Laboratory test surveillance following acute kidney injury

Assessing trends and variability in outpatient dual testing for chronic kidney disease with urine albumin and serum creatinine, 2009-2018: a retrospective cohort study in the Veterans Health Administration System

BACKGROUND

Simultaneous urine testing for albumin (UAlb) and serum creatinine (SCr), that is, 'dual testing,' is an accepted quality measure in the management of diabetes. As chronic kidney disease (CKD) is defined by both UAlb and SCr testing, this approach could be more widely adopted in kidney care.

OBJECTIVE

We assessed time trends and facility-level variation in the performance of outpatient dual testing in the integrated Veterans Health Administration (VHA) system.

DESIGN, SUBJECTS AND MAIN MEASURES

This retrospective cohort study included patients with any inpatient or outpatient visit to the VHA system during the period 2009-2018. Dual testing was defined as UAlb and SCr testing in the outpatient setting within a calendar year. We assessed time trends in dual testing by demographics, comorbidities, high-risk (eg, diabetes) specialty care and facilities. A generalised linear mixed-effects model was applied to explore individual and facility-level predictors of receiving dual testing.

KEY RESULTS

We analysed data from approximately 6.9 million veterans per year. Dual testing increased, on average, from 17.4% to 21.2%, but varied substantially among VHA centres (0.3%-43.7% in 2018). Dual testing was strongly associated with diabetes (OR 10.4, 95% CI 10.3 to 10.5, p<0.0001) and not associated with VHA centre complexity level. However, among patients with high-risk conditions including diabetes, <50% received dual testing in any given year. As compared with white veterans, black veterans were less likely to be tested after adjusting for other individual and facility characteristics (OR 0.93, 95% CI 0.92 to 0.93, p<0.0001).

CONCLUSIONS

Dual testing for CKD in high-risk specialties is increasing but remains low. This appears primarily due to low rates of testing for albuminuria. Promoting dual testing in high-risk patients will help to improve disease management and patient outcomes.

Intraoperative hypotension is associated with persistent acute kidney disease after noncardiac surgery: a multicentre cohort study

BACKGROUND

Whilst intraoperative hypotension is associated with postoperative acute kidney injury (AKI), the link between intraoperative hypotension and acute kidney disease (AKD), defined as continuing renal dysfunction for up to 3 months after exposure, has not yet been studied.

METHODS

We conducted a retrospective multicentre cohort study using data from noncardiac, non-obstetric surgery extracted from a US electronic health records database. Primary outcome was the association between intraoperative hypotension, at three MAP thresholds (≤75, ≤65, and ≤55 mm Hg), and the following two AKD subtypes: (i) persistent (initial AKI incidence within 7 days of surgery, with continuation between 8 and 90 days post-surgery) and (ii) delayed (renal impairment without AKI within 7 days, with AKI occurring between 8 and 90 days post-surgery). Secondary outcomes included healthcare resource utilisation for patients with either AKD subtype or no AKD.

RESULTS

A total of 112 912 surgeries qualified for the study. We observed a rate of 2.2% for delayed AKD and 0.6% for persistent AKD. Intraoperative hypotension was significantly associated with persistent AKD at MAP ≤55 mm Hg (hazard ratio 1.1; 95% confidence interval: 1.38-1.22; P<0.004). However, IOH was not significantly associated with delayed AKD across any of the MAP thresholds. Patients with delayed or persistent AKD had higher healthcare resource utilisation across both hospital and intensive care admissions, compared with patients with no AKD.

CONCLUSIONS

Intraoperative hypotension is associated with persistent but not delayed acute kidney disease. Both types of acute kidney disease appear to be associated with increased healthcare utilisation. Correction of intraoperative hypotension is a potential opportunity to decrease postoperative kidney injury and associated costs.

Tumor lysis syndrome, acute kidney injury and disease-free survival in critically ill patients requiring urgent chemotherapy

Background

Tumor lysis syndrome (TLS) is a life-threatening complication during the treatment of malignant neoplasia. We sought to describe characteristics and predictors of acute kidney injury (AKI), remission and mortality in high-risk TLS patients. In this retrospective monocentric study, we included all patients with the diagnosis of biological and/or clinical TLS from 2012 to 2018. The primary outcome was the prevalence of AKI during the acute phase of TLS. Secondary outcomes were overall mortality and remission of the underlying malignancy at 1 year.

Results

Among 153 patients with TLS, 123 (80.4%) patients experienced AKI and 83 (54.2%) required renal replacement therapy. mSOFA score (OR = 1.15, IC 95% [1.02–1.34]), age (OR = 1.05, IC 95% [1.02–1.08]) and male gender (OR = 6.79, IC 95% [2.59–19.44]) were associated with AKI. Rasburicase use (HR = 2.45, IC 95% [1.17–5.15]) was associated with remission of the underlying malignancy at 1 year. Parameters associated with mortality at 1 year were mechanical ventilation (HR = 1.96, IC 95% [1.02–3.78]), vasopressors (HR = 3.13, IC 95% [1.59–6.15]), age (HR = 1.02, IC 95% [1–1.03]), spontaneous TLS (HR = 1.65, IC 95% [1.01–2.69]) and delay of chemotherapy administration (HR = 1.01, IC 95% [1–1.03]).

Conclusions

AKI is highly prevalent in TLS patients. Rasburicase is associated with better outcomes regarding remission of the underlying malignancy. As rasburicase may be an indirect marker of a high degree of tumor lysis and chemosensitivity, more studies are warranted to confirm the protective role of urate oxidase. Delaying chemotherapy may be deleterious in terms of long-term outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-00990-1.

Discharge Documentation and Follow-Up of Critically Ill Patients With Acute Kidney Injury Treated With Kidney Replacement Therapy: A Retrospective Cohort Study

Leading organisations recommend follow-up of acute kidney injury (AKI) survivors, as these patients are at risk of long-term complications and increased mortality. Information transfer between specialties and from tertiary to primary care is essential to ensure timely and appropriate follow-up. Our aim was to examine the association between completeness of discharge documentation and subsequent follow-up of AKI survivors who received kidney replacement therapy (KRT) in the Intensive Care Unit (ICU). We retrospectively analysed the data of 433 patients who had KRT for AKI during ICU admission in a tertiary care centre in the UK between June 2017 and May 2018 and identified patients who were discharged from hospital alive. Patients with pre-existing end-stage kidney disease and patients who were transferred from hospitals outside the catchment area were excluded. The primary objective was to assess the completeness of discharge documentation from critical care and hospital; secondary objectives were to determine cardiovascular medications reconciliation after AKI, and to investigate kidney care and outcomes at 1 year. The development of AKI and the need for KRT were mentioned in 85 and 82% of critical care discharge letters, respectively. Monitoring of kidney function post-discharge was recommended in 51.6% of critical care and 36.3% of hospital discharge summaries. Among 35 patients who were prescribed renin-angiotensin-aldosterone system inhibitors before hospitalisation, 15 (42.9%) were not re-started before discharge from hospital. At 3 months, creatinine and urine protein were measured in 88.2 and 11.8% of survivors, respectively. The prevalence of chronic kidney disease stage III or worse increased from 27.2% pre-hospitalisation to 54.9% at 1 year (p < 0.001). Our data demonstrate that discharge summaries of patients with AKI who received KRT lacked essential information. Furthermore, even in patients with appropriate documentation, renal follow-up was poor suggesting the need for more education and streamlined care pathways.

Survival and kidney recovery among recipients of continuous renal replacement therapy

Continuous renal replacement therapy (CRRT) is widely used in the care of critically ill patients with acute kidney injury (AKI). Despite hopeful trends suggested by recent studies, mortality among CRRT recipients with severe AKI remains extremely high. Moreover, CRRT does not confer a reduction in mortality in trials comparing CRRT to intermittent RRT modalities. Among AKI survivors, some preliminary studies suggest a higher likelihood of kidney recovery and dialysis independence in CRRT recipients. AKI survivors are at risk for a broad array of adverse outcomes; strategies that may mitigate these risks are discussed.

Nomenclature and diagnostic criteria for acute kidney injury - 2020 consensus of the Taiwan AKI-task force

Acute kidney injury (AKI) is a common syndrome that has a significant impact on prognosis in various clinical settings. To evaluate whether new evidence supports changing the current definition/classification/staging systems for AKI suggested by the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guideline, the Taiwan AKI-TASK Force, composed of 64 experts in various disciplines, systematically reviewed the literature and proposed recommendations about the current nomenclature and diagnostic criteria for AKI. The Taiwan Acute Kidney Injury (TW-AKI) Consensus 2020 was established following the principles of evidence-based medicine to investigate topics covered in AKI guidelines. The Taiwan AKI-TASK Force determined that patients with AKI have a higher risk of developing chronic kidney disease, end-stage renal disease, and death. After a comprehensive review, the TASK Force recommended using novel biomarkers, imaging examinations, renal biopsy, and body fluid assessment in the diagnosis of AKI. Clinical issues with regards to the definitions of baseline serum creatinine (sCr) level and renal recovery, as well as the use of biomarkers to predict renal recovery are also discussed in this consensus. Although the present classification systems using sCr and urine output for the diagnosis of AKI are not perfect, there is not enough evidence to change the current criteria in clinical practice. Future research should investigate and clarify the roles of the aforementioned tools in clinical practice for AKI.

Serum Creatinine Monitoring After Acute Kidney Injury in the PICU

OBJECTIVES

It is unknown whether children with acute kidney injury during PICU admission have kidney function monitored after discharge. Objectives: 1) describe postdischarge serum creatinine monitoring after PICU acute kidney injury and 2) determine factors associated with postdischarge serum creatinine monitoring.

DESIGN

Secondary analysis of longitudinal cohort study data.

SETTING

Two PICUs in Montreal and Edmonton, Canada.

PATIENTS

Children (0-18 yr old) surviving PICU admission greater than or equal to 2 days from 2005 to 2011. Exclusions: postcardiac surgery and prior kidney disease. Exposure: acute kidney injury by Kidney Disease: Improving Global Outcomes serum creatinine definition.

INTERVENTIONS

None.

MEASUREMENTS

Primary outcome: postdischarge serum creatinine measured by 90 days, 1 year, and 5-7 years.

SECONDARY OUTCOMES

Healthcare events and nephrology follow-up.

ANALYSIS

Proportions with outcomes; logistic regression to evaluate factors associated with the primary outcome. Kaplan-Meier analysis of time to serum creatinine measurement and healthcare events.

MAIN RESULTS

Of n = 277, 69 (25%) had acute kidney injury; 29/69 (42%), 34/69 (49%), and 51/69 (74%) had serum creatinine measured by 90 days, 1 year, and 5-7 year postdischarge, respectively. Acute kidney injury survivors were more likely to have serum creatinine measured versus nonacute kidney injury survivors at all time points (p ≤ 0.01). Factors associated with 90-day serum creatinine measurement were inpatient nephrology consultation (unadjusted odds ratio [95% CI], 14.9 [1.7-127.0]), stage 2-3 acute kidney injury (adjusted odds ratio, 3.4 [1.1-10.2]), and oncologic admission diagnosis (adjusted odds ratio, 10.0 [1.1-93.5]). A higher proportion of acute kidney injury versus nonacute kidney injury survivors were readmitted by 90 days (25 [36%] vs 44 [21%]; p = 0.01) and 1 year (33 [38%] vs 70 [34%]; p = 0.04). Of 24 acute kidney injury survivors diagnosed with chronic kidney disease or hypertension at 5-7 year follow-up, 16 (67%) had serum creatinine measurement and three (13%) had nephrology follow-up postdischarge.

CONCLUSIONS

Half of PICU acute kidney injury survivors have serum creatinine measured within 1-year postdischarge and follow-up is suboptimal for children developing long-term kidney sequelae. Knowledge translation strategies should emphasize the importance of serum creatinine monitoring after childhood acute kidney injury.

Acute Kidney Disease to Chronic Kidney Disease

Acute kidney injury (AKI) and chronic kidney disease are common interconnected syndromes that represent a public health problem. Acute kidney disease (AKD) is defined as the post-AKI status of acute or subacute kidney damage/dysfunction manifested by persistence of AKI beyond 7 to 90 days after the initial AKI diagnosis. Limited clinical data exist regarding AKD epidemiology but its incidence is observed in ∼25% of AKI survivors. Useful risk-stratification tools to predict risk of AKD and its prognosis are needed. Interventions on fluid management, nephrotoxic exposure, and follow-up care hold promise to ameliorate the burden of AKD and its complications.

The effect of admission and pre-admission serum creatinine as baseline to assess incidence and outcomes of acute kidney injury in acute medical admissions

BACKGROUND

Acute kidney injury (AKI) in hospital-admitted patients is a common complication associated with increased mortality. The diagnosis of AKI relies on the ascertainment of peak increase in serum creatinine (SCr). This study evaluated the incidence of AKI using the increase from mean 7-365 days pre-admission (AKIpre) and admission (AKIadm) SCr levels, and examined the associations of AKI and changes in SCr levels with all-cause mortality.

METHODS

A total of 2436 patients admitted to a tertiary hospital were recruited and followed-up for a median of 47.70 (interquartile range 18.20) months. AKI incidence and severity were defined according to the Kidney Disease: Improving Global Outcomes-AKI Guidelines. Follow-up data were collected from the Hospital Episode Statistics and Office of National Statistics. Mortality was evaluated during a short- (30 days), mid- (1 year) and long-term (4 years) period.

RESULTS

No difference in the AKI rates using AKIpre and AKIadm (12.5% versus 12.2%; P = 0.695) or in the AKI severity (P = 0.261) was evident. Agreement between the two definitions was modest (Kappa-statistic = 0.596, P < 0.001). Patients with AKIpre or AKIadm had increased all-cause mortality compared with those without AKI during all follow-up periods. In fully adjusted regression analysis, AKIpre [hazard ratio (HR) = 2.226, 95% confidence interval (CI) 1.140-4.347; P = 0.027] and AKIadm (HR = 2.105, 95% CI 1.090-4.064; P = 0.027) remained associated with 30-day mortality. Results for the 1- and 4-year periods were similar. Increases of >4.00 μmol/L and >6.06% from pre-admission or >6.00 μmol/L and >17.24% from admission SCr levels presented increased mortality risk during follow-up.

CONCLUSIONS

Use of admission or pre-admission SCr provides similar incidence rates, but they diagnose different sets of patients. Even minor increases in SCr, below those required for the classification of AKI, were associated with increased mortality. These findings can help the clinicians to identify patients at higher risk for adverse outcomes.

Individualized acute kidney injury after care

PURPOSE OF REVIEW

The aim of this study was to summarize the current evidence around the impact of individualizing patient care following an episode of acute kidney injury (AKI) in the ICU.

RECENT FINDINGS

Over the last years, evidence has demonstrated that the follow-up care after episodes of AKI is lacking and standardization of this process is likely needed. Although this is informed largely by large retrospective cohort studies, a few prospective observational trials have been performed. Medication reconciliation and patient/caregiver education are important tenants of follow-up care, regardless of the severity of AKI. There is evidence the initiation and/or reinstitution of renin-angiotensin-aldosterone agents may improve patient's outcomes following AKI, although they may increase the risk for adverse events, especially when reinitiated early. In addition, 3 months after an episode of AKI, serum creatinine and proteinuria evaluation may help identify patients who are likely to develop progressive chronic kidney disease over the ensuing 5 years. Lastly, there are emerging differences between those who do and do not require renal replacement therapy (RRT) for their AKI, which may require more frequent and intense follow-up in those needing RRT.

SUMMARY

Although large scale evidence-based guidelines are lacking, standardization of post-ICU-AKI is needed.

Quality of Care for Acute Kidney Disease: Current Knowledge Gaps and Future Directions

Acute kidney injury (AKI) and acute kidney disease (AKD) are common complications in hospitalized patients and are associated with adverse outcomes. Although consensus guidelines have improved the care of patients with AKI and AKD, guidance regarding quality metrics in the care of patients after an episode of AKI or AKD is limited. For example, few patients receive follow-up laboratory testing of kidney function or post-AKI or AKD care through nephrology or other providers. Recently, the Acute Disease Quality Initiative developed a consensus statement regarding quality improvement goals for patients with AKI or AKD specifically highlighting efforts regarding quality and safety of care after hospital discharge after an episode of AKI or AKD. The goal is to use these measures to identify opportunities for improvement that will positively affect outcomes. We recommend that health care systems quantitate the proportion of patients who need and actually receive follow-up care after the index AKI or AKD hospitalization. The intensity and appropriateness of follow-up care should depend on patient characteristics, severity, duration, and course of AKI of AKD, and should evolve as evidence-based guidelines emerge. Quality indicators for discharged patients with dialysis requiring AKI or AKD should be distinct from end-stage renal disease measures. Besides, there should be specific quality indicators for those still requiring dialysis in the outpatient setting after AKI or AKD. Given the limited preexisting data guiding the care of patients after an episode of AKI or AKD, there is ample opportunity to establish quality measures and potentially improve patient care and outcomes. This review will provide specific evidence-based and expert opinion–based guidance for the care of patients with AKI or AKD after hospital discharge.

Post-Acute Kidney Injury Proteinuria and Subsequent Kidney Disease Progression: The Assessment, Serial Evaluation, and Subsequent Sequelae in Acute Kidney Injury (ASSESS-AKI) Study

IMPORTANCE

Among patients who had acute kidney injury (AKI) during hospitalization, there is a need to improve risk prediction such that those at highest risk for subsequent loss of kidney function are identified for appropriate follow-up.

OBJECTIVE

To evaluate the association of post-AKI proteinuria with increased risk of future loss of renal function.

DESIGN, SETTING, AND PARTICIPANTS

The Assessment, Serial Evaluation, and Subsequent Sequelae in Acute Kidney Injury (ASSESS-AKI) Study was a multicenter prospective cohort study including 4 clinical centers in North America included 1538 patients enrolled 3 months after hospital discharge between December 2009 and February 2015.

EXPOSURES

Urine albumin-to-creatinine ratio (ACR) quantified 3 months after hospital discharge.

MAIN OUTCOMES AND MEASURES

Kidney disease progression defined as halving of estimated glomerular filtration rate (eGFR) or end-stage renal disease.

RESULTS

Of the 1538 participants, 769 (50%) had AKI durring hospitalization. The baseline study visit took place at a mean (SD) 91 (23) days after discharge. The mean (SD) age was 65 (13) years; the median eGFR was 68 mL/min/1.73 m2; and the median urine ACR was 15 mg/g. Overall, 547 (37%) study participants were women and 195 (13%) were black. After a median follow-up of 4.7 years, 138 (9%) participants had kidney disease progression. Higher post-AKI urine ACR level was associated with increased risk of kidney disease progression (hazard ratio [HR], 1.53 for each doubling; 95% CI, 1.45-1.62), and urine ACR measurement was a strong discriminator for future kidney disease progression (C statistic, 0.82). The performance of urine ACR was stronger in patients who had had AKI than in those who had not (C statistic, 0.70). A comprehensive model of clinical risk factors (eGFR, blood pressure, and demographics) including ACR provided better discrimination for predicting kidney disease progression after hospital discharge among those who had had AKI (C statistic, 0.85) vs those who had not (C statistic, 0.76). In the entire matched cohort, after taking into account urine ACR, eGFR, demographics, and traditional chronic kidney risk factors determined 3 months after discharge, AKI (HR, 1.46; 95% CI, 0.51-4.13 for AKI vs non-AKI) or severity of AKI (HR, 1.54; 95% CI, 0.50-4.72 for AKI stage 1 vs non-AKI; HR, 0.56; 95% CI, 0.07-4.84 for AKI stage 2 vs non-AKI; HR, 2.24; 95% CI, 0.33-15.29 for AKI stage 3 vs non-AKI) was not independently associated with more rapid kidney disease progression.

CONCLUSIONS AND RELEVANCE

Proteinuria level is a valuable risk-stratification tool in the post-AKI period. These results suggest there should be more widespread and routine quantification of proteinuria after hospitalized AKI.

Acute kidney injury calculated using admission serum creatinine underestimates 30-day and 1-year mortality after acute stroke

BACKGROUND

Acute kidney injury (AKI) diagnosis requires ascertainment of change from a known baseline. Although pre-admission serum creatinine (SCr) is recommended, to date, all studies of AKI in acute stroke have used the first SCr on admission.

METHODS

All patients admitted with an acute stroke to an emergency hospital were recruited. We compared use of pre-admission SCr with admission SCr to diagnose AKI. Regression analyses were used to identify risk factors for 30-day and 1-year mortality, respectively.

RESULTS

A total of 1354 patients were recruited from December 2012 to September 2015. Incidence of AKI was 18.7 and 19.9% using pre-admission SCr and admission SCr, respectively. Diagnosis of AKI was associated with significantly increased 30-day and 1-year mortality. Diagnosis of AKI using pre-admission SCr had a stronger relationship with both 30-day and 1-year mortality. In 443 patients with a pre-admission SCr and at least two SCr during admission, AKI diagnosed using pre-admission SCr had a stronger relationship than AKI diagnosed using admission SCr with 30-day mortality [odds ratio (OR) = 2.64; 95% confidence interval (CI) 1.36-5.12; P = 0.004 versus OR = 2.10; 95% CI 1.09-4.03; P = 0.026] and 1-year mortality [hazard ratio (HR) = 1.90, 95% CI 1.32-2.76; P = 0.001 versus HR = 1.47; 95% CI 1.01-2.15; P = 0.046] in fully adjusted models.

CONCLUSIONS

AKI after stroke is common and is associated with increased 30-day and 1-year mortality. Using first SCr on admission gives a comparable AKI incidence to pre-admission SCr, but underestimates 30-day and 1-year mortality risk.

Long-term risk of adverse outcomes after acute kidney injury: a systematic review and meta-analysis of cohort studies using consensus definitions of exposure

Reliable estimates of the long-term outcomes of acute kidney injury (AKI) are needed to inform clinical practice and guide allocation of health care resources. This systematic review and meta-analysis aimed to quantify the association between AKI and chronic kidney disease (CKD), end-stage kidney disease (ESKD), and death. Systematic searches were performed through EMBASE, MEDLINE, and grey literature sources to identify cohort studies in hospitalized adults that used standardized definitions for AKI, included a non-exposed comparator, and followed patients for at least 1 year. Risk of bias was assessed by the Newcastle-Ottawa Scale. Random effects meta-analyses were performed to pool risk estimates; subgroup, sensitivity, and meta-regression analyses were used to investigate heterogeneity. Of 4973 citations, 82 studies (comprising 2,017,437 participants) were eligible for inclusion. Common sources of bias included incomplete reporting of outcome data, missing biochemical values, and inadequate adjustment for confounders. Individuals with AKI were at increased risk of new or progressive CKD (HR 2.67, 95% CI 1.99-3.58; 17.76 versus 7.59 cases per 100 person-years), ESKD (HR 4.81, 95% CI 3.04-7.62; 0.47 versus 0.08 cases per 100 person-years), and death (HR 1.80, 95% CI 1.61-2.02; 13.19 versus 7.26 deaths per 100 person-years). A gradient of risk across increasing AKI stages was demonstrated for all outcomes. For mortality, the magnitude of risk was also modified by clinical setting, baseline kidney function, diabetes, and coronary heart disease. These findings establish the poor long-term outcomes of AKI while highlighting the importance of injury severity and clinical setting in the estimation of risk.

Mesenchymal Stem Cells Contribute to Improvement of Renal Function in a Canine Kidney Injury Model

BACKGROUND/AIM

The kidney excretes waste materials and regulates important metabolic functions, and renal disorders constitute a significant medical problem and can result in fatalities. In the present study, mesenchymal stem cells derived from canine umbilical cord blood (cUCB-MSCs) were isolated and evaluated for their ability to improve renal function in a canine model of acute kidney injury (AKI).

MATERIALS AND METHODS

The canine AKI model was developed by i.v. injection of cisplatin and gentamycin into 14 male beagle dogs. cUCB-MSCs were administered into the renal corticomedullary junction following AKI induction. Survival time, clinical signs, blood analysis and histological parameters were analyzed.

RESULTS

The group treated with AKI plus cUCB-MSCs had decreased blood urea nitrogen and creatinine levels, and showed an extended life-span and improved histological manifestations. MSCs were detected around the tubules of these kidneys at the histological level.

CONCLUSION

Taken together, our findings suggest that cUCB-MSCs could be an alternative therapeutic agent for canine AKI.

Acute kidney injury is a risk factor for subsequent proteinuria

Acute kidney injury (AKI) is associated with subsequent chronic kidney disease (CKD), but the mechanism is unclear. To clarify this, we examined the association of AKI and new-onset or worsening proteinuria during the 12 months following hospitalization in a national retrospective cohort of United States Veterans hospitalized between 2004-2012. Patients with and without AKI were matched using baseline demographics, comorbidities, proteinuria, estimated glomerular filtration rate, blood pressure, angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (ACEI/ARB) use, and inpatient exposures linked to AKI. The distribution of proteinuria over one year post-discharge in the matched cohort was compared using inverse probability sampling weights. Subgroup analyses were based on diabetes, pre-admission ACEI/ARB use, and AKI severity. Among the 90,614 matched AKI and non-AKI pairs, the median estimated glomerular filtration rate was 62 mL/min/1.73m². The prevalence of diabetes and hypertension were 48% and 78%, respectively. The odds of having one plus or greater dipstick proteinuria was significantly higher during each month of follow-up in patients with AKI than in patients without AKI (odds ratio range 1.20-1.39). Odds were higher in patients with Stage II or III AKI (odds ratios 1.32-1.81) than in Stage I AKI (odds ratios 1.18-1.32), using non-AKI as the reference group. Results were consistent regardless of diabetes status or baseline ACEI/ARB use. Thus, AKI is a risk factor for incident or worsening proteinuria, suggesting a possible mechanism linking AKI and future CKD. The type of proteinuria, physiology, and clinical significance warrant further study as a potentially modifiable risk factor in the pathway from AKI to CKD.

Strategies to Enhance Rehabilitation After Acute Kidney Injury in the Developing World

Acute kidney injury (AKI) is independently associated with new-onset chronic kidney disease (CKD), end-stage kidney disease, cardiovascular disease, and all-cause mortality. However, only a minority of patients receive follow-up care after an episode of AKI in the developing world, and the optimal strategies to promote rehabilitation after AKI are ill-defined. On this background, a working group of the 18th Acute Dialysis Quality Initiative applied the consensus-building process informed by a PubMed review of English-language articles to address questions related to rehabilitation after AKI. The consensus statements propose that all patients should be offered follow-up within 3 months of an AKI episode, with more intense follow-up (e.g., <1 month) considered based on patient risk factors, characteristics of the AKI event, and the degree of kidney recovery. Patients should be monitored for renal and nonrenal events post-AKI, and we suggest that the minimum level of monitoring consist of an assessment of kidney function and proteinuria within 3 months of the AKI episode. Care should be individualized for higher risk patients, particularly patients who are still dialysis dependent, to promote renal recovery. Although evidence-based treatments for survivors of AKI are lacking and some outcomes may not be modifiable, we recommend simple interventions such as lifestyle changes, medication reconciliation, blood pressure control, and education, including the documentation of AKI in the patient’s medical record. In conclusion, survivors of AKI represent a high-risk population, and these consensus statements should provide clinicians with guidance on the care of patients after an episode of AKI.

Follow-up Care in Acute Kidney Injury: Lost in Transition

Acute kidney injury (AKI) is an increasingly common condition that is associated with long-term health outcomes. Recent studies have demonstrated that AKI, particularly when severe or persistent, is associated with all-cause mortality, CKD, ESRD, cardiovascular events, and reduced quality of life. However, data from multiple health care systems indicate that most patients do not see a nephrologist, although 1 study has suggested patients with AKI requiring dialysis may benefit from doing so. These observations raise the greater questions of what are the elements of care that may improve outcomes in survivors of AKI and which survivors need to be seen. Potential opportunities to improve care include appropriate risk stratification, closer monitoring of kidney function, management of CKD complications, blood pressure control, medication reconciliation, and education. Nephrologists are in an ideal position to lead and advocate for outpatient care pathways for survivors of AKI. In this article, we review the evidence supporting patient follow-up after AKI, describe the current state of follow-up care, and examine strategies to improve long-term outcomes for this high-risk population.

Acute kidney disease and renal recovery: consensus report of the Acute Disease Quality Initiative (ADQI) 16 Workgroup

Consensus definitions have been reached for both acute kidney injury (AKI) and chronic kidney disease (CKD) and these definitions are now routinely used in research and clinical practice. The KDIGO guideline defines AKI as an abrupt decrease in kidney function occurring over 7 days or less, whereas CKD is defined by the persistence of kidney disease for a period of >90 days. AKI and CKD are increasingly recognized as related entities and in some instances probably represent a continuum of the disease process. For patients in whom pathophysiologic processes are ongoing, the term acute kidney disease (AKD) has been proposed to define the course of disease after AKI; however, definitions of AKD and strategies for the management of patients with AKD are not currently available. In this consensus statement, the Acute Disease Quality Initiative (ADQI) proposes definitions, staging criteria for AKD, and strategies for the management of affected patients. We also make recommendations for areas of future research, which aim to improve understanding of the underlying processes and improve outcomes for patients with AKD.

Hospital discharge communications during care transitions for patients with acute kidney injury: a cross-sectional study

Background

High quality hospital discharge communications about acute kidney injury (AKI) could facilitate continuity of care after hospital transitions and reduce patients’ post-hospitalization health risks.

Methods

We characterized the presence and quality (10 elements) of written hospital discharge communications (physician discharge summaries and patient instructions) for patients hospitalized with AKI at a single institution in 2012 through medical record review.

Results

In 75 randomly selected hospitalized patients with AKI, fewer than half of physician discharge summaries and patient instructions documented the presence (n = 33, 44 % and n = 10, 13 %, respectively), cause (n = 32, 43 % and n = 1, 1 %, respectively), or course of AKI (n = 23, 31 %, discharge summary only) during hospitalization. Few provided recommendations for treatment and/or observation specific to AKI (n = 11, 15 and 6, 8 % respectively). In multivariable analyses, discharge communications containing information about AKI were most prevalent among patients with AKI Stage 3, followed by patients with Stage 2 and Stage 1 (adjusted percentages (AP) [95 % CI]: 84 % [39–98 %], 43 % [11–82 %], and 24 % [reference], respectively; p trend = 0.008). AKI discharge communications were also more prevalent among patients with known chronic kidney disease (CKD) versus those without (AP [95 % CI]: 92 % [51–99 %] versus 39 % [reference], respectively, p = 0.02) and among patients discharged from medical versus surgical services (AP [95 % CI]: 73 % [33–93 %] versus 23 % [reference], respectively, p = 0.01). Communications featured 4 median quality elements. Quality elements were greater in communications for patients with more severe AKI (Stage 3 (number of additional quality elements (β) [95 % CI]: 2.29 [0.87–3.72]), Stage 2 (β [95 % CI]: 0.62 [−0.65–1.90]) and Stage 1 (reference); p for trend = 0.002).

Conclusions

Few hospital discharge communications in AKI patients described AKI or provided recommendations for AKI care. Improvements in the quality of hospital discharge communications to improve care transitions of patients with AKI are needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-016-1697-7) contains supplementary material, which is available to authorized users.

Improving acute kidney injury diagnostics using predictive analytics

PURPOSE OF REVIEW

Acute kidney injury (AKI) is a multifactorial syndrome affecting an alarming proportion of hospitalized patients. Although early recognition may expedite management, the ability to identify patients at-risk and those suffering real-time injury is inconsistent. The review will summarize the recent reports describing advancements in the area of AKI epidemiology, specifically focusing on risk scoring and predictive analytics.

RECENT FINDINGS

In the critical care population, the primary underlying factors limiting prediction models include an inability to properly account for patient heterogeneity and underperforming metrics used to assess kidney function. Severity of illness scores demonstrate limited AKI predictive performance. Recent evidence suggests traditional methods for detecting AKI may be leveraged and ultimately replaced by newer, more sophisticated analytical tools capable of prediction and identification: risk stratification, novel AKI biomarkers, and clinical information systems. Additionally, the utility of novel biomarkers may be optimized through targeting using patient context, and may provide more granular information about the injury phenotype. Finally, manipulation of the electronic health record allows for real-time recognition of injury.

SUMMARY

Integrating a high-functioning clinical information system with risk stratification methodology and novel biomarker yields a predictive analytic model for AKI diagnostics.

Creatinine-based definitions: from baseline creatinine to serum creatinine adjustment in intensive care

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency medicine 2016. Other selected articles can be found online at http://www.biomedcentral.com/collections/annualupdate2016. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Acute Kidney Injury in the Surgical Patient

Perioperative acute kidney injury (AKI) is a common, morbid, and costly surgical complication. Current efforts to understand and manage AKI in surgical patients focus on prevention, mitigation of further injury when AKI has occurred, treatment of associated conditions, and facilitation of renal recovery. Lesser severity AKI is now understood to be much more common, and more morbid, than was previously thought. The ability to detect AKI within hours of onset would be helpful in protecting the kidney and in preserving renal function, and several imaging and biomarker modalities are currently being evaluated.

Facility variation and predictors of serum potassium monitoring after initiation of a mineralocorticoid receptor antagonist in patients with heart failure

BACKGROUND

Mineralocorticoid receptor antagonists (MRAs) have been shown to reduce morbidity and mortality in patients with heart failure (HF) with reduced ejection fraction but are associated with hyperkalemia. We sought to evaluate the frequency, variation, and predictors associated with serum potassium monitoring in patients with HF initiated on an MRA among facilities in the Veterans Affairs (VA) Health Care System.

METHODS

We performed a retrospective cohort analysis of patients with HF across 133 Veterans Affairs facilities from 2003 to 2013 who were given a new prescription of an MRA. The primary outcome was the mean percentage of patients per facility with serum potassium monitoring within 14 days of MRA dispensing. Univariate and covariate analyses were performed to determine factors associated with monitoring.

RESULTS

There were 142,880 patients identified with HF initiated on an MRA who met the study inclusion and exclusion criteria. The mean (SD) percentage of patients per facility with serum potassium monitoring within 14 days was 41.6% (standard deviation 8.0%; minimum 18.9%, maximum 56.7%). Facilities with a higher frequency of monitoring were associated with membership in the Council on Teaching Hospitals (n = 70, P < .0001), had academic affiliations (n = 100, P < .0001), and a higher annual volume of patients with HF (≥200 patients, P < .0001).

CONCLUSIONS

In a large multicenter national sample of patients with HF receiving a new MRA prescription, the frequency of serum potassium monitoring was below recommended guidelines. Academic facilities and those with a higher volume of patients with HF were associated with an increased frequency of monitoring.

Making sense of health care delivery Where does the close to community health care worker fit in? - The case for congestive heart failure

Close to community health care workers (CTC-HCW) is an increasingly used term to describe the emergence of a new partner in health services delivery. In strengthening arguments for this part of the health workforce the authorities, health staffers, supporters, sceptics and perhaps clients will look to the academicians and the evidence base to determine the fate of this group. There is no doubt, CTC-HCW are a vital resource, whose importance is tied to socio-demo-geographic variables. Regardless of what the common perceptions of its importance are, the evolving evidence base could suggest either way. In this short commentary we would like to highlight the importance of a balanced and common sense approach in these arguments. An important example is heart failure where the majority have an associated comorbidity and one in four would also suffer with cognitive or mood disturbances. It is unclear how the CTC-HCW would fare for this devastating syndrome. In moving forward it is important we understand there are: strengths and limitations in the evidence gathering processes; indecision as to the questions; uncertainty of the starting points to gather evidence; and sociodemogeographic biases, which have to be factored before determining the fate of this much needed health care resource.