Mechanics of nasal mask‐delivered HFOV in neonates: A physiologic study

Abstract

Objectives To clarify if nasal mask influences noninvasive high‐frequency oscillatory ventilation (NHFOV) mechanics to optimize the clinical use of nasal mask‐delivered NHFOV. Working Hypothesis Nasal mask may affect the mechanical efficacy of NHFOV. Methodology We designed a physiologic study composed of an in vitro phase aiming to investigate pressure transmission and volume delivery in a bench model of nasal mask‐delivered NHFOV. In a second phase, we measured the leaks in vivo in a series of neonates receiving nasal mask‐delivered NHFOV or other forms of noninvasive respiratory support with same nasal masks. Results In vitro pressure transmission is lower with nasal mask (pressure at the lung [Plung]: 2 [0.8]), than with the endotracheal tube (Plung 9.5 [1.5] cmH2O; P = 0.007). Same applies for volume delivery (Vol: 0.6 [0.2] vs 1.8 [0.5] mL; P = 0.0001). Increasing ventilatory boundaries slowly affects pressure and volume delivery. Ventilating the model with maximal parameters (∆P = 55 cmH2O; frequency = 8 Hz) we obtained a Vol 1.5 (0.2) mL. The nasal mask provides lower volume delivery and ventilation, compared with nasal prongs studied in previously published studies. Changing frequency allows a better performance than changing ∆P. In vivo leaks are approximately 30% and are similar during NHFOV or other forms of nasal mask‐delivered noninvasive ventilation. Conclusions Nasal mask‐delivered NHFOV is feasible, but it may require more aggressive ventilatory parameters to increase volume delivery and ventilation. The use of the nasal mask is associated with some leaks, but this is independent from the type of noninvasive respiratory support applied.

Minimally invasive surfactant therapy versus InSurE in preterm neonates of 28 to 34 weeks with respiratory distress syndrome on non-invasive positive pressure ventilation—a randomized controlled trial

“…These may impact on the efficacy of NIPPV as some of them were suboptimal. Moreover, the use of such different interfaces cannot reduce the leak and improve pressure transmission while the mouth is open, even if NIPPV is used [27]. We have used a low threshold of 30% FiO2 for indication of surfactant therapy instead of a higher one which may have some bearing on the results.…”

Nasal HFOV Versus Nasal IPPV as a Post Extubation Respiratory Support in Preterm Infants - a Randomised Controlled Trial

“…However none of the previous studies have used both simulatenously. Mask delivered nHFOV has more dampening effect, therefore theoretically would require more aggressive ventilatory parameters [10]. In our case, cycling of the interfaces were done for comfort of the babies and whether it caused a drop in e cacy of nHFOV cannot be ascertained.…”

MISA (Minimally Invasive Surfactant Administration) Versus Insure (Intubation, Surfactant, Extubation) In Preterms Less Than 34 Weeks With RDS

“…This could have low the requirements of IMV in the research groups. Non-invasive ventilation, which has previously been indicated as being preferred for premature neonates undergoing MIST, can be used to counteract the negative effects of MIST linked to limited air flow and airway resistance (10) . Even in physiological research, NIPPV has been demonstrated to be effective in preventing leaks and tracheal blockage caused by MIST catheterization (5) .…”