Data collection included demographic data, comorbidity data, laboratory data, indication for CRRT defined by the pediatric nephrology note, and characteristics of each subject’s hospital and ICU course (e.g., length of stay, requirement for vasoactive agents, requirement for mechanical ventilation, etc.). Pediatric Risk of Mortality (PRISM) III scores were calculated at ICU admission [27 (link)].
AKI was classified by the RIFLE and pRIFLE criteria based on serum creatinine, estimated creatinine clearance (eCCl), and urine output in the 24 h prior to initiation of CRRT [28 (link)] [29 (link)]. The pRIFLE was modified slightly to exclude the “failure” component of eCCl < 35 ml/min/1.73 m2 for children ≤14 days. Estimated glomerular filtration rate (GFR) was calculated using the Schwartz equation in patients <18 years old [30 (link)] and the Modification of Diet in Renal Disease (MDRD) formula in patients >18 years old [31 (link)].
For fluid status determination we recorded weight upon hospital admission, weight at ICU admission, weight upon CRRT initiation, fluid intake from ICU admission until CRRT initiation, and fluid output from ICU admission until CRRT initiation. It is standard of care at our institution to weigh patients on ECLS daily. Fluid intake included blood products, intravenous fluids and flushes, medications, and all forms of nutritional support. Fluid output included urine output, drain output, blood loss, nasogastric tube output, stool volume, and wound drainage. For each patient, the daily flow charts were reviewed and 24 h totals of fluid intake and output were recorded for each patient for every day on the intensive care unit prior to CRRT initiation. These daily totals were then used to calculate the degree of fluid overload as described by Goldstein et al. [16 (link)]:
This method was then compared with two weight-based formulas. These formulas calculated fluid overload based upon ICU admission weight and hospital admission weight:
The primary outcome was all-cause ICU mortality.
AKI was classified by the RIFLE and pRIFLE criteria based on serum creatinine, estimated creatinine clearance (eCCl), and urine output in the 24 h prior to initiation of CRRT [28 (link)] [29 (link)]. The pRIFLE was modified slightly to exclude the “failure” component of eCCl < 35 ml/min/1.73 m2 for children ≤14 days. Estimated glomerular filtration rate (GFR) was calculated using the Schwartz equation in patients <18 years old [30 (link)] and the Modification of Diet in Renal Disease (MDRD) formula in patients >18 years old [31 (link)].
For fluid status determination we recorded weight upon hospital admission, weight at ICU admission, weight upon CRRT initiation, fluid intake from ICU admission until CRRT initiation, and fluid output from ICU admission until CRRT initiation. It is standard of care at our institution to weigh patients on ECLS daily. Fluid intake included blood products, intravenous fluids and flushes, medications, and all forms of nutritional support. Fluid output included urine output, drain output, blood loss, nasogastric tube output, stool volume, and wound drainage. For each patient, the daily flow charts were reviewed and 24 h totals of fluid intake and output were recorded for each patient for every day on the intensive care unit prior to CRRT initiation. These daily totals were then used to calculate the degree of fluid overload as described by Goldstein et al. [16 (link)]:
This method was then compared with two weight-based formulas. These formulas calculated fluid overload based upon ICU admission weight and hospital admission weight:
The primary outcome was all-cause ICU mortality.
