RT Journal Article
SR Electronic
T1 In Vitro Evaluation of Heat and Moisture Exchangers Designed for Spontaneously Breathing Tracheostomized Patients
JF Respiratory Care
FD American Association for Respiratory Care
SP 1878
OP 1885
DO 10.4187/respcare.02405
VO 58
IS 11
A1 Brusasco, Claudia
A1 Corradi, Francesco
A1 Vargas, Maria
A1 Bona, Margherita
A1 Bruno, Federica
A1 Marsili, Maria
A1 Simonassi, Francesca
A1 Santori, Gregorio
A1 Severgnini, Paolo
A1 Kacmarek, Robert M
A1 Pelosi, Paolo
YR 2013
UL http://rc.rcjournal.com/content/58/11/1878.abstract
AB BACKGROUND: Heat and moisture exchangers (HMEs) are commonly used in chronically tracheostomized spontaneously breathing patients, to condition inhaled air, maintain lower airway function, and minimize the viscosity of secretions. Supplemental oxygen (O2) can be added to most HMEs designed for spontaneously breathing tracheostomized patients. We tested the efficiency of 7 HMEs designed for spontaneously breathing tracheostomized patients, in a normothermic model, at different minute ventilations (V̇E) and supplemental O2 flows. METHODS: HME efficiency was evaluated using an in vitro lung model at 2 V̇E (5 and 15 L/min) and 4 supplemental O2 flows (0, 3, 6, and 12 L/min). Wet and dry temperatures of the inspiratory flow were measured, and absolute humidity was calculated. In addition, HME efficiency at 0, 12, and 24 h use was evaluated, as well as resistance to flow at 0 and 24 h. RESULTS: The progressive increase in O2 flow from 0 to 12 L/min was associated with a reduction in temperature and absolute humidity. Under the same conditions, this effect was greater at lower V̇E. The HME with the best performance provided an absolute humidity of 26 mg H2O/L and a temperature of 27.8°C. No significant changes in efficiency or resistance were detected during the 24 h evaluation. CONCLUSIONS: The efficiency of HMEs in terms of temperature and absolute humidity is significantly affected by O2 supplementation and V̇E.