a1 Surgical Intensive Care Unit, University Medical Center Groningen, University of Groningen, Hanzeplein, Groningen, The Netherlands
a2 Department of Anaesthesiology, Tjongerschans Hospital, Thialfweg, Heerenveen, The Netherlands
a3 Care Service Medical Instrumentation, University Medical Center Groningen, University of Groningen, Hanzeplein, Groningen, The Netherlands
a4 Department of Anaesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein, Groningen, The Netherlands
a5 Department of Paediatrics, Division of Intensive Care, University Medical Center Groningen, University of Groningen, Hanzeplein, Groningen, The Netherlands
a6 Department of Surgery, University Medical Center Groningen, University of Groningen, Hanzeplein, Groningen, The Netherlands
(Accepted March 24 2007)
Correspondence:
c1 Correspondence to: Willem Dieperink, Surgical Intensive Care Unit, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands. E-mail: w.dieperink@chir.umcg.nl; Tel: +31 50 3612306; Fax: +31 50 3619986