Renal Association Clinical Practice Guidelines on acute kidney injury

Renal Biomarkers in the Early Detection of Acute Kidney Injury After Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

Cardiac surgery-associated (CSA) acute kidney injury (AKI) is a severe postoperative complication in patients undergoing off-pump coronary artery bypass grafting (OPCAB). Early detection of postoperative CSA-AKI may be key to improving patient outcomes. This study explored the use of renal biomarkers measured immediately after surgery for the early detection of CSA-AKI in patients undergoing OPCAB.Methods and Results: In all, 111 patients who underwent OPCAB at Kumamoto University Hospital between June 2020 and October 2022 were included in this study. Urinary neutrophil gelatinase-associated lipocalin, liver-type fatty acid-binding protein, and N-acetyl-β-D-glucosaminidase (NAG) were measured upon arrival in the intensive care unit (ICU) after surgery. AKI was diagnosed using KDIGO criteria. Of the 111 patients, 32 (28.8%) developed postoperative AKI. Regarding AKI staging, 19 (59.4%), 11 (34.4%), and 2 (6.3%) patients had Stage 1, 2, and 3 AKI, respectively. There were significant differences in chronic kidney disease, preoperative estimated glomerular filtration rate (eGFR), and NAG between the AKI and non-AKI groups. Multivariate analysis showed that preoperative eGFR (odds ratio [OR] for 5-mL/min/1.73 m2increase in eGFR 0.75; 95% confidence interval [CI] 0.63-0.89) and increasing urinary NAG concentrations at ICU admission (OR 2.44; 95% CI 1.30-4.60) were significant risk factors for CSA-AKI in OPCAB patients.

CONCLUSIONS

NAG and eGFR may be valuable biomarkers for the early detection of CSA-AKI in patients undergoing OPCAB.

Designing acute kidney injury clinical trials

Acute kidney injury (AKI) is a common clinical condition with various causes and is associated with increased mortality. Despite advances in supportive care, AKI increases not only the risk of premature death compared with the general population but also the risk of developing chronic kidney disease and progressing towards kidney failure. Currently, no specific therapy exists for preventing or treating AKI other than mitigating further injury and supportive care. To address this unmet need, novel therapeutic interventions targeting the underlying pathophysiology must be developed. New and well-designed clinical trials with appropriate end points must be subsequently designed and implemented to test the efficacy of such new interventions. Herein, we discuss predictive and prognostic enrichment strategies for patient selection, as well as primary and secondary end points that can be used in different clinical trial designs (specifically, prevention and treatment trials) to evaluate novel interventions and improve the outcomes of patients at a high risk of AKI or with established AKI.

Surgical Emergencies in the ICU

Surgical emergencies are common in the critical care setting and require prompt diagnosis and management. Here, we discuss some of the surgical emergencies involving the gastrointestinal, hepatobiliary, and genitourinary sites. In addition, foreign body aspiration and necrotizing soft-tissue infections have been elaborated. Clinicians should be aware of the risk factors, keys examination findings, diagnostic modalities, and medical as well as surgical treatment options for these potentially fatal illnesses.

Early Initiation of Renal Replacement Therapy Among Burned Patients With Acute Kidney Injury

BACKGROUND

Burned patients with acute kidney injury (AKI) requiring renal replacement therapy (RRT) have exceedingly high mortality rates of 73% to 100%. Since January 2011, we have been adopting an early RRT approach in managing burned patients with AKI. Our hypothesis was that early initiation of RRT leads to improved outcome and survival among burned patients with AKI.

METHODOLOGY

We conducted a retrospective analysis of Burns Database in Singapore General Hospital from January 2011 to February 2016. Indications for dialysis included serum creatinine of greater than 1.5 times baseline or urine output of less than 0.5 mL/kg per hour for at least 6 consecutive hours. Patients with similar condition from January 2006 to December 2010 were recruited for comparison.

RESULT

A total of 27 patients with burns and AKI were recruited from January 2011 to February 2016. The mean age was 45.4 years and 88.9% were male. The mean total burn surface area (TBSA) was 54.8%. The total volume of fluid resuscitation was 2.7 mL/kg per TBSA. The time from onset of burn to RRT was 6.4 days. Most patients presented with stage 1 AKI (51.9%), whereas 22.2% and 25.9% had stage 2 and stage 3 AKI, respectively. Most patients (74.1%) received CRRT and 18.5% received SLED. The mortality rate was 37.0% with majority of death (70%) due to sepsis/multiorgan failure. Only 1 patient required long-term RRT after discharge, and there was no occurrence of abdominal compartment syndrome. The mean age of 15 patients from 2006 to 2010 was 47.8 years. The mean TBSA was 49.5%. Only 26.7% of patients were started on RRT. The mortality rate was 66.7%, which was higher than that of subjects from 2011 to 2016 (37.0%) (P = 0.039).

CONCLUSIONS

Optimal timing of RRT for burned patients with AKI has not been established and data on early RRT approach are scarce. The findings of our study suggested that early RRT was associated with lower mortality rates among burned victims with AKI.

Dynamic Contrast Enhanced-MR CEST Urography: An Emerging Tool in the Diagnosis and Management of Upper Urinary Tract Obstruction

Upper urinary tract obstructions (UTOs) are blockages that inhibit the flow of urine through its normal course, leading to impaired kidney function. Imaging plays a significant role in the initial diagnosis of UTO, with anatomic imaging (primarily ultrasound (US) and non-contrast computed tomography (CT)) serving as screening tools for the detection of the dilation of the urinary collecting systems (i.e., hydronephrosis). Whether hydronephrosis represents UTO or a non-obstructive process is determined by functional imaging (typically nuclear medicine renal scintigraphy). If these exams reveal evidence of UTO but no discernable source, multiphase contrast enhanced CT urography and/or dynamic contrast enhanced MR urography (DCE-MRU) may be performed to delineate a cause. These are often performed in conjunction with direct ureteroscopic evaluation. While contrast-enhanced CT currently predominates, it can induce renal injury due to contrast induced nephropathy (CIN), subject patients to ionizing radiation and is limited in quantifying renal function (traditionally assessed by renal scintigraphy) and establishing the extent to which hydronephrosis is due to functional obstruction. Traditional MRI is similarly limited in its ability to quantify function. DCE-MRU presents concerns regarding nephrogenic systemic fibrosis (NSF), although decreased with newer gadolinium-based contrast agents, and regarding cumulative gadolinium deposition in the basal ganglia. DCE-MR CEST urography is a promising alternative, employing new MRI contrast agents and imaging schemes and allowing for concurrent assessment of renal anatomy and functional parameters. In this review we highlight clinical challenges in the diagnosis and management of UTO, identify key advances in imaging agents and techniques for DCE-MR CEST urography and provide perspective on how this technique may evolve in clinical importance.

Long-term outcomes of acute kidney injury and strategies for improved care

Acute kidney injury (AKI), once viewed predominantly as a self-limited and reversible condition, is now recognized as a growing problem associated with significant risks of adverse long-term health outcomes. Many cohort studies have established important relationships between AKI and subsequent risks of recurrent AKI, hospital re-admission, morbidity and mortality from cardiovascular disease and cancer, as well as the development of chronic kidney disease and end-stage kidney disease. In both high-income countries (HICs) and low-income or middle-income countries (LMICs), several challenges exist in providing high-quality, patient-centered care following AKI. Despite advances in our understanding about the long-term risks following AKI, large gaps in knowledge remain about effective interventions that can improve the outcomes of patients. Therapies for high blood pressure, glycaemic control (for patients with diabetes), renin-angiotensin inhibition and statins might be important in improving long-term cardiovascular and kidney outcomes after AKI. Novel strategies that incorporate risk stratification approaches, educational interventions and new models of ambulatory care following AKI have been described, and some of these are now being implemented and evaluated in clinical studies in HICs. Care for AKI in LMICs must overcome additional barriers due to limited resources for diagnosis and management.

Hyperuricemia is associated with acute kidney injury and all-cause mortality in hospitalized patients

AIM

Hyperuricemia is a risk factor for high morbidity and mortality in several diseases. However, the relationship between uric acid (UA) and the risk of acute kidney injury (AKI) and mortality remain unresolved in hospitalized patients.

METHODS

Data from 18 444 hospitalized patients were retrospectively reviewed. The odds ratio (OR) for AKI and the hazard ratio (HR) for all-cause mortality were calculated based on the UA quartiles after adjustment for multiple variables. All analyses were performed after stratification by sex.

RESULTS

The fourth quartile group (male, UA > 6.7 mg/dL; female, UA > 5.4 mg/dL) showed a higher risk of AKI compared with the first quartile group (male, UA < 4.5 mg/dL; female, UA < 3.6 mg/dL), with the following OR: 3.2 (2.55-4.10) in males (P < 0.001); and 3.1 (2.40-4.19) in females (P < 0.001). There were more patients who did not recover from AKI in the fourth quartile compared with the first quartile, with the following OR: 2.0 (1.32-3.04) in males (P = 0.001) and 2.4 (1.43-3.96) in females (P = 0.001). The fourth quartile group had a higher risk of all-cause mortality compared with the first quartile group, with the following HR: 1.4 (1.20-1.58) in males (P < 0.001) and 1.2 (1.03-1.46) in females (P = 0.019). The in-hospital mortality risk was also higher in the fourth quartile compared with the first quartile, which was significant only in males (OR, 2.1 (1.33-3.31) (P = 0.002)).

CONCLUSION

Hyperuricemia increases the risks of AKI and all-cause mortality in hospitalized patients.

Acute Kidney Injury in Subjects With Chronic Kidney Disease Undergoing Total Joint Arthroplasty

BACKGROUND

Chronic kidney disease (CKD) has been associated with higher incidence of complications after total joint arthroplasty (TJA) but the incidence, risk factors and outcomes of acute kidney injury (AKI) in this setting remains insufficiently understood.

METHODS

We assessed the impact of baseline CKD on the risk of developing AKI after TJA performed between 1/2012 and 12/2016 in a single-center, retrospective cohort study. CKD was defined by estimated glomerular filtration rate <60 mL/min/1.73 m² on 2 separate occasions within 3 months prior TJA. AKI was defined using a modified Kidney Disease: Improving Global Outcomes criteria based on serum creatinine (sCr) only to assess the severity of AKI. Complete AKI recovery was defined as the lowest post-AKI sCr within 20% of pre-AKI sCr values and partial recovery if within 30%, all within 90 days after TJA.

RESULTS

Twenty-four percent of the 1,212 subjects undergoing TJA had pre-existing CKD. The overall incidence of AKI in the CKD subjects was 30%; of these, 55% had stage-1 AKI, 1% had stage-2 AKI and 44% had stage-3 AKI. AKI was more common in African Americans, those with diabetes or heart failure, requiring perioperative transfusions or receiving diuretics before surgery. While 82% of the AKI subjects achieved complete recovery of kidney function, 4% had only partial recovery and 14% did not reach a post-AKI sCr level within 30% of pre-AKI values. The incidence (P < 0.001) but not the severity (P = 0.202) of AKI correlated with stages of baseline CKD.

CONCLUSIONS

The presence of CKD was associated with a high incidence of AKI after TJA. In these subjects, more than half the cases of AKI were of mild degree and had a favorable outcome. However, 18% of them did not have complete recovery of kidney function. Stages of baseline CKD were associated with increased incidence but not severity of AKI after TJA.

The impact of the NHS electronic-alert system on the recognition and management of acute kidney injury in acute medicine

To address inconsistencies in the recognition and management of acute kidney injury (AKI), an electronic-alert (e-alert) system was implemented by NHS England in 2015. This study aimed to describe its impact within acute medicine in the West Midlands. All admissions to included acute medical units were screened for AKI in two phases, before and after the e-alert was introduced. Data describing recognition and management of patients with AKI were collected. In the 10 units that participated in both phases, recognition of AKI by clinicians significantly improved from 67.9% in 2015 to 76.1% in 2016 (p=0.04). Further analysis of the data found that the presence of an e-alert had a limited effect on recognition and management, suggesting it was not the primary cause of the improvements. Multiple avenues of research have been recommended to clarify the impact of the e-alert system and to improve deficiencies in management that were identified in the data.

An Organizational-Level Program of Intervention for AKI: A Pragmatic Stepped Wedge Cluster Randomized Trial

BACKGROUND

Variable standards of care may contribute to poor outcomes associated with AKI. We evaluated whether a multifaceted intervention (AKI e-alerts, an AKI care bundle, and an education program) would improve delivery of care and patient outcomes at an organizational level.

METHODS

A multicenter, pragmatic, stepped-wedge cluster randomized trial was performed in five UK hospitals, involving patients with AKI aged ≥18 years. The intervention was introduced sequentially across fixed three-month periods according to a randomly determined schedule until all hospitals were exposed. The primary outcome was 30-day mortality, with pre-specified secondary endpoints and a nested evaluation of care process delivery. The nature of the intervention precluded blinding, but data collection and analysis were independent of project delivery teams.

RESULTS

We studied 24,059 AKI episodes, finding an overall 30-day mortality of 24.5%, with no difference between control and intervention periods. Hospital length of stay was reduced with the intervention (decreases of 0.7, 1.1, and 1.3 days at the 0.5, 0.6, and 0.7 quantiles, respectively). AKI incidence increased and was mirrored by an increase in the proportion of patients with a coded diagnosis of AKI. Our assessment of process measures in 1048 patients showed improvements in several metrics including AKI recognition, medication optimization, and fluid assessment.

CONCLUSIONS

A complex, hospital-wide intervention to reduce harm associated with AKI did not reduce 30-day AKI mortality but did result in reductions in hospital length of stay, accompanied by improvements in in quality of care. An increase in AKI incidence likely reflected improved recognition.

Acute kidney injury and disease: Long-term consequences and management

With increasing longevity and the presence of multiple comorbidities, a significant proportion of hospitalized patients, and an even larger population in the community, is at increased risk of developing an episode of acute kidney injury (AKI). Because of improvements in short-term outcomes following an episode of AKI, survivors of an episode of AKI are now predisposed to develop its long-term sequel. The identification of risk for progression to chronic kidney disease (CKD) is complicated by the absence of good biomarkers that identify this risk and the variability of risk associated with clinical factors including, but not limited to, the number of AKI episodes, severity, duration of previous AKI and pre-existing CKD that has made the prediction for long-term outcomes in survivors of AKI more difficult. Being a significant contributor to the growing incidence of CKD, there is a need to implement measures to prevent AKI in both the community and hospital settings, target interventions to treat AKI that are also associated with better long-term outcomes, accurately identify patients at risk of adverse consequences following an episode of AKI and institute therapeutic strategies to improve these long-term outcomes. We discuss the lasting renal and non-renal consequences following an episode of AKI, available biomarkers and non-invasive testing to identify ongoing intra-renal pathology and review the currently available and future treatment strategies to help reduce these adverse long-term outcomes.

Predictive factors of Clostridioides difficile infection in hospitalized patients with new diarrhea: A retrospective cohort study

Introduction and objective

Diagnostic testing for Clostridioides difficile infection (CDI) by nucleic acid amplification test (NAAT) cannot distinguish between colonization and infection. A positive NAAT may therefore represent a false positive for infection, since diarrhea due to various aetiologies may occur in hospitalized patients. Our objective was to help answer the question: “does this medical inpatient with diarrhea have CDI?”

Design

We conducted a retrospective cohort study (n = 248) on the Clinical Teaching Units of the Royal Victoria Hospital (Montréal, Canada). Patients were included if they had a NAAT between January 2014 and September 2015 and their admission diagnosis was not CDI. CDI cases and non-CDI cases were compared, and independent predictors of CDI were determined by logistic regression.

Results

Several factors were independently associated with CDI, including: hemodialysis (OR: 13.5, 95% CI: 2.85–63.8), atrial fibrillation (OR: 3.70, 95% CI: 1.52–9.01), whether the patient received empiric treatment (OR: 3.01, 95% CI: 1.04–8.68), systemic antibiotic therapy prior to testing (OR: 4.23, 95% CI: 1.71–10.5), previous positive NAAT (OR: 3.70, 95% CI: 1.41–9.72), and a leukocyte count of 11x10⁹/L or higher (OR: 3.43, 95% CI: 1.42–8.26). The area under the curve was 0.80.

Conclusion

For patients presenting with hospital-onset diarrhea, various parameters can help differentiate between CDI and other causes. A clinical prediction calculator derived from our cohort (http://individual.utoronto.ca/leet/cdiff.html) might assist clinicians in estimating the risk of CDI for inpatients; those with low pre-test probability may not require immediate testing, treatment, nor prolonged isolation.

An Observational Cohort Feasibility Study to Identify Microvesicle and Micro-RNA Biomarkers of Acute Kidney Injury Following Pediatric Cardiac Surgery

OBJECTIVES

Micro-RNA, small noncoding RNA fragments involved in gene regulation, and microvesicles, membrane-bound particles less than 1 μm known to regulate cellular processes including responses to injury, may serve as disease-specific biomarkers of acute kidney injury. We evaluated the feasibility of measuring these signals as well as other known acute kidney injury biomarkers in a mixed pediatric cardiac surgery population.

DESIGN

Single center prospective cohort feasibility study.

SETTING

PICU.

PATIENTS

Twenty-four children (≤ 17 yr) undergoing cardiac surgery with cardiopulmonary bypass without preexisting inflammatory state, acute kidney injury, or extracorporeal life support.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acute kidney injury was defined according to modified Kidney Diseases Improving Global Outcomes criteria. Blood and urine samples were collected preoperatively and at 6-12 and 24 hours. Microvesicles derivation was assessed using flow cytometry and NanoSight analysis. Micro-RNAs were isolated from plasma and analyzed by microarray and quantitative real-time polymerase chain reaction. Data completeness for the primary outcomes was 100%. Patients with acute kidney injury (n = 14/24) were younger, underwent longer cardiopulmonary bypass, and required greater inotrope support. Acute kidney injury subjects had different fractional content of platelets and endothelial-derived microvesicles before surgery. Platelets and endothelial microvesicles levels were higher in acute kidney injury patients. A number of micro-RNA species were differentially expressed in acute kidney injury patients. Pathway analysis of candidate target genes in the kidney suggested that the most often affected pathways were phosphatase and tensin homolog and signal transducer and activator of transcription 3 signaling.

CONCLUSIONS

Microvesicles and micro-RNAs expression patterns in pediatric cardiac surgery patients can be measured in children and potentially serve as tools for stratification of patients at risk of acute kidney injury.

Effects of Intensive Blood Pressure Treatment on Acute Kidney Injury Events in the Systolic Blood Pressure Intervention Trial (SPRINT)

BACKGROUND

Treating to a lower blood pressure (BP) may increase acute kidney injury (AKI) events.

STUDY DESIGN

Data for AKI resulting in or during hospitalization or emergency department visits were collected as part of the serious adverse events reporting process of the Systolic Blood Pressure Intervention Trial (SPRINT).

SETTING & PARTICIPANTS

9,361 participants 50 years or older with 1 or more risk factors for cardiovascular disease.

INTERVENTIONS

Participants were randomly assigned to a systolic BP target of <120 (intensive arm) or <140mmHg (standard arm).

OUTCOMES & MEASUREMENTS

Primary outcome was the number of adjudicated AKI events. Secondary outcomes included severity of AKI and degree of recovery of kidney function after an AKI event. Baseline creatinine concentration was defined as the most recent SPRINT outpatient creatinine value before the date of the AKI event.

RESULTS

There were 179 participants with AKI events in the intensive arm and 109 in the standard arm (3.8% vs 2.3%; HR, 1.64; 95% CI, 1.30-2.10; P<0.001). Of 288 participants with an AKI event, 248 (86.1%) had a single AKI event during the trial. Based on modified KDIGO (Kidney Disease: Improving Global Outcomes) criteria for severity of AKI, the number of AKI events in the intensive versus standard arm by KDIGO stage was 128 (58.5%) versus 81 (62.8%) for AKI stage 1, 42 (19.2%) versus 18 (14.0%) for AKI stage 2, and 42 (19.2%) versus 25 (19.4%) for AKI stage 3 (P=0.5). For participants with sufficient data, complete or partial resolution of AKI was seen for 169 (90.4%) and 9 (4.8%) of 187 AKI events in the intensive arm and 86 (86.9%) and 4 (4.0%) of 99 AKI events in the standard arm, respectively.

LIMITATIONS

Trial results are not generalizable to patients with diabetes mellitus or without risk factors for cardiovascular disease.

CONCLUSIONS

More intensive BP lowering resulted in more frequent episodes of AKI. Most cases were mild and most participants had complete recovery of kidney function.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT01206062.

Comparison of Three Methods Estimating Baseline Creatinine For Acute Kidney Injury in Hospitalized Patients: a Multicentre Survey in Third-Level Urban Hospitals of China

BACKGROUND/AIMS

A lack of baseline serum creatinine (SCr) data leads to underestimation of the burden caused by acute kidney injury (AKI) in developing countries. The goal of this study was to investigate the effects of various baseline SCr analysis methods on the current diagnosis of AKI in hospitalized patients.

METHODS

Patients with at least one SCr value during their hospital stay between January 1, 2011 and December 31, 2012 were retrospectively included in the study. The baseline SCr was determined either by the minimum SCr (SCrMIN) or the estimated SCr using the MDRD formula (SCrGFR-75). We also used the dynamic baseline SCr (SCrdynamic) in accordance with the 7 day/48 hour time window. AKI was defined based on the KDIGO SCr criteria.

RESULTS

Of 562,733 hospitalized patients, 350,458 (62.3%) had at least one SCr determination, and 146,185 (26.0%) had repeat SCr tests. AKI was diagnosed in 13,883 (2.5%) patients using the SCrMIN, 21,281 (3.8%) using the SCrGFR-75 and 9,288 (1.7%) using the SCrdynamic. Compared with the non-AKI patients, AKI patients had a higher in-hospital mortality rate regardless of the baseline SCr analysis method.

CONCLUSIONS

Because of the scarcity of SCr data, imputation of the baseline SCr is necessary to remedy the missing data. The detection rate of AKI varies depending on the different imputation methods. SCrGFR-75 can identify more AKI cases than the other two methods.

Practice Guidelines for Nutrition in Critically Ill Patients: A Relook for Indian Scenario

Background and Aim:

Intensive-care practices and settings may differ for India in comparison to other countries. While international guidelines are available to direct the use of enteral nutrition (EN), there are no recommendations specific to Indian settings. Advisory board meetings were arranged to develop the practice guidelines specific to Indian context, for the use of EN in critically ill patients and to overcome challenges in this field.

Methods:

Various existing guidelines, meta-analyses, randomized controlled trials, controlled trials, and review articles were reviewed for their contextual relevance and strength. A systematic grading of practice guidelines by advisory board was done based on strength of the supporting evidence. Wherever Indian studies were not available, references were taken from the international guidelines.

Results:

Based on the literature review, the recommendations for developing the practice guidelines were made as per the grading criteria agreed upon by the advisory board. The recommendations were to address challenges regarding EN versus parenteral nutrition; nutrition screening and assessment; nutrition in hemodynamically unstable; route of nutrition; tube feeding and challenges; tolerance; optimum calorie-protein requirements; selection of appropriate enteral feeding formula; micronutrients and immune-nutrients; standard nutrition in hepatic, renal, and respiratory diseases and documentation of nutrition practices.

Conclusion:

This paper summarizes the optimum nutrition practices for critically ill patients. The possible solutions to overcome the challenges in this field are presented as practice guidelines at the end of each section. These guidelines are expected to provide guidance in critical care settings regarding appropriate critical-care nutrition practices and to set up Intensive Care Unit nutrition protocols.

Risk factors for community-acquired acute kidney injury in patients with and without chronic kidney injury and impact of its initial management on prognosis: a prospective observational study

Background

We aimed to describe clinical characteristics of patients with community-acquired acute kidney injury (CA-AKI), the effectiveness of initial management of CA-AKI, its prognosis and the impact of medication on its occurrence in patients with previous chronic kidney injury (CKI).

Methods

We undertook a prospective observational study within the Emergency Department (ED) of a University Hospital, screening for any patient >16 years admitted with an eGFR <60 ml/mn/1.73 m² and a rise in serum creatinine as compared to previous values. Patients’ medical files were reviewed by a panel of nephrologists in the subsequent days and at one and three-years follow-up.

Results

From May 1st to June 21st 2013, there were 8464 admissions in the ED, of which 653 had an eGFR <60 ml/mn/1.73 m². Of these, 352 had previous CKI, 341 had CA-AKI, and 104 had CA-ACKI (community-acquired acute on chronic kidney injury). Occurrence of superimposed CA-AKI in CKI patients was associated with male gender and with use of diuretics, but not with use of ARBs or ACEIs.

Adequate management of CA-AKI defined as identification, diagnostic procedures and therapeutic intervention within 24 h, was recorded in 45% of the cases and was not associated with improved outcomes.

Three-year mortality was 21 and 48% in CKI and CA-ACKI patients respectively, and 40% in patients with only CA-AKI (p < 0.001). Mortality was significantly associated with age, hypertension, ischemic heart disease and CA-AKI.

Progression of renal insufficiency was associated with male gender and age.

Conclusions

CA-AKI is more frequently encountered in male patients and those treated with diuretics and is an independent risk factor for long-term mortality. Its initial adequate management failed to improve outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12882-017-0792-2) contains supplementary material, which is available to authorized users.

Improving the completeness of acute kidney injury follow-up information in hospital electronic discharge letters

Objectives

Acute kidney injury (AKI) is common in hospitalised patients, often mandates changes to regular medications and can be unresolved at hospital discharge. General practitioners (GPs) require apposite AKI-related information in electronic discharge letters (EDLs). In 2015 NHS England introduced a care quality standard that all EDLs should include four items of information for patients with AKI. We performed a 12-month quality improvement project (QIP) aimed at achieving above 90% compliance with the quality standard.

Methods

Hospital-wide episodes of AKI were detected using the nationally approved electronic AKI alerts system. 25 patient AKI episodes were audited per month for 12 months using the electronic patient record. The target compliance rate was staggered at 35%, 65% and 90% for each subsequent 3-month block. Baseline compliance was 22%. Measures taken to improve compliance included email information, grand rounds, ward-level meetings, computer screensavers, nurse support, clinical governance meetings, and face-to-face rapid education. Annotation of AKI within the computer EDL system was progressively enhanced such that in the final quarter the presence of an AKI-alert mandated the user to complete the AKI annotation before the EDL could be signed off.

Results

The completion rate improved to 37% in the second quarter, 51% in the third quarter and 92% in the fourth quarter. This change has been sustained in the 14 months since.

Conclusions

By the end of the study, omissions relating to AKI information were reduced from 78% to less than 10%, indicating our QIP was highly effective—meeting the quality standard. The single most important factor in improving documentation was to mandate user review of AKI aftercare in patients with electronic AKI alerts. Our study encompassed hospital-wide inpatients, and our results could be replicated at other acute hospitals that have implemented an EDL system connected to an AKI alert system.

Analysis of the association of fluid balance and short-term outcome in traumatic brain injury

INTRODUCTION

A balance of fluid intake and output (fluid balance) influences outcomes of critical illness, but the level of such influence remains poorly understood for traumatic brain injury (TBI) and was quantitatively examined in this study.

METHODS

We conducted a retrospective cohort study of 351 moderate and severe TBI patients to associate the degree of fluid balance with clinical outcomes of TBI. Fluid balance and intracranial pressure (ICP) were continuously recorded for 7days on patients admitted to neurocritical care unit (NCCU). The short-term outcome was dichotomized into improvement and deterioration groups based on changes in Glasgow Coma Scale (GCS) measured between admission and 30days after admission. Fluid balance was calculated as: Fluid intake (mL) - fluid outputs (mL)/day×5 and used to group patients in tertiles to study its effect on TBI outcome.

RESULTS

Patients at the low (<637mL) and upper (>3673mL) tertiles of fluid balance were associated with poor outcomes. Those in the upper tertile also had a higher incidence of acute kidney injury (AKI) and refractory intracranial hypertension (RIH). There was a negative correlation between the cumulative fluid balance and the short-term outcome for patients in the low tertile and a positive correlation between the cumulative fluid balance and the short-term outcome in the upper fluid balance group. Levels of fluid balance were also associated with serum creatinine (Cr, r=0.451, P<0.0001) and days in NCCU (r=0.188, P=0.001). More patients in the upper tertile had ICP higher than 20mmHg (P=0.009). A fluid balance in the upper tertile is an independent predictor of poor 30-day clinical outcomes after the adjustment for confounding variables in a multivariable logistic regression model.

CONCLUSION

We found that fluid balance in low and upper tertiles were associated with poor short-term outcomes and ICP variations. Fluid balance in the upper tertile may be an independent predictor for poor 30-day outcome, primarily due to high AKI and RIH.

Computerized clinical decision support for the early recognition and management of acute kidney injury: a qualitative evaluation of end-user experience

BACKGROUND

Although the efficacy of computerized clinical decision support (CCDS) for acute kidney injury (AKI) remains unclear, the wider literature includes examples of limited acceptability and equivocal benefit. Our single-centre study aimed to identify factors promoting or inhibiting use of in-patient AKI CCDS.

METHODS

Targeting medical users, CCDS triggered with a serum creatinine rise of ≥25 μmol/L/day and linked to guidance and test ordering. User experience was evaluated through retrospective interviews, conducted and analysed according to Normalization Process Theory. Initial pilot ward experience allowed tool refinement. Assessments continued following CCDS activation across all adult, non-critical care wards.

RESULTS

Thematic saturation was achieved with 24 interviews. The alert was accepted as a potentially useful prompt to early clinical re-assessment by many trainees. Senior staff were more sceptical, tending to view it as a hindrance. 'Pop-ups' and mandated engagement before alert dismissal were universally unpopular due to workflow disruption. Users were driven to close out of the alert as soon as possible to review historical creatinines and to continue with the intended workflow.

CONCLUSIONS

Our study revealed themes similar to those previously described in non-AKI settings. Systems intruding on workflow, particularly involving complex interactions, may be unsustainable even if there has been a positive impact on care. The optimal balance between intrusion and clinical benefit of AKI CCDS requires further evaluation.

Contrast Media Injector Technology - Renal Safety During Coronarography

Aim:

This study sought to assess whether the volume and osmolarity of contrast media (CM) influences the occurrence of contrast induced nephropathy (CIN) following coronarography procedure. CIN can be defined as an increase in the serum concentration of creatinine greater than a 25% from baseline during the period of 12 to 48 hours after the administration of radiocontrast media.

Material and methods:

We examined 100 patients without diabetes with serum creatinine concentration from 45 mmol/l to 141 mmol/l and 100 patients with diabetes with serum creatinine concentration from 46 mmol/l to 161 mmol/l who underwent coronary angiography. During procedure they received iso-osmolar contrast medium, Visipaque 320 (iodixanol-320), for group without diabetes from 40 to 340 ml and for group with diabetes from 49 to 310 ml.

Results:

CIN occurred in 27 (13,5%) of the 200 study patients. There was a trend toward higher prevalence of CIN (16% vs.11%, p = 0.086) in the diabetic group compared with the non-diabetic group. Patient with diabetes received less contrast media, they are younger but number patients with CIN are higher.

Conclusion:

Increasing contrast media dose is associated with the occurrence of CIN following coronarography. But, another risk factors like diabetes mellitus, old age, male sex and preexisting kidney disease have influence of developing CIN after coronarography.

Epidemiology and Clinical Correlates of AKI in Chinese Hospitalized Adults

BACKGROUND AND OBJECTIVES

Comprehensive epidemiologic data on AKI are particularly lacking in Asian countries. This study sought to assess the epidemiology and clinical correlates of AKI among hospitalized adults in China.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a multicenter retrospective cohort study of 659,945 hospitalized adults from a wide range of clinical settings in nine regional central hospitals across China in 2013. AKI was defined and staged according to Kidney Disease Improving Global Outcomes criteria. The incidence of AKI in the cohort was estimated using a novel two-step approach with adjustment for the frequency of serum creatinine tests and other potential confounders. Risk factor profiles for hospital-acquired (HA) and community-acquired (CA) AKI were examined. The in-hospital outcomes of AKI, including mortality, renal recovery, length of stay, and daily cost, were assessed.

RESULTS

The incidence of CA-AKI and HA-AKI was 2.5% and 9.1%, respectively, giving rise to an overall incidence of 11.6%. Although the risk profiles for CA-AKI and HA-AKI differed, preexisting CKD was a major risk factor for both, contributing to 20% of risk in CA-AKI and 12% of risk in HA-AKI. About 40% of AKI cases were possibly drug-related and 16% may have been induced by Chinese traditional medicines or remedies. The in-hospital mortality of AKI was 8.8%. The risk of in-hospital death was higher among patients with more severe AKI. Preexisting CKD and need for intensive care unit admission were associated with higher death risk in patients at any stage of AKI. Transiency of AKI did not modify the risk of in-hospital death. AKI was associated with longer length of stay and higher daily costs, even after adjustment for confounders.

CONCLUSION

AKI is common in hospitalized adults in China and is associated with significantly higher in-hospital mortality and resource utilization.

Acute concentrated phenol dermal burns: Complications and management

Phenol burns can result in multiple organ failure. This is a case report of acute severe phenol dermal burn after accidental splash of 94% phenol on 35-year-old patient's body who was brought to hospital after 90 min of exposure. Decontamination was done with high-density water and glycerol. Early complications in form of metabolic acidosis and acute renal failure required hemodialysis. Extensive protein denaturation was managed with IV albumin and high protein diet. Patient also developed pleural effusion and acute respiratory distress syndrome, but these were successfully managed by intercostal drain tube insertion and noninvasive ventilation. The patient survived after multiple organ failures and widespread burns despite the fact that it has been observed that outcome of phenol burns with >60² inches of skin affected or two or more organs failure involving renal system is nearly fatal.

Critically ill patients requiring acute renal replacement therapy are at an increased risk of long-term renal dysfunction, but rarely receive specialist nephrology follow-up

BACKGROUND

Episodes of acute kidney injury (AKI) have been associated with the development of chronic kidney disease (CKD). However, follow-up pathways for patients who have survived AKI complicating critical illness are not well established. We hypothesised that patients who had AKI requiring renal replacement therapy (RRT) in intensive care are at risk of CKD, but are rarely referred for nephrology follow-up at hospital discharge.

METHODS

We performed a retrospective analysis of all patients who survived AKI requiring renal replacement therapy in intensive care units (ICUs) in the East London region, examining renal function at baseline, hospital discharge and 3-6 months follow-up. We excluded patients who were known to renal services prior to index admission.

RESULTS

From 5,544 critical care admissions, we identified 219 patients who survived to be discharged, having undergone RRT for AKI, that were not previously known to renal services. Of these, 124 (57%) had creatinine measured within 3-6 months after discharge, 104 having a pre-morbid baseline for comparison. Only 26 patients (12%) received specialist nephrology follow-up. At 3-6 months follow-up, the estimated glomerular filtration rate was significantly lower than baseline (48 vs. 60 ml/min/1.73 m(2); p < 0.001), with the prevalence of CKD stage III-V rising from 49 to 70% (p < 0.001).

CONCLUSIONS

Follow-up of patients who required RRT for AKI in ICU is inconsistent despite evidence of a significant increase in the prevalence of CKD. There is strong justification for the development of robust pathways to identify survivors of AKI in order to detect and manage CKD and its complications.

Pathophysiology of ischaemic acute kidney injury

Acute kidney injury is common, dangerous and costly, affecting around one in five patients emergency admissions to hospital. Although survival decreases as disease worsens, it is now apparent that even modest degrees of dysfunction are not only associated with higher mortality but are an independent risk factor for death. This review focuses on the pathophysiology of acute kidney injury secondary to ischaemia - its commonest aetiology. The haemodynamic disturbances, endothelial injury, epithelial cell injury and immunological mechanisms underpinning its initiation and extension will be discussed along with the considerable and complex interplay between these factors that lead to an intense, pro-inflammatory state. Mechanisms of tubular recovery will be discussed but also the pathophysiology of abnormal repair with its direct consequences for long-term renal function. Finally, the concept of 'organ cross-talk' will be introduced as a potential explanation for the higher mortality observed with acute kidney injury that might be deemed modest in conventional biochemical terms.

Does intravenous contrast-enhanced computed tomography cause acute kidney injury? Protocol of a systematic review of the evidence

BACKGROUND

Contrast-induced acute kidney injury is a common cause of iatrogenic acute kidney injury (AKI). Most of the published estimates of AKI after contrast use originate from the cardiac catheterization literature despite contrast-enhanced computed tomography (CT) scans being the more common setting for contrast use. This systematic review aims to summarize the current evidence about (1)the risk of AKI following intravenous (IV) contrast-enhanced CT scans and(2) the risk of clinical outcomes (i.e. death, hospitalization and need for renal replacement therapy) due to IV contrast-enhanced CT scans.

METHODS/DESIGN

A systematic literature search for published studies will be performed using MEDLINE, EMBASE and The COCHRANE Library databases. Unpublished studies will be identified by searching through grey literature. No language restriction will be applied.The review will consider all studies that have examined the association between IV contrast media and AKI. To be selected, the study should include two arms: one group of exposed patients who received IV contrast material before CT scans and one group of unexposed group who did not receive contrast material before CT scans. Two authors will independently screen titles and abstracts obtained from electronic databases, extract data and will assess the quality of the studies selected using the Cochrane's 'Risk of Bias' assessment tool for randomized trials and the Newcastle-Ottawa Scale for observational studies. A random-effects meta-analysis will be performed if there is no remarkable heterogeneity between studies.

DISCUSSION

This systematic review will provide synthesis of current evidence around the effect of IV contrast material on AKI and other clinical outcomes. Results will be helpful for making evidence-based recommendations and guidelines for clinical and radiologic settings.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42013003799.

Summary of clinical practice guidelines for acute kidney injury

Clinical practice guidelines are intended to standardize the diagnosis and treatment of diseases in order to improve both patient outcomes and resource utilization, using evidence-based criteria. As recently as a decade ago, there was no agreed upon definition of acute kidney injury (AKI), making it difficult to conduct proper clinical studies on the epidemiology and treatment of the disorder. Following the advent of the Risk, Injury, Failure, Loss, and End-stage (RIFLE) criteria for defining AKI, several guidelines for the diagnosis and management of AKI have been developed. In our review, we present a narrative description and comparison of the major published guidelines. Overall, there has been significant agreement among the various guidelines, and each seems well-reasoned and clinically useful. Perhaps the most striking conclusion upon review of the various guidelines is the limited scope of knowledge about optimal management of patients with AKI.

Prevention, detection and management of acute kidney injury: concise guideline

Acute kidney injury (AKI) is considered a silent disease that commonly occurs in patients with acute illness; however, given that it has few specific symptoms and signs in its early stages, detection can be delayed. AKI can also occur in patients with no obvious acute illness or secondary to more rare causes. In both these scenarios, patients are often under the care of specialists outside of nephrology, who might fail to detect that AKI is developing and might not be familiar with its optimum management. Therefore, there is a need to increase the awareness of AKI among many different healthcare specialists. In this article, we summarise the key recommendations from the National Institute for Health and Care Excellence (NICE) AKI guideline. The guideline provides recommendations for adult and paediatric patients on the prevention, early detection and management of AKI, as well as information on AKI and sources of support. Implementation of this guideline will contribute to improving patient safety and saving lives.

Incidence, outcomes, and comparisons across definitions of AKI in hospitalized individuals

BACKGROUND AND OBJECTIVES

At least four definitions of AKI have recently been proposed. This study sought to characterize the epidemiology of AKI according to the most recent consensus definition proposed by the Kidney Disease Improving Global Outcomes (KDIGO) Work Group, and to compare it with three other definitions.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a retrospective cohort study of 31,970 hospitalizations at an academic medical center in 2010. AKI was defined and staged according to KDIGO criteria, the Acute Dialysis Quality Initiative's RIFLE criteria, the Acute Kidney Injury Network (AKIN) criteria, and a definition based on a model of creatinine kinetics (CK). Outcomes of interest were incidence, in-hospital mortality, length of stay, costs, readmission rates, and posthospitalization disposition.

RESULTS

AKI incidence was highest according to the KDIGO definition (18.3%) followed by the AKIN (16.6%), RIFLE (16.1%), and CK (7.0%) definitions. AKI incidence appeared markedly higher in those with low baseline serum creatinine according to the KDIGO, AKIN, and RIFLE definitions, in which AKI may be defined by a 50% increase over baseline. AKI according to all definitions was associated with a significantly higher risk of death and higher resource utilization. The adjusted odds ratios for in-hospital mortality in those with AKI were highest with the CK definition (5.2; 95% confidence interval [95% CI], 4.1 to 6.6), followed by the RIFLE (2.9; 95% CI, 2.2 to 3.6), KDIGO (2.8; 95% CI, 2.2 to 3.6), and AKIN (2.6; 95% CI, 2.0 to 3.3) definitions. Concordance in diagnosis and staging was high among the KDIGO, AKIN, and RIFLE definitions.

CONCLUSIONS

The incidence of AKI in hospitalized individuals varies depending on the definition used. AKI according to all definitions is associated with higher in-hospital mortality and resource utilization. AKI may be inappropriately diagnosed in those with low baseline serum creatinine using definitions that incorporate percentage increases over baseline.

Adherence to a healthy lifestyle and all-cause mortality in CKD

BACKGROUND AND OBJECTIVE

Among general populations, a healthy lifestyle has been associated with lower risk of death. This study evaluated this association in individuals with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 2288 participants with CKD (estimated GFR < 60 ml/min per 1.73 m(2) or microalbuminuria) in the Third National Health and Nutrition Examination Survey were included. A weighted healthy lifestyle score was calculated (range, -4 to 15, with 15 indicating healthiest lifestyle) on the basis of the multivariable Cox proportional hazards model regression coefficients of the following lifestyle factors: smoking habit, body mass index (BMI), physical activity, and diet. Main outcome was all-cause mortality, ascertained through December 31, 2006.

RESULTS

After median follow-up of 13 years, 1319 participants had died. Compared with individuals in the lowest quartile of weighted healthy lifestyle score, adjusted hazard ratios (95% confidence intervals) of all-cause mortality were 0.53 (0.41-0.68), 0.52 (0.42-0.63), and 0.47 (0.38-0.60) for individuals in the second, third, and fourth quartiles, respectively. Mortality increased 30% among individuals with a BMI of 18.5 to <22 kg/m(2) versus 22 to <25 kg/m(2) (P<0.05); decreased mortality was associated with never-smoking versus current smoking (0.54 [0.41-0.70]) and regular versus no physical activity (0.80 [0.65-0.99]). Diet was not significantly associated with mortality.

CONCLUSIONS

Compared with nonadherence, adherence to a healthy lifestyle was associated with lower all-cause mortality risk in CKD. Examination of individual components of the healthy lifestyle score, with adjustment for other components, suggested that the greatest reduction in all-cause mortality was related to nonsmoking.

Hemodialysis adequacy and the hospitalized end-stage renal disease patient--raising awareness

Assessment of hemodialysis adequacy may require different approaches for the stable, outpatient with end-stage renal disease (ESRD) and for the sick, inpatient with acute kidney injury (AKI). Variability of urea distribution volume, urea generation, and treatment schedule, for instance, complicates dialysis dosing in the latter group although progress has been made in our understanding of their needs. There is a third population, however, for whom hemodialysis dosing requirements remain unclear--the hospitalized ESRD patient. This commentary discusses the key urea kinetic differences between stable ESRD and AKI to give the context to where, on the intervening spectrum, the hospitalized ESRD patient might lie. The limited literature examining hemodialysis dosing in this population is discussed along with those outstanding questions that might form the basis of a future research agenda.

Preoperative geriatric assessment: comprehensive, multidisciplinary and proactive

With the changing global demographic pattern, our health care systems increasingly have to deal with a greater number of elderly patients, which consequently also takes its toll on our surgical services. The elderly are not simply older adults. They represent a heterogeneous branch of the population with specific physiological, psychological, functional and social issues that require individualised attention prior to surgery. Increased acknowledgement that chronological age alone is not an exclusion criterion, along with advances in surgical and anaesthetic techniques have today lead to decreased reluctance to deny the elderly surgical treatment. In order to ensure a safe perioperative period, we believe that a comprehensive, multidisciplinary and proactive preoperative assessment will be helpful to detect the multiple risk factors and comorbidities common in older patients, to assess functional status and simultaneously allow room for early preoperative interventions and planning of the intra- and postoperative period. In this review we outline the currently available preoperative geriatric risk assessment tools and provide an insight on how a comprehensive, multidisciplinary and proactive approach can help improve perioperative outcome.

Hemofiltration or hemodialysis for acute kidney injury?

The optimal choice of modality for acute renal replacement therapy is unclear at present. Diffusive therapy (hemodialysis) removes small solutes mainly, whereas convective therapies (hemofiltration and hemodiafiltration) may also eliminate larger molecules such as myoglobin or cytokines. Conversely, convective therapies might predispose patients to filter clotting and thus increased costs. A systematic review and meta-analysis of clinical trials could not find evidence for clinical benefits of either modality. Thus, the decision on renal replacement therapy modality still is based on the clinical status of the individual patient, the expertise of the medical and nursing staff, and local circumstances and availability.

Acute kidney injury: top ten tips

Acute kidney injury (AKI) is associated with increased patient morbidity and mortality, and represents a significant financial burden for the NHS. The National Confidential Enquiry into Patient Outcomes and Death (NCEPOD)'s report, Adding insult to injury, demonstrated that only 50% of patients who died from AKI received good care and 30% of patients had predictable and avoidable AKI. It is therefore essential to identify patients at risk of AKI early and to treat patients who develop it promptly. This article proposes how this may be achieved by highlighting ten top tips that describe the points along the patient pathway where it is possible to intervene and prevent or treat AKI. The tips emphasise the importance of good basic medical care and the need for engagement with patients, healthcare professionals and hospital processes. The implementation of these tips in hospitals across the UK could potentially improve patient outcomes and reduce associated costs.

Diagnosis and management of acute kidney injury: deficiencies in the knowledge base of non-specialist, trainee medical staff

Enhanced education has been recommended to improve non-specialist management of acute kidney injury (AKI). However, the extent of any gaps in knowledge has yet to be defined fully. The aim of this study was to assess understanding of trainee doctors in the prevention, diagnosis and initial management of AKI. An anonymised questionnaire was completed by hospital-based trainees across Newcastle Renal Unit's catchment area. Responses were evaluated against a panel of pre-defined ideal answers. The median score was 9.5 out of 20 (n = 146; range 0-17) and was lower in more junior trainees. Fifty percent of trainees could not define AKI, 30% could not name more than two risk factors for AKI and 37% could not name even one indication for renal referral. These serious gaps in knowledge highlight the need for enhanced education aimed at all training grades. Organisational changes may also be required to optimise patient safety.

Invited manuscript poster on renal-related education American Society of Nephrology, Nov. 16-21, 2010. Do medical trainees receive adequate training in the management of acute kidney injury?

There has been increased interest in acute kidney injury (AKI) over the past decade following the recognition of the association of relatively small rises in serum creatinine with worse patient outcomes. This association has resulted in newly proposed definitions in AKI based on changes in serum creatinine. In 2009, the National Confidential Enquiry into Patient Outcomes and Death Adding Insult to Injury AKI study reported that only 50% of patients who died with a diagnosis of AKI received good care. The study identified multiple deficiencies and made a number of recommendations which included improving the training of undergraduate and postgraduate trainees in the management of AKI. The aim of the evaluation was to try and identify the perception of medical trainees in Leeds Teaching Hospitals of the training they had received on AKI. A simple questionnaire was used and captured the views of 73 trainees (including 13 final-year medical students). The evaluation indicated that the majority of trainees were unaware of newly proposed definitions of AKI, and many trainees felt that the training they had received in AKI was inadequate for their needs. Following this evaluation, we have made a number of changes to the training that is delivered to both undergraduate and postgraduate trainees in Leeds on the management of AKI.

Detection of patients with acute kidney injury by the clinical laboratory using rises in serum creatinine: comparison of proposed definitions and a laboratory delta check

BACKGROUND

Timely detection of acute kidney injury (AKI) in hospital patients has been hampered by the multiple definitions of AKI and difficulties applying their criteria. A laboratory delta check may provide an effective means of detecting patients developing AKI. This study compared three of the proposed AKI definitions and a delta check to detect AKI using serum creatinine results of hospital inpatients.

METHODS

Serum creatinine results for 2822 inpatients were gathered retrospectively from the clinical biochemistry database. All serum creatinine results within 30 d of admission were included for each patient and assessed for AKI according to four criteria: Risk, Injury, Failure (RIFLE), Acute Kidney Injury Network (AKIN), Waikar & Bonventre or a delta check (increase of >26 μmol/L between two successive values).

RESULTS

A total of 149 (11.3%) patients were defined as having AKI by at least one of the four criteria. Different populations of patients were identified by each criterion. The number of patients identified and the incidence of AKI were as follows: RIFLE 94 (7.1%), AKIN 125 (9.5%), Waikar & Bonventre 100 (7.6%) and delta check 146 (11.1%). The delta check detected 132 (98%) of all 135 cases detected by the other three criteria. A further 14 patients were detected solely by the delta check.

CONCLUSIONS

The different definitions proposed for AKI detect different populations of patients. A laboratory delta check detected 98% of all the patients identified by AKIN, RIFLE and Waikar & Bonventre combined and could therefore provide a practical way of detecting AKI patients.