The natural history of direct hyperbilirubinemia associated with extracorporeal membrane oxygenation.

OBJECTIVE--To determine the incidence and natural history of direct hyperbilirubinemia in neonates treated with extracorporeal membrane oxygenation. DESIGN--A prospective series of patients. SETTING--A level 3 neonatal intensive care unit and center for extracorporeal membrane oxygenation in Ohio. PARTICIPANTS--Sixty-seven consecutive patients treated with extracorporeal membrane oxygenation in 33 months. INTERVENTION--None. MEASUREMENTS/RESULTS--Twenty-six (39%) developed direct hyperbilirubinemia. In 14 (54%), bilirubin levels were mildly elevated and occurred only during extracorporeal membrane oxygenation therapy. Levels were more severely elevated in the remaining 12 patients (46 +/- 10 mumol/L 2.7 +/- 0.6 mg/dL] vs 159 +/- 101 mumol/L 9.3 +/- 5.9 mg/dL], P less than .0001). Duration and severity of hyperbilirubinemia were correlated. Hyperbilirubinemia resolved in all patients by 9 weeks after extracorporeal membrane oxygenation therapy. No structural abnormalities or infectious agents were identified as causes. Aluminum levels were evaluated for 40 patients, were not in the toxic range, and did not correlate with hyperbilirubinemia. Multiple linear regression analysis suggested that hyperbilirubinemia in these cases resulted from interaction of injuries, with the primary contributor being hemolysis during extracorporeal membrane oxygenation. CONCLUSIONS--Direct hyperbilirubinemia occurs frequently in patients treated with extracorporeal membrane oxygenation and may be severe. However, direct hyperbilirubinemia typically resolves without short-term sequelae. Hemolysis may be an important contributing factor.