Influence of heat and moisture exchanger use on measurements performed with manovacuometer and respirometer in healthy adults

Abstract

BackgroundThe use of evaluation tools such as the manovacuometer and respirometer is frequent and disinfection is usually limited to the external surfaces, which is insufficient and raises concerns because of the potential spread of infectious diseases. Hydrophobic heat and moisture exchangers (HME) are used in mechanical ventilation and have microbiological filters, which can possibly reduce contamination, increasing the safety of related procedures. It is unknown, however, if the addition of an exchanger affects the measurements obtained. Aim of this study was to verify if the use of an HME interferes in maximal inspiratory and expiratory pressures assessed using the manovacuometer and vital capacity evaluated using the respirometer in healthy adults.MethodsA controlled transversal trial was carried out. Twenty healthy young adults were included in the study. Vital capacity by respirometer and, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were assessed with and without the use of HME.ResultsNo significant difference was found between the values pre and post HME use in vital capacity measurements: (3878.8 ± 202.2 mL vs. 3925.5 ± 206.0 mL, p = 0.116) and the respiratory muscle strength measurements: MIP (−99.0 ± 8.9 vs −95.5 ± 9.0 cm H2O, p = 0.149) and MEP (92.5 ± 7.5 vs 92.5 ± 7.7 cm H2O, p = 1.0) respectively.ConclusionWe conclude that the use of HME does not modify the lung volumes or respiratory muscle strength, and can be used in order to reduce the occurrence of pulmonary infection.

Ventilatory changes during the use of heat and moisture exchangers in patients submitted to mechanical ventilation with support pressure and adjustments in ventilation parameters to compensate for these possible changes: a self-controlled intervention study in humans

“…Although we did not find a significant increase in resistance in our previous studies ( 34 ) using the HME, nor any changes in lung volume and muscle strength, ( 46 ) other studies have shown that resistance to gas flow during use of the HME increased with increasing material density ( 10 , 20 ) and may also increase with increasing flow ( 22 , 47 ) and duration of use. ( 22 , 30 , 31 , 34 , 48 , 49 ) This increase in resistance in the ventilatory circuit may lead to an incorrect evaluation of respiratory system mechanics, inappropriate treatment (bronchodilators) or difficulty in mechanical ventilation weaning, ( 31 ) in addition to increasing the patient's breathing effort.…”

“…Lucato et al ( 46 ) recently conducted a study in which they evaluated the vital capacity and maximum inspiratory pressure of 20 healthy young adults in two situations: with and without an HME coupled to a ventilometer or pressure manometer. The use of the HME did not modify either pulmonary volumes or respiratory muscle strength and could be used safely with these devices to reduce the occurrence of pulmonary infection.…”

Influence of a heat and moisture exchanger with a microbiological filter on measurements of maximal respiratory pressures and vital capacity in patients with COPD

“…Lucato et al 5 demonstrated that the dead space volume and resistance caused by the addition of an HME did not change the VC or respiratory muscle strength values in volunteers evaluated during spontaneous breathing. To our knowledge, there have been no studies aimed at determining whether the addition of a microbiological filter has a relevant impact on those variables in patients with impaired pulmonary function.…”

“…(3) Therefore, a viable alternative would be to use heat and moisture exchangers (HMEs) on such equipment.A hydrophobic HME contains an inline, disposable, hygroscopic, bacteriostatic sponge (microbiological filter, Figures 1B and 1D) that reduces device contamination, thus protecting patients from microbial contamination. (4) Lucato et al (5) demonstrated that the dead space volume and resistance caused by the addition of an HME did not change the VC or respiratory muscle strength values in volunteers evaluated during spontaneous breathing. To our knowledge, there have been no studies aimed at determining whether the addition of a microbiological filter has a relevant impact on those variables in patients with impaired pulmonary function.…”

Análise comparativa da força dos músculos respiratórios em indivíduos saudáveis no solo e na piscina

“…They involve objective measures to diagnose various diseases 4 . Manovacuometry is a simple, non-invasive and easy-to-apply resource 5 used to assess respiratory pressures, which reflect the respiratory muscle strength 6 . Inspiratory muscle strength is evaluated through maximal inspiratory pressure (Mip) and expiratory muscle strength is measured through maximum expiratory pressure (Mep) 7 .…”