Leakage in nasal high‐frequency oscillatory ventilation improves carbon dioxide clearance—A bench study

Abstract

A moderate oral leakage rather improves than impairs gas exchange during non-invasive ventilatory support with nHFOV. Pediatr Pulmonol. 2017;52:367-372. © 2016 Wiley Periodicals, Inc.

Non-invasive high-frequency oscillatory ventilation in preterm infants: a randomised controlled cross-over trial

“…While moderate leakage enhances CO 2 clearance when using nHFOV, varying degrees of leakage may have influenced our results. In our bench model for nHFOV, we were able to demonstrate significant increased CO 2 washout in the presence of a moderate leak flow 15. However, in this study, both modes of respiratory support may have been equally affected.…”

Carbon dioxide diffusion coefficient in noninvasive high‐frequency oscillatory ventilation

“…A neonatal mechanical ventilator (Sophie, Stephan, Gackenbach, Germany, and Leoni Plus, Heinen & Löwenstein, Bad Ems, Germany) was connected to a model of the neonatal respiratory system (Figure ) via regular medium sized nasal prongs (EasyFlow; Stephan, Gackenbach, Germany) as described previously . Briefly, the model consisted of a plastic tube serving as trachea connected to a newborn model lung with a total volume of 45 mL and a compliance of 0.6 mL/cmH 2 O (Model 8409742; Dräger Medical, Lubeck, Germany).…”

“…However, leak flow via the mouth or nares is inevitable during noninvasive ventilation and may impair ventilation by decreasing the pressure amplitude and thus oscillatory pulmonal tidal volume. While moderate leak flow may not impair nHFOV efficacy it remains challenging to assess the extent of leak flow and its impact on CO 2 removal during noninvasive ventilation . Clinical indicators for impaired ventilation using nHFOV, such as decreased chest wall vibrations, are imprecise in spontaneously breathing preterm infants.…”

2017 pediatric pulmonology year in review part 2—neonatology

“…As would be expected, adding holes to the mask decreased dead space at the cost of stable airway pressure. Adding leak was also necessary to improve non‐invasive nasal high frequency oscillation (HFO) as reported by Klotz and colleagues . These studies are limited, simplified models, and the relevance to clinical effects on gas exchange and outcome remains to be seen.…”