[1] Acad Med Ctr, Emma Childrens Hosp, Pediat Intens Care Unit, NL-1100 DE Amsterdam, Netherlands
[2] Acad Med Ctr, Lab Endocrinol & Radiochem, NL-1100 DE Amsterdam, Netherlands
[3] Vrije Univ Amsterdam, Med Ctr, Netherlands Red Cross Blood Transfus Serv, Cent Lab, Amsterdam, Netherlands
[4] Vrije Univ Amsterdam, Med Ctr, Dept Clin Chem, Amsterdam, Netherlands