The use of medium cutoff dialyzers in patients with multiple myeloma and acute kidney injury requiring hemodialysis: A systematic review.

BACKGROUND: Patients with multiple myeloma and high serum levels of circulating free light chains (FLC) have increased risk of acute kidney injury (AKI) secondary to cast nephropathy and is associated with poor survival. Despite removal of FLC by medium cutoff (MCO) dialyzer, the role of MCO hemodialysis (HD) in the treatment of cast nephropathy and its clinical benefits remain unknown. METHODS: A systematic review was conducted to establish the effectiveness of MCO dialyzer and clinical outcomes, compared to other forms of dialyzers in the removal of FLC, in myeloma patients with AKI. The primary outcome was effectiveness of MCO-HD in reducing serum FLC. The secondary outcomes were HD independence, estimated glomerular filtrate rate, mortality rates, length of hospitalization, rebound of serum FLC before the next dialysis, removal of other molecules during dialysis, and adverse events. RESULTS: We identified three case series, with a total of 17 patients. There were no randomized controlled trials (RCTs) or cohort studies. These case series showed that MCO dialyzer was effective in the removal of FLC and led to a reduction in FLC concentration post-dialysis. The majority of the case series did not have comparator arm and renal and/or other clinical outcomes. CONCLUSION: MCO dialyzer appeared to be effective in the removal of FLC based on the existing limited data. However, more data, particularly large-scale RCTs, are needed to assess the use of MCO dialyzer in reducing serum FLC and its effect on clinical outcomes in patients with multiple myeloma and AKI.

Regional citrate anticoagulation vs systemic heparin anticoagulation for double-filtration plasmapheresis.

INTRODUCTION: Double-filtration plasmapheresis (DFPP) has been utilized for immunomodulation in kidney transplantation. Anticoagulation is important to maintain circuit patency during DFPP. We aimed to compare the efficacy and safety of regional citrate anticoagulation (RCA) with systemic heparin anticoagulation during DFPP in kidney transplant recipients. METHODS: A retrospective cohort study was conducted to compare the efficacy and safety of RCA (RCA-DFPP) to systemic heparin anticoagulation (Hep-DFPP) for DFPP among kidney transplant recipients in a single tertiary center. RESULTS: A total of 112 sessions of DFPP were performed for 23 subjects, of which 62 sessions were RCA-DFPP and 50 sessions were Hep-DFPP. There were 13 sessions (11.6%) of premature circuit clotting, 10 sessions (16.1%) for RCA-DFPP and 3 sessions (6.0%) for Hep-DFPP (P = .10). All premature circuit clotting episodes occurred in subjects who underwent DFPP through a vascular catheter. Premature circuit clotting was associated with the use of a vascular catheter (odds ratio [OR] 14.2, 95% confidence interval [CI] 2.7-73.7; P < .01) and high postfilter ionized calcium (OR 12.7, 95% CI 1.4-112.5; P < .01). There was no major bleeding event. Hep-DFPP was associated with higher occurrence of hypocalcemia (OR 1.1, 95% CI 1.0-1.2; P < .01) and metabolic acidosis (OR 1.4, 95% CI 1.2-2.0; P = .04), while hypomagnesemia was more common for RCA-DFPP (OR 2.9, 95% CI 1.1-7.4; P = .03). CONCLUSION: Amongst kidney transplant patients who receive DFPP therapy, RCA-DFPP may be comparable to Hep-DFPP for the maintenance of circuit patency. Functioning vascular access is vital in avoiding premature clotting of the circuit. Close monitoring of electrolyte imbalances and coagulopathy related to DFPP is recommended.

Regional Citrate Anticoagulation during Double-Filtration Plasmapheresis in Kidney Transplant Recipients: A Single-Center Retrospective Cohort Study.

INTRODUCTION: Double-filtration plasmapheresis (DFPP) may be used for immunomodulation in kidney transplant (KTx). While DFPP reduces plasma product exposure, risk of circuit clotting merits adequate anticoagulation. Regional citrate anticoagulation (RCA) avoids the risks of systemic anticoagulation, but a protocol for RCA-DFPP is not previously widely described. METHODS: We conducted a single-center retrospective cohort study involving adult (≥21 years old) KTx recipients who underwent RCA-DFPP from 2018 to 2020 to investigate efficacy and safety for an RCA protocol during DFPP in KTx recipients. RESULTS: Fifty-one (85%) of 60 RCA-DFPP sessions in 17 patients completed without circuit clotting. Circuit clotting was associated with high post-filter ionized calcium (28 vs. 3.7%, odds ratio 10.1, 95% CI 1.1-89.4, p = 0.037). Hypo- and hypercalcemia developed in 5 (8.3%) and 8 (13.3%) sessions, respectively, but no adverse effects were noted despite severe hypocalcemia in one. There was no significant change in pre- and post-RCA-DFPP sodium, bicarbonate, albumin, and platelet levels. With regards DFPP procedure, prolongation of prothrombin time (PT) and activated partial thromboplastin time (aPTT) was observed following 38 (64.4%) and 12 (20.3%) sessions, respectively. Severely prolonged (>1.5 × upper limit normal) PT and aPTT were recorded in 2 sessions each. Expectedly, hypofibrinogenemia developed after 31 (51.7%) sessions: including 4 (6.7%) severe hypofibrinogenemia (<0.5 g/L). Two patients developed bleeding requiring blood product transfusion. The median total volume of fluids administered per session was 1.495 (1.373-1.612) L; post-RCA-DFPP significant weight gain of 0.5 (0-1.25) kg was noted. Diuretic was commenced or dose increased following 20 (33.3%) sessions for fluid balance management. DISCUSSION/CONCLUSION: Protocol-based RCA for DFPP is feasible and safe in KTx recipients. However, DFPP-related coagulopathy can develop consequent to treatment; caution should be exercised for patients with bleeding risk. Close monitoring and management of the patients' electrolytes, especially hypocalcemia and hypomagnesemia, and fluid status is recommended.

Description of parallel and sequential configurations for concurrent therapeutic plasma exchange and continuous kidney replacement therapy in adults.

Therapeutic plasma exchange (TPE) and continuous kidney replacement therapy (CKRT) are extracorporeal therapeutic procedures often implemented in management of patients. Critically ill patients may be afflicted with disease processes that require both TPE and CKRT. Performing TPE discontinuous with CKRT is technically easier, however, it disrupts CKRT and may compromise with CKRT efficiency or hemofilter life. Concurrent TPE with CKRT offers several advantages including simultaneous control of disease process and correction of electrolyte, fluid, and acid-base disturbances that may accompany TPE. Additionally, TPE may be performed by either centrifugation method or membrane plasma separation method. The technical specifications of these methods may influence the methodology of concurrent connections. This report describes and reviews two different approaches to circuit arrangements when establishing concurrent TPE and CKRT.

Augmented Adsorptive Blood Purification during Continuous Veno-Venous Haemodiafiltration in a Severe Septic, Acute Kidney Injury Patient: Use of oXiris®: A Single Centre Case Report.

The use of the oXiris® haemofilter during continuous veno-venous haemodiafiltration (CVVHDF) for acute kidney injury (AKI) and severe sepsis is not completely understood. Although this filter has in vitro adsorptive properties for blood-borne cytokines and other humoural mediators of sepsis, its clinical usefulness is uncertain. Given its inherent adsorptive limitation for septic mediators, we developed a CVVHDF protocol in which the oXiris haemofilter was electively changed every 12 h even though there was no clotting or adverse circuit pressures. Augmented filter membrane adsorption was conducted for 3 consecutive days. We treated a critically ill patient with severe sepsis secondary to a gram-negative bacterial infection and sepsis-associated acute kidney injury (SA- AKI) in this way. The patient required high-dose vasopressor support, required mechanical ventilation, had received 12 h of CVVHDF with conventional M100 haemofilter, was on broad spectrum antibiotics and other conventional intensive care unit (ICU) care, prior to institution of the frequent oXiris haemofilter change protocol. Following the start of elective 12 hourly oXiris filter change, the patient showed reduction in the need for vasopressor and by Day 4 of this SA- AKI frequent filter change protocol, vasopressor requirement ceased, he was extubated. He survived ICU and but not hospital stay. To this end, more clinical studies are needed.

A prospective study of clinical characteristics and outcomes of acute kidney injury in a tertiary care Centre.

BACKGROUND: Acute kidney injury (AKI) is a major global health problem. We aim to evaluate the epidemiology, risk factors and outcomes of AKI episodes in our single centre. METHODOLOGY: We prospectively identified 422 AKI and acute on chronic kidney disease episodes in 404 patients meeting KDIGO definitions using electronic medical records and clinical data from 15th July to 22nd October 2016, excluding patients with baseline estimated GFR (eGFR) of < 15 mL/min. Patients were followed up till 6 months after AKI diagnosis. RESULTS: The mean age was 65.8 ± 14.1. Majority of patients were male (58.2%) of Chinese ethnicity (68.8%). One hundred and thirty-two patients (32.6%) were diagnosed in acute care units. Seventy-five percent of patients developed AKI during admission in a non-Renal specialty. Mean baseline eGFR was 50.2 ± 27.7 mL/min. Mean creatinine at AKI diagnosis was 297 ± 161 µmol/L. Renal consultations were initiated at KDIGO Stages 1, 2 and 3 in 58.9, 24.5 and 16.6% of patients, respectively. Three hundred and ten (76.7%) patients had a single etiology of AKI with the 3 most common etiologies of AKI being pre-renal (27.7%), sepsis-associated (25.5%) and ischemic acute tubular necrosis (15.3%). One hundred and nine (27%) patients received acute renal replacement therapy. In-hospital mortality was 20.3%. Six-month mortality post-AKI event was 9.4%. On survival analysis, patients with KDIGO Stage 3 AKI had significantly shorter survival than other stages. CONCLUSION: AKI is associated with significant in-hospital to 6-month mortality. This signifies the pressing need for AKI prevention, early detection and intervention in mitigating reversible risk factors in order to optimize clinical outcomes.

Impact of simulation-based learning on immediate outcomes of temporary haemodialysis catheter placements by nephrology fellows.

AIM: Traditional apprenticeship model (AM) of teaching in invasive procedures such as temporary haemodialysis catheter (THDC) insertion can result in propagation of errors and complications. Simulation-based learning (SBL) offers standardization of skills and allows trainees to repeatedly practice invasive procedures prior to performing them on actual patient. METHODS: Retrospective cohort study of first-, second- and third-year Nephrology Fellows from a tertiary teaching hospital from September 2008 to September 2015. The intervention group (n = 9) received simulation training in ultrasound-guided THDC placement. The historical control group (n = 12) received training through traditional AM. The primary and secondary outcomes were the immediate complications and success rates of THDC insertion. RESULTS: A total of 2481 THDCs were placed in 1787 patients. Success rate of internal jugular THDC placement for AM vs. SBL Fellow was 99.8% versus 100% (P = 0.90), while the success rate for femoral THDC placement was 99.6% versus 99.2% (P = 0.53). SBL Fellows reported fewer overall peri-procedure complications (8.3% vs. 11.2%, P = 0.02) and mechanical complications (1% vs. 2.4%, P = 0.02) compared to AM Fellows. The rate of reported technical difficulty was similar (7.5% vs. 9.2%, P = 0.17). After adjusting for side and site of THDC placement, body mass index and laboratory indices, THDC inserted by AM Fellows were independently associated with increased overall peri-procedure complications (OR = 1.396, 95% CI: 1.052-1.854, P = 0.02) and mechanical complications (OR = 2.481, 95% CI: 1.178-4.810, P = 0.02). CONCLUSIONS: Simulation-based learning was associated with lower procedure related complications and should be an integral component in the teaching of procedural skills in Nephrology.

Severe gastrointestinal cytomegalovirus disease in two patients with renal vasculitis after immunosuppression.

Although the use of current immunosuppressive regimens has significantly improved the outcomes of autoimmune renal diseases, infectious complications remain an important clinical concern. Cytomegalovirus (CMV) infection has been shown to be one of the major causes of mortality in this group of patients. We report two cases of renal vasculitis (Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA)) that developed into severe gastrointestinal CMV disease and manifested with massive small bowel bleeding, resulting in an eventual fatal outcome for one of the patients. Risk factors, pathogenesis, role of immunosuppression in the development of CMV infection, and antiviral treatment are discussed in this review. These cases highlight the need for further research to evaluate the complex mechanisms between immunosuppression and CMV occurrence as well as the role of antiviral prophylaxis in high-risk patients undergoing immunosuppressive therapies.
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Non-steroidal anti-inflammatory drugs in chronic kidney disease and risk of acute adverse kidney events according to route of administration.

BACKGROUND: Topical non-steroidal anti-inflammatory drugs (NSAIDs) have lower risks for cardiovascular disease and gastrointestinal adverse effects compared to oral NSAIDs, but there are little data regarding their kidney risks in chronic kidney disease (CKD). We evaluated the risk of adverse acute kidney outcomes in CKD according to route of NSAID administration. METHODS: Retrospective cohort study of adults with CKD (eGFR less than 60 ml/min/1.73 m2) who received prescriptions between 2015 and 2017 from a major healthcare cluster in Singapore. The adverse acute kidney outcomes were acute kidney injury (AKI) and need for nephrology specialist consult within 30 days. RESULTS: Among 6298 adults with CKD (mean age 72.1 ± 13.3 years and eGFR 41.9 ± 12.2 ml/min/1.73 m2), systemic and topical NSAIDs were prescribed in 16.7% and 32.0%, respectively. Incident AKI (any severity), KDIGO Stage 2 or 3 AKI, and need for nephrology specialist consult occurred in 16.7%, 2.6%, and 10.6% of the study cohort, respectively. After adjusting for age, diabetes, recent cardiovascular hospitalization, baseline eGFR, RAAS blocker and diuretic, systemic NSAIDs, and topical NSAIDs, compared with the no-NSAID group, were independently associated with incident AKI [adjusted OR 1.77 (95% CI 1.46-2.15) and 1.38 (1.18-1.63), respectively]. Moderate and severe AKI (adjusted OR 1.68, 95% CI 1.09-2.58, p = 0.02) and need for nephrology consults (adjusted OR 1.41, 95% CI 1.09-1.82, p = 0.008) were also increased in systemic NSAIDs. CONCLUSION: Among adults with CKD, both systemic and topical NSAIDs were independently associated with acute adverse kidney outcomes.

Development and validation of an interpretable clinical score for early identification of acute kidney injury at the emergency department.

Acute kidney injury (AKI) in hospitalised patients is a common syndrome associated with poorer patient outcomes. Clinical risk scores can be used for the early identification of patients at risk of AKI. We conducted a retrospective study using electronic health records of Singapore General Hospital emergency department patients who were admitted from 2008 to 2016. The primary outcome was inpatient AKI of any stage within 7 days of admission based on the Kidney Disease Improving Global Outcome (KDIGO) 2012 guidelines. A machine learning-based framework AutoScore was used to generate clinical scores from the study sample which was randomly divided into training, validation and testing cohorts. Model performance was evaluated using area under the curve (AUC). Among the 119,468 admissions, 10,693 (9.0%) developed AKI. 8491 were stage 1 (79.4%), 906 stage 2 (8.5%) and 1296 stage 3 (12.1%). The AKI Risk Score (AKI-RiSc) was a summation of the integer scores of 6 variables: serum creatinine, serum bicarbonate, pulse, systolic blood pressure, diastolic blood pressure, and age. AUC of AKI-RiSc was 0.730 (95% CI 0.714-0.747), outperforming an existing AKI Prediction Score model which achieved AUC of 0.665 (95% CI 0.646-0.679) on the testing cohort. At a cut-off of 4 points, AKI-RiSc had a sensitivity of 82.6% and specificity of 46.7%. AKI-RiSc is a simple clinical score that can be easily implemented on the ground for early identification of AKI and potentially be applied in international settings.

Non-Steroidal Anti-Inflammatory Drugs and Risk of Acute Kidney Injury and Hyperkalemia in Older Adults: A Retrospective Cohort Study and External Validation of a Clinical Risk Model.

AIM: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used analgesics among older adults. Adverse effects may be avoided by careful patient selection. We aimed to evaluate the incidence of acute kidney injury (AKI) and/or hyperkalemia, risk factors, and the accuracy of an NSAID risk prediction model in a cohort of Asian older adults. METHODS: We conducted a retrospective cohort study of older adults, age 65 years and above, who received prescriptions between March 2015 and December 2017 from Singapore's largest cluster of public healthcare institutions. Factors associated with 30-day incident acute kidney injury and/or hyperkalemia were evaluated with multivariable regression analysis. Calibration and discrimination of the Nash prediction model were assessed using the Hosmer-Lemeshow goodness-of-fit test and C-statistic, respectively. RESULTS: The primary outcome occurred in 16.7% of 12,798 older adults. Topical NSAIDs (adjusted OR 1.29, 95% CI 1.15-1.45), systemic NSAIDs of 1-14 days' duration (adjusted OR 1.43, 95% CI 1.27-1.62), and systemic NSAIDs > 14 days (adjusted OR 1.84, 95% CI 1.37-2.49) were independently associated with the primary outcome, compared with no NSAID. Diabetes mellitus, cardiovascular disease, lower estimated glomerular filtration rate (eGFR), and diuretics were also independently associated with increased incident AKI and/or hyperkalemia. When applied to older adults with systemic NSAIDs > 14 days (n = 305), the Nash risk model had poor calibration (p < 0.001) and poor discrimination with C-statistic 0.527 (0.438, 0.616). CONCLUSIONS: Longer NSAID duration and systemic compared with topical route were associated with incremental odds for acute renal events. Further studies are required to improve the available risk model to guide NSAID prescriptions in older adults.

Effectiveness and acceptability of a multidisciplinary approach in improving the care of patients with advanced chronic kidney disease: a pilot study.

OBJECTIVE: This study aimed at determining the feasibility of conducting a large-scale pragmatic effectiveness study on the implementation of multidisciplinary care (MDC) program for patients with advanced chronic kidney disease (CKD). METHODS: This is a single-arm pre-post intervention design pilot study over 12 months. Participants with an estimated glomerular filtration rate (eGFR) between 11 and 20 ml/min/1.73m2 were screened and recruited at the initial MDC clinic visit and followed for 12 months. Clinical parameters, KDQOL™-36, questionnaires, and interviews were collected, administered, and analysed for enrolment and completion rates, baseline characteristics, implementation fidelity, adherence to CKD interventions, eGFR decline, CKD complications, health-related quality of life, and participants' acceptability of the program. RESULTS: The study enrolment and completion rates were 43.1% (50/116 screened) and 66.0% (33/50 recruited) respectively. The participants had a mean age of 68.5 years (SD9.0) and a mean eGFR of 15.4 ml/min/1.73m2(3.2). After 12 months of MDC program, there was increased adherence to CKD interventions (difference  - 0.6(1.0), 95%CI  - 1.1,  - 0.1, p = 0.02). There was good participants' acceptability of the program with participants being more satisfied with the waiting time and having a better understanding of kidney failure after attending the program. No difference in the eGFR decline noted (difference 0.0 ml/min/1.73m2(5.3), 95%CI  - 1.9, 1.9, p = 1.00). CONCLUSION: Our pilot data suggest increased adherence to CKD interventions and good acceptability to MDC program, albeit no difference in eGFR decline probably because of the small sample size. However, reasons for overall low enrolment and completion rates need to be explored and addressed while designing a future large-scale randomised controlled trial.

Healthcare professionals' perceptions of the role of a multidisciplinary approach in improving the care of patients with advanced chronic kidney disease.

OBJECTIVE: To explore and understand the experiences of healthcare professionals (HCPs) delivering care in a multidisciplinary care (MDC) clinic for advanced chronic kidney disease (CKD) patients. METHODS: This is a qualitative study based on semi-quantitative questionnaire and semi-structured interviews with thematic analysis and deductive mapping onto the Theoretical Framework of Acceptability. Sixteen HCPs caring for advanced CKD patients in a MDC clinic in a tertiary teaching hospital in Singapore were recruited based on maximum variation sampling procedures. RESULTS: The majority of the HCPs were supportive of a MDC clinic. There was a positive overall opinion of the programme [median 7.0 of 10.0 (IQR 7.0-8.0)], high satisfaction ratings for interaction with other members of team [6.9 (5.3-8.0)] and time spent with patients [7.0 (5.3-7.0)]. Thematic analysis of the interviews identified the value of MDC clinic in the provision of one-stop care, the improvement in communication and collaboration between HCPs, the facilitation of patient activation to make planned kidney care decisions, and the optimisation of medications. The main challenges were lack of continuity of care, manpower constraints, poor patient navigation between HCPs, poor patient attendance with allied HCPs, and the perception of increased cost and time spent by patients in each MDC clinic visit. The proposed interventions were notification of patients beforehand of the MDC clinic schedule and provision of navigation to patients within the MDC clinic. CONCLUSION: A multidisciplinary care clinic for advanced chronic kidney disease patients was viewed positively by the majority of the healthcare professionals, with areas for improvement.

Renal outcomes of intensive care burn patients in an Asian tertiary centre.

INTRODUCTION: Acute kidney injury (AKI) is a frequent complication of severe burn injury and is associated with a high mortality rate of up to 80%. We aimed to establish the incidence, mortality rate, and factors related to mortality in adult patients with severe burn injury and AKI with renal replacement therapy (RRT) in Singapore. METHODS: We performed a retrospective cohort study of severely burned patients who were admitted to the Burns Intensive Care Unit (BICU) at the Singapore General Hospital (SGH) from January 2008 to December 2016. We compared patients with AKI with RRT who survived with those who did not survive. As there were changes in the protocol for burns management after 2013, we also compared patients with AKI with RRT who survived with non-survivors in each of the 2008-2012 and 2013-2016 cohorts. RESULTS: Data of 201 patients were studied. The incidence of AKI with RRT use in severe burn injury was 21.9% and their mortality rate was 50.0%. The non-survivors had significantly higher median burned total body surface area (p = 0.043), earlier AKI (p = 0.046), earlier use of RRT (p = 0.035), lower rate of renal recovery (p = <0.0001), higher rates of adult respiratory distress syndrome (ARDS) (p = 0.005) and shock with vasopressors (p = 0.009) compared to the survivors. The survival rate was 36.8% in the 2008-2012 cohort, but improved to 60.0% in the 2013-2016 cohort. In the 2008-2012 cohort, the non-survivors developed AKI earlier (day 0 admission vs. day 3 admission, p = 0.039), and were initiated on RRT at lower serum creatinine level (173.5 µmol/L vs. 254.0 µmol/L, p = 0.042), when compared to the survivors in this same cohort. On the other hand, there were no significant differences in the renal status and fluid balance parameters between the non-survivors and survivors in the 2013-2016 cohort. CONCLUSIONS: The incidence of AKI with RRT in the Singapore study cohort was high, but their mortality rate was relatively lower compared to other study cohorts. Severity of AKI and use of RRT were associated with poor prognosis. Large scale study is required to further study the risk factors for mortality in this group of patients and establish cause-and-effect relationship.

Incidence, risk factors and outcomes of malignancies after kidney transplantation in Singapore: a 12-year experience.

INTRODUCTION: Data on malignancy after kidney transplantation (KTX) is limited in our region, leading to challenges in the care of renal allograft recipients. We aimed to examine the epidemiology, risk factors and outcomes of post-KTX patients. METHODS: A retrospective cohort study was conducted of 491 patients who underwent KTX from 1 January 2000 to 31 December 2011. Data linkage analysis was done between our centre and the National Registry of Diseases Office to determine the standardised incidence ratio (SIR), standardised mortality ratio (SMR) and risk factors for malignancy after KTX. RESULTS: 31 patients (61.3% male) developed malignancy during this period, and their median age at diagnosis was 50 (range 18-65) years. Median time to malignancy diagnosis was 2.6 (range 0.3-7.9) years, with cumulative incidence of 1%, 4% and 10% at one, five and ten years, respectively. The commonest malignancy type was lymphoma, followed by kidney cancer, colorectal cancer and malignancy of the male genital organs. Multivariate analysis identified cyclosporine use as an independent risk factor for malignancy. Compared to the general population, KTX recipients had higher malignancy and mortality rates after malignancy diagnosis (SIR 3.36; SMR 9.45). Survival rates for KTX recipients with malignancy versus those without malignancy were 100%, 93% and 64% versus 97%, 93% and 83% at one, five and ten years, respectively. CONCLUSION: KTX was associated with higher mortality and incidence of malignancy. Newer immunosuppressive agents and induction therapies were not found to be risk factors for malignancy, possibly due to our relatively small sample size.

Biomarkers in acute kidney injury (AKI).

Acute kidney injury is common in critically ill patients and portends a significant impact on mortality, progressive chronic kidney disease, and cardiovascular disease and mortality. Though most physicians alter therapy depending on changes in serum creatinine, this often represents delayed intervention. Various AKI biomarkers have been discovered and validated to improve timely detection, differentiation and stratification into risk groups for progressive renal decline, need for renal replacement therapy or death. This chapter will review AKI biomarkers validated over the past decade. We also describe the clinical performance of the biomarkers. We suggest that using AKI biomarkers to complement serum creatinine (or cystatin C) and urine output will better integrate patient care through earlier recognition and clinical outcome prediction after AKI.