Effect of Leak and Breathing Pattern on the Accuracy of Tidal Volume Estimation by Commercial Home Ventilators: A Bench Study

Influence of Dynamic Leaks in Volume-Targeted Pressure Support Noninvasive Ventilation: A Bench Study

“…7 At the same time, dynamic (unintentional) leak values were monitored (pneumotachograph 2) and registered.…”

“…Focusing on this issue, several bench studies have demonstrated that the estimation of V T by home ventilators may be modified by the leak. In a model of continuous leaks simulated through a calibrated orifice, 2 studies have shown underestimations of V T of different magnitudes by commercial devices, 6,7 and, in a dynamic leak model, with excess leaks during inspiration or expiration, Sogo and colleagues 8 found that the increase in inspiratory leaks led to an overestimation of the V T . Inaccurate V T estimations may also manifest in the volume-targeted pressure support modes.…”

Hot Topics in Noninvasive Ventilation: Report of a Working Group at the International Symposium on Sleep-Disordered Breathing in Leuven, Belgium

“…Rabec et al 116 were the first to evaluate the validity (reliability) of data collected by built-in software in a home ventilator and found that machine-derived leak and V E data highly correlated with objective laboratory-based measures of these parameters. 114,125 These studies showed an underestimation of V T for the 11 ventilators tested. The ability of a home ventilator to maintain a stable V T is related to the pressurization capacities of the device, 126 as well as to its assessment of V T , especially in the presence of leaks.…”

“…As discussed above, the impact of leaks on ventilatory efficacy depends not only on the absolute amount of leaks, but also on the capability of the device to compensate for them. 114,125 Furthermore, the influence of leaks could vary with the underlying pathology (ie, the difference in respiratory mechanics). 144 Therefore, detecting unintentional leaks and particularly their impact on quality of ventilation is of major importance when monitoring NIV.…”

Choosing a ventilator for home mechanical ventilation

“…Some HCVs compute an estimate of the expiratory VT [56]. However, it has been shown that the accuracy of VT measurement by the intentional leak ventilator algorithms is not significantly different from that measured by the ventilator flow sensor with a ventilator with a double or single respiratory circuit and the expiratory valve in absence of non-intentional leaks [24,39,56]. However, in presence of a high linear or non-linear, intentional or nonintentional, inspiratory or expiratory leak most of this accuracy can be lost [39,56].…”