Use of heat and moisture exchanging (HME) filters in mechanically ventilated ICU patients: Influence on airway flow-resistance

Abstract

The gas conditioning efficiency and design performance of the tested HMEs did not create a significant obstacle to airflow medium term mechanical ventilation; however, these devices should be cautiously used in patients with heavy bronchial secretions.

Unfavorable mechanical effects of heat and moisture exchangers in ventilated patients

“…Artificial noses have been reported to increase considerably the resistive load of the ventilator circuit in vitro [7]. However, an in vivo study suggests that artificial noses play a minor role in increasing airway resistance, but only in rare cases in which the filter membrane is exposed to particularly abundant secretions [8]. Lack of relevant mechanical interference was also confirmed by a study on patients with chronic obstructive pulmonary disease (COPD), in which the application of artificial noses was associated with no increase in dynamic pulmonary hyperinflation [9].…”

Effect of the humidification device on the work of breathing during noninvasive ventilation

“…The latter are frequently used because of their simplicity and lower cost [23,24]. Because HMEs are placed between the Y-piece and the patient, they add substantial deadspace to the circuit [25,26,27,28], and they can also marginally increase the resistance to flow [29,30]. It has been suggested in intubated patients that an increase of 5-10 cmH 2 O in the pressure support (PS) level is necessary to compensate the effects of the HME deadspace.…”

Comparison of the effects of heat and moisture exchangers and heated humidifiers on ventilation and gas exchange during non-invasive ventilation

“…Moreover, HMEs may increase resistance to flow [4,5]. Some studies [6,7,8,9] tion showed that the additional dead space of the HME induced an increase in minute ventilation to maintain efficient alveolar ventilation.…”