Introduction
Preterm infants are prone to various conditions because of their
immature organs. Respiratory failure related to organ immaturity is the
most common cause of death in preterm infants. Invasive mechanical
ventilation (IMV), which has been widely used in past decades to support
neonates with respiratory failure, has many complications (air-leaks,
ventilator-associated lung injury and bronchopulmonary dysplasia (BPD))
(1). Life-saving strategies that minimize injury to the lung and other
organ systems, thereby reducing long-term morbidity, have been the focus
of recent attention.
Given the emergence of noninvasive nasal airway interfaces for newborns,
noninvasive ventilation has become a suitable technique for the
treatment of neonatal respiratory diseases. The American Academy of
Pediatrics and European Consensus Guidelines recommend early
non-invasive ventilation for the treatment of respiratory diseases in
preterm infants, citing its promising curative effects (2, 3).
Noninvasive intermittent positive pressure ventilation (NIPPV)
superimposes an intermittent peak pressure on continuous positive airway
pressure (CPAP). The popularity of NIPPV has risen since its recent
comparison to nasal CPAP, in which NIPPV significantly decreased the
rates of respiratory failure, reintubation and the need for a ventilator
(4). Synchronized NIPPV is the best respiratory support modality
post-extubation (5), although synchronization is difficult to achieve
and often unavailable. A more recent alternative is noninvasive high
frequency oscillatory ventilation (NHFOV), which has the characteristics
of high frequency ventilation and nasal CPAP, and does not need
synchronization; it also has the advantages of being noninvasive, highly
efficient in CO2 removal and has a lower volume/barotrauma (6). Compared
with NIPPV and a nasal CPAP, NHFOV can reduce the need for IMV in
infants treated for respiratory distress syndrome (RDS) (7). However,
some RCTs have not reported a reduced intubation rate, a shortened time
for oxygen therapy or non-invasive ventilator-assisted ventilation when
using NHFOV versus NIPPV (8, 9). Given these conflicting findings, we
conducted a comprehensive systematic review and meta-analysis to
evaluate relevant evidence from published studies.