Prevalence of Bone Mineral Disease in Children with Acute Kidney Disease on Continuous Renal Replacement Therapy: A Case Control Study

Background Continuous kidney replacement therapy (CKRT) with regional citrate anticoagulation (RCA) is preferred in critically ill children with acute kidney disease (AKD). It is unclear whether CKRT exacerbates risk of bone mineral disease in AKD. We designed a case-control study to evaluate osteopenia and mineral balance markers in prolonged CKRT with RCA compared to prolonged immobilization. Methods Cases were AKD patients on CKRT with RCA and controls immobilized ≥ 28 days, matched with propensity scoring. Data collected at day 0, 14 and 28. Two blinded radiologists independently evaluated for osteopenia/fractures; reliability assessed by kappa statistics. Results Osteopenia in cases higher at day 14 (20/53 cases v/s 10/49 controls, p 0.05), and at day 28 (21/53 cases v/s 11/49 controls, p 0.06). Younger age, CKRT, gastrointestinal/liver comorbidity increased odds of osteopenia in cases and controls. Citrate rate adjusted for blood flow had higher odds of day 28 osteopenia. New fractures higher in cases (13/53) than controls (3/49) (p 0.01). Younger age, osteopenia at baseline, day 14, and 28 had higher odds of fractures in cases. Radiologist agreement for osteopenia was moderate (Kappa 0.62). Conclusions This is the first comparative study in children with AKD on prolonged CKRT and bone complications. Increased fractures and osteopenia noted in children undergoing prolonged CKRT compared to immobilization. Increased risk of fractures associated with presence/persistence of osteopenia and younger age. Increased osteopenia on CKRT suggested factors beyond immobilization, like age, anticoagulation, metabolic demands, dialytrauma, baseline osteopenia, hyperparathyroidism, and underlying primary disease, may play a significant role.