4Boyer A, Thiery G, Lasry S, et al. Long- term mechanical ventilation with hygroscopic heat and moisture exchangers used for 48 hours: a prospective clinical, hygrometric, and bacteriologic study. Crit Care Med,2003,31(3) :823-829.
5Thiery G, Boyer A, Pigne E, et al. Heat and moisture exchangers in mechanically ventilated intensive care unit patients: a plea for an independent assessment of their performance. Crit Care Med, 2003,31 (3): 699-704.
6Heyland DK, Cook DJ, Dodek PM. Prevention of ventilator- associated pneumonia: current practice in Canadian intensive care units. J Crit Care,2002,17(3): 161-167.
7Heffner JE,Hess D.Tracheostomy management in the chronically ventilated patient[J].Clin Chest Med,2001,22(1):55-69