[1] Washington Univ, Sch Med, Dept Anesthesiol, St Louis, MO 63110 USA
[2] Washington Univ, Sch Med, Blood Bank, St Louis, MO USA
[3] Kings Coll Hosp London, Dept Anaesthesia, London, England
[4] Kings Coll Hosp London, Dept Cardiothorac Surg, London, England
[5] Guys Kings & St Thomas Med Sch, Dept Haematol, London, England