[1] Landspitali Univ Hosp, Dept Anesthesia & Intens Care, Reykjavik, Iceland
[2] Landspitali Univ Hosp, Dept Pediat, Reykjavik, Iceland
[3] Landspitali Univ Hosp, Dept Cardiol, Reykjavik, Iceland
[4] Landspitali Univ Hosp, Dept Cardiothorac Surg, Reykjavik, Iceland
[5] Univ Iceland, Dept Anesthesia & Intens Care, Akureyri Hosp, IS-101 Reykjavik, Iceland
[6] Univ Iceland, Fac Med, IS-101 Reykjavik, Iceland