Yimei Wang

Serum Uric Acid Is Inversely Related to Acute Ischemic Stroke Morbidity in Hemodialysis Patients

Aim: Elevated serum uric acid (sUA) is usually associated with a high occurrence of acute ischemic stroke (AIS) in the general population. The aim of this study is to evaluate the role of sUA in AIS among hemodialysis (HD) patients. Methods: We followed up the occurrence of AIS in 226 HD patients for 18 months from January 2009 to June 2010. The parameters included demographic characteristics, duration of HD, sUA, serum albumin, and other parameters. Logistic regression was performed to evaluate the function of SUC levels in the occurrence of AIS. Results: A total of 43 patients suffered from AIS. By univariate logistic regression analysis an inverse association was observed in sUA level with the risk of AIS (p = 0.005), but the significance of this inverse association was attenuated while adjusted for age, gender and pulse pressure (PP) (p = 0.029), and even weakened while adjusted for age, gender, PP and diabetes nephropathy (DN) (p = 0.065), and finally abolished after adjustment for age, gender, PP, DN, hsCRP and pre-albumin. Conclusion: This study indicates an inverse association between sUC and the occurrence of AIS in HD patients. Demographic characteristics and malnutrition-microinflammation syndrome seem to play a significant role in this association.

Dynamic Predictive Scores for Cardiac Surgery–Associated Acute Kidney Injury

Background Cardiac surgery–associated acute kidney injury (CSA‐AKI) is a common complication with a poor prognosis. In order to identify modifiable perioperative risk factors for AKI, which existing risk scores are insufficient to predict, a dynamic clinical risk score to allow clinicians to estimate the risk of CSA‐AKI from preoperative to early postoperative periods is needed. Methods and Results A total of 7233 cardiac surgery patients in our institution from January 2010 to April 2013 were enrolled prospectively and distributed into 2 cohorts. Among the derivation cohort, logistic regression was used to analyze CSA‐AKI risk factors preoperatively, on the day of ICU admittance and 24 hours after ICU admittance. Sex, age, valve surgery combined with coronary artery bypass grafting, preoperative NYHA score >2, previous cardiac surgery, preoperative kidney (without renal replacement therapy) disease, intraoperative cardiopulmonary bypass application, intraoperative erythrocyte transfusions, and postoperative low cardiac output syndrome were identified to be associated with CSA‐AKI. Among the other 1152 patients who served as a validation cohort, the point scoring of risk factor combinations led to area under receiver operator characteristics curves (AUROC) values for CSA‐AKI prediction of 0.74 (preoperative), 0.75 (on the day of ICU admission), and 0.82 (postoperative), and Hosmer–Lemeshow goodness‐of‐fit tests revealed a good agreement of expected and observed CSA‐AKI rates. Conclusions The first dynamic predictive score system, with Kidney Disease: Improving Global Outcomes (KDIGO) AKI definition, was developed and predictive efficiency for CSA‐AKI was validated in cardiac surgery patients.

Acute Kidney Injury Epidemiology: From Recognition to Intervention

Acute kidney injury (AKI) is very common among hospitalized patients, and the incidence of AKI has increased over the past few decades. This increase might be due to an aging population and increased comorbidities. Other factors that may explain this are the more sensitive diagnostic criteria and better recognition. AKI is associated with increased mortality and increased risks of chronic kidney disease and end-stage renal disease. The best ways to lower the chances of having kidney damage are to prevent, recognize and treat AKI as early as possible. The incidence of AKI in China is significantly lower than in developed countries. Inadequate early diagnosis and management remain the major challenges for Chinese nephrologists.

Reversible preoperative renal dysfunction does not add to the risk of postoperative acute kidney injury after cardiac valve surgery

Objective To evaluate the impact of the renal dysfunction (RD) type and change of postoperative cardiac function on the risk of developing acute kidney injury (AKI) in patients who underwent cardiac valve surgery. Method Reversible renal dysfunction (RRD) was defined as preoperative RD in patients who had not been initially diagnosed with chronic kidney disease (CKD). Cardiac function improvement (CFI) was defined as postoperative left ventricular ejection function – preoperative left ventricular ejection function (ΔEF) >0%, and cardiac function not improved (CFNI) as ΔEF ≤0%. Results Of the 4,805 (94%) cardiac valve surgery patients, 301 (6%) were RD cases. The AKI incidence in the RRD group (n=252) was significantly lower than in the CKD group (n=49) (36.5% vs 63.3%, P=0.018). The AKI and renal replacement therapy incidences in the CFI group (n=174) were significantly lower than in the CFNI group (n=127) (33.9% vs 50.4%, P=0.004; 6.3% vs 13.4%, P=0.037). After adjustment for age, gender, and other confounding factors, CKD and CKD + CFNI were identified as independent risk factors for AKI in all patients after cardiac valve surgery. Multivariate logistic regression analysis showed that the risk factors for postoperative AKI in preoperative RD patients were age, gender (male), hypertension, diabetes, chronic heart failure, cardiopulmonary bypass time (every 1 min added), and intraoperative hypotension, while CFI after surgery could reduce the risk. Conclusion For cardiac valve surgery patients, preoperative CKD was an independent risk factor for postoperative AKI, but RRD did not add to the risk. Improved postoperative cardiac function can significantly reduce the risk of postoperative AKI.

Dysnatremia is an Independent Indicator of Mortality in Hospitalized Patients

Background Dysnatremia is a risk factor for poor outcomes. We aimed to describe the prevalence and outcomes of various dysnatremia in hospitalized patients. High-risk patients must be identified to improve the prognosis of dysnatremia. Material/Methods This prospective study included all adult patients admitted consecutively to a university hospital between October 1, 2014 and September 30, 2015. Result All 90 889 patients were included in this study. According to the serum sodium levels during hospitalization, the incidence of hyponatremia and hypernatremia was 16.8% and 1.9%, respectively. Mixed dysnatremia, which was defined when both hyponatremia and hypernatremia happened in the same patient during hospitalization, took place in 0.3% of patients. The incidence of dysnatremia was different in various underlying diseases. Multiple logistic regression analyses showed that all kinds of dysnatremia were independently associated with hospital mortality. The following dysnatremias were strong predictors of hospital mortality: mixed dysnatremia (OR 22.344, 95% CI 15.709–31.783, P=0.000), hypernatremia (OR 13.387, 95% CI 10.642–16.840, P=0.000), and especially hospital-acquired (OR 16.216, 95% CI 12.588–20.888, P=0.000) and persistent (OR 22.983, 95% CI 17.554–30.092, P=0.000) hypernatremia. Hyponatremia was also a risk factor for hospital mortality (OR 2.225, 95% CI 1.857–2.667). However, the OR increased to 56.884 (95% CI 35.098–92.193) if hyponatremia was over-corrected to hypernatremia. Conclusions Dysnatremia was independently associated with poor outcomes. Hospital-acquired and persistent hypernatremia were strong risk factors for hospital mortality. Effective prevention and proper correction of dysnatremia in high-risk patients may reduce the hospital mortality.

High-dose versus low-dose haemofiltration for the treatment of critically ill patients with acute kidney injury: an updated systematic review and meta-analysis.

Objective The purpose of this study was to perform a systematic review and meta-analysis to evaluate the effect of high-dose versus low-dose haemofiltration on the survival of critically ill patients with acute kidney injury (AKI). We hypothesised that high-dose treatments are not associated with a higher risk of mortality. Design Meta-analysis. Setting Randomised controlled trials and two-arm prospective and retrospective studies were included. Participants Critically ill patients with AKI. Interventions Continuous renal replacement therapy. Primary and secondary outcome measures Primary outcomes: 90-day mortality, intensive care unit (ICU) mortality, hospital mortality; secondary outcomes: length of ICU and hospital stay. Result Eight studies including 2970 patients were included in the analysis. Pooled results showed no significant difference in the 90-mortality rate between patients treated with high-dose or low-dose haemofiltration (pooled OR=0.90, 95% CI 0.73 to 1.11, p=0.32). Findings were similar for ICU (pooled OR=1.12, 95% CI 0.94 to 1.34, p=0.21) and hospital mortality (pooled OR=1.03, 95% CI 0.81 to 1.30, p=0.84). Length of ICU and hospital stay were similar between high-dose and low-dose groups. Pooled results are not overly influenced by any one study, different cut-off points of prescribed dose or different cut-off points of delivered dose. Meta-regression analysis indicated that the results were not affected by the percentage of patients with sepsis or septic shock. Conclusion High-dose and low-dose haemofiltration produce similar outcomes with respect to mortality and length of ICU and hospital stay in critically ill patients with AKI. This study was not registered at the time the data were collected and analysed. It has since been registered on 17 February 2017 at http://www.researchregistry.com/, registration number: reviewregistry211.

Remote Ischemic Preconditioning Ameliorates Acute Kidney Injury due to Contrast Exposure in Rats through Augmented O-GlcNacylation

Remote ischemic preconditioning (RIPC) is an adaptive response, manifesting when local short-term ischemic preconditioning reduces damage to adjacent or distant tissues or organs. O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation of intracellular proteins denotes a type of posttranslational modification that influences multiple cytoplasmic and nuclear protein functions. Growing evidence indicates that stress can induce an acute increase in O-GlcNAc levels, which can be cytoprotective. The current study aimed to determine whether RIPC can provide renoprotection against contrast-induced acute kidney injury (CI-AKI) by augmenting O-GlcNAc signaling. We established a stable model of CI-AKI using 5/6 nephrectomized rats exposed to dehydration followed by iohexol injection via the tail vein. We found that RIPC increased UDP-GlcNAc levels through the hexosamine biosynthetic pathway as well as global renal O-GlcNAcylation. RIPC-induced elevation of O-GlcNAc signaling ameliorated CI-AKI based on the presence of less tubular damage and apoptosis and the amount of reactive oxygen species. In addition, the use of alloxan, an O-GlcNAc transferase inhibitor, and azaserine, a glutamine fructose-6-phosphate amidotransferase inhibitor, neutralized the protective effect of RIPC against oxidative stress and tubular apoptosis. In conclusion, RIPC attenuates local oxidative stress and tubular apoptosis induced by contrast exposure by enhancing O-GlcNAc glycosylation levels; this can be a potentially useful approach for lowering the risk of CI-AKI.

Acute Kidney Injury in Cardiac Surgery

Patients who have undergone cardiac surgery are at high risk of acute kidney injury (AKI) and often associated with poor short- and long-term outcomes. It is considered that the burden of AKI can be reduced and the quality of care can be improved by raising the appropriate awareness and using the right tools for early prevention and better management, by (1) improving awareness by understanding the epidemiology and pathophysiology; (2) using tools for risk assessment for early prevention; (3) increasing the use of electronic screening for early diagnosis; and (4) developing right clinical strategies for better treatment. In this review, we will update some typical studies as well as some new concepts, which focus on the quality of care of CSA-AKI.

Quality Measures in Acute Kidney Injury Management

Acute kidney injury (AKI) is common in clinical practice and associated with increased risk for death and major morbidity. Although some meaningful clinical guidelines were published, the quality of AKI healthcare remains suboptimal. Some AKI quality improvement methods, such as guidelines-based training programs, the referral from nephrology, and electronic data system have been found to be potentially beneficial, but further validation is required. Quality measures (QMs) for structure, process, and outcome of AKI care need to be further developed, evaluated, and implemented to ensure utmost quality of AKI care. However, many unknowns remain in this field. Some commonly used QMs like mortality are still difficult to realize in AKI quality control because of the heterogeneity in AKI practice. More evidence is needed to improve the AKI quality control system. These are challenges that will need to be addressed in the future.

Acute Kidney Injury Risk Assessment

Acute kidney injury (AKI) is a common global health challenge, affecting patient morbidity adversely and resulting in an estimated 1.4 million deaths per year. Since the International Society of Nephrology proposed a goal of eliminating preventable deaths from AKI by 2025, implementation of this program remains far from optimistic not only because of the lack of resources but also because of the scarce data addressing the epidemiology and causes of AKI, especially in developing countries, the relative insufficient health care resources to diagnose and treat AKI, and the delayed awareness of the impact of AKI on patient outcomes. Therefore, quality measures of the AKI management are crucial to ensure a better outcome achieved with integrated resource.