[1] Univ Lausanne, Univ Lausanne Hosp, Med & Surg Dept Pediat, Inst Higher Educ & Res Healthcare, Biopole 2,Route Corniche 10, CH-1011 Lausanne, Switzerland
[2] Univ Plymouth, Sch Nursing & Midwifery, Fac Hlth & Human Sci, 3 Portland Villas,Room 101, Plymouth PL4 8AA, Devon, England
[3] Univ Lausanne, Med & Surg Dept Pediat, Pediat Intens Care Unit, Rue Bugnon 46, CH-1011 Lausanne, Switzerland
[4] Univ Lille, Pediat Intens Care Unit, CHU Lille, EA 2694,Sante Publ Epidemiol & Qualite Soins, F-59000 Lille, France