Long-term Health Care Utilization and Associated Costs After Dialysis-Treated Acute Kidney Injury in Children

Kidney and blood pressure outcomes 11 years after pediatric critical illness and longitudinal impact of AKI: a prospective cohort study

BACKGROUND

Acute kidney injury (AKI) is common in critically ill children and associated with adverse short-term outcomes; however, long-term outcomes are not well described.

METHODS

This longitudinal prospective cohort study examined the prevalence of chronic kidney disease (CKD) and hypertension (HTN) 11 vs. 6 years after pediatric intensive care unit (PICU) admission and association with AKI. We examined children (age < 19 years) without pre-existing kidney disease 11 ± 1.5 years after PICU admission at a single center. AKI was defined using serum creatinine criteria. The primary outcome was a composite of CKD or HTN. CKD was defined as estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m2 or albuminuria. Multivariable analyses compared outcomes at 11- vs. 6-year follow-up and association with AKI during PICU admission.

RESULTS

Of 96 children evaluated 11 years after PICU admission, 16% had evidence of CKD or HTN (vs. 28% at 6 years, p < 0.05). Multivariable analysis did not show improvement in outcomes from 6- to 11-year follow-up. eGFR decreased from 6- to 11-year follow-up (adjusted coefficient - 11.7, 95% CI - 17.6 to - 5.9) and systolic and diastolic blood pressures improved. AKI was associated with composite outcome at 6-year (adjusted odds ratio (aOR) 12.7, 95% CI 3.2-51.2, p < 0.001), but not 11-year follow-up (p = 0.31). AKI was associated with CKD (aOR 10.4, 95% CI 3.1-34.7) at 11 years.

CONCLUSIONS

This study provides novel data showing that adverse kidney and blood pressure outcomes remain highly prevalent 10 years after critical illness in childhood. The association with AKI wanes over time.

Long-Term Kidney Outcomes after Pediatric Acute Kidney Injury

Key Points

Among 4173 children with AKI, 18% had major adverse kidney events (death, kidney failure, or CKD) during a median 10-year follow-up. AKI survivors were at 2–4 times higher risk of major adverse kidney events, hypertension, and subsequent AKI versus matched hospitalized comparators. This justifies improved surveillance after pediatric AKI to detect CKD and hypertension early and improve long-term kidney health.

Background

AKI is common in hospitalized children. Pediatric AKI receiving acute KRT is associated with long-term CKD, hypertension, and death. We aim to determine the outcomes after AKI in children who did not receive acute KRT because these remain uncertain.

Methods

Retrospective cohort study of all hospitalized children (0–18 years) surviving AKI without acute KRT between 1996 and 2020 in Ontario, Canada, identified by validated diagnostic codes in provincial administrative health databases. Children with prior KRT, CKD, or AKI were excluded. Cases were matched with up to four hospitalized comparators without AKI by age, neonatal status, sex, intensive care unit admission, cardiac surgery, malignancy, hypertension, hospitalization era, and a propensity score for AKI. Patients were followed until death, provincial emigration, or censoring in March 2021. The primary outcome was long-term major adverse kidney events (a composite of all-cause mortality, long-term KRT, or incident CKD).

Results

We matched 4173 pediatric AKI survivors with 16,337 hospitalized comparators. Baseline covariates were well-balanced following propensity score matching. During a median 9.7-year follow-up, 18% of AKI survivors developed long-term major adverse kidney event versus 5% of hospitalized comparators (hazard ratio [HR], 4.0; 95% confidence interval [CI], 3.6 to 4.4). AKI survivors had higher rates of long-term KRT (2% versus <1%; HR, 11.7; 95% CI, 7.5 to 18.4), incident CKD (16% versus 2%; HR, 7.9; 95% CI, 6.9 to 9.1), incident hypertension (17% versus 8%; HR, 2.3; 95% CI, 2.1 to 2.6), and AKI during subsequent hospitalization (6% versus 2%; HR, 3.7; 95% CI, 3.1 to 4.5), but no difference in all-cause mortality (3% versus 3%; HR, 0.9; 95% CI, 0.7 to 1.1).

Conclusions

Children surviving AKI without acute KRT were at higher long-term risk of CKD, long-term KRT, hypertension, and subsequent AKI versus hospitalized comparators.

Systematic Review and Meta-Analysis of the Incidence of Chronic Kidney Disease After Pediatric Critical Illness

OBJECTIVE

Survivors of pediatric critical illnesses are at risk of significant long-term organ sequelae. Chronic kidney disease (CKD) is a complication of critical illness (and ICU interventions) associated with growth impairment, cardiovascular disease, and early death. Our objective was to synthesize the evidence on the incidence of CKD among survivors of pediatric critical illness.

DATA SOURCES

MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Register of Controlled Trials from inception to February 2024.

STUDY SELECTION

Observational studies reporting the incidence of de novo CKD among survivors of pediatric critical illness.

DATA EXTRACTION

Two reviewers independently extracted data on study design, setting, population, demographics, diagnostic criteria, and outcome.

DATA SYNTHESIS

Meta-analysis was used to describe the incidence of CKD among survivors, risk of bias (RoB) assessed using the Joanna Briggs Institute Tool, and strength and reliability of evidence assessed with GRADE (Grading of Recommendations, Assessment, Development, and Evaluations). CKD was quantified as an estimated glomerular filtration rate (eGFR) less than 90 mL/min/1.73 m2 (outcome 1), eGFR less than 60 mL/min/1.73 m2 (outcome 2), and end-stage renal disease (ESRD) as eGFR less than 15 mL/min per 1.73 m2 (outcome 3). Twelve studies (3642 patients) met selection criteria and reported at least one measure of CKD. The median duration of follow-up was 2, 3.6, and 5 years, respectively, for outcomes 1, 2, and 3. For each threshold, the pooled estimate of CKD incidence was 24% (95% CI, 16-32%) for eGFR less than 90, 14% (95% CI, 6-23%) less than 60, and 4% (95% CI, 0-7%) for ESRD. The overall quality assessment indicated a moderate RoB.

CONCLUSIONS

Among a heterogenous population of pediatric critical illness survivors, an important minority of survivors developed CKD or ESRD. This study highlights the importance of diagnostic criteria for reporting, a greater focus on postcritical care surveillance and follow-up to identify those with CKD. Further study would facilitate the delineation of high-risk groups and strategies for improved outcomes.

Continuous renal replacement therapy in neonates and children: what does the pediatrician need to know? An overview from the Critical Care Nephrology Section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

Continuous renal replacement therapy (CRRT) is the preferred method for renal support in critically ill and hemodynamically unstable children in the pediatric intensive care unit (PICU) as it allows for gentle removal of fluids and solutes. The most frequent indications for CRRT include acute kidney injury (AKI) and fluid overload (FO) as well as non-renal indications such as removal of toxic metabolites in acute liver failure, inborn errors of metabolism, and intoxications and removal of inflammatory mediators in sepsis. AKI and/or FO are common in critically ill children and their presence is associated with worse outcomes. Therefore, early recognition of AKI and FO is important and timely transfer of patients who might require CRRT to a center with institutional expertise should be considered. Although CRRT has been increasingly used in the critical care setting, due to the lack of standardized recommendations, wide practice variations exist regarding the main aspects of CRRT application in critically ill children.     Conclusion: In this review, from the Critical Care Nephrology section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC), we summarize the key aspects of CRRT delivery and highlight the importance of adequate follow up among AKI survivors which might be of relevance for the general pediatric community. What is Known: • CRRT is the preferred method of renal support in critically ill and hemodynamically unstable children in the PICU as it allows for gentle removal of fluids and solutes. • Although CRRT has become an important and integral part of modern pediatric critical care, wide practice variations exist in all aspects of CRRT. What is New: • Given the lack of literature on guidance for a general pediatrician on when to refer a child for CRRT, we recommend timely transfer to a center with institutional expertise in CRRT, as both worsening AKI and FO have been associated with increased mortality. • Adequate follow-up of PICU patients with AKI and CRRT is highlighted as recent findings demonstrate that these children are at increased risk for adverse long-term outcomes.

Quality of life after acute kidney injury

PURPOSE OF REVIEW

Deciphering the effect of acute kidney injury (AKI) during critical illness on long-term quality of life versus the impact of conditions that brought on critical illness is difficult.

RECENT FINDINGS

Reports on patient-centred outcomes such as health-related quality of life (HRQOL) have provided insight into the long-lasting impact of critical illness complicated by AKI. However, these data stem from observational studies and randomized controlled trials, which have been heterogeneous in their patient population, timing, instruments used for assessment and reporting. Recent studies have corroborated these findings including lack of effect of renal replacement therapy compared to severe AKI on outcomes and worse physical compared to cognitive dysfunction.

SUMMARY

In adults, more deficits in physical than mental health domains are found in survivors of AKI in critical care, whereas memory deficits and learning impairments have been noted in children. Further study is needed to understand and develop interventions that preserve or enhance the quality of life for individual patients who survive AKI following critical illness, across all ages.

Early recognition and prevention of acute kidney injury in hospitalised children

Acute kidney injury is common in hospitalised children and is associated with poor patient outcomes. Once acute kidney injury occurs, effective therapies to improve patient outcomes or kidney recovery are scarce. Early identification of children at risk of acute kidney injury or at an early injury stage is essential to prevent progression and mitigate complications. Paediatric acute kidney injury is under-recognised by clinicians, which is a barrier to optimisation of inpatient care and follow-up. Acute kidney injury definitions rely on functional biomarkers (ie, serum creatinine and urine output) that are inadequate, since they do not account for biological variability, analytical issues, or physiological responses to volume depletion. Improved predictive tools and diagnostic biomarkers of kidney injury are needed for earlier detection. Novel strategies, including biomarker-guided care algorithms, machine-learning methods, and electronic alerts tied to clinical decision support tools, could improve paediatric acute kidney injury care. Clinical prediction models should be studied in different paediatric populations and acute kidney injury phenotypes. Research is needed to develop and test prevention strategies for acute kidney injury in hospitalised children, including care bundles and therapeutics.

Acute Kidney Injury: Gaps and Opportunities for Knowledge and Growth

Acute kidney injury (AKI) occurs frequently in hospitalized patients, regardless of age or prior medical history. Increasing awareness of the epidemiologic problem of AKI has directly led to increased study of global recognition, diagnostic tools, both reactive and proactive management, and analysis of long-term sequelae. Many gaps remain, however, and in this article we highlight opportunities to add significantly to the increasing bodies of evidence surrounding AKI. Practical considerations related to initiation, prescription, anticoagulation, and monitoring are discussed. In addition, the importance of AKI follow-up evaluation, particularly for those surviving the receipt of renal replacement therapy, is highlighted as a push for global equity in the realm of critical care nephrology is broached. Addressing these gaps presents an opportunity to impact patient care directly and improve patient outcomes.