Advanced renal artery stenosis (RAS) may cause progressive deterioration in renal function. We correlated the histopathological findings and clinical characteristics in selected patients with atherosclerotic RAS who underwent nephrectomy of their small kidneys for resistant renovascular hypertension. We studied 62 patients who underwent nephrectomy of a small kidney for uncontrolled hypertension between 1990 and 2000. The mean patient age was 65.4 ± 9.6 years; 28 (45%) were men. Significant tubulointerstitial atrophy with relative glomerular sparing was the predominant pattern of injury in 44 (71%) patients. In 14 (23%) patients, diffuse global glomerulosclerosis was present. The severity of tubulointerstitial atrophy and the extent of glomerulosclerosis were both associated with smaller kidney size (P = 0.002). Three patterns of vascular involvement were present: atheroembolic, atherosclerotic and hypertensive vascular changes, which were documented in 39, 98 and 52% of subjects, respectively. The presence and severity of these vascular changes positively correlated with both atherosclerotic risk factors, such as hypertension, dyslipidaemia and renal insufficiency, and cardiovascular morbidity, including abdominal aortic aneurysm and myocardial infarction. Patients on statin therapy were noted to have less evidence of renal fibrosis as measured by transforming growth factor-beta staining (P = 0.003). The severity of renal histopathological findings in patients who underwent nephrectomy for resistant hypertension correlated with an increased prevalence of cardiovascular disease, a greater degree of renal dysfunction and more severe dyslipidaemia. Statin therapy may affect development of intra-renal injury by slowing the progression of fibrosis.

Background: Few internal medicine residency programs provide formal ultrasound training. This study sought to assess the feasibility of simulation based ultrasound training among first year internal medicine residents and measure their comfort at effectively using ultrasound to perform invasive procedures before and after this innovative model of ultrasound training. Methods: A simulation based ultrasound training module was implemented during intern orientation that incorporated didactic and practical experiences in a simulation and cadaver laboratory. Participants completed anonymous pre and post surveys in which they reported their level of confidence in the use of ultrasound technology and their comfort in identifying anatomic structures including: lung, pleural effusion, bowel, peritoneal cavity, ascites, thyroid, and internal jugular vein. Survey items were structured on a 5-point Likert scales (1 = extremely unconfident, 5 = extremely confident). Results: Seventy-five out of seventy-six interns completed the pre-intervention survey and 55 completed the post-survey. The mean confidence score (SD) increased to 4.00 (0.47) (p < 0.0001). The mean (SD) comfort ranged from 3.61 (0.84) for peritoneal cavity to 4.48 (0.62) for internal jugular vein. Confidence in identifying all anatomic structures showed an increase over the pre-intervention means (p < 0.002). Conclusion: A simulation based ultrasound learning module can improve the self-reported confidence with which residents identify structures important in performing invasive ultrasound guided procedures. Incorporating an ultrasound module into residents' education may address perceived need for ultrasound training, improve procedural skills, and enhance patient safety.

Background and objectives: eGFR equations have been evaluated in kidney transplant recipients with variable performance. We assessed the performance of the Modification of Diet in Renal Disease equation and the Chronic Kidney Disease Epidemiology Collaboration equations on the basis of creatinine, cystatin C, and both (eGFR creatinine-cystatin C) compared with measured GFR by iothalamate clearance and evaluated their non-GFR determinants and associations across 15 cardiovascular risk factors. Design, setting, participants, & measurements: A cross-sectional cohort of 1139 kidney transplant recipients >1 year after transplant was analyzed. eGFR bias, precision, and accuracy (percentage of estimates within 30% of measured GFR) were assessed. Interaction of each cardiovascular risk factor with eGFR relative to measured GFR was determined. Results: Median measured GFR was 55.0 ml/min per 1.73 m². eGFR creatinine overestimated measured GFR by 3.1% (percentage of estimates within 30% of measured GFR of 80.4%), and eGFR Modification of Diet in Renal Disease underestimated measured GFR by 2.2% (percentage of estimates within 30% of measured GFR of 80.4%). eGFR cystatin C underestimated measured GFR by −13.7% (percentage of estimates within 30% of measured GFR of 77.1%), and eGFR creatinine-cystatin C underestimated measured GFR by −8.1% (percentage of estimates within 30% of measured GFR of 86.5%). Lower measured GFR associated with older age, women, obesity, longer time after transplant, lower HDL, lower hemoglobin, lower albumin, higher triglycerides, higher proteinuria, and an elevated cardiac troponin T level but did not associate with diabetes, smoking, cardiovascular events, pretransplant dialysis, or hemoglobin A1c. These risk factor associations differed for five risk factors with eGFR creatinine, six risk factors for eGFR Modification of Diet in Renal Disease, ten risk factors for eGFR cystatin C, and four risk factors for eGFR creatinine-cystatin C. Conclusions: Thus, eGFR creatinine and eGFR creatinine-cystatin C are preferred over eGFR cystatin C in kidney transplant recipients because they are less biased, more accurate, and more consistently reflect the same risk factor associations seen with measured GFR.

Background: We aimed to develop and validate an automated machine learning (autoML) prediction model for cardiac surgery-associated acute kidney injury (CSA-AKI). Methods: Using 69 preoperative variables, we developed several models to predict post-operative AKI in adult patients undergoing cardiac surgery. Models included autoML and non-autoML types, including decision tree (DT), random forest (RF), extreme gradient boosting (XGBoost), and artificial neural network (ANN), as well as a logistic regression prediction model. We then compared model performance using area under the receiver operating characteristic curve (AUROC) and assessed model calibration using Brier score on the independent testing dataset. Results: The incidence of CSA-AKI was 36%. Stacked ensemble autoML had the highest predictive performance among autoML models, and was chosen for comparison with other non-autoML and multivariable logistic regression models. The autoML had the highest AUROC (0.79), followed by RF (0.78), XGBoost (0.77), multivariable logistic regression (0.77), ANN (0.75), and DT (0.64). The autoML had comparable AUROC with RF and outperformed the other models. The autoML was well-calibrated. The Brier score for autoML, RF, DT, XGBoost, ANN, and multivariable logistic regression was 0.18, 0.18, 0.21, 0.19, 0.19, and 0.18, respectively. We applied SHAP and LIME algorithms to our autoML prediction model to extract an explanation of the variables that drive patient-specific predictions of CSA-AKI. Conclusion: We were able to present a preoperative autoML prediction model for CSA-AKI that provided high predictive performance that was comparable to RF and superior to other ML and multivariable logistic regression models. The novel approaches of the proposed explainable preoperative autoML prediction model for CSA-AKI may guide clinicians in advancing individualized medicine plans for patients under cardiac surgery.

Lupus nephritis (LN) is a serious and common complication of systemic lupus erythematosus (SLE) that predisposes to significant morbidity and mortality. Studies show that prompt diagnosis and treatment improves patient survival. We present a case of a 49-year-old female with an atypical presentation of LN who initially presented with new-onset hypertension, edema, arthritis, serositis and recently diagnosed leukocytoclastic vasculitis who later developed acute kidney injury, hematuria and nephrotic syndrome. Laboratory testing showed mixed cryoglobulinemia and elevated perinuclear anti-neutrophil cytoplasmic (p-ANCA) and myeloperoxidase (MPO) antibodies. SLE-related serologies were negative. Kidney biopsy showed diffuse proliferative global glomerulonephritis with a full-house nephropathy pattern on immunofluorescence suggestive of LN. Due to high clinical suspicion and renal biopsy findings, she was treated for LN with prompt renal response to immunosuppression. Cryoglobulins, p-ANCA and MPO titers normalized and the negative SLE serologies remained negative. Literature review on antinuclear antibody (ANA)-negative and seronegative LN revealed the following patient presentations: (1) renal-limited or renal and extra-renal manifestations of SLE with negative serologies and (2) renal and extra-renal manifestations of SLE with negative serologies at presentation who develop positive serologies later in follow-up. Both groups represent a unique and challenging cohort of patients who may require longer follow-up and further testing to rule out other glomerular diseases that may mimic LN on renal biopsy. The absence of SLE-related serologies should be weighed against a high pre-test probability of ANA-negative or seronegative LN. If highly suspected, the patient should be treated promptly with close monitoring.

Objective Native Americans suffer from lower rates of kidney transplantation compared with whites. Our goal was to elicit patients’ perceptions of and attitudes about kidney transplant and the impact of financial burden and cultural taboos. Design This is an exploratory qualitative interview study of 12 Native American patients recruited after completion of the kidney transplant evaluation. Setting Semistructured interviews were conducted. Interviews were coded using inductive methods, followed by interpretive coding by the investigators. Results Thematic analysis revealed the following themes: (1) experience with kidney transplant education by the healthcare team; (2) cultural beliefs regarding kidney transplant; (3) personal motivation and attitude towards kidney transplant; (4) financial burden of kidney transplant and post-transplant care and (5) attitude about living donation. Most participants were educated about transplant as a treatment option after dialysis initiation. All patients in this study recognised that some taboos exist about the process of organ procurement and transplantation; however, the traditional views did not negatively impact their decision to pursue kidney transplant evaluation. Patients shared the common theme of preferring an organ from a living rather than a deceased person; however, the majority did not have a living donor and preferred not to receive an organ from a family member. Most patients did not perceive transplant-related cost as negatively impacting their attitude about receiving a transplant even for patients with below poverty level income. Conclusions Native American patients presenting for kidney transplant were less likely to be educated about transplant before dialysis initiation; did not perceive financial burden and cultural beliefs were not discussed as obstacles to transplant. While a living donor was the preferred option, enthusiasm for living donation from family members was limited.