Israel Medical Association Journal

A 55-year-old male with a history of Dubin-Johnson syndrome (DJS), obesity, and smoking presented to the emergency department with generalized weakness and jaundice. On admission, he was hypotensive (blood pressure 87/56 mmHg), and profound jaundice was noted. Laboratory investigations revealed severe acute kidney injury with a creatinine level of 5.53 mg/dl and blood urea nitrogen of 92 mg/dl. Liver function tests were mildly elevated, and his lipid profile was within normal limits. Total bilirubin was markedly elevated at 52.5 mg/dl, predominantly direct (40.9 mg/dl). The patient was anuric at the time of catheter insertion.

A non-contrast abdominal computed tomography scan showed normal kidney size and appearance without hydronephrosis. The liver was normal size with sharp borders. The patient was treated with intravenous fluids, inotropic support, and intravenous antibiotics. Despite these interventions, he remained anuric with worsening hyperkalemia, necessitating urgent hemodialysis.

Within 10 minutes of initiating hemodialysis, a yellowish discoloration appeared in the effluent tubing of the dialysate. Simultaneously, the dialyzer fibers, which are typically pinkish in color, began to develop a yellowish tint. By the end of the session, the dialyzer appeared distinctly yellow, likely due to bilirubin deposition [Figure 1A–1C].

Background: Hyperbilirubinemia of the newborn is common. Rarely is an underlying disease other than physiologic hyperbilirubinemia considered the cause of high bilirubin levels. Some of the laboratory tests recommended by the American Academy of Pediatrics are expensive and do not always lead to diagnosis.

Objective: To evaluate the efficacy of standard laboratory tests performed on newborn infants requiring phototherapy for hyperbilirubinaemia.

Methods: We conducted a retrospective chart review that included neonates born during a 6 month period with birth weight > 2500 g treated with phototherapy for hyperbilirubinemia (n=282) according to published guidelines. The main outcome measures were primary and maximal bilirubin values (mg/dl), time to jaundice (in days), the number of bilirubin tests undertaken and whether the patient showed abnormal functioning, and the number of days in follow-up.

Results: Thirty-three neonates (11.7%) were positive in at least one laboratory test (defined as "Abnormal" in our study), 45.5% of whom met the criteria for phototherapy during the first 48 hours of life. Among the newborns who were negative for all laboratory tests (defined as "Normal"), only 6.8% met phototherapy criteria within their first 48 hours of life (P < 0.001). In the Normal group there was a consistent decrease in total serum bilirubin values shortly after phototherapy was begun, while the Abnormal group presented an increase in serum bilirubin values during the first 12 hours of phototherapy. None of the infants had conjugated (direct) hyperbilirubinemia during the study period.

Conclusions: Most neonates presenting with a laboratory identifiable etiology for hyperbilirubinemia (i.e., hemolysis) can be distinguished from those who test negative, mainly based on the timing of presentation and response to phototherapy. A more meticulous selection of patients and reduction in the magnitude of routine laboratory testing can safely reduce discomfort to infants with hyperbilirubinemia as well as costs.