Preoperative proteinuria is associated with increased rates of acute kidney injury after partial nephrectomy

Risk factors and predictive model for acute kidney Injury Transition to acute kidney disease in patients following partial nephrectomy

PURPOSE

Acute kidney disease (AKD) is believed to be involved in the transition from acute kidney injury (AKI) to chronic kidney disease in general populations, but little is understood about this possibility among kidney surgical populations. This study aimed to elucidate the incidence of AKD after partial nephrectomy and risk factors that promote the AKI to AKD transition.

METHODS

From January 2010 to January 2020, this study retrospectively collected a dataset of consecutive patients with renal masses undergoing partial nephrectomy in 4 urological centers. Cox proportional regression analyses were adopted to identify risk factors that promoted the AKI to AKD transition. To avoid overfitting, the results were then verified by logistic least absolute shrinkage and selection operator (LASSO) regression. A nomogram was then constructed and validated for AKI to AKD transition prediction.

RESULTS

AKI and AKD occurred in 228 (21.4%) and 42 (3.9%) patients among a total of 1062 patients, respectively. In patients with AKI, multivariable Cox regression analysis and LASSO regression identified that age (HR 1.078, 1.029-1.112, p < 0.001), baseline eGFR (HR 1.015, 1.001-1.030, p < 0.001), RENAL score (HR1.612, 1.067-2.437, p = 0.023), ischemia time > 30 min (HR 7.284, 2.210-23.999, p = 0.001), and intraoperative blood loss > 300ml (HR 8.641, 2.751-27.171, p < 0.001) were risk factors for AKD transition. These five risk factors were then integrated into a nomogram. The nomogram showed excellent discrimination, calibration, and clinical net benefit ability.

CONCLUSION

Around 3.9% patients following partial nephrectomy would transit from AKI to AKD. Intraoperative blood loss and ischemia time need to be diminished to avoid on-going functional decline. Our nomogram can accurately predict the transition from AKI to AKD.

Severe acute kidney disease is associated with worse kidney outcome among acute kidney injury patients

Acute kidney disease (AKD) comprises acute kidney injury (AKI). However, whether the AKD staging system has prognostic values among AKI patients with different baseline estimated glomerular filtration (eGFR) remains a controversial issue. Algorithm-based approach was applied to identify AKI occurrence and to define different AKD stages. Risk ratio for major adverse kidney events (MAKE), including (1) eGFR decline > 35% from baseline, (2) initiation of dialysis, (3) in-hospital mortality of different AKD subgroups were identified by multivariable logistic regression. Among the 4741 AKI patients identified from January 2015 to December 2018, AKD stages 1–3 after AKI was common (53% in the lower baseline eGFR group and 51% in the higher baseline eGFR group). In the logistic regression model adjusted for demographics and comorbidities at 1-year follow-up, AKD stages 1/2/3 (AKD stage 0 as reference group) were associated with higher risks of MAKE (AKD stage: odds ratio, 95% confidence interval [95% CI], AKD 1: 1.85, 1.56–2.19; AKD 2: 3.43, 2.85–4.12; AKD 3: 10.41, 8.68–12.49). Regardless of baseline eGFR, staging criteria for AKD identified AKI patients who were at higher risk of kidney function decline, dialysis and mortality. Post-AKI AKD patients with severer stage need intensified care and timely intervention.

Renal surgery for kidney cancer: is preoperative proteinuria a predictor of functional and survival outcomes after surgery? A systematic review of the literature

INTRODUCTION

Proteinuria is considered both a known marker for the severity of Chronic Kidney Disease (CKD) and a robust predictor of future renal function and cardiovascular morbidity and mortality in a general population. The urological community has long overlooked proteinuria as a marker of renal function. Recently, the American Urological Association (AUA) clinical practice guideline addressed this issue and suggested introducing proteinuria assessment prior to kidney cancer surgery. The aim of this systematic review was to provide evidence of proteinuria as a predictor of renal function impairment and survival outcomes after kidney surgery for renal tumors.

EVIDENCE ACQUISITION

A systematic search was performed by using three search engines (PubMed, Embase®, and Web of Science) from January 2010 to November 2020. Study selection followed the PRISMA guidelines. After screening, ten articles and abstracts fully compatible with the PICOS were included in this systematic review.

EVIDENCE SYNTHESIS

Overall, a total of 11,705 patients who underwent partial nephrectomy (PN) or radical nephrectomy (RN) were analyzed. When used as a binomial variable, proteinuria prior to surgery was detected from 10% to 33% of patients. Relying on both proteinuria and estimated glomerular filtration rate (eGFR) in the assessment of renal function yielded up to 33% higher rates of patients with preoperative renal impairment. Moreover, proteinuria increased the risk of long-term renal impairment after PN and RN as well as patients with preoperative proteinuria undergoing PN exhibited a greater risk of postoperative acute kidney injury (AKI). Among eligible studies, proteinuria was associated with diabetes, obesity, metabolic syndrome, hypertension and cardiovascular disease. Finally, proteinuria was an independent predictor of overall mortality, but not of cancer-specific mortality.

CONCLUSIONS

Proteinuria yields a prognostic power beyond that provided by estimated glomerular filtration rate (eGFR) among patients undergoing renal cancer surgery, supporting its introduction in the preoperative assessment of renal function. However, well-designed multicentre prospective studies would be necessary to corroborate these results and provided urological community with high-grade recommendation for clinical practice.

Pre-operative proteinuria and post-operative acute kidney injury in noncardiac surgery: the NARA-Acute Kidney Injury cohort study

Background

Little is known about the association between pre-operative proteinuria and post-operative acute kidney injury (AKI) in noncardiac surgery.

Methods

This is a retrospective cohort study. Adults who underwent noncardiac surgery under general anesthesia from 2007 to 2011 at Nara Medical University Hospital were included. Those with obstetric or urological surgery, missing data for analyses or pre-operative dialysis were excluded. Exposure of interest was pre-operative proteinuria, defined as (+) or more by dipstick test. The outcome variable was post-operative AKI, defined by Kidney Disease: Improving Global Outcomes criteria, within 1 week after surgery. Multivariable logistic regression analyses were performed.

Results

Among 5168 subjects, 309 (6.0%) developed AKI. Pre-operative proteinuria was independently associated with post-operative AKI, with an odds ratio (OR) [95% confidence interval (CI)] of 1.80 (1.30–2.51). A sensitivity analysis restricted to elective surgery yielded a similar result. As proteinuria increased, the association with AKI became stronger [OR (95% CI) 1.14 (0.75–1.73), 1.24 (0.79–1.95), 2.75 (1.74–4.35) and 3.95 (1.62–9.62) for urinary protein (+/−), (+), (2+) and (3+), respectively]. Subgroup analyses showed proteinuria was especially associated with post-operative AKI among subjects with renin–angiotensin system inhibitors, other anti-hypertensives, hypoalbuminemia or impaired renal function (P for interaction = 0.05, 0.003, 0.09 or 0.02, respectively).

Conclusions

In noncardiac surgery, pre-operative proteinuria was independently associated with post-operative AKI. Subjects with proteinuria should be managed with caution to avoid AKI peri-operatively.