[1] Copenhagen Univ Hosp, Dept Pediat, Danish Pediat Pulm Serv, Rigshosp, 9 Kobenhavn O2100, Copenhagen, Denmark
[2] Copenhagen Univ Hosp, Dept Surg & Transplantat, Rigshosp, Copenhagen, Denmark
[3] Copenhagen Univ Hosp, Rigshosp, Heart Ctr, Dept Cardiothorac Surg, Copenhagen, Denmark
[4] Univ Southern Denmark, Odense Univ Hosp, Dept Pediat, Odense, Denmark
[5] UCL, Clin Operat Res Unit, London, England
[6] Univ Copenhagen, Inst Clin Med, Fac Hlth & Med Sci, Copenhagen, Denmark