1Salemi,C,Padilla,S,Canola,T et al.Heat-and moisture ex- changers used with biweekly circuit tubing changes: ef- fect on costs and pneumonia rates[J]. Infection con- trol and hospital epidemiology,2000,21(11).
2Daumal,F,Colpart,E,Manoury,B et al.Chang- ing heat and moisture exchangers every 48 hours does not in- crease the incidence of nosocomial pneumonia[J]. Infec- tion control and hospital epidemiology,1999,20(5).