CRRT in critically Ill children: Clinical profile from a tertiary care hospital in South India

Abstract

Background : Continuous renal replacement therapy (CRRT) is a valuable tool in a pediatric intensive care unit (PICU), however the literature available from developing countries is scarce. Methods : Retrospective analysis of children who underwent CRRT during the past 1 year (June 2016 to May 2017). 24 sessions of CRRT was performed in 22 patients using Prismaflex® Baxter. Serum levels of urea, creatinine, and liver function tests were done in all patients. Activated clotting time (ACT) was monitored in all patients every 1 hourly till target ACT was achieved (180 – 220 seconds), thereafter every 4 hourly if the ACT continues in the target range. Unfractionated heparin was used for anticoagulation. Blood priming was done in patients with hematocrit less than 30% or in infants weighing less than 10 kg. Hemodialysis catheter (8.5Fr) was used in all patients, placed in the right internal jugular vein (IJV) under ultrasound guidance. Transthoracic echocardiography was used in all patients to confirm the position of the catheter tip within the right atrium. Central venous access in the femoral vein and arterial blood pressure monitoring was done in all patients as per unit protocol. Primary outcome measure was death during the procedure. Data collected were part of PRBC transfusion in pediatric ICU study and fluid balance study at JIPMER. Results : The median age of patients was 2 years (1 to 6 IQR). Mean bodyweight was 13.4 kg, 6.6 SD. Continuous venovenous hemofiltration (CVVH) was done in 5 patients (22.7%) and 17 patients (67.3%) were started on continuous venovenous hemodiafiltration (CVVHDF). Mortality during the procedure among the patients who underwent CRRT was 50% (n=11). Mean PRISM III score was 14. Out of 22 patients, 15 patients (68.7%) were on vasoactive medications at the time of initiation of CRRT. Median fluid overload (FO%) was 0.62 (0.45 to 1.62 IQR). Average time to start CRRT since PICU admission was 55 hours. The common indications were acute kidney injury with fluid overload (n=9), acute liver failure with hyperammonemia (n=3), organic acidemia with severe high anion gap acidosis (n=1), unknown poisoning with high anion gap acidosis (n=2), pigment nephropathy following wasp sting (n=1) and electrocution (n=1). CRRT along with venovenous extra corporeal membrane oxygenation (vv ECMO) (n=1) was done in a case of hemophagolymphohistiocytosis syndrome with ARDS. Effluent dose 35ml/kg/hour in all patients except in 2 cases of acute liver failure where the effluent dose was increased up to 42ml/kg/hour due to persistent hyperammonemia. CRRT with plasma exchange using P2 plasma filter was done with CRRT circuit modification in 2 cases of thrombocytopenia associated multiorgan failure (TAMOF). Mean duration of CRRT was (55 hours, SD 23.8). Maximum circuit life with systemic heparin as anticoagulant was 92 hours. Filter clotting and new circuit requirement was encountered in 6 patients (27.7%). Conclusion : CRRT can be used safely in critically ill children. The circuit life can be prolonged with serial ACT monitoring and titration of anticoagulation.