[1] Ctr Hosp Univ Vaudois CHUV, Adult Intens Care Unit, Serv Med Intens Adulte, 46 Ave Bugnon, CH-1011 Lausanne, Switzerland
[2] Reseau Hosp Neuchatelois RHNE, Intens Care Unit, Neuchatel, Switzerland
[3] Univ Lausanne, Fac Biol & Med, Lausanne, Switzerland