RT Journal Article
SR Electronic
T1 A novel, simplified ex vivo method for measuring water exchange performance of Heat and Moisture Exchangers for tracheostomy application
JF Respiratory Care
FD American Association for Respiratory Care
SP respcare.02369
DO 10.4187/respcare.02369
A1 Cindy van den Boer
A1 Sara H. Muller
A1 Andrew D. Vincent
A1 Klaus Züchner
A1 Michiel W.M. van den Brekel
A1 Frans J.M. Hilgers
YR 2013
UL http://rc.rcjournal.com/content/early/2013/03/12/respcare.02369.abstract
AB Background: Breathing through a tracheostomy results in insufficient warming and humidification of inspired air. This loss of air-conditioning can be partially compensated for with the application of a Heat and Moisture Exchanger (HME) over the tracheostomy. In vitro (ISO 9360-2:2001) and in vivo measurements of the effects of an HME are complex and technically challenging. Aim of this study is to develop a simple method to measure the ex vivo HME performance comparable with previous in vitro and in vivo results. Materials and methods: HMEs are weighed at the end of inspiration and at the end of expiration at different breathing volumes. Four HMEs (Atos Medical, Hörby, Sweden) with known in vivo humidity and in vitro water loss values were tested. The associations between weight change, volume and absolute humidity were determined using both linear and non-linear mixed effects models. Results: The rating between the four HMEs by weighing correlates with previous intra-tracheal measurements (R2 = 0.98), and the ISO-standards (R2 = 0.77). Conclusion: Assessment of the weight change between end of inhalation and end of exhalation is a valid and simple method of measuring the water exchange performance of an HME.