Long-Term Risk of Chronic Kidney Disease After Continuous Renal Replacement Therapy in Critically Ill Children: Single-Center PICU Cohort in Sweden, 2008-2021.

OBJECTIVE: Continuous renal replacement therapy (CRRT) is the preferred method of kidney support for critically ill children with severe acute kidney injury (AKI) or fluid overload (FO). The number of survivors after pediatric CRRT is increasing, but there are insufficient data describing the risk of developing chronic kidney disease (CKD) in these patients. DESIGN: A register-based study from a tertiary multidisciplinary hospital, 2008-2021. SETTING: PICU patients 18 years or younger treated with CRRT due to AKI or FO at Karolinska University Hospital from 2008 to 2021 were included. Detailed PICU data from PICU survivors were combined with data from the Swedish National Patient Register aiming to investigate the long-term risk of CKD development. Secondary outcomes included risk of hypertension, end-stage renal disease and mortality. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: We identified and included 156 PICU survivors with a mean follow-up time of 6.4 years (sd 3.2). CKD developed in 19 of 156 (12.2%) patients, resulting in an incidence of 18.9 (95% CI, 11.4-29.6) cases per 1000 person-years. Median time to CKD diagnosis was 11.5 months (interquartile range 3-62.5). Hypertension occurred in 17 of 156 patients (10.9%), and the composite outcome of CKD or hypertension in 28 of 156 patients (17.9%). The incidence of post-PICU mortality was 6 per 1000 person-years (95% CI, 2.2-13.1). In multivariable analysis, CRRT duration (p = 0.02) and estimated glomerular filtration rate (eGFR) at hospital discharge (p = 0.02) were associated with CKD development. We failed to identify an association between age at CRRT initiation or PICU illness and subsequent development of CKD. CONCLUSIONS: In our center in Sweden, 2008-2021, we found that a significant proportion of children surviving critical illness requiring CRRT are subsequently diagnosed with CKD or hypertension over time, demonstrating that rigorous follow-up of PICU patients undergoing CRRT is warranted.