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 (International Organization for Standardization [ISO] standard 9360-2:2001) and in vivo measurements of the effects of an HME are complex and technically challenging. The aim of this study was to develop a simple method to measure the ex vivo HME performance comparable with previous in vitro and in vivo results. METHODS: HMEs were 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 4 HMEs by weighing correlated with previous intra-tracheal measurements (R(2) = 0.98), and the ISO standard (R(2) = 0.77). CONCLUSIONS: 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.
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 (International Organization for Standardization [ISO] standard 9360-2:2001) and in vivo measurements of the effects of an HME are complex and technically challenging. The aim of this study was to develop a simple method to measure the ex vivo HME performance comparable with previous in vitro and in vivo results. METHODS: HMEs were 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 4 HMEs by weighing correlated with previous intra-tracheal measurements (R(2) = 0.98), and the ISO standard (R(2) = 0.77). CONCLUSIONS: 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.
Entities:
Keywords:
heat and moisture exchanger; humidity; respiration; total laryngectomy; tracheostomy
Authors: Cindy van den Boer; Sara H Muller; Andrew D Vincent; Klaus Züchner; Michiel W M van den Brekel; Frans J M Hilgers Journal: Eur Arch Otorhinolaryngol Date: 2013-05-01 Impact factor: 2.503
Authors: Maartje Leemans; Sara H Muller; Maarten J A van Alphen; Wim Vallenduuk; Richard Dirven; Michiel W M van den Brekel Journal: Head Neck Date: 2020-12-08 Impact factor: 3.147