity). The model was further validated with boosting and random forest models which demonstrated similar performance and area under the curve (AUC) (0.84, 95% CI = 0.83-0.85). CONCLUSION: Utilizing machine learning methods, we have developed a clinical algorithm that predicts the risk of major lower extremity amputation for inpatients with diabetes with 77.8% accuracy.

Managing Up: Approaching Mentoring From a Mentee's Perspective.

OBJECTIVE: Discuss the evolution of mentorship models in surgical training and how educating the surgical trainees with the concepts from "manage up" theory can empower them to maximize the benefits afforded by mentoring relationships. METHODS: "Manage up" theory is derived from the business world where the subordinate takes ownership of the mentoring relationship with their superior by assessing the strengths and weaknesses of both parties and applying that information in managing a productive relationship. DISCUSSION: Surgery residency programs implement a variety of structured and unstructured mentorship programs to promote mentoring relationships and to encourage professional development. Mentees in successful mentoring relationships demonstrate characteristics and skills that residency programs can promote through formal training. Components of "manage up" theory can be applied by surgical trainees in approaching their mentors and in managing their mentor-mentee relationships. CONCLUSIONS: The benefits gained from a successful mentoring relationship for both the mentor and the mentee depend on active roles played by both parties. Strong evidence supports the need for educating mentees through formal curricula to empower them to assume an active role in their mentoring relationships.

The gut barrier and chronic diseases.

PURPOSE OF REVIEW: The purpose of this review is to provide an update regarding the gut barrier and its involvement with chronic diseases, as well as to review biomarkers for identification of gut barrier integrity. This review is timely and relevant as our knowledge is increasing regarding the role of the gut microbiome and the gut barrier in health and disease. RECENT FINDINGS: This review provides an overview of: the gut barrier, which is complex and comprised of the mucus layer and the intestinal apical junctional protein complex; the gut microbiome in its relation to regulating the integrity of the gut barrier; select acute and chronic conditions that are known to be associated with gut dysbiosis and impaired gut integrity or 'leaky gut'; and current means for identifying loss in gut barrier integrity. SUMMARY: Many chronic conditions are associated with gut dysbiosis and systemic inflammation. Identifying whether the gut barrier is compromised in these conditions could help to inform potential therapeutics as a means to correct losses in gut barrier integrity and mitigate associated medical conditions.

A comparison of revascularization methods for peripheral arterial disease in diabetics: Changing trends in lower extremity revascularization from 2008 to 2014.

OBJECTIVES: This study examined the current demographic and outcome trends regarding endovascular and open revascularization for people with diabetes. METHODS: The National Inpatient Sample database was utilized to identify diabetic patients who underwent lower extremity revascularization and amputation procedures between 2008 and 2014. International Classification of Diseases 9th edition codes were used to identify the procedures, diagnoses, and comorbidities. RESULTS: We identified 38,143 diabetic patients who underwent endovascular revascularization and 25,415 who underwent open revascularization between 2008 and 2014. The number of endovascular and open revascularization procedures decreased steadily by 17.5% and 12.43% during the study period, respectively. The total charges for the endovascular procedure were greater than the open procedure ($98,761 vs. $80,782, p ≤ 0.001) despite similar median length of stay (5 days (inner quartile range (IQR) = 1-10) vs. 5 days (IQR = 3-10), p ≤ 0.001). Compared to open, the in-patient amputation rate for endovascular patients has been increasing faster for both minor (11.75% vs. 0.37%) and major amputations (3.08% vs. 0.19%). Although the post-procedure amputation rates between endovascular and open procedures were increased for endovascular patients (odds ratio [OR] = 1.71, confidence interval [CI] = 1.35-2.18, p ≤ 0.001) in 2008, by 2014 the risk of major amputation was doubled in endovascular patients (OR = 2.88, CI = 2.27-3.64, p ≤ 0.001). African Americans were more likely to undergo minor amputation than Whites (p ≤ 0.001). Lastly, diabetic patients with uncontrolled diabetes, systemic infection, weight loss, congestive heart failure, gangrene, and end-stage renal disease were more likely to undergo endovascular repair. CONCLUSIONS: As more medically complex patients undergo endovascular revascularization, endovascular revascularization for diabetic patients is becoming associated with higher total cost despite similar length of stay, minor amputation, and major amputation rates. Further studies are needed to continuously evaluate the post-procedural outcomes and cost effectiveness of this trend.

Machine learning prediction of diabetic foot ulcers in the inpatient population.

BACKGROUND: The objective of this study was to create an algorithm that could predict diabetic foot ulcer (DFU) incidence in the in-patient population. MATERIALS AND METHODS: The Nationwide Inpatient Sample datasets were examined from 2008 to 2014. The International Classification of Diseases 9th Edition Clinical Modification (ICD-9-CM) and the Agency for Healthcare Research and Quality comorbidity codes were used to assist in the data collection. Chi-square testing was conducted, using variables that positively correlated with DFUs. For descriptive statistics, the Student T-test, Wilcoxon rank sum test, and chi-square test were used. There were six predictive variables that were identified. A decision tree model CTREE was utilized to help develop an algorithm. RESULTS: 326,853 patients were noted to have DFU. The major variables that contributed to this diagnosis (both with p < 0.001) were cellulitis (OR 63.87, 95% CI [63.87-64.49]) and Charcot joint (OR 25.64, 95% CI [25.09-26.20]). The model performance of the six-variable testing data was 79.5% (80.6% sensitivity and 78.3% specificity). The area under the curve (AUC) for the 6-variable model was 0.88. CONCLUSION: We developed an algorithm with a 79.8% accuracy that could predict the likelihood of developing a DFU.

Evaluation of Current Pressure Ulcer Staging.

BACKGROUND: We sought to assess health professionals' satisfaction with the National Pressure Injury Advisory Panel staging system (NPUAP). METHODS: A paper survey assessing the satisfaction with the NPUAP was distributed to participants of a national wound care meeting. A total of 88 surveys were completed. Results were tabulated using SPSS. RESULTS: The survey response rate was 50%. Nearly all respondents (95.0%) used NPAUP for documentation. 75.3% indicated that a better staging system was needed. When participants were asked to evaluate their current staging system, 63.5% stated that the system does not adequately reflect patient's clinical condition, 61.6% felt that the current staging system was not easily reproducible, 58.0% believed that the current staging system was generally easy-to-use, and 43.9% indicated that it is unable to suggest management recommendations. When asked about an ideal classification system, the respondents proposed incorporating tissue necrosis (97.6%), depth of tissue involvement (96.3%), discharge documentation (92.5%), presence of osteomyelitis (90%), local infection (88.8%), and systemic infection (80.0%). Overall, 67.0% of the participants wanted to use a classification system that would reflect the progress of injury healing and could be used to indicate the need for intervention. DISCUSSION: Health care workers caring for pressure injury patients indicated dissatisfaction with the NPAUP.

Catheter Directed Lysis and Thrombectomy Are Equally Effective for Extensive Deep Vein Thrombosis.

BACKGROUND: There is currently little consensus on the role of thrombectomy compared with catheter-directed lysis (CDL) for acute, extensive, proximal deep vein thrombosis (DVT). We sought to determine whether any differences in outcomes exist between thrombectomy and CDL in terms of postoperative venous patency, pulmonary emboli (PE), and bleeding/hematoma. METHODS: In an institutional review board-approved retrospective cohort study, patients from a single academic medical center with confirmed lower extremity DVT were divided into thrombectomy and CDL cohorts. Demographic information, comorbidities and laboratory data, postoperative patency, postoperative bleeding, postoperative PE, popliteal hematoma, and recurrence of DVT were collected. Type I error level was set at 0.05. RESULTS: Eighty-seven patients were identified, 51.7% received CDL, and 48.3% underwent thrombectomy. Patient comorbidities and hypercoagulable states were not significantly different among the groups. The two techniques did not have significantly different postoperative patency (P = 0.472), bleeding (P = 0.598), PE (P = 0.868), popliteal hematoma (P = 0.331), or recurrence of DVT (P = 0.835). CONCLUSIONS: In selecting optimum treatment for acute, extensive, proximal DVT, our retrospective cohort study found no significant differences among treatment groups in safety, efficacy, recurrence, and progression to PE. We conclude that modality of treatment should be decided based on hospital resources, surgeon experience, and comfort with each technique, patient's physiologic status, and associated costs.

Synthesis and biological evaluation of aminothiazoles against Histoplasma capsulatum and Cryptococcus neoformans.

The design and synthesis of a library of forty novel 2-aminoazole analogues as well as their evaluation as antifungal compounds against Histoplasma capsulatum and Cryptococcus neoformans is described. These structures were derived from N-[5-(1-naphthalenylmethyl)-2-thiazolyl]cyclohexanecarboxamide (41F5), a fungistatic agent previously identified through phenotypic screening (Antimicrob Agents Chemother. 2013;57:4349). Modifications to improve potency and water-solubility of 41F5 focused primarily on the 5-naphthalenyl group, the thiazole core, and the methylene linker between these two structural elements. In general, compounds with lipophilic [5+6] bicyclic ring systems, such as the 7-benzothiophenyl- and 4-indanyl groups, at the 5-position were 2-3 times more active against both fungal species as compared to 41F5. Also, introduction of a carbonyl group at the methylene linker of 41F5 resulted in a 2-3-fold increase in potency. These highly active compounds also showed generally low toxicities against murine P388D1 macrophages resulting in selectivity indices ranging from 63 to >200. Compounds that were highly active against fluconazole-sensitive C. neoformans strains had almost identical activity against fluconazole-resistant variants of this fungus indicating that 14α-demethylase is not their molecular target. Highly active compounds also retained activity against H. capsulatum phagocytosed into P388D1 macrophages.