[1] Shandong First Med Univ, Dept Crit Care Med, Shandong Prov Hosp, 324 Jingwu Weiqi Rd, Jinan 250021, Shandong, Peoples R China
[2] Shandong Univ, Shandong Prov Hosp, Cheeloo Coll Med, Dept Crit Care Med, Jinan 250021, Peoples R China
[3] Shandong First Med Univ, Dept Intens Care Unit, Cent Hosp, Jinan 250013, Peoples R China
[4] Shandong First Med Univ, Shandong Prov Hosp, Dept Stat & Med Records Management, Jinan, Peoples R China