Update on nasal high frequency oscillatory ventilation: A living review.

Non-invasive high-frequency oscillatory ventilation (NHFOV) is the main non-conventional ventilatory mode used in newborn infants. NHFOV has been spreading, while knowledge about its physiology, mechanics and clinical application has increased overtime. This is to be considered as a living review, since we here update the knowledge that was originally summarized in a previously published review. We first focus on physiology of such a complex respiratory support technique with practical data on interfaces, patient-ventilator interaction and devices to provide NHFOV. We then move to the evidence-based review of parallel randomized clinical trial published so far. We provide both qualitative and quantitative synthesis of results for the two commonest outcomes, i.e. need for intubation and invasive ventilation and CO₂ elimination. We also provide our protocol to use NHFOV together with other respiratory support modes and we provide suggestions on parameters boundaries and identification of patients to treat. We finally identify still open questions needing future research to optimize the use of NHFOV In preterm infants.