Peritoneal Dialysis Clearance of Unconjugated Bilirubin in Children and Neonates

Background: Neonates with unconjugated hyperbilirubinemia are vulnerable to a neurological disorder with devastating permanent sequelea (kernicterus). The two traditional methods to manage these patients are phototherapy and exchange blood transfusion. Peritoneal dialysis is a widely applied therapeutic measure to clear the plasma from its uremic toxins as well some of these exogenous toxins.
Objectives: This study was conducted to measure the peritoneal clearance of unconjugated bilirubin (uB) and thus give a provisional idea of the applicability of peritoneal dialysis in management of neonates with unconjugated hyperbilirubinemia.
Methods: The study included 7 patients (3 children & 4 neonates) who had unconjugated hyperbilirubinemia and were treated with acute peritoneal dialysis for a concomitant renal impairment. Patients were divided into 3 groups according to the underlying pathology. Group I consisted of 2 patients with hepatorenal failure, Group II included 3 neonates with neonatal sepsis and multiorgan failure and Group III was one child and one neonate with unconjugated hyperbilirubinemia due to hemolysis and renal failure from hypotension and shock. Patients were subjected to history taking, complete physical examination and initial investigations to verify the underlying etiology. For all patients the level of uB and urea were measured in the serum at the beginning (P1), end (P2) and mid-dialysis (P), the ascitic fluid (A) at the beginning of dialysis and in the peritoneal fluid.at the mid-dialysis (D). The percentile of P2/P I., the ratio of, D/P and A/P and the peritoneal clearance were calculated for both uB and urea.
Results: For urea, the mean percentile ratio of P2/P 1 was 55% for D/P was 0.45 and A/P was 0.62. Peritoneal clearance of urea was 26.64 1./hour/1.73 m2. For uB P2 increased than P1 in group I, decreased in group III and was variable in group II. The mean ratio of P2/P1 was 135% in group I, 22% in group II and 97% in group III. Ascitic fluid was present only in the 2 cases of group I, the A/P was 0.35. The peritoneal fluid uB (P) was detected in 4 cases (2 in group I & 2 in group II). In these 4 cases the mean D/P ratio of uB was 0.03 and the peritoneal clearance of uB was 1.7 Uhourll 73 m2.
Conclusion: Unconjugated bilirubin can be dialyzed by peritoneal dialysis. Its clearance is about 1/15 that of urea. The high protein content of the peritoneal fluid (ascitic fluid) may improve clearance of unconjugated bilirubin. Further studies are needed to prove efficiency of peritoneal dialysis in the management of neonates with unconjugated hyperbilirubinemia.