[1] Department of Anaesthetics,
[2] University College London Hospitals,undefined
[3] Mortimer Street,undefined
[4] W1N 8AA,undefined
[5] London,undefined
[6] UK e-mail: miriam.chapman@virgin.net Tel.: + 44-1 71-3 80-94 77 Fax: + 44-1 71-5 80 64 23,undefined
[7] Departments of Anaesthetics and Intensive Care,undefined
[8] University College London Hospitals,undefined
[9] London,undefined
[10] UK,undefined
[11] Department of Intensive Care Medicine,undefined
[12] University College London Hospitals,undefined
[13] London,undefined
[14] UK,undefined
[15] Department of Intensive Care,undefined
[16] Universite Libre de Bruxelles,undefined
[17] Hôpital Erasme,undefined
[18] Bruxelles,undefined
[19] Belgium,undefined