Renal angina: an emerging paradigm to identify children at risk for acute kidney injury

Cardiac biomarkers and acute kidney injury after cardiac surgery

OBJECTIVES

To examine the relationship of cardiac biomarkers with postoperative acute kidney injury (AKI) among pediatric patients undergoing cardiac surgery.

METHODS

Data from TRIBE-AKI, a prospective study of children undergoing cardiac surgery, were used to examine the association of cardiac biomarkers (N-type pro-B-type natriuretic peptide, creatine kinase-MB [CK-MB], heart-type fatty acid binding protein [h-FABP], and troponins I and T) with the development of postoperative AKI. Cardiac biomarkers were collected before and 0 to 6 hours after surgery. AKI was defined as a ≥ 50% or 0.3 mg/dL increase in serum creatinine, within 7 days of surgery.

RESULTS

Of the 106 patients included in this study, 55 (52%) developed AKI after cardiac surgery. Patients who developed AKI had higher median levels of pre- and postoperative cardiac biomarkers compared with patients without AKI (all P < .01). Preoperatively, higher levels of CK-MB and h-FABP were associated with increased odds of developing AKI (CK-MB: adjusted odds ratio 4.58, 95% confidence interval [CI] 1.56-13.41; h-FABP: adjusted odds ratio 2.76, 95% CI 1.27-6.03). When combined with clinical models, both preoperative CK-MB and h-FABP provided good discrimination (area under the curve 0.77, 95% CI 0.68-0.87, and 0.78, 95% CI 0.68-0.87, respectively) and improved reclassification indices. Cardiac biomarkers collected postoperatively did not significantly improve the prediction of AKI beyond clinical models.

CONCLUSIONS

Preoperative CK-MB and h-FABP are associated with increased risk of postoperative AKI and provide good discrimination of patients who develop AKI. These biomarkers may be useful for risk stratifying patients undergoing cardiac surgery.

Anti-inflammatory effects of triptolide in LPS-induced acute lung injury in mice

Triptolide is one of the main active components of Chinese herb Tripterygium wilfordii Hook F, which has been demonstrated to have anti-inflammatory properties. The aim of this study was to investigate the effects of triptolide on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and to clarify the possible mechanisms. Mice were administered intranasally with LPS to induce lung injury. Triptolide was administered intraperitoneally 1 h before LPS challenge. Triptolide-treated mice exhibited significantly reduced leukocyte, myeloperoxidase (MPO) activity, edema of the lung, as well as TNF-α, IL-1β, and IL-6 production in the bronchoalveolar lavage fluid compared with LPS-treated mice. Additionally, Western blot analysis showed that triptolide inhibited the phosphorylation of inhibitor-kappa B kinase-alpha (IκB-α), p65, nuclear factor kappa B (NF-κB), p38, extracellular receptor kinase (ERK), and Jun N-terminal kinase (JNK) and the expression of Toll-like receptor 4 (TLR4) caused by LPS. In conclusion, our results suggested that the promising anti-inflammatory mechanism of triptolide may be that triptolide activates peroxisome proliferation-activated receptor gamma (PPAR-γ), thereby attenuating an LPS-induced inflammatory response. Triptolide may be a promising potential therapeutic reagent for ALI treatment.

Assessment of Worldwide Acute Kidney Injury, Renal Angina and Epidemiology in critically ill children (AWARE): study protocol for a prospective observational study

Background

Acute kidney injury (AKI) is associated with poor outcome in critically ill children. While data extracted from retrospective study of pediatric populations demonstrate a high incidence of AKI, the literature lacks focused and comprehensive multicenter studies describing AKI risk factors, epidemiology, and outcome. Additionally, very few pediatric studies have examined novel urinary biomarkers outside of the cardiopulmonary bypass population.

Methods/Design

This is a prospective observational study. We anticipate collecting data on over 5000 critically ill children admitted to 31 pediatric intensive care units (PICUs) across the world during the calendar year of 2014. Data will be collected for seven days on all children older than 90 days and younger than 25 years without baseline stage 5 chronic kidney disease, chronic renal replacement therapy, and outside of 90 days of a kidney transplant or from surgical correction of congenital heart disease. Data to be collected includes demographic information, admission diagnoses and co-morbidities, and details on fluid and vasoactive resuscitation used. The renal angina index will be calculated integrating risk factors and early changes in serum creatinine and fluid overload. On days 2–7, all hemodynamic and pertinent laboratory values will be captured focusing on AKI pertinent values. Daily calculated values will include % fluid overload, fluid corrected creatinine, and KDIGO AKI stage. Urine will be captured twice daily for biomarker analysis on Days 0–3 of admission. Biomarkers to be measured include neutrophil gelatinase lipocalin (NGAL), kidney injury molecule-1 (KIM-1), liver-type fatty acid binding protein (l-FABP), and interleukin-18 (IL-18). The primary outcome to be quantified is incidence rate of severe AKI on Day 3 (Day 3 – AKI). Prediction of Day 3 – AKI by the RAI and after incorporation of biomarkers with RAI will be analyzed.

Discussion

The Assessment of Worldwide Acute Kidney Injury, Renal Angina and Epidemiology (AWARE) study, creates the first prospective international pediatric all cause AKI data warehouse and biologic sample repository, providing a broad and invaluable resource for critical care nephrologists seeking to study risk factors, prediction, identification, and treatment options for a disease syndrome with high associated morbidity affecting a significant proportion of hospitalized children.

Trial registration

ClinicalTrials.gov: NCT01987921

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0016-6) contains supplementary material, which is available to authorized users.

Fluid overload in a South African pediatric intensive care unit

OBJECTIVE

Fluid resuscitation is integral to resuscitation guidelines and critical care. However, fluid overload (FO) yields increased morbidity.

METHODS

Prospective observational study of Red Cross War Memorial Children's Hospital pediatric intensive care unit admissions (February to March 2013). FO % = (fluid in minus fluid out) [liters]/weight [kg] × 100%.

PRIMARY OUTCOMES

FO ≥ 10%, 28 day mortality.

RESULTS

Median [interquartile range (IQR)] age: 9.5 (2.0-39.0) months, median (IQR) admission weight: 7.9 (3.6-13.7) kg. Median (IQR) FO with admission weight: 3.5 (2.1-4.9)%; three patients had FO ≥ 10%. The 28 day mortality was 10% (n = 10). Patients who died had higher mean (IQR) FO using admission weight [4.9 (2.9-9.3)% vs. 3.4 (1.9-4.8)%; p = 0.04].

CONCLUSIONS

Low FO ≥ 10% prevalence with 28 day mortality 10%. Higher FO% with admission weight associated with mortality (p = 0.04). We advocate further investigation of FO% as a simple bedside tool.

Biology of sepsis: its relevance to pediatric nephrology

Because of its multi-organ involvement, the syndrome of sepsis provides clinical challenges to a wide variety of health care providers. While multi-organ dysfunction triggered by sepsis requires general supportive critical care provided by intensivists, the impact of sepsis on renal function and the ability of renal replacement therapies to modulate its biologic consequences provide a significant opportunity for pediatric nephrologists and related care providers to impact outcomes. In this review, we aim to highlight newer areas of understanding of the pathobiology of sepsis with special emphasis on those aspects of particular interest to pediatric nephrology. As such, we aim to: (1) review the definition of sepsis and discuss advances in our mechanistic understanding of sepsis; (2) review current hypotheses regarding sepsis-induced acute kidney injury (AKI) and describe its epidemiology based on evolving definitions of AKI; (3) review the impact of renal failure on the immune system, highlighting the sepsis risk in this cohort and strategies that might minimize this risk; (4) review how renal replacement therapeutic strategies may impact sepsis-induced AKI outcomes. By focusing the review on these specific areas, we have omitted other important areas of the biology of sepsis and additional interactions with renal function from this discussion; however, we have aimed to provide a comprehensive list of references that provide contemporary reviews of these additional areas.

Acute kidney injury: global health alert

Acute kidney injury (AKI) is increasingly prevalent in developing and developed countries and is associated with severe morbidity and mortality. Most etiologies of AKI can be prevented by interventions at the individual, community, regional and in-hospital levels. Effective measures must include community-wide efforts to increase an awareness of the devastating effects of AKI and provide guidance on preventive strategies, as well as early recognition and management. Efforts should be focused on minimizing causes of AKI, increasing awareness of the importance of serial measurements of serum creatinine in high risk patients, and documenting urine volume in acutely ill people to achieve early diagnosis; there is as yet no definitive role for alternative biomarkers. Protocols need to be developed to systematically manage prerenal conditions and specific infections. More accurate data about the true incidence and clinical impact of AKI will help to raise the importance of the disease in the community, increase awareness of AKI by governments, the public, general and family physicians and other health care professionals to help prevent the disease. Prevention is the key to avoid the heavy burden of mortality and morbidity associated with AKI.

Neutrophil gelatinase-associated lipocalin: ready for routine clinical use? An international perspective

Acute kidney injury (AKI) remains a challenge in terms of diagnosis and classification, its morbidity and mortality remaining high in the face of improving clinical protocols. Current clinical criteria use serum creatinine (sCr) and urine output to classify patients. Ongoing research has identified novel biomarkers that may improve the speed and accuracy of patient evaluation and prognostication, yet the route from basic science to clinical practice remains poorly paved. International evidence supporting the use of plasma neutrophil gelatinase-associated lipocalin (NGAL) as a valuable biomarker of AKI and chronic kidney disease (CKD) for a number of clinical scenarios was presented at the 31st International Vicenza Course on Critical Care Nephrology, and these data are detailed in this review. NGAL was shown to be highly useful alongside sCr, urinary output, and other biomarkers in assessing kidney injury; in patient stratification and continuous renal replacement therapy (CRRT) selection in paediatric AKI; in assessing kidney injury in conjunction with sCr in sepsis; in guiding resuscitation protocols in conjunction with brain natriuretic peptide in burn patients; as an early biomarker of delayed graft function and calcineurin inhibitor nephrotoxicity in kidney transplantation from extended criteria donors; as a biomarker of cardiovascular disease and heart failure, and in guiding CRRT selection in the intensive care unit and emergency department. While some applications require further clarification by way of larger randomised controlled trials, NGAL nevertheless demonstrates promise as an independent biological marker with the potential to improve earlier diagnosis and better assessment of risk groups in AKI and CKD. This is a critical element in formulating quick and accurate decisions for individual patients, both in acute scenarios and in long-term care, in order to improve patient prognostics and outcomes.

Derivation of urine output thresholds that identify a very high risk of AKI in patients with septic shock

BACKGROUND AND OBJECTIVES

To promote early detection of AKI, recently proposed pretest probability models combine sub-Kidney Disease Improving Global Outcomes (KDIGO) AKI criteria with baseline AKI risk. The primary objective of this study was to determine sub-KDIGO thresholds that identify patients with septic shock at highest risk for AKI.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a retrospective analysis of 390 adult patients admitted to the medical intensive care unit (ICU) of a tertiary, academic medical center with septic shock between January 2008 and December 2010. Hourly urine output was collected from the time of septic shock recognition (hour 0) to hour 96, urine catheter removal, or ICU discharge (whichever occurred first). All available serum creatinine (SCr) measurements were collected until hour 96. The AKI pretest probability model was assessed during the first 12 hours of resuscitation and included the initial episode of oliguria, increase from baseline to peak SCr level, and Acute Physiology and Chronic Health Evaluation (APACHE) III score in a multivariable receiver-operator characteristic (ROC) analysis. The primary outcome was the incidence of stage II or III (stage II+) AKI defined by KDIGO criteria. Secondary outcomes included the need for RRT and 28-day mortality.

RESULTS

Ninety-eight (25%) patients developed stage II+ AKI after septic shock recognition. APACHE III score and increase in SCr level in the first 12 hours were not statistically associated with stage II+ AKI in multivariable ROC analysis. Consecutive oliguria for 3 hours had fair predictive ability for achieving stage II+ AKI criteria (area under ROC curve, 0.73; 95% confidence interval [95% CI], 0.68 to 0.78), and oliguria for 5 hours demonstrated optimal accuracy (82%; 95% CI, 79% to 86%).

CONCLUSIONS

Three to 5 hours of consecutive oliguria in patients with septic shock may provide a valuable measure of AKI risk. Further validation to support this finding is needed.

Utilization of small changes in serum creatinine with clinical risk factors to assess the risk of AKI in critically lll adults

BACKGROUND AND OBJECTIVES

Disease biomarkers require appropriate clinical context to be used effectively. Combining clinical risk factors, in addition to small changes in serum creatinine, has been proposed to improve the assessment of AKI. This notion was developed in order to identify the risk of AKI early in a patient's clinical course. We set out to assess the performance of this combination approach.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A secondary analysis of data from a prospective multicenter intensive care unit cohort study (September 2009 to April 2010) was performed. Patients at high risk using this combination approach were defined as an early increase in serum creatinine of 0.1-0.4 mg/dl, depending on number of clinical factors predisposing to AKI. AKI was defined and staged using the Acute Kidney Injury Network criteria. The primary outcome was evolution to severe AKI (Acute Kidney Injury Network stages 2 and 3) within 7 days in the intensive care unit.

RESULTS

Of 506 patients, 214 (42.2%) patients had early creatinine elevation and were deemed at high risk for AKI. This group was more likely to subsequently develop the primary endpoint (16.4% versus 1.0% [not at high risk], P<0.001). The sensitivity of this grouping for severe AKI was 92%, the specificity was 62%, the positive predictive value was 16%, and the negative predictive value was 99%. After adjustment for Sequential Organ Failure Assessment score, serum creatinine, and hazard tier for AKI, early creatinine elevation remained an independent predictor for severe AKI (adjusted relative risk, 12.86; 95% confidence interval, 3.52 to 46.97). Addition of early creatinine elevation to the best clinical model improved prediction of the primary outcome (area under the receiver operating characteristic curve increased from 0.75 to 0.83, P<0.001).

CONCLUSION

Critically ill patients at high AKI risk, based on the combination of clinical factors and early creatinine elevation, are significantly more likely to develop severe AKI. As initially hypothesized, the high-risk combination group methodology can be used to identify patients at low risk for severe AKI in whom AKI biomarker testing may be expected to have low yield. The high risk combination group methodology could potentially allow clinicians to optimize biomarker use.

Moving beyond supportive care--current status of specific therapies in pediatric acute kidney injury

Acute kidney injury (AKI) remains a significant challenge, leading to increased morbidity, mortality, and medical costs. Therapy for AKI to this point has largely been supportive; specific interventions to treat established AKI have had minimal effect. Review of the pathogenesis of AKI reveals complex, interacting mechanisms, including changes in microcirculation, the immune system, and inflammation, and cell death from both necrosis and apoptosis. Past definitions of AKI have been imprecise; newer methods for AKI identification and classification, including novel biomarkers and improved criteria for defining AKI, may permit earlier intervention with greater potential for success. With improved understanding of pathophysiology and the opportunity for intervention before AKI is fully established, clinicians may be able to move beyond supportive care and improve outcomes.

Early postoperative fluid overload precedes acute kidney injury and is associated with higher morbidity in pediatric cardiac surgery patients

OBJECTIVE

Fluid overload has been independently associated with increased morbidity and mortality in pediatric patients with renal failure, acute lung injury, and sepsis. Pediatric patients who undergo cardiopulmonary bypass are at risk for poor cardiac, pulmonary, and renal outcomes. They are also at risk of fluid overload from cardiopulmonary bypass, which stimulates inflammation, release of antidiuretic hormone, and capillary leak. This study tested the hypothesis that patients with fluid overload in the early postcardiopulmonary bypass period have worse outcomes than those without fluid overload. We also examined the timing of the association between postcardiopulmonary bypass acute kidney injury and fluid overload.

DESIGN, SETTING, AND PATIENTS

Secondary analysis of a prospective observational study of 98 pediatric patients after cardiopulmonary bypass at a tertiary care, academic, PICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Early postoperative fluid overload, defined as a fluid balance 5% above body weight by the end of postoperative day 1, occurred in 30 patients (31%). Patients with early fluid overload spent 3.5 days longer in the hospital, spent 2 more days on inotropes, and were more likely to require prolonged mechanical ventilation than those without early fluid overload (all p < 0.001). Fluid overload was associated with the development of acute kidney injury and more often preceded it than followed it. Conversely, acute kidney injury was not associated with more fluid accumulation. Patients with fluid overload were administered higher fluid volume over the study period, 395.4 ± 150 mL/kg vs. 193.2 ± 109.1 mL/kg (p < 0.001), and had poor urinary response to diuretics. Cumulative fluid administered was an excellent predictor of pediatric-modified Risk, Injury, Failure, Loss, and End-stage "Failure" (area under the receiver-operating characteristic curve, 0.963; 95% CI, 0.916-1.000; p = 0.002).

CONCLUSIONS

Early postoperative fluid overload is independently associated with worse outcomes in pediatric cardiac surgery patients who are 2 weeks to 18 years old. Patients with fluid overload have higher rates of postcardiopulmonary bypass acute kidney injury, and the occurrence of fluid overload precedes acute kidney injury. However, acute kidney injury is not consistently associated with fluid overload.

Renal recovery

Acute kidney injury (AKI) research in the past decade has mostly focused upon development of a standard AKI definition, validation of early novel biomarkers to predict AKI prior to serum creatinine rise and predict AKI severity, and assessment of aspects of renal replacement therapies and their impact on survival. Given the independent association between AKI and mortality in the acute phase, such focus makes imminent sense. More recently, the recognition that AKI is associated with subsequent development of chronic kidney disease and end-stage renal disease, with the attendant increase in mortality, has led to interest in the clinical epidemiology and the mechanistic understanding of renal recovery after an AKI episode in critically ill patients. We review the current knowledge surrounding renal recovery after an AKI episode, including renal replacement therapy initiation timing and modality impact, biomarker assessment and mechanistic targets to guide potential future clinical trials.

Kidney-lung cross-talk and acute kidney injury

There is a growing appreciation for the role that acute kidney injury (AKI) plays in the propagation of critical illness. In children, AKI is not only an independent predictor of morbidity and mortality, but is also associated with especially negative outcomes when concurrent with acute lung injury (ALI). Experimental data provide evidence that kidney-lung crosstalk occurs and can be bidirectionally deleterious, although details of the precise molecular mechanisms involved in the AKI-ALI interaction remain incomplete. Clinically, ALI, and the subsequent clinical interventions used to stabilize gas exchange, carry consequences for the homeostasis of kidney function. Meanwhile, AKI negatively affects lung physiology significantly by altering the homeostasis of fluid balance, acid-base balance, and vascular tone. Experimental AKI research supports an "endocrine" role for the kidney, triggering a cascade of extra-renal inflammatory responses affecting lung homeostasis. In this review, we will discuss the pathophysiology of kidney-lung crosstalk, the multiple pathways by which AKI affects kidney-lung homeostasis, and discuss how these phenomena may be unique in critically ill children. Understanding how AKI may affect a "balance of communication" that exists between the kidneys and the lungs is requisite when managing critically ill children, in whom imbalance is the norm.

Renal complications and therapy in the PICU: hypertension, CKD, AKI, and RRT

This article provides the bedside clinician an overview of the unique renal complications that are seen commonly in the pediatric intensive care unit. These sections are purposely succinct to give a quick guide to the clinician for the care of these children. We have identified four major areas that should result in discussion and cooperative care between intensive care physicians and nephrologists for the care of these children: (1) hypertension, (2) chronic kidney failure, (3) acute kidney injury, and (4) renal replacement therapy.

Derivation and validation of the renal angina index to improve the prediction of acute kidney injury in critically ill children

Reliable prediction of severe acute kidney injury (AKI) has the potential to optimize treatment. Here we operationalized the empiric concept of renal angina with a renal angina index (RAI) and determined the predictive performance of RAI. This was assessed on admission to the pediatric intensive care unit, for subsequent severe AKI (over 200% rise in serum creatinine) 72 h later (Day-3 AKI). In a multicenter four cohort appraisal (one derivation and three validation), incidence rates for a Day 0 RAI of 8 or more were 15-68% and Day-3 AKI was 13-21%. In all cohorts, Day-3 AKI rates were higher in patients with an RAI of 8 or more with the area under the curve of RAI for predicting Day-3 AKI of 0.74-0.81. An RAI under 8 had high negative predictive values (92-99%) for Day-3 AKI. RAI outperformed traditional markers of pediatric severity of illness (Pediatric Risk of Mortality-II) and AKI risk factors alone for prediction of Day-3 AKI. Additionally, the RAI outperformed all KDIGO stages for prediction of Day-3 AKI. Thus, we operationalized the renal angina concept by deriving and validating the RAI for prediction of subsequent severe AKI. The RAI provides a clinically feasible and applicable methodology to identify critically ill children at risk of severe AKI lasting beyond functional injury. The RAI may potentially reduce capricious AKI biomarker use by identifying patients in whom further testing would be most beneficial.

Preoperative prediction of acute kidney injury--from clinical scores to biomarkers

Early acute kidney injury (AKI) diagnosis in critically ill children has been an important recent research focus because of the known association of AKI with poor outcomes and the requirement of early intervention to mitigate negative effects of AKI. In children having surgery, the preoperative period offers a unique opportunity to predict postoperative acute kidney injury (AKI), well before AKI occurs. Pediatric AKI epidemiologic studies have begun to identify which preoperative factors may predict development of postoperative cardiac surgery. Using these clinical risk factors, it may be possible to derive preoperative clinical risk scores and improve upon our ability to risk-stratify children into AKI treatment trials, pre-emptively provide conservative renal injury prevention strategies, and ultimately improve patient outcomes. Developing risk scores requires rigorous methodology and validation before widespread use. There is little information currently on the use of preoperative biological or physiological biomarkers to predict postoperative AKI, representing an important area of future research. This review will provide an overview of methodology of preoperative risk score development, discuss pediatric-specific issues around deriving such risk scores, including the combination of preoperative clinical and biologic biomarkers for AKI prediction, and suggest future research avenues.

Acute kidney injury based on corrected serum creatinine is associated with increased morbidity in children following the arterial switch operation

BACKGROUND AND OBJECTIVES

Evaluate risk factors for and impact of acute kidney injury on children following the arterial switch operation.

DESIGN

Single-center retrospective chart review.

SETTING

A tertiary children's hospital.

PATIENTS

A total of 92 patients receiving the arterial switch operation from 1997 to 2008 at severe acute kidney injury was defined as a 100% serum creatinine rise over baseline.

RESULTS

Of 92 patients, 18 (20%) developed severe acute kidney injury. Neither patient age or weight nor cardiopulmonary bypass time correlated with the development of acute kidney injury. Acute kidney injury was associated with the following: higher postoperative day 1 (POD1) fluid balance, higher inotrope scores (POD1 and POD2), and longer: postoperative ICU length of stay (p = 0.005), overall ICU length of stay (p = 0.05), and postoperative hospital length of stay (p = 0.006). The time to peak creatinine for acute kidney injury patients was between POD1 and POD2. Correction of serum creatinine for fluid balance increased the population defined as severe acute kidney injury and strengthened the association of acute kidney injury with postoperative morbidity.

CONCLUSIONS

Acute kidney injury following the arterial switch operation is associated with increased morbidity. In this single center, single population, and homogenous cohort of patients, the development of acute kidney injury was not correlated with age, size, or cardiopulmonary bypass time, but was still associated with prolonged duration of ventilation and hospitalization. Notably, the failure to correct serum creatinine for fluid balance underestimates the prevalence and impact of acute kidney injury.

Acute kidney injury: global health alert

Acute kidney injury (AKI) is increasingly prevalent in developing and developed countries and is associated with severe morbidity and mortality. Most etiologies of AKI can be prevented by interventions at the individual, community, regional, and in-hospital levels. Effective measures must include community-wide efforts to increase an awareness of the devastating effects of AKI and provide guidance on preventive strategies, and early recognition and management. Efforts should be focused on minimizing the causes of AKI, increasing awareness of the importance of serial measurements of serum creatinine in high-risk patients, and documenting urine volume in acutely ill people to achieve early diagnosis; there is as yet no definitive role for alternative biomarkers. Protocols need to be developed to systematically manage prerenal conditions and specific infections. More accurate data about the true incidence and clinical impact of AKI will help raise the importance of the disease in the community and increase awareness of AKI by governments, the public, and general and family physicians and other health care professionals to help prevent the disease. Prevention is the key to avoid the heavy burden of mortality and morbidity associated with AKI.

Pediatric Risk, Injury, Failure, Loss, End-Stage renal disease score identifies acute kidney injury and predicts mortality in critically ill children: a prospective study

OBJECTIVES

To determine whether Pediatric Risk, Injury, Failure, Loss, End-Stage renal disease (pRIFLE) criteria serve to characterize the pattern of acute kidney injury in critically ill pediatric patients. To identify if pRIFLE score will predict morbidity and mortality in our patient's cohort.

DESIGN

Prospective cohort.

SETTING

Multidisciplinary, tertiary care, ten-bed PICU.

PATIENTS

A total of 266 patients admitted to PICU from November 2009 to November 2010.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The incidence of acute kidney injury in the PICU was 27.4%, of which 83.5% presented within 72 hours of admission to the PICU. Patients with acute kidney injury were younger; weighed less; were more likely to be on fluid overload greater than or equal to 10%; and were more likely to be on inotropic support, diuretics, or aminoglycosides. No difference in gender, use of other nephrotoxins, or mechanical ventilation was observed. Fluid overload greater than or equal to 10% was an independent predictor of morbidity and mortality. In multivariate analysis, acute kidney injury and failure categories, as defined by pRIFLE, predicted mortality, hospital length of stay, and PICU length of stay.

CONCLUSIONS

In this cohort of critically ill pediatric patients, acute kidney injury identified by pRIFLE and fluid overload greater than or equal to 10% predicted increased morbidity and mortality. Implementation of pRIFLE scoring and close monitoring of fluid overload upon admission may help develop early interventions to prevent and treat acute kidney injury in critically ill children.

Acute kidney injury: Global health alert

Acute kidney injury (AKI) is increasingly prevalent in developing and developed countries and is associated with severe morbidity and mortality. Most etiologies of AKI can be prevented by interventions at the individual, community, regional and in-hospital levels. Effective measures must include community-wide efforts to increase an awareness of the devastating effects of AKI and provide guidance on preventive strategies, as well as early recognition and management. Efforts should be focused on minimizing causes of AKI, increasing awareness of the importance of serial measurements of serum creatinine in high risk patients, and documenting urine volume in acutely ill people to achieve early diagnosis; there is as yet no definitive role for alternative biomarkers. Protocols need to be developed to systematically manage prerenal conditions and specific infections. More accurate data about the true incidence and clinical impact of AKI will help to raise the importance of the disease in the community, increase awareness of AKI by governments, the public, general and family physicians and other health care professionals to help prevent the disease. Prevention is the key to avoid the heavy burden of mortality and morbidity associated with AKI.

Pediatric Acute Kidney Injury: Different From Acute Renal Failure But How And Why

Acute kidney injury [AKI] refers to a clinical syndrome encompassing various etiologies and occurring in a variety of clinical settings, with manifestations ranging from subtle biochemical and structural changes, to minimal elevation in serum creatinine, to anuric renal failure. Understanding the spectrum of AKI and the importance of the early pre-clinical damage stage has resulted in an improved ability to define and stage pediatric AKI, to understand the AKI-to-CKD transition, and harness novel damage biomarkers to predict AKI and its adverse outcomes. These concepts are expanded upon in this review, with an emphasis on publications from the past three years.

Acute kidney injury biomarkers: renal angina and the need for a renal troponin I

Acute kidney injury (AKI) in hospitalized patients is independently associated with increased morbidity and mortality in pediatric and adult populations. Continued reliance on serum creatinine and urine output to diagnose AKI has resulted in our inability to provide successful therapeutic and supportive interventions to prevent and mitigate AKI and its effects. Research efforts over the last decade have focused on the discovery and validation of novel urinary biomarkers to detect AKI prior to a change in kidney function and to aid in the differential diagnosis of AKI. The aim of this article is to review the AKI biomarker literature with a focus on the context in which they should serve to add to the clinical context facing physicians caring for patients with, or at-risk for, AKI. The optimal and appropriate utilization of AKI biomarkers will only be realized by understanding their characteristics and placing reasonable expectations on their performance in the clinical arena.