8Valles J,Artigas A,Rello J,et al.Continuous aspiration of subglottic secretions in preventing ventilator-associated pneumonia.Ann Intern Med,1995,122:179-186.
9Kollef MH,Skubas NJ,Sundt TM.A randomized clinical trial of continuous aspiration of subglottic secretions in cardiac surgery patients.Chest,1999,116:1339-1346.
10Knaus WA,Draper EA,Wagner DP,et al.APACHE Ⅱ:a severity of disease classification system.Crit Care Med,1985,13:818-829.