Evaluation and management of critically ill children with acute kidney injury

Acute Kidney Injury in Neonatal Intensive Care Unit: Epidemiology, Diagnosis and Risk Factors

Acute kidney injury (AKI) is associated with long-term consequences and poor outcomes in the neonatal intensive care unit. Its precocious diagnosis represents one of the hardest challenges in clinical practice due to the lack of sensitive and specific biomarkers. Currently, neonatal AKI is defined with urinary markers and serum creatinine (sCr), with limitations in early detection and individual treatment. Biomarkers and risk factor scores were studied to predict neonatal AKI, to early identify the stage of injury and not the damage and to anticipate late increases in sCr levels, which occurred when the renal function already began to decline. Sepsis is the leading cause of AKI, and sepsis-related AKI is one of the main causes of high mortality. Moreover, preterm neonates, as well as patients with post-neonatal asphyxia or after cardiac surgery, are at a high risk for AKI. Critical patients are frequently exposed to nephrotoxic medications, representing a potentially preventable cause of AKI. This review highlights the definition of neonatal AKI, its diagnosis and new biomarkers available in clinical practice and in the near future. We analyze the risk factors involving patients with AKI, their outcomes and the risk for the transition from acute damage to chronic kidney disease.

Acute kidney injury: the experience of a tertiary center of Pediatric Nephrology

INTRODUCTION

Acute kidney injury (AKI) is an abrupt deterioration of kidney function. The incidence of pediatric AKI is increasing worldwide, both in critically and non-critically ill settings. We aimed to characterize the presentation, etiology, evolution, and outcome of AKI in pediatric patients admitted to a tertiary care center.

METHODS

We performed a retrospective observational single-center study of patients aged 29 days to 17 years and 365 days admitted to our Pediatric Nephrology Unit from January 2012 to December 2021, with the diagnosis of AKI. AKI severity was categorized according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The outcomes considered were death or sequelae (proteinuria, hypertension, or changes in renal function at 3 to 6 months follow-up assessments).

RESULTS

Forty-six patients with a median age of 13.0 (3.5-15.5) years were included. About half of the patients (n = 24, 52.2%) had an identifiable risk factor for the development of AKI. Thirteen patients (28.3%) were anuric, and all of those were categorized as AKI KDIGO stage 3 (p < 0.001). Almost one quarter (n = 10, 21.7%) of patients required renal replacement therapy. Approximately 60% of patients (n = 26) had at least one sequelae, with proteinuria being the most common (n = 15, 38.5%; median (P25-75) urinary protein-to-creatinine ratio 0.30 (0.27-0.44) mg/mg), followed by reduced glomerular filtration rate (GFR) (n = 11, 27.5%; median (P25-75) GFR 75 (62-83) mL/min/1.73 m2).

CONCLUSIONS

Pediatric AKI is associated with substantial morbidity, with potential for proteinuria development and renal function impairment and a relevant impact on long-term prognosis.

High Serum Albumin Levels were Associated with Acute Kidney Injury in Pediatric Surgical Intensive Care Units

INTRODUCTION

There are limited studies revealing the association between serum albumin concentrations and acute kidney injury (AKI) in critically ill children.

METHODS

This was a multicenter retrospective study. Children consecutively admitted to four pediatric surgical intensive care units (PSICUs) between January 2016 and December 2020 were screened for analysis. Patients without recorded albumin values during the PSICU stay were excluded. Data were extracted from the electronic medical records systems of the hospitals. AKI was defined according to the Kidney Disease Improving Global Outcome (KDIGO) guidelines. The associations between serum albumin levels and AKI were assessed by using logistic regression models.

RESULTS

A total of 7802 children were included in the analysis. The median age of the children was 1.0 (interquartile range (IQR), 0.0-4.0) years. There were 3214 (41.2 %) children who developed AKI. In the univariate logistic regression model, serum albumin levels were associated with AKI (odds ratio (OR) = 1.04, 95 % confidence interval (CI) 1.04-1.05). After adjusting for covariates, serum albumin showed an independent association with AKI (OR = 1.04, 95 % CI 1.03-1.05). Albumin levels above 39.43 g/L (OR = 1.036, 95 % CI 1.002-1.070) were associated with AKI in the unadjusted cubic spline. In the adjusted cubic spline, albumin levels above 40.41 g/L (OR = 1.061, 95 % CI 1.003-1.122) were associated with AKI.

CONCLUSION

High serum albumin was associated with AKI in critically ill children in the PSICU. Further studies are needed to validate our findings.

TYPE OF STUDY

Prognostic Study.

LEVEL OF EVIDENCE

LEVEL II.

Pediatric acute kidney injury: new advances in the last decade

Pediatric acute kidney injury (AKI) is a frequently missed complication. AKI has a significant impact on both short- and long-term outcomes in children. Within the last decade, there have been major landmark developments in this field of critical care pediatric nephrology. The topic was searched by two independent researchers using Google Scholar and PubMed and related studies published in the last 10 years. The terms used for the search were 'pediatric acute kidney injury,' 'pediatric acute renal failure,' 'pediatric dialysis,' 'biomarkers,' 'nephrotoxins,' 'nephrotoxicity in children,' and 'pediatric critical care nephrology.' We found that AKI is common in critically ill neonates and children. Among the various definitions, the Kidney Disease: Improving Global Outcomes (KDIGO) definition is most commonly used. In addition, it is imperative to risk stratify sick children at admission in the hospital to predict AKI and worse outcomes as this aids in early management. There are now major landmark trials that describe the epidemiology, prevention, and management guidelines in this field and health care professionals need to be aware they should diagnose AKI early. Overall, this review highlights the landmark studies in the last decade and shows that early diagnosis and management of AKI in 'at risk' children can improve outcomes.

NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN AS AN EARLY BIOMARKER OF ACUTE KIDNEY INJURY IN NEWBORNS

The aim of the study was to determine the incidence, risk factors and efficiency of the neutrophil gelatinase-associated lipocalin (NGAL) biomarker in early diagnosis of acute kidney injury (AKI) in newborns. The study was designed as a prospective, clinical, epidemiological investigation conducted in the period of three years, which included 50 newborns with AKI hospitalized in the Neonatal Intensive Care Unit, University Children’s Hospital in Skopje. The estimated prevalence of AKI was 6.4%, while the prevalence according to RIFLE classification was 8.7%. Perinatal asphyxia was a common predisposing factor associated to kidney injury. The mortality rate was 32% and was significantly higher in the group of newborns with congenital heart diseases. There was a significant difference between NGAL values and creatinine values on the day of admission. There was a significant difference in NGAL values between newborns with AKI and lethal outcome and newborns without lethal outcome (p<0.001). In conclusion, AKI is a life-threatening condition. It is an independent contributor to mortality. Urinary NGAL is an early predictive biomarker of AKI in critically ill newborns.

Fluid balance after continuous renal replacement therapy initiation and outcome in paediatric multiple organ failure

BACKGROUND

Patients with multiple organ failure (MOF) often receive large amounts of resuscitation fluid, making them at high risk of fluid overload (FO). Our main objective was to investigate if the ability to achieve a negative fluid balance during the first 3 continuous renal replacement therapy (CRRT) days was associated with mortality in children with MOF.

METHODS

Retrospective cohort study in a tertiary multidisciplinary academic paediatric hospital. The study included 63 patients (age 0-18 years) with 3 or more failing organs receiving CRRT due to acute kidney injury and/or fluid overload.

RESULTS

The median age was 4 months, and PICU mortality was 29%. Survivors had significantly lower degree of FO at CRRT initiation, (median 15% (Interquartile range 9-22)) than non-survivors (24% (17%-37%), P = 0.002). On PICU admission, PIM-3 score was significantly higher in non-survivors (P = 0.01), but at CRRT initiation there was no difference in PELOD-2 score (P = 0.98). Mortality in patients achieving a cumulative net negative fluid balance during the first 3 days after CRRT initiation was 12%, compared to 86% in those not achieving this (P < 0.0001). In multivariate analysis, the inability to achieve a net negative fluid balance during 3 days after CRRT initiation (P < 0.0001) and FO >20% at CRRT initiation (P = 0.0019) remained associated with mortality.

CONCLUSION

Our results suggest that early fluid removal is associated with improved patient outcome in critically ill children receiving CRRT, and that prompt measures should be taken to prevent fluid overload in critical illness. These results need to be verified in further, prospective studies.

Neutrophil Phenotype Correlates With Postoperative Inflammatory Outcomes in Infants Undergoing Cardiopulmonary Bypass

OBJECTIVES

Infants with congenital heart disease frequently require cardiopulmonary bypass, which causes systemic inflammation. The goal of this study was to determine if neutrophil phenotype and activation status predicts the development of inflammatory complications following cardiopulmonary bypass.

DESIGN

Prospective cohort study.

SETTING

Tertiary care PICU with postoperative cardiac care.

PATIENTS

Thirty-seven patients 5 days to 10 months old with congenital heart disease requiring cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Laboratory and clinical data collected included length of mechanical ventilation, acute kidney injury, and fluid overload. Neutrophils were isolated from whole blood at three time points surrounding cardiopulmonary bypass. Functional analyses included measurement of cell surface protein expression and nicotinamide adenine dinucleotide phosphate oxidase activity. Of all patients studied, 40.5% displayed priming of nicotinamide adenine dinucleotide phosphate oxidase activity in response to N-formyl-Met-Leu-Phe stimulation 24 hours post cardiopulmonary bypass as compared to pre bypass. Neonates who received steroids prior to bypass demonstrated enhanced priming of nicotinamide adenine dinucleotide phosphate oxidase activity at 48 hours. Patients who displayed priming post cardiopulmonary bypass were 8.8 times more likely to develop severe acute kidney injury as compared to nonprimers. Up-regulation of neutrophil surface CD11b levels pre- to postbypass occurred in 51.4% of patients, but this measure of neutrophil priming was not associated with acute kidney injury. Subsequent analyses of the basal neutrophil phenotype revealed that those with higher basal CD11b expression were significantly less likely to develop acute kidney injury.

CONCLUSIONS

Neutrophil priming occurs in a subset of infants undergoing cardiopulmonary bypass. Acute kidney injury was more frequent in those patients who displayed priming of nicotinamide adenine dinucleotide phosphate oxidase activity after cardiopulmonary bypass. This pilot study suggests that neutrophil phenotypic signature could be used to predict inflammatory organ dysfunction.

Comparison of enteral versus intravenous potassium supplementation in hypokalaemia in paediatric patients in intensive care post cardiac surgery: open-label randomised equivalence trial (EIPS)

OBJECTIVES

The primary objective was to compare the efficacy of enteral potassium replacement (EPR) and intravenous potassium replacement (IVPR) as first-line therapy. Secondary objectives included comparison of adverse effects and number of doses required to resolve the episode of hypokalaemia.

TRIAL DESIGN

The EIPS trial is designed as a randomised, equivalence trial between two treatment arms.

STUDY SETTING

The study was conducted at the paediatric cardiac intensive care unit (PCICU) at Aga Khan University Hospital, Karachi.

PARTICIPANTS

41 patients (aged 1 month to 15 years) who were admitted to PCICU post cardiac surgery were recruited (23 IVPR arm and 18 EPR arm).

INTERVENTION

Intervention arms were block randomised on alternate weeks for IVPR and EPR.

OUTCOME MEASURE

Change in serum potassium levels in (mmol/L) and percentage change after each event of potassium replacement by the intravenous or enteral route.

RESULTS

Both groups (41 patients) had similar baseline characteristics. Mean age was 4.7 (SD±4) years while the most common surgical procedure was ventricular septal defect repair (12 patients, 29.3%). No mortality was observed in either arm. Four episodes of vomiting and one arrhythmia were seen in the EPR group. After adjusting for age, potassium level at the beginning of the episode, average urine output, inotropic score and diuretic dose, it was found that there was no statistically significant difference in change in potassium levels after EPR and IVPR: 0.86 mmol/L (±0.8) and 0.82 mmol/L (±0.7) respectively (p=0.86, 95% CI -0.08 to 1.10), or percentage change in potassium level after enteral and intravenous replacement: 26% (±30) and 24% (±20) (95% CI -3.42 to 4.03, p=0.87).

CONCLUSION

EPR may be an equally efficacious alternative first-line therapy in treating hypokalaemia after surgery in selective patients with congenital heart disease.

ETHICS AND DISSEMINATION

This study has been approved by Ethics Review Committee at AKU.

TRIAL REGISTRATION NUMBER

NCT02015962.

Optimising the use of medicines to reduce acute kidney injury in children and babies

The majority of medications in children are administered in an unlicensed or off-label manner. Paediatricians are obliged to prescribe using the limited evidence available. The 2007 EU regulation on the use of paediatric drugs means pharmaceutical companies are now obliged to (and receive incentives for) contributing to paediatric drug data and carrying out paediatric clinical trials. This is important, as the efficacy and adverse effect profiles of medicines vary across childhood. Additionally, there are significant age-related changes in the pharmacodynamic and pharmacokinetic activity of many drugs. This may be related to physiological (differential expressions of cytochrome P450 enzymes or variable glomerular filtration rates at different ages for example) and psychological (increasing autonomy and risk perception in teenage years) changes. Increasing numbers of children are surviving life-threatening childhood conditions due to medical advances. This means there is an increasing population who are at risk of the consequences of the long-term, early exposure to nephrotoxic agents. The kidney is an organ that is particularly vulnerable to damage as a consequence of drugs. Drug-induced acute kidney injury (AKI) episodes in children and babies are principally due to non-steroidal anti-inflammatory drugs, antibiotics or chemotherapeutic agents. The renal tubules are vulnerable to injury because of their concentrating ability and high-energy hypoxic environment. This review focuses on drug-induced AKI and the methods to minimise its effect, including general management plus the role of child-specific pharmacokinetic data, the use of pharmacogenomics and early detection of AKI using urinary biomarkers and electronic triggers.

The path to chronic kidney disease following acute kidney injury: a neonatal perspective

The risk of acute kidney injury (AKI) in hospitalized critically ill neonatal populations without primary renal disease continues to be high, in both term and premature infants. Observational studies have revealed high rates of chronic kidney disease (CKD) in survivors of neonatal AKI. Proposed mechanisms underlying the progression of CKD following AKI include nephron loss and hyperfiltration, vascular insufficiency and maladaptive repair mechanisms. Other factors, including prematurity and low birth weight, have an independent relationship with the development of CKD, but they may also be positive effect modifiers in the relationship of AKI and CKD. The large degree of heterogeneity in the literature on AKI in the neonatal population, including the use of various AKI definitions and CKD outcomes, has hampered the medical community's ability to properly assess the relationship of AKI and CKD in this vulnerable population. Larger prospective cohort studies with control groups which utilize recently proposed neonatal AKI definitions and standardized CKD definitions are much needed to properly quantify the risk of CKD following an episode of AKI. Until there is further evidence to guide us, we recommend that all neonates with an identified episode of AKI should have an appropriate longitudinal follow-up in order to identify CKD at its earliest stages.

Urinary C-type natriuretic peptide excretion: a promising biomarker to detect underlying renal injury and remodeling both acutely and chronically

Acute kidney injury (AKI) refers to a sudden decline in renal function. A growing body of evidence demonstrates that AKI is a risk factor for the future development or accelerated progression of chronic kidney disease (CKD), whereas the actual distinction between AKI and CKD remains unknown. CNP is predominantly present in the kidney and possesses multiple renoprotective properties. Urinary CNP excretion tends to be high in AKI, whereas back to the baseline in CKD. The dynamic changes in urinary CNP excretion may help detect underlying renal injury and remodeling both acutely and chronically.

Fluid Overload Is Associated With Late Poor Outcomes in Neonates Following Cardiac Surgery

OBJECTIVES

Acute kidney injury is a severe complication of cardiac surgery associated with increased morbidity and mortality; yet, acute kidney injury classification for neonates remains challenging. We characterized patterns of postoperative fluid overload as a surrogate marker for acute kidney injury and as a risk factor of poor postoperative outcomes in neonates undergoing cardiac surgery.

DESIGN

Retrospective cohort study.

SETTING

Single, congenital heart center destination program.

PATIENTS

Four hundred thirty-five neonates undergoing cardiac surgery with cardiopulmonary bypass from January 2006 through December 2010.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographics, diagnosis, and perioperative clinical variables were collected, including daily weights and serum creatinine levels. A composite poor clinical outcome (death, need for renal replacement therapy or extracorporeal life support within 30 postoperative days) was considered the primary outcome measure. Twenty-one neonates (5%) had a composite poor outcome with 7 (2%) requiring renal replacement therapy, 8 (2%) requiring extracorporeal life support, and 14 (3%) dying between 3 and 30 days post surgery. Neonates with a composite poor outcome had significantly higher maximum fluid overload (> 20%) and were slower to diurese. A receiver-operating characteristic curve determined that fluid overload greater than or equal to 16% and serum creatinine greater than or equal to 0.9 on postoperative day 3 were the optimal cutoffs for significant discrimination on the primary outcome (area under the curve = 0.71 and 0.76, respectively). In multivariable analysis, fluid overload greater than or equal to 16% (adjusted odds ratio = 3.7) and serum creatinine adjusted odds ratio 0.9 (adjusted odds ratio = 6.6) on postoperative day 3 remained an independent risk factor for poor outcome. Fluid overload greater than or equal 16% was also significantly associated with cardiac arrest requiring cardiopulmonary resuscitation, prolonged ICU stay, and chest reexploration.

CONCLUSIONS

This study highlights the importance of monitoring fluid balance in the neonatal cardiac surgical population and suggests that daily fluid overload, a readily available, noninvasive marker of renal function, may be a sensitive and specific predictor of adverse outcomes.

Continuous renal replacement therapy in children: fluid overload does not always predict mortality

BACKGROUND

Mortality among critically ill children requiring continuous renal replacement therapy (CRRT) is high. Several factors have been identified as outcome predictors. Many studies have specifically reported a positive association between the fluid overload at CRRT initiation and the mortality of critically ill pediatric patients.

METHODS

This study is a retrospective single-center analysis including all patients admitted to the pediatric intensive care unit (PICU) of our hospital who received CRRT between 2000 and 2012. One hundred thirty-one patients were identified and subsequently classified according to primary disease. Survival rates, severity of illness and fluid balance differed among subgroups. The primary outcome was patient survival to PICU discharge.

RESULTS

Overall survival to PICU discharge was 45.8 %. Based on multiple regression analysis, mortality was independently associated with onco-hematological disease [odds ratio (OR) 11.7, 95 % confidence interval (CI) 1.3-104.7; p = 0.028], severe multiple organ dysfunction syndrome (MODS) (OR 5.1, 95 % CI 1.7-15; p = 0.003) and hypotension (OR 11.6, 95 % CI 1.4-93.2; p = 0.021). In the subgroup analysis, a fluid overload (FO) of more than 10 % (FO>10 %) at the beginning of CRRT seems to be a negative predictor of mortality (OR 10.9, 95 % CI 0.78-152.62; p = 0.07) only in children with milder disease (renal patients). Due to lack of statistical power, the independent effect of fluid overload on mortality could not be analyzed in all subgroups of patients.

CONCLUSIONS

In children treated with CRRT the underlying diagnosis and severity of illness are independent risk factors for mortality. The degree of FO is a negative predictor only in patients with milder disease.

Theophylline Population Pharmacokinetics and Dosing in Children Following Congenital Heart Surgery With Cardiopulmonary Bypass

Children undergoing cardiac surgery requiring cardiopulmonary bypass (CPB) frequently develop acute kidney injury due to renal ischemia. Theophylline, which improves renal perfusion via adenosine receptor inhibition, is a potential targeted therapy. However, children undergoing cardiac surgery and CPB commonly have alterations in drug pharmacokinetics. To help understand optimal aminophylline (salt formulation of theophylline) dosing strategies in this population, a population-based pharmacokinetic model was developed using nonlinear mixed-effects modeling (NONMEM) from 71 children (median age 5 months; 90% range 1 week to 10 years) who underwent cardiac surgery requiring CPB and received aminophylline as part of a previous randomized controlled trial. A 1-compartment model with linear elimination adequately described the pharmacokinetics of theophylline. Weight scaled via allometry was a significant predictor of clearance and volume. In addition, allometric scaled clearance increased with age implemented as a power maturation function. Compared to prior reports in noncardiac children, theophylline clearance was markedly reduced across age. In the final population pharmacokinetic model, optimized empiric dosing regimens were developed via Monte Carlo simulations. Doses 50% to 75% lower than those recommended in noncardiac children were needed to achieve target serum concentrations of 5 to 10 mg/L.

Association Between Progression and Improvement of Acute Kidney Injury and Mortality in Critically Ill Children

OBJECTIVE

To determine whether the progression and/or improvement of acute kidney injury in critically ill children is associated with mortality.

DESIGN

Retrospective.

SETTING

Multidisciplinary, tertiary care, 24-bed PICU.

PATIENTS

A TOTAL OF: 8,260 patients who were 1 month to 21 years old with no chronic kidney disease admitted between May 2003 and March 2012.

INTERVENTIONS

We analyzed patients based on their acute kidney injury stage as per the Kidney Disease Improving Global Outcomes acute kidney injury serum creatinine staging criteria on ICU admission, peak (highest acute kidney injury stage reached), and trough (lowest acute kidney injury stage after the peak) during their ICU stay. Nonrenal organ dysfunction was measured with a modified Pediatric Logistic Organ Dysfunction score. The primary outcome was 28-day mortality. p values were based on Yates-corrected chi-square test and logistic regression.

MEASUREMENTS AND MAIN RESULTS

Of the 8,260 patients, 529 (6.4%) had acute kidney injury on ICU admission and 974 (11.8%) had acute kidney injury during their ICU course. The 28-day mortality was 2.7% for patients with no acute kidney injury and 25.3% for patients with acute kidney injury. Patients in whom acute kidney injury developed or had worsening acute kidney injury from admission to peak and reached acute kidney injury stage 2 or 3 had higher mortality than those who remained at an acute kidney injury stage 1 (17.3-17.8% vs 32.2-37.9%; p ≤ 0.003). Patients whose acute kidney injury resolved after the peak had lower mortality than those who retained the same degree of acute kidney injury (9-13.5% vs 37.3-44%; p ≤ 0.04). Patients with acute kidney injury that resolved still had higher mortality than those who never developed acute kidney injury (11.2% vs 2.7%; p < 0.001). Multivariate regression demonstrated that the association between mortality and acute kidney injury progression was independent of severity of illness at admission and the severity of nonrenal organ dysfunction during the first week of ICU stay (p ≤ 0.01).

CONCLUSION

Progression of acute kidney injury per the Kidney Disease Improving Global Outcomes staging criteria is independently associated with increased mortality in the PICU while its improvement is associated with a stepwise decrease in mortality.

Urinary kidney injury molecule-1 rapid test predicts acute kidney injury in extremely low-birth-weight neonates

BACKGROUND

The new urinary and serum biomarkers are discovered and are being investigated. With them we can diagnose acute kidney injury (AKI) faster and more precisely and they also have a significant role in the outcome prediction.

METHODS

The study included 22 extremely low-birth-weight neonates who were hospitalized in the neonatal intensive care units. They were divided into two groups based on serum creatinine (SCr) level-with and without AKI. Detection and quantification of urinary kidney injury molecule-1 (uKIM-1) was done on the third day of life, using commercially available KIM-1 rapid test. Subsequently, measurements were repeated only in subjects who were diagnosed with AKI, at different values of SCr.

RESULTS

Logistic regression analysis showed that AKI is an independent risk factor for mortality. In a group of neonates with AKI, 50% of neonates administered the KIM-1 rapid test showed positive findings. KIM-1 rapid test was positive in patients with a wide range of SCr levels (range of 78.73-385 µmol/l), but all subjects had oliguria and died in the next 24 h.

CONCLUSION

KIM-1 is a significant predictor of death. On the other hand, our study failed to prove that KIM-1 rapid test has any significance for early prediction of AKI.

Influence of Acute Kidney Injury Defined by the Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease Score on the Clinical Course of PICU Patients

OBJECTIVE

To evaluate the predictive value of the pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease criteria for disease course severity in patients with or without acute kidney injury admitted to a PICU.

DESIGN

Retrospective cohort study.

SETTING

A 12-bed PICU at a tertiary referral center in Southern Brazil.

PATIENTS

All patients admitted to the study unit over a 1-year period.

INTERVENTIONS

A database of all eligible patients was analyzed retrospectively.

MEASUREMENTS AND MAIN RESULTS

Patients were classified by pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease score at admission and worst pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease score during PICU hospitalization. The outcomes of interest were length of PICU stay, duration of mechanical ventilation, duration of vasoactive drug therapy, and mortality. The Pediatric Index of Mortality 2 was used to assess overall disease severity at the time of PICU admission. Of 375 patients, 169 (45%) presented acute kidney injury at the time of admission and 37 developed acute kidney injury during PICU stay, for a total of 206 of 375 patients (55%) diagnosed with acute kidney injury during the study period. The median Pediatric Index of Mortality 2 score predicted a mortality rate of 9% among non-acute kidney injury patients versus a mortality rate of 16% among acute kidney injury patients (p = 0.006). The mortality of patients classified as pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease F was double that predicted by Pediatric Index of Mortality 2 (7 vs 3.2). Patients classified as having severe acute kidney injury (pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease I + F) exhibited higher mortality (14.1%; p = 0.001) and prolonged PICU length of stay (median, 7 d; p = 0.001) when compared with other patients. Acute kidney injury is a very frequent occurrence among patients admitted to PICUs.

CONCLUSIONS

The degree of acute kidney injury severity, as assessed by the pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease criteria, is a good predictor of morbidity and mortality in this population. Pediatric Index of Mortality 2 tends to underestimate mortality in pediatric patients with severe acute kidney injury.

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.

Acute kidney injury in preterm infants admitted to a neonatal intensive care unit

BACKGROUND

The factors that contribute to the development of acute kidney injury (AKI) and treatment outcome among prematurely born neonates are not clearly understood.

METHODS

This retrospective study included 150 prematurely born neonates. AKI was defined as an increase of serum creatinine levels ≥0.3 mg/dl compared to basal values.

RESULTS

The majority of neonates with AKI (94.8 %) had a body weight <1,500 g. Logistic regression analysis showed that the Apgar score in the 5th minute <5, serum lactate levels >5 on the first day of life, core body temperature <36 ºC on the first day of life, occurrence of sepsis, intracranial hemorrhage, necrotizing enterocolitis, patent ductus arteriosus, as well as a treatment with vancomycin or dopamine were independent risk factors for the development of AKI. After the groups of neonates with and without AKI were adjusted, the calculated risk ratio for a negative outcome of treatment (death) was 2.215 (CI 1.27-3.86) for neonates with AKI. Neonates with AKI had higher serum sodium levels in the third and fourth days of life.

CONCLUSIONS

AKI is associated with high mortality in preterm neonates. It is very important to identify, as quickly as possible, all infants who are at high risk of developing AKI.

Laboratory predictors of acute dialysis in hemolytic uremic syndrome

BACKGROUND

Strict guidelines on use of dialysis in children with post-diarrheal hemolytic uremic syndrome (D + HUS) are lacking. This study investigated laboratory predictors of acute dialysis because they are more objective than clinical features. Added to this, given that urine output is also an objective parameter, its ability to predict dialysis requirements was also investigated.

METHODS

Out of 153 D + HUS children reviewed, 88 received dialysis and 65 did not. Initial laboratory parameters and diuresis between both groups were analyzed.

RESULTS

Dialyzed patients had higher creatinine, urea, alanine aminotransferase, hematocrit and leukocyte count; and lower sodium, bicarbonate, and pH compared to non-dialyzed ones. Serum creatinine was the only independent predictor (P = 0.003) of dialysis; therefore, its ability to predict dialysis was estimated on receiver operating characteristic (ROC) curve analysis and using the Acute Kidney Injury Network (AKIN) staging system. Area under the ROC curve was 0.92 (95% confidence interval [95%CI]: 0.83-1) with a creatinine cut-off of 1.25 mg/dL (sensitivity, 100%; specificity, 76.5%) for children <1 year, and 0.93 (95%CI: 0.88-0.98) with a threshold of 2 mg/dL (sensitivity, 91%; specificity, 87.5%) for older children. AKIN stage 3 at admission predicted dialysis with a sensitivity of 92% and specificity of 84.2%. Urine output had the highest accuracy for dialysis prediction (sensitivity, 100%; specificity, 95.3%).

CONCLUSIONS

Initial serum creatinine concentration was the best laboratory predictor of dialysis, but the first 24 h diuresis was even better for this purpose. But, given that serum creatinine is an immediate available parameter, the cut-offs identified may label D + HUS children who will probably need dialysis, prompting early referral to centers able to provide dialysis.

Acute kidney injury in neonates: from urine output to new biomarkers

In the past 10 years, great effort has been made to define and classify a common syndrome previously known as acute renal failure and now renamed “acute kidney injury (AKI).” Initially suggested and validated in adult populations, AKI classification was adapted to the pediatric population and recently has been modified for the neonatal population. Several studies have been performed in adults and older children using this consensus definition, leading to improvement in the knowledge of AKI incidence and epidemiology. In spite of these advances, the peculiar renal pathophysiology of critically ill newborn patients makes it difficult to interpret urine output (UO) and serum creatinine (SCr) levels in these patients to diagnose AKI. Also, new urine biomarkers have emerged as a possible alternative to diagnose early AKI in the neonatal population. In this review, we describe recent advances in neonatal AKI epidemiology, discuss difficulties in diagnosing AKI in newborns, and show recent advances in new AKI biomarkers and possible long-term consequences after AKI episode.

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.

Management of unstable pediatric hemato-oncology patient: results of a Web-based survey to pediatric oncologists in Spain

The current management and monitoring of unstable pediatric hemato-oncology patient (UPHOP) in the oncology ward is not well defined. To evaluate this concept, an anonymous Web-based survey was sent to the 150 Spanish pediatric oncologists registered in the Spanish Society of Pediatric Hemato-Oncology. The response rate was 57 %, with the following main results: Pediatric intensive consulting was available for 97 %, and it was made in case of UPHOP by 37 % of oncologists, up to 65 % if hemodynamic instability. In case of inotropic support initiation, 32 % of respondents never consulted the intensivist. Dopamine is first chosen inotropic; 28 % of surveyed considered there is no limit in its dosage or it is superior to 20 μg/kg/min before an intensivist consulting. Pediatric intensive care admission was considered necessary in case of fever with hemodynamic instability by 15 % of respondents. Respiratory monitoring was mainly done by clinical signs (67 %). In case of respiratory insufficiency, the noninvasive respiratory support by high-flow ventilation with nasal cannula was applied by 57 % in the oncology ward. In case of acute kidney injury, diuretics were generally the initial therapy. The anticonvulsive drugs most frequently applied were valproic acid (93 %), diazepam (88 %), and phenytoin (81 %).

CONCLUSION

A consensus should be achieved among oncologists and intensivists. The creation and training of rapid response teams could be useful to improve the UPHOP management.

Acute kidney injury: A pediatric experience over 10 years at a tertiary care center

BACKGROUND

The etiology of acute kidney injury (AKI) varies in different countries. In addition, the etiology of AKI in hospitalized children is multifactorial. The importance of diagnosing AKI is not only because of short-term high morbidity and mortality rate, but also for its effect on developing chronic kidney disease.

OBJECTIVES

we studied retrospectively AKIs of children who were hospitalized over 10 years in a University hospital.

MATERIALS AND METHODS

A retrospective analysis of the medical recorded data of 180 children less than 18 years treated for AKI in Alzahra Hospital, Isfahan, Iran, were performed during the period of March 2001 to February 2011. For each patient, demographic and anthropometric data, laboratory data, electrocardiographic findings, ultrasound results, etiology of AKI and short-term outcomes were recorded.

RESULTS

The male to female ratio was 1.57 to 1. Mean age was 5.28 ± 6.3 (SD) years and the median was 1.8 years. The more frequent age group was children less than 2 years. The mortality rate was 22.2% (40 patients). The mortality was not correlated with age (p= 0.74). Renal replacement therapy was recommended for 62 patients (34.4%). Mean of the first and last glomerular filtration rate (GFR) were 18.33± 1.12 ml/min/1.73 m² and 52.53 ± 2.98 ml/min/1.73 m², respectively. The most common urinary sediment finding in approximately 70% of the patients was either renal epithelial cell or renal cell cast. Increased kidney echogenicity was the most common ultrasound finding (48%). Using ANOVA regression analysis, the etiology of disease was the only predictor of mortality (p=0.0001).

CONCLUSIONS

We concluded that the mortality is still high in AKI. Furthermore, the poor outcome (defined as low GFR) are higher among patients with low levels of first GFR and higher RIFLE score.