A Comparison of Traditional and Novel Definitions (RIFLE, AKIN, and KDIGO) of Acute Kidney Injury for the Prediction of Outcomes in Acute Decompensated Heart Failure

Worsening or 'pseudo-worsening' renal function? The prognostic value of hemoconcentration in patients admitted with acute heart failure

INTRODUCTION

Renal insufficiency, as evidenced by an increase in creatinine, is associated with higher mortality in patients with acute heart failure (AHF). Conversely, hemoconcentration (HC) in AHF is associated with lower mortality, but can also cause an increase in creatinine. Our aim was to assess the prognosis of HC in patients hospitalized for AHF presenting with or without worsening renal function (WRF).

METHODS

A total of 618 consecutive patients admitted for AHF were included. WRF was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria and HC was defined as an elevation of hemoglobin during hospitalization compared to the admission value. Six-month all-cause mortality was analyzed.

RESULTS

The patients' mean age was 79±11 years; 58% were women. Mortality at six months was 38% and 49% of patients had WRF. HC occurred in 38.9% of patients with WRF and was associated with improved survival (HR 1.6, 95% CI 1.10-2.34; p=0.02) compared to WRF without HC. HC was associated with better survival in KDIGO stages 1 and 2 (HR 1.8; 95% CI 1.1-2.8; p=0.01). For patients without chronic kidney disease (CKD) with WRF in stages 1 and 2, HC was associated with significantly better survival (HR 2.3; 95% CI 1.2-4.2; p=0.01).

CONCLUSION

In patients admitted for AHF without renal failure or CKD, WRF with HC is associated with a better prognosis, similar to that of patients without WRF, and should therefore be reclassified as 'pseudo-WRF'.

Renal function and acute heart failure outcome

The interaction between acute heart failure (AHF) and renal dysfunction is complex. Several studies have evaluated the prognostic value of this syndrome. The aim of this systematic review, which includes non-selected samples, was to investigate the impact of different renal function variables on the AHF prognosis. The categories included in the studies reviewed included: creatinine, blood urea nitrogen (BUN), the BUN/creatinine quotient, chronic kidney disease, the formula to estimate the glomerular filtration rate, criteria of acute renal injury and new biomarkers of renal damage such as neutrophil gelatinase-associated lipocalin (NGAL and cystatin c). The basal alterations of the renal function, as well as the acute alterations, transient or not, are related to a worse prognosis in AHF, it is therefore necessary to always have baseline, acute and evolutive renal function parameters.

Immune responsive resolvin D1 programs myocardial infarction-induced cardiorenal syndrome in heart failure

Resolvins are innate, immune responsive, bioactive mediators generated after myocardial infarction (MI) to resolve inflammation. The MI-induced bidirectional interaction between progressive left ventricle (LV) remodeling and kidney dysfunction is known to advance cardiorenal syndrome (CRS). Whether resolvins limit MI-induced cardiorenal inflammation is unclear. Thus, to define the role of exogenous resolvin D (RvD)-1 in post-MI CRS, we subjected 8- to 12-wk-old male C57BL/6 mice to coronary artery ligation. RvD1 was injected 3 h after MI. MI mice with no treatment served as MI controls (d 1 and 5). Mice with no surgery served as naive controls. In the injected mice, RvD1 promoted neutrophil (CD11b⁺/Ly6G⁺) egress from the infarcted LV, compared with the MI control group at d 5, indicative of neutrophil clearance and thereby resolved inflammation. Further, RvD1-injected mice showed higher reparative macrophages (F4/80⁺/Ly6C^low/CD206⁺) in the infarcted LV than did MI control mice at d 5 after MI. RvD1 suppressed the miRNA storm at d 1 and limited the MI-induced edematous milieu in a remote area of the LV compared with the MI control at d 5 after MI. Also, RvD1 preserved the nephrin expression that was diffuse in the glomerular membrane at d 5 and 28 in MI controls, indicating renal injury. RvD1 attenuated MI-induced renal inflammation, decreasing neutrophil gelatinase-associated lipocalin and proinflammatory cytokines and chemokines in the kidney compared with the MI control. In summary, RvD1 clears MI-induced inflammation by increasing resolving leukocytes and facilitates renoprotective mechanisms to limit CRS in acute and chronic heart failure.-Halade, G. V., Kain, V., Serhan, C. N. Immune responsive resolvin D1 programs myocardial infarction-induced cardiorenal syndrome in heart failure.

Worsening renal function definition is insufficient for evaluating acute renal failure in acute heart failure

Aims

Whether or not the definition of a worsening renal function (WRF) is adequate for the evaluation of acute renal failure in patients with acute heart failure is unclear.

Methods and results

One thousand and eighty‐three patients with acute heart failure were analysed. A WRF, indicated by a change in serum creatinine ≥0.3 mg/mL during the first 5 days, occurred in 360 patients while no‐WRF, indicated by a change <0.3 mg/dL, in 723 patients. Acute kidney injury (AKI) upon admission was defined based on the ratio of the serum creatinine value recorded on admission to the baseline creatinine value and placed into groups based on the degree of AKI: no‐AKI (n = 751), Class R (risk; n = 193), Class I (injury; n = 41), or Class F (failure; n = 98). The patients were assigned to another set of four groups: no‐WRF/no‐AKI (n = 512), no‐WRF/AKI (n = 211), WRF/no‐AKI (n = 239), and WRF/AKI (n = 121). A multivariate logistic regression model found that no‐WRF/AKI and WRF/AKI were independently associated with 365 day mortality (hazard ratio: 1.916; 95% confidence interval: 1.234–2.974 and hazard ratio: 3.622; 95% confidence interval: 2.332–5.624). Kaplan–Meier survival curves showed that the rate of any‐cause death during 1 year was significantly poorer in the no‐WRF/AKI and WRF/AKI groups than in the WRF/no‐AKI and no‐WRF/no‐AKI groups and in Class I and Class F than in Class R and the no‐AKI group.

Conclusions

The presence of AKI on admission, especially Class I and Class F status, is associated with a poor prognosis despite the lack of a WRF within the first 5 days. The prognostic ability of AKI on admission may be superior to WRF within the first 5 days.

Co-administration of vancomycin and piperacillin-tazobactam is associated with increased renal dysfunction in adult and pediatric burn patients

Background

Burn patients are prone to infections which often necessitate broad antibiotic coverage. Vancomycin is a common antibiotic after burn injury and is administered alone (V), or in combination with imipenem-cilastin (V/IC) or piperacillin-tazobactam (V/PT). Sparse reports indicate that the combination V/PT is associated with increased renal dysfunction. The purpose of this study was to evaluate the short-term impact of the three antibiotic administration types on renal dysfunction.

Methods

All pediatric and adult patients admitted to our centers between 2004 and 2016 with a burn injury were included in this retrospective review if they met the criteria of exposition to either V, V/IC, or V/PT for at least 48 h, had normal baseline creatinine, and no pre-existing renal dysfunction. Creatinine was monitored for 7 days after initial exposure; the absolute and relative increase was calculated, and patient renal outcomes were classified according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria depending on creatinine increases and estimated creatinine clearance. Secondary endpoints (demographic and clinical data, incidences of septicemia, and renal replacement therapy) were analyzed. Antibiotic doses were modeled in logistic and linear multivariable regression models to predict categorical KDIGO events and relative creatinine increase.

Results

Out of 1449 patients who were screened, 718 met the inclusion criteria, 246 were adults, and 472 were children. Between the study cohorts V, V/IC, and V/PT, patient characteristics at admission were comparable. V/PT administration was associated with a statistically higher serum creatinine, and lower creatinine clearance compared to patients receiving V alone or V/IC in adults and children after burn injury. The incidence of KDIGO stages 1, 2, and 3 was higher after V/PT treatment. In children, the incidence of KDIGO stage 3 following administration of V/PT was greater than after V/IC. In adults, the incidence of renal replacement therapy was higher after V/PT compared with V or V/IC. Multivariate modeling demonstrated that V/PT is an independent predictor of renal dysfunction.

Conclusion

Co-administration of vancomycin and piperacillin-tazobactam is associated with increased renal dysfunction in pediatric and adult burn patients when compared to vancomycin alone or vancomycin plus imipenem-cilastin. The mechanism of this increased nephrotoxicity remains elusive and warrants further scientific evaluation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1899-3) contains supplementary material, which is available to authorized users.

Left ventricular global longitudinal strain following revascularization in acute ST elevation myocardial infarction - A comparison of primary angioplasty and Streptokinase-based pharmacoinvasive strategy

Objective

Tenecteplase-based pharmacoinvasive percutaneous coronary intervention (PCI) has been shown to yield outcomes comparable to primary PCI in the setting of acute ST elevation myocardial infarction (STEMI). This study was designed to compare the efficacy of pharmacoinvasive PCI following successful thrombolysis with Streptokinase versus primary PCI in patients with STEMI.

Methodology

We conducted a prospective single center observational study in 120 patients with STEMI who underwent primary PCI (n = 60) and Streptokinase-based pharmacoinvasive PCI (n = 60). Patients with Killips class 3 or 4 at presentation, and those with evidence of failed fibrinolysis were excluded. The primary outcome was LV systolic function after angioplasty, as assessed by 2D global longitudinal strain (GLS) using speckle tracking echocardiography (STE), as well as 2D LVEF using Simpson's biplane method.

Results

LV systolic function after PCI was significantly lower in the pharmacoinvasive arm as compared to the primary PCI arm, both by 2D STE (GLS: −9% vs −11%; p = 0.03) and 2D Simpson's biplane method (LVEF: 40.7% vs 45.1%; p = 0.02). TIMI flow in the culprit vessel prior to angioplasty was better in the pharmacoinvasive arm indicating successful thrombolysis, whereas post angioplasty flow was not different. There was no in-hospital mortality in either group. There was a trend toward increased incidence of acute kidney injury in the pharmacoinvasive arm.

Conclusion

LV systolic function is significantly better after primary angioplasty as compared to pharmacoinvasive PCI following successful thrombolysis with Streptokinase.

3-month prognostic impact of severe acute renal failure under veno-venous ECMO support: Importance of time of onset

PURPOSE

Veno-venous ECMO is increasingly used for the management of refractory ARDS. In this context, acute kidney injury (AKI) is a major and frequent complication, often associated with poor outcome. We aimed to identify characteristics associated with severe renal failure (Kidney Disease Improving Global Outcome (KDIGO) 3) and its impact on 3-month outcome.

METHODS

Between May 2009 and April 2016, 60 adult patients requiring VV-ECMO in our University Hospital were prospectively included.

RESULTS

AKI occurrence was frequent (75%; n=45), 51% of patients (n=31) developed KDIGO 3 - predominantly prior to ECMO insertion - and renal replacement therapy was required in 43% (n=26) of cases. KDIGO 3 was associated with a lower mechanical ventilation weaning rate (24% vs 68% for patients with no AKI or other stages of AKI; p<0.001) and a higher 90-day mortality rate (72% vs 32%, p=0.002). Multivariate logistic regression suggested that KDIGO 3 occurrence prior to ECMO insertion, as well as PaCO2>57mmHg and mSOFA>12 were independent risks factors for 90-day mortality.

CONCLUSION

KDIGO 3 AKI occurrence is correlated with the severity of patients' clinical condition prior to ECMO insertion and is negatively associated with 90-day survival.

Interleukin-17 as a predictor of sepsis in polytrauma patients: a prospective cohort study

Sepsis is one of the most serious complications after major trauma, and may be associated with increased mortality. We sought to determine whether there is an association between serum levels of interleukin-17 (IL-17) at the time of admission to the intensive care unit (ICU) and the development of sepsis. We evaluated 100 adult patients with major trauma admitted to the surgical ICU over a 6-month period. Serum levels of IL-17, IL-6, and TNF-α were determined by enzyme-linked immunosorbent assays (ELISA). The IL-17 rs1974226 genotype was determined by real-time PCR. In both non-adjusted and adjusted analyses, IL-17 was the only biomarker significantly associated with sepsis [median serum IL-17 of 72 pg/mL in sepsis versus 37 pg/mL in those without sepsis, P = 0.0001; adjusted odds ratio (OR) 3.2, P = 0.02]. No significant association was found among IL-17 rs1974226 genotypes and related serum cytokine levels. These data suggest that elevated serum IL-17 may increase the susceptibility for septic complications in polytrauma patients and so could be a useful biomarker for trauma patient management.

Evaluation of acute kidney injury (AKI) with RIFLE, AKIN, CK, and KDIGO in critically ill trauma patients

PURPOSE

The aim of our study was to evaluate the effects of AKI development on mortality with four different classification systems (RIFLE, AKIN, CK, KDIGO) in critically ill trauma patients followed in the intensive care unit.

METHODS

A retrospective review of 2034 patients in our intensive care unit was conducted between July 2010 and August 2013. A total of 198 patients with primary trauma were included in the study to evaluate the development of AKI.

RESULTS

When the presence of AKI was investigated according to the four criteria (RIFLE, AKIN, CK, and KDIGO), the highest incidence of AKI was found according to the KDIGO classification (74.2%), followed by AKIN (72.2%), RIFLE (69.7%), and CK (59.1%). It was observed that more AKI developed according to KDIGO in patients with multiple trauma and thoracic trauma (p = 0.031, p = 0.029). Sixty-two (31%) of the 198 trauma patients monitored in the intensive care unit died; mortality was frequently found high in AKI stage 2 and 3 patients. According to the CK classification, there was a significant increase in mortality in patients with AKI on the first day (p = 0.045). AKI classifications by RIFLE, AKIN, CK, and KDIGO were independently associated with the risk of in-hospital death.

CONCLUSION

In this study, the presence of AKI was found to be an independent risk factor in the development of in-hospital mortality according to all classification systems (RIFLE, AKIN, CK, and KDIGO) in critically traumatic patients followed in ICU, and the compatibility between RIFLE, AKIN, and KDIGO was the highest among the classification systems.

Initiation and Cessation Timing of Renal Replacement Therapy in Patients with Type 1 Cardiorenal Syndrome: An Observational Study

BACKGROUND/AIMS

Renal replacement therapy (RRT) is a rescue therapy for patients with type 1 cardiorenal syndrome (CRS) with poor prognoses. However, the optimal timing for initiation and cessation of RRT remains controversial. The purpose of this study was to determine the optimal timing of initiation and cessation of RRT for patients with type 1 CRS.

METHODS

In this retrospective analysis, patients with refractory type 1 CRS receiving RRT were divided into 3 groups according to weaning from RRT and death within 90 days. Baseline characteristics, underlying heart disease, comorbidities, drug use before RRT, indicators of RRT initiation, and prognosis were compared between the 3 groups.

RESULTS

Fifty-two patients were enrolled, which included 27 males and 25 females with a mean age of 70.7 ± 16.1 years and a 90-day mortality rate of 65.4%. The mean urine output before RRT initiation was 800 mL/ 24 h in the RRT-independent group, 650 mL/24 h in the RRT-dependent group, and 345 mL/ 24 h in the death group (p = 0.021). Additionally, there were obvious differences in fluid balance between the 3 groups (167, 250, and 1,270 mL, respectively, p = 0.016). Patients could be successfully weaned from RRT when urine output was >880 mL and fluid balance volume was <150 mL.

CONCLUSION

The mean fluid balance of survivors was remarkably less than that of the death group at RRT initiation. RRT termination can be considered when urine output is >880 mL/24 h and volume balance is <150 mL/24 h.

Effect of endoskeleton stent graft design on pulse wave velocity in patients undergoing endovascular repair of the aortic arch

PURPOSE

Pulse wave velocity (PWV), which measures vascular stiffness, is a powerful predictor of cardiovascular event. Treatment of aneurysms with endovascular prosthesis has been reported to increase PWV. The purpose of this study was to evaluate whether an endoskeleton stent graft design has less effect on PWV than the exoskeleton stent graft design.

METHODS

Between July 2008 and September 2016, 74 patients underwent endovascular treatment of aortic arch aneurysm in our institution. PWV before and after surgery were compared between those who underwent treatment with Najuta, an endoskeleton stent graft (n = 51), and those treated with other commercially available exoskeleton stent grafts (n = 23).

RESULTS

Preoperative PWV (endoskeleton: 2004 ± 379.2 cm/s vs. exoskeleton: 2083 ± 454.5 cm/s, p = 0.47) was similar between the two groups. Factors that were associated with preoperative PWV were age (r = 0.37, 95% CI 0.15-0.56, p = 0.002) and mean arterial pressure (r = 0.53, 95% CI 0.34-0.68, p < 0.001). There was a significant increase in PWV in patients treated by exoskeleton stent grafts (before: 2083 ± 454.5 cm/s vs. after: 2305 ± 479.7 cm/s, p = 0.023) while endoskeleton stent graft showed no change in PWV (before: 2003 ± 379.2 vs. after: 2010 ± 521.1, p = 0.56). In a multivariate analysis, mean arterial pressure (coef 17.5, 95% CI 6.48-28.59, p = 0.002) and exoskeleton stent graft (coef 359.4, 95% CI 89.36-629.43, p = 0.010) were independently associated with PWV after surgery.

CONCLUSIONS

Physiological changes after endovascular treatment should be considered including effect on vascular stiffness. Endoskeleton stent graft may provide aneurysm repair with minimum effect in PWV after surgery.

Discontinuation/Dose Reduction of Angiotensin-Converting Enzyme Inhibitors/Angiotensin Receptor Blockers during Acute Decompensated Heart Failure in African-American Patients with Reduced Left-Ventricular Ejection Fraction

Objectives: Patients with heart failure (HF) and reduced left-ventricular ejection fraction (LVEF) benefit from angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blocker (ARB) therapy. While dose reduction/discontinuation (r/d) of β-blockers (BB) and furosemide in acute decompensated HF (ADHF) worsen outcomes, data on ACEI/ARB are lacking. Methods: To determine the frequency and reasons for ACEI/ARB therapy r/d in ADHF patients, we studied 174 patients with LVEF <40% on ACEI/ARB and BB therapy upon admission over 1 year. Results: ACEI/ARB doses were r/d in 17.2% because of acute kidney injury (56.7%), hypotension (23.3%), and hyperkalemia (10%). Clinical characteristics were similar between patients with r/d and continued therapy. Admission and discharge creatinine (Cr) levels were higher in the r/d group. On multivariate analysis, admission Cr and admission systolic blood pressures were independent predictors of r/d. Among patients with renal dysfunction cited as the r/d reason, Cr did not significantly rise in 23.5%. The r/d group had a longer length of stay (LOS). Conclusions: ACEI/ARB dose is reduced and/or discontinued in nearly one-fifth of all ADHF admissions, and LOS is longer in the ACEI/ARB r/d group. While impaired renal function is the most frequently cited reason, nearly one-fourth of the patients had stable renal function. ACEI/ARB r/d therapy in the setting of ADHF merits further study.

Advances in the Management of Acute Cardiorenal Syndrome in China: Biomarkers for Predicting Development and Outcomes

BACKGROUND

Acute cardiorenal syndrome (CRS) is a common clinical condition associated with adverse outcomes. Early identification of acute kidney injury in this setting remains challenging given that serum creatinine level is a marker of renal function and not kidney injury.

SUMMARY

Several renal injury-related molecules are now available, which may help elucidate the complexities of the organ crosstalk, enabling more accurate risk stratification and effective interventions.

KEY MESSAGES

This review highlights the major studies that have characterized the diagnostic and prognostic predictive power of these biomarkers with reference to acute CRS. Although more research is needed, the current results are very promising.

Identifying High-Risk Medications Associated with Acute Kidney Injury in Critically Ill Patients: A Pharmacoepidemiologic Evaluation

BACKGROUND

Nephrotoxic medications are a common cause of acute kidney injury (AKI). Critically ill children receive more medication than other inpatients; however, the risk of nephrotoxic medication-induced AKI in these children is not well understood.

OBJECTIVE

The aim of this study was to determine the association between exposure to nephrotoxic medications in the intensive care unit (ICU) and the development of AKI amongst critically ill children, adjusting for differences in underlying risk.

METHODS

We conducted a nested case-control study among a cohort of patients admitted to a paediatric intensive care unit between January 2006 and June 2009. Cases were identified according to the RIFLE criteria. Using incidence density sampling, controls were matched 1:1 according to pre-ICU nephrotoxic drug exposure. Administration of nephrotoxic medications and other known risk factors of AKI were evaluated during the ICU stay prior to the diagnosis of AKI.

RESULTS

A total of 914 patients in the cohort developed AKI and had an identifiable matched control. Eighty-seven percent of cases and 74% of controls were exposed to one or more nephrotoxic medications in the ICU during the study period. Furosemide (administered to 67.8% of patients), vancomycin (28.7%), and gentamicin (21.4%) were the most frequently administered nephrotoxic drugs. Patients who developed AKI were more likely to be exposed to at least one nephrotoxic medication and risk increased with increasing number of nephrotoxic medications. Ganciclovir (adjusted odds ratio [AOR] 4.7; 95% CI 1.7-13.0), furosemide (AOR 1.9; 95% CI 1.4-2.4), and gentamicin (AOR 1.8; 95% CI 1.4-2.4) significantly increased the odds of developing AKI after adjusting for underlying differences in risk factors of AKI.

CONCLUSION

This is the first study to assess the association between risk-adjusted nephrotoxic medication exposure and the development of AKI in critically ill children. Nephrotoxic medication exposure was common amongst children in the ICU and we found AKI was associated with the administration of specific drugs after adjustment for important risk factors.

Acute kidney injury in patients with severe sepsis or septic shock: a comparison between the 'Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease' (RIFLE), Acute Kidney Injury Network (AKIN) and Kidney Disease: Improving Global Outcomes (KDIGO) classifications

PURPOSE

Using the Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease (RIFLE), Acute Kidney Injury Network (AKIN) and Kidney Disease: Improving Global Outcomes (KDIGO) systems, the incidence of acute kidney injury (AKI) and their ability to predict in-hospital mortality in severe sepsis or septic shock was compared.

MATERIALS AND METHODS

We performed a retrospective analysis of 457 critically ill patients with severe sepsis or septic shock hospitalized between January 2008 and December 2014. Multivariate logistic regression was employed to evaluate the association between the RIFLE, AKIN and KDIGO systems with in-hospital mortality. Model fit was assessed by the goodness-of-fit test and discrimination by the area under the receiver operating characteristic (AUROC) curve. Statistical significance was defined as P < 0.05.

RESULTS

RIFLE (84.2%) and KDIGO (87.5%) identified more patients with AKI than AKIN (72.8%) (P < 0.001). AKI defined by AKIN and KDIGO was associated with in-hospital mortality {AKIN: adjusted odds ratio [OR] 2.3[95% confidence interval (CI) 1.3-4], P = 0.006; KDIGO: adjusted OR 2.7[95% CI 1.2-6.2], P = 0.021} while AKI defined by RIFLE was not [adjusted OR 2.0 (95% CI 1-4), P = 0.063]. The AUROC curve for in-hospital mortality was similar between the three classifications (RIFLE 0.652, P < 0.001; AKIN 0.686, P < 0.001; KDIGO 0.658, P < 0.001).

CONCLUSIONS

RIFLE and KDIGO diagnosed more patients with AKI than AKIN, but the prediction ability for in-hospital mortality was similar between the three systems.

Incidence, Mortality and Positive Predictive Value of Type 1 Cardiorenal Syndrome in Acute Coronary Syndrome

OBJECTIVES

To determine whether the risk of cardiovascular mortality associated with cardiorenal syndrome subtype 1 (CRS1) in patients who were hospitalized for acute coronary syndrome (ACS) was greater than the expected risk based on the sum of its components, to estimate the predictive value of CRS1, and to determine whether the severity of CRS1 worsens the prognosis.

METHODS

Follow-up study of 1912 incident cases of ACS for 1 year after discharge. Cox regression models were estimated with time to event (in-hospital death, and readmission or death during the first year after discharge) as the dependent variable.

RESULTS

The incidence of CRS1 was 9.2/1000 person-days of hospitalization (95% CI = 8.1-10.5), but these patients accounted for 56.6% (95% CI = 47.4-65.) of all mortality. The positive predictive value of CRS1 was 29.6% (95% CI = 23.9-36.0) for in-hospital death, and 51.4% (95% CI = 44.8-58.0) for readmission or death after discharge. The risk of in-hospital death from CRS1 (RR = 18.3; 95% CI = 6.3-53.2) was greater than the sum of risks associated with either acute heart failure (RR = 7.6; 95% CI = 1.8-31.8) or acute kidney injury (RR = 2.8; 95% CI = 0.9-8.8). The risk of events associated with CRS1 also increased with syndrome severity, reaching a RR of 10.6 (95% CI = 6.2-18.1) for in-hospital death at the highest severity level.

CONCLUSIONS

The effect of CRS1 on in-hospital mortality is greater than the sum of the effects associated with each of its components, and it increases with the severity of the syndrome. CRS1 accounted for more than half of all mortality, and its positive predictive value approached 30% in-hospital and 50% after discharge.

Case report: severe bradycardia, a reversible cause of "Cardio-Renal-Cerebral Syndrome"

Background

Cardio-Renal Syndromes were first classified in 2008 and divided into five subtypes. The type 1 Cardio-Renal Syndrome (CRS) is characterized by acute decompensation of heart failure leading to acute kidney injury (AKI). Bradyarrhythmia was not mentioned in the classification as a cause for low cardiac output (CO) in type 1 CRS. Besides, CRS was not previously associated with central nervous system (CNS) injury despite the fact that cardiac, renal and neurological diseases can coexist.

Case presentation

We report the case of a 93-year old diabetic man who presented for obnubilation. He had a slow atrial fibrillation, was not hypotensive and was not taking any beta-blocker. He developed, simultaneously, during his hospitalization, severe bradycardia (<35 beats per minute), oligoanuria and further neurological deterioration without profound hypotension. An ECG revealed a complete atrioventricular (AV) block and all his symptoms were completely reversed after pacemaker insertion. His creatinine decreased progressively afterwards and at discharge, he was conscious, alert and well oriented.

Conclusion

Our case highlights the importance of an early recognition of low cardiac output secondary to severe bradyarrhythmia and its concurrent repercussion on the kidney and the brain. This association of the CRS with CNS injury-that we called “Cardio-Renal-Cerebral Syndrome”–was successfully treated with permanent pacemaker implantation.

Urinary Biomarkers at the Time of AKI Diagnosis as Predictors of Progression of AKI among Patients with Acute Cardiorenal Syndrome

BACKGROUND AND OBJECTIVES

A major challenge in early treatment of acute cardiorenal syndrome (CRS) is the lack of predictors for progression of AKI. We aim to investigate the utility of urinary angiotensinogen and other renal injury biomarkers in predicting AKI progression in CRS.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

In this prospective, multicenter study, we screened 732 adults who admitted for acute decompensated heart failure from September 2011 to December 2014, and evaluated whether renal injury biomarkers measured at time of AKI diagnosis can predict worsening of AKI. In 213 patients who developed Kidney Disease Improving Global Outcomes stage 1 or 2 AKI, six renal injury biomarkers, including urinary angiotensinogen (uAGT), urinary neutrophil gelatinase-associated lipocalin (uNGAL), plasma neutrophil gelatinase-associated lipocalin, urinary IL-18 (uIL-18), urinary kidney injury molecule-1, and urinary albumin-to-creatinine ratio, were measured at time of AKI diagnosis. The primary outcome was AKI progression defined by worsening of AKI stage (50 patients). The secondary outcome was AKI progression with subsequent death (18 patients).

RESULTS

After multivariable adjustment, the highest tertile of three urinary biomarkers remained associated with AKI progression compared with the lowest tertile: uAGT (odds ratio [OR], 10.8; 95% confidence interval [95% CI], 3.4 to 34.7), uNGAL (OR, 4.7; 95% CI, 1.7 to 13.4), and uIL-18 (OR, 3.6; 95% CI, 1.4 to 9.5). uAGT was the best predictor for both primary and secondary outcomes with area under the receiver operating curve of 0.78 and 0.85. These three biomarkers improved risk reclassification compared with the clinical model alone, with uAGT performing the best (category-free net reclassification improvement for primary and secondary outcomes of 0.76 [95% CI, 0.46 to 1.06] and 0.93 [95% CI, 0.50 to 1.36]; P<0.001). Excellent performance of uAGT was further confirmed with bootstrap internal validation.

CONCLUSIONS

uAGT, uNGAL, and uIL-18 measured at time of AKI diagnosis improved risk stratification and identified CRS patients at highest risk of adverse outcomes.

Risk Factors of Acute Kidney Injury in Critically Ill Children

OBJECTIVES

Acute kidney injury may be promoted by critical illness, preexisting medical conditions, and treatments received both before and during ICU admission. We aimed to estimate the frequency of acute kidney injury during ICU treatment and to determine factors, occurring both before and during the ICU stay, associated with the development of acute kidney injury.

DESIGN

Cohort study of critically ill children.

SETTING

University-affiliated PICU.

PATIENTS

Eligible patients were admitted to the ICU between January 2006 and June 2009. We excluded those admitted with known primary renal failure, chronic renal failure or postrenal transplant, conditions with known renal complications, or metabolic conditions treated with dialysis. Patients were also excluded if they had a short ICU stay (< 6 hr) and those who had no creatinine or urine output measurements during their ICU stay.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 3,865 pediatric patients who met the inclusion criteria, 915 (23.7%) developed acute kidney injury, as classified by the Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease criteria, during their ICU stay. Patients at high risk for development of acute kidney injury included those urgently admitted to the ICU (adjusted odds ratio, 1.88), those who developed respiratory dysfunction during their ICU care (adjusted odds ratio, 2.90), and those who treated with extracorporeal membrane oxygenation (adjusted odds ratio, 2.72). The single greatest risk factor for acute kidney injury was the administration of nephrotoxic medications during ICU admission (adjusted odds ratio, 3.37).

CONCLUSIONS

This study, the largest evaluating the incidence of RIFLE-defined acute kidney injury in critically ill children, found that one-quarter of patients admitted to the ICU developed acute kidney injury. We identified a number of potentially modifiable risk factors, the largest of which was the administration of nephrotoxic medication. The results of this study may be used to inform targeted interventions to reduce acute kidney injury and improve the outcomes of critically ill children.

Assessment of the RIFLE criteria for the diagnosis of Acute Kidney Injury; a retrospective study in South-Western Ghana

BACKGROUND

Acute kidney injury (AKI) affects 3-7 % of patients admitted to the hospital and approximately 25-30 % of patients in the intensive care unit. RIFLE, a newly developed international consensus classification for AKI, defines three grades of severity-class R (risk), I (injury) and F (failure). The aim of this study was to evaluate whether the RIFLE system of classification can detect the incidence of AKI using retrospective data of in-patients at the Effia-Nkwanta Regional Hospital.

METHODS

A total of 1070 in-patients' records spanning a period of 6 months, from July 2014 to December 2014, was used. Demographic data and hospital admission serum creatinine of each participant were used for the calculation of estimated glomerular filtration rate (eGFR) using the 4-variable modification of diet in renal disease (MDRD) equation. Also, the baseline serum creatinine was estimated assuming a standard GFR of 75 ml/min/1.73 m(2) using the simplified MDRD equation.

RESULTS

Males had higher serum creatinine, eGFR, and baseline serum creatinine than females (P < 0.0001). However, the level of increase in baseline serum creatinine was higher in females than males (P = 0.0212). The percentage ratios of the various classes from the SCr/ePCr (hospital admission serum creatinine/estimated plasma creatinine) criteria (R-1.45, I-1.53 and F-3.26) were higher than that of the eGFR criteria (R-0.34, I-0.11, F-0.12). The SCr/ePCr criteria gave more risk (89.7 %) than that of the eGFR criteria (23.1 %). The number of Injury and normal patients from the eGFR criteria was higher than the SCr/ePCr criteria.

CONCLUSION

AKI was common in the ICU population with SCr/ePCr detecting more AKI than the eGFR criteria. Males had more injury and failure than females using the eGFR criteria whereas the SCr/ePCr gave females more risk and injury than males. A prospective cohort study must be employed in subsequent studies using the RIFLE criteria to assess the incidence of AKI in hospitalized patients with known diseases or medical conditions.

A Clinical Approach to the Acute Cardiorenal Syndrome

Acute kidney injury is a frequent complication of acute heart failure syndromes, portending an adverse prognosis. Acute cardiorenal syndrome represents a unique form of acute kidney injury specific to acute heart failure syndromes. The pathophysiology of acute cardiorenal syndrome involves renal venous congestion, ineffective forward flow, and impaired renal autoregulation caused by neurohormonal activation. Biomarkers reflecting different aspects of acute cardiorenal syndrome pathophysiology may allow patient phenotyping to inform prognosis and treatment. Adjunctive vasoactive, neurohormonal, and diuretic therapies may relieve congestive symptoms and/or improve renal function, but no single therapy has been proved to reduce mortality in acute cardiorenal syndrome.

[Acute cardiorenal syndromes]

Heart and kidney are closely interacting organs which function interdependently. Organ crosstalk between these two organs is based on humoral regulation and by inflammatory mediators, which are similar to those dominating systemic inflammation syndrome. The close interaction between heart and kidney results in organ dysfunction following both chronic and acute functional impairment of the respective counterpart. These changes are summarized under the term cardiorenal syndrome (CRS) which is subdivided into 5 types. In the setting of emergency medicine and intensive care units, CRS types 1 and 3 are the most common. CRS type 1 is characterized by acute kidney injury (AKI) developing as a consequence of acute heart failure. CRS type 3 is represented by acute cardiac failure following AKI, often occurring as a consequence of nephrotoxins. Diagnosis of CRS should preferably be made on basis of the Kidney Disease: Improving Global Outcomes (KDIGO) criteria for the diagnosis and staging of AKI. The cardiac diagnostic workup should include echocardiography, electrocardiogram (ECG), cardiac enzymes, and brain natriuretic peptide (BNP). The therapeutic approach in CRS is primarily aimed at treating the causative organ dysfunction. In case of CRS type 3 this means ensuring adequate kidney perfusion, cautious fluid management, and avoiding additional nephrotoxins. In case of diuretic resistant fluid overload, early initiation of extracorporeal fluid removal, preferably by renal replacement therapy, should be considered.

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.

Incidence and mortality of postoperative acute kidney injury in non-dialysis patients: comparison between the AKIN and KDIGO criteria

OBJECTIVES

This retrospective study determines whether the kidney disease: improving global outcomes (KDIGO) criteria are superior to acute kidney injury network (AKIN) criteria in detecting non-dialysis AKI events and predicting mortality in chronic kidney disease (CKD) patients after surgery.

METHODS

Surgical patients who were admitted to the intensive care unit were enrolled. Non-dialysis AKI cases were defined using either KDIGO or AKIN creatinine criteria and stratified by CKD stages. The adjusted hazard ratios (AHRs) for in-hospital mortality are compared to those without AKI. The cumulative survival curves and the predictability for mortality are accessed by Kaplan-Meier method and calculating the area under the curve (AUC) for the receiver operating characteristic (ROC) curve, respectively.

RESULTS

From a total of 826 postoperative patients, the overall in-hospital mortality rate was 11.6% (96 cases) and that for AKI according to KDIGO and AKIN criteria was 30.0% (248 cases) and 31.0% (256 cases). The cumulative survival curve stratified by CKD and AKI stages were comparable between KDIGO and AKIN criteria. The discriminative power for mortality stratified by CKD stages for KDIGO and AKIN criteria are as followed: all subjects: 0.678 versus 0.670 (both ps <0.001); non-CKD: 0.800 versus 0.809 (both ps <0.001); early-stage CKD: 0.676 versus 0.676 (both ps <0.001); late-stage CKD: 0.674 versus 0.660 (ps were <0.001 and 0.003).

CONCLUSION

The KDIGO criteria are superior to AKIN criteria in predicting mortality after surgery, especially in those with advanced CKD.

Perioperative optimal blood pressure as determined by ultrasound tagged near infrared spectroscopy and its association with postoperative acute kidney injury in cardiac surgery patients

OBJECTIVES

Perioperative blood pressure management by targeting individualized optimal blood pressure, determined by cerebral blood flow autoregulation monitoring, may ensure sufficient renal perfusion. The purpose of this study was to evaluate changes in the optimal blood pressure for individual patients, determined during cardiopulmonary bypass (CPB) and during early postoperative period in intensive care unit (ICU). A secondary aim was to examine if excursions below optimal blood pressure in the ICU are associated with risk of cardiac surgery-associated acute kidney injury (CSA-AKI).

METHODS

One hundred and ten patients undergoing cardiac surgery had cerebral blood flow monitored with a novel technology using ultrasound tagged near infrared spectroscopy (UT-NIRS) during CPB and in the first 3 h after surgery in the ICU. The correlation flow index (CFx) was calculated as a moving, linear correlation coefficient between cerebral flow index measured using UT-NIRS and mean arterial pressure (MAP). Optimal blood pressure was defined as the MAP with the lowest CFx. Changes in optimal blood pressure in the perioperative period were observed and the association of blood pressure excursions (magnitude and duration) below the optimal blood pressure [area under the curve (AUC) < OptMAP mmHgxh] with incidence of CSA-AKI (defined using Kidney Disease: Improving Global Outcomes criteria) was examined.

RESULTS

Optimal blood pressure during early ICU stay and CPB was correlated (r = 0.46, P < 0.0001), but was significantly higher in the ICU compared with during CPB (75 ± 8.7 vs 71 ± 10.3 mmHg, P = 0.0002). Thirty patients (27.3%) developed CSA-AKI within 48 h after the surgery. AUC < OptMAP was associated with CSA-AKI during CPB [median, 13.27 mmHgxh, interquartile range (IQR), 4.63-20.14 vs median, 6.05 mmHgxh, IQR 3.03-12.40, P = 0.008], and in the ICU (13.72 mmHgxh, IQR 5.09-25.54 vs 5.65 mmHgxh, IQR 1.71-13.07, P = 0.022).

CONCLUSIONS

Optimal blood pressure during CPB and in the ICU was correlated. Excursions below optimal blood pressure (AUC < OptMAP mmHgXh) during perioperative period are associated with CSA-AKI. Individualized blood pressure management based on cerebral autoregulation monitoring during the perioperative period may help improve CSA-AKI-related outcomes.

Acute Kidney Injury in Cardiorenal Syndrome Type 1 Patients: A Systematic Review and Meta-Analysis

BACKGROUND

We evaluated the epidemiology and outcome of acute kidney injury (AKI) in patients with cardiorenal syndrome type 1 (CRS-1) and its subgroups: acute heart failure (AHF), acute coronary syndrome (ACS) and after cardiac surgery (CS).

SUMMARY

We performed a systematic review and meta-analysis. CRS-1 was defined by AKI (based on RIFLE, AKIN and KDIGO), worsening renal failure (WRF) and renal replacement therapy (RRT). We investigated the three most common clinical causes of CRS-1: AHF, ACS and CS. Out of 332 potential papers, 64 were eligible - with AKI used in 41 studies, WRF in 25 and RRT in 20. The occurrence rate of CRS-1, defined by AKI, WRF and RRT, was 25.4, 22.4 and 2.6%, respectively. AHF patients had a higher occurrence rate of CRS-1 compared to ACS and CS patients (AKI: 47.4 vs. 14.9 vs. 22.1%), but RRT was evenly distributed among the types of acute cardiac disease. AKI was associated with an increased mortality rate (risk ratio = 5.14, 95% CI 3.81-6.94; 24 studies and 35,227 patients), a longer length of stay in the intensive care unit [LOSICU] (median duration = 1.37 days, 95% CI 0.41-2.33; 9 studies and 10,758 patients) and a longer LOS in hospital [LOShosp] (median duration = 3.94 days, 95% CI 1.74-6.15; 8 studies and 35,227 patients). Increasing AKI severity was associated with worse outcomes. The impact of CRS-1 defined by AKI on mortality was greatest in CS patients. RRT had an even greater impact compared to AKI (mortality risk ratio = 9.2, median duration of LOSICU = 10.6 days and that of LOShosp = 20.2 days).

KEY MESSAGES

Of all included patients, almost one quarter developed AKI and approximately 3% needed RRT. AHF patients experienced the highest occurrence rate of AKI, but the impact on mortality was greatest in CS patients.

The RIFLE versus AKIN classification for incidence and mortality of acute kidney injury in critical ill patients: A meta-analysis

The sensitivity and accuracy of the Risk/Injury/Failure/Loss/End-stage (RIFLE) versus acute kidney injury Network (AKIN) criteria for acute kidney injury (AKI) in critically ill patients remains uncertain. Therefore, we performed a systematic review and meta-analysis to investigate the incidence and prognostic value of the RIFLE versus AKIN criteria for AKI in critically ill patients. Literatures were identified by searching Medline, Embase, PubMed, and China National Knowledge Infrastructure (CNKI) database. Nineteen studies with 171,889 participants were included. The pooled estimates of relative risk (RR) were analyzed. We found that the RIFLE and AKIN criteria is different for the incidence of AKI in intensive care unit (ICU) patients (P = 0.02, RR = 0.88), while not for cardiac surgery patients (P = 0.30, RR = 0.93). For AKI-related hospital mortality, the AKIN criteria did not show a better ability in predicting hospital mortality in either ICU (P = 0.19, RR = 1.01) or cardiac surgery patients (P = 0.61, RR = 0.98) compared to RIFLE criteria. Our findings supported that the AKIN criteria can identify more patients in classifying AKI compared to RIFLE criteria, but not showing a better ability in predicting hospital mortality. Moreover, both RIFLE and AKIN criteria for AKI in cardiac surgery patients had better predictive ability compared with the ICU patients.

Impact of Acute Kidney Injury on Outcome in Patients With Severe Acute Respiratory Failure Receiving Extracorporeal Membrane Oxygenation

OBJECTIVES

Extracorporeal lung support is currently used in the treatment of patients with severe respiratory failure until organ recovery and as a bridge to further therapeutic modalities. The aim of our study was to evaluate the impact of acute kidney injury on outcome in patients with acute respiratory distress syndrome under venovenous extracorporeal membrane oxygenation support and to analyze the association between prognosis and the time of occurrence of acute kidney injury and renal replacement therapy initiation.

DESIGN

Retrospective observational study.

SETTING

A large European extracorporeal membrane oxygenation center, University Medical Center Regensburg, Germany.

PATIENTS

A total of 262 consecutive adult patients with acute respiratory distress syndrome have been treated with extracorporeal membrane oxygenation between January 2007 and May 2012.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Patient median age was 49 years (range, 18-78 yr); 183 (69.8%) were male. The leading cause of lung failure was pneumonia. The median Sequential Organ Failure Assessment score was 12.0 (8.8-15.0), and the median lung injury score was 3.3 (3.3-3.7). The median extracorporeal membrane oxygenation support duration was 9 days (6-15 d). One hundred eighty-three patients (69.8%) were successfully weaned and 156 patients (59.9%) survived to hospital discharge. One hundred thirty-one patients (50.0%) were treated with renal replacement therapy during extracorporeal membrane oxygenation support. The survival rate was significantly lower in patients requiring renal replacement therapy compared with those without renal replacement therapy (47.3% vs 71.8%; p < 0.001) overall. The Kaplan-Meier survival curves differed significantly for patients without renal replacement therapy versus patients with renal replacement therapy prior to extracorporeal membrane oxygenation support (p = 0.003). Furthermore, the multivariate logistic regression analysis suggests that the necessity of renal replacement therapy prior to extracorporeal membrane oxygenation insertion was an independent risk factor for mortality (95% CI, 0.77-0.88; p < 0.001). However, the necessity of renal replacement therapy during extracorporeal membrane oxygenation support was not an independent risk factor for mortality in these patients (p = 0.37).

CONCLUSIONS

Acute kidney injury is a major complication in acute respiratory distress syndrome probably mirroring severe systemic disease. In our cohort, development of acute kidney injury requiring renal replacement therapy prior to extracorporeal membrane oxygenation insertion was negatively associated with survival, whereas acute kidney injury that developed during extracorporeal membrane oxygenation support was not.

Practical considerations to drug dosing in children with acute kidney injury

Medication dosing for children with acute kidney injury (AKI) needs to be individualized based on pharmacokinetic and pharmacodynamic principles of the prescribed drugswhenever possible to optimize therapeutic outcome and to minimize toxicity. The pediatric RIFLE criteria should be prospectively utilized to identify patients at highest risk of developing AKI. Serum creatinine and urine output along with volume status should be utilized to guide drug dosing when urinary biomarkers including kidney injury molecule 1, interleukin-18, or neutrophil gelatinase-associated lipocalin are not readily available. Because of the presence of a positive fluid balance in early stages of AKI, the dosing regimen for many drugs, especially antimicrobial agents, should be initiated at a larger loading dose based on the expected volume of distribution to achieve target serum concentrations.When possible, therapeutic drug monitoring should be utilized for those medications where serum drug concentrations can be obtained in a clinically relevant time frame. For these medications, close monitoring of serum drug concentrations is highly recommended. This review addresses drug-dosing strategies in pediatric patients with AKI including the roles of therapeutic drug monitoring and newer kidney injury biomarkers.

Cardiorenal Syndrome Type 1: Renal Dysfunction in Acute Decompensated Heart Failure

OBJECTIVE

To present a review of cardiorenal syndrome type 1 (CRS1).

METHODS

Review of the literature.

RESULTS

Acute kidney injury occurs in approximately one-third of patients with acute decompensated heart failure (ADHF) and the resultant condition was named CRS1. A growing body of literature shows CRS1 patients are at high risk for poor outcomes, and thus there is an urgent need to understand the pathophysiology and subsequently develop effective treatments. In this review we discuss prevalence, proposed pathophysiology including hemodynamic and nonhemodynamic factors, prognosticating variables, data for different treatment strategies, and ongoing clinical trials and highlight questions and problems physicians will face moving forward with this common and challenging condition.

CONCLUSION

Further research is needed to understand the pathophysiology of this complex clinical entity and to develop effective treatments.

The acute cardiorenal syndrome type I: considerations on physiology, epidemiology, and therapy

Acute cardiorenal syndrome, also known as cardiorenal syndrome type 1, is defined as an abrupt worsening of cardiac function that occurs in at least 30 % of patients with acute decompensated heart failure and can lead to the development of acute kidney injury. The changes in renal function that occur in this setting have variable prognostic implications, as both poorer and better outcomes have been reported when renal function worsens during treatment of heart failure decompensation. Furthermore, it remains unclear when worsening renal function is actually a manifestation of true acute kidney injury or simply an indicator of hemoconcentration. Given these gaps in the understanding of the significance of renal function changes in the setting of decompensated heart failure, it is not surprising that studies on the effects of available therapies, including diuretics, vasoactive drugs, and mechanical fluid removal have yielded inconsistent results. The purpose of this review is to analyze critically the current knowledge on the pathophysiology, epidemiology, prognosis, and treatment of acute cardiorenal syndrome.

Novel markers and therapies for patients with acute heart failure and renal dysfunction

BACKGROUND

Acute kidney injury complicates decompensated heart failure in ∼33% of cases and is associated with morbidity and mortality; thus, we sought to systematically review this topic in order to summarize novel diagnostic and therapeutic approaches.

METHODS

Structured PubMed searches on these topics were conducted in February 2014 and relevant literature was identified. The PubMed search identified a total of 192 articles that were individually screened for inclusion in this analysis, and 58 were included.

RESULTS

Acute kidney injury, defined by substantial increases in serum creatinine, is associated consistently with prolonged length of stay, rehospitalization, and mortality. Biomarker studies suggested that natriuretic peptides are prognostic for shorter- and longer-term mortality. Novel proteins indicating kidney damage and albumin in the urine are associated with acute kidney injury. The most promising acute pharmacologic treatment appears to be serelaxin, which has been shown to improve acute heart failure symptoms, hemodynamic parameters, and renal function.

CONCLUSIONS

The presence of acute kidney injury results in worse clinical outcomes for patients with acute heart failure. Novel biomarkers and therapies hold the promise of improving both cardiac and renal outcomes in these patients.

Acute Kidney Injury Subsequent to Cardiac Surgery

Acute kidney injury (AKI) after cardiac surgery is a common and underappreciated syndrome that is associated with poor shortand long-term outcomes. AKI after cardiac surgery may be epiphenomenon, a signal for adverse outcomes by virtue of other affected organ systems, and a consequence of multiple factors. Subtle increases in serum creatinine (SCr) postoperatively, once considered inconsequential, have been shown to reflect a kidney injury that likely occurred in the operating room during cardiopulmonary bypass (CPB) and more often in susceptible individuals. The postoperative elevation in SCr is a delayed signal reflecting the intraoperative injury. Preoperative checklists and the conduct of CPB represent opportunities for prevention of AKI. Newer definitions of AKI provide us with an opportunity to scrutinize perioperative processes of care and determine strategies to decrease the incidence of AKI subsequent to cardiac surgery. Recognizing and mitigating risk factors preoperatively and optimizing intraoperative practices may, in the aggregate, decrease the incidence of AKI. This review explores the pathophysiology of AKI and addresses the features of patients who are the most vulnerable to AKI. Preoperative strategies are discussed with particular attention to a readiness for surgery checklist. Intraoperative strategies include minimizing hemodilution and maximizing oxygen delivery with specific suggestions regarding fluid management and plasma preservation.

AKI in hospitalized children: comparing the pRIFLE, AKIN, and KDIGO definitions

BACKGROUND AND OBJECTIVES

Although several standardized definitions for AKI have been developed, no consensus exists regarding which to use in children. This study applied the Pediatric RIFLE (pRIFLE), AKI Network (AKIN), and Kidney Disease Improving Global Outcomes (KDIGO) criteria to an anonymized cohort of hospitalizations extracted from the electronic medical record to compare AKI incidence and outcomes in intensive care unit (ICU) and non-ICU pediatric populations.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Observational, electronic medical record-enabled study of 14,795 hospitalizations at the Lucile Packard Children's Hospital between 2006 and 2010. AKI and AKI severity stage were defined by the pRIFLE, AKIN, and KDIGO definitions according to creatinine change criteria; urine output criteria were not used. The incidences of AKI and each AKI stage were calculated for each classification system. All-cause, in-hospital mortality and total hospital length of stay (LOS) were compared at each subsequent AKI stage by Fisher exact and Kolmogorov-Smirnov tests, respectively.

RESULTS

AKI incidences across the cohort according to pRIFLE, AKIN, and KDIGO were 51.1%, 37.3%, and 40.3%. Mortality was higher among patients with AKI across all definitions (pRIFLE, 2.3%; AKIN, 2.7%; KDIGO, 2.5%; P<0.001 versus no AKI [0.8%-1.0%]). Within the ICU, pRIFLE, AKIN, and KDIGO demonstrated progressively higher mortality at each AKI severity stage; AKI was not associated with mortality outside the ICU by any definition. Both in and outside the ICU, AKI was associated with significantly higher LOS at each AKI severity stage across all three definitions (P<0.001). Definitions resulted in differences in diagnosis and staging of AKI; staging agreement ranged from 76.7% to 92.5%.

CONCLUSIONS

Application of the three definitions led to differences in AKI incidence and staging. AKI was associated with greater mortality and LOS in the ICU and greater LOS outside the ICU. All three definitions demonstrated excellent interstage discrimination. While each definition offers advantages, these results underscore the need to adopt a single, universal AKI definition.