Nasal High Frequency Oscillation Ventilation(NHFOV) for Respiratory Distress Syndrome

Early weaning from invasive ventilation and avoiding re-intubation remains a focus. Nowadays, early use of noninvasive respiratory support strategies has been suggested to be the most effective pathway to reduce those risks. NCPAP is a widely used way of noninvasive ventilation strategies in preterm infants. However, there is only 60% success rate in avoiding intubation. Supplying with the combined advantages of HFOV and NCPAP with high CO2 removal, no need for synchronisation, less volume/barotraumas, non-invasion and increased functional residual capacity, nasal high frequency oscillation ventilation (NHFOV) is considered as a strengthened version of NCPAP. Thus, NHFOV may be more effective as post-extubation respiratory support to avoid re-intubation and subsequent complications/sequelae comparing with NCPAP in preterm infants. To date, NHFOV was used increasingly in neonatal intensive care unit (NICU) around the world due to its convenient operation and no consideration of synchronisation, and several small studies have reported the beneficial effects of NHFOV in preterm infants. However, there were rare randomized controlled studies compared NHFOV with NCPAP as post-extubation respiratory support strategies in preterm infants.

The purpose of the present study was to compare NHFOV with NCPAP as post-extubation respiratory support on the need for endotracheal ventilation and subsequent complications in preterm infants.

• NHFOV (Device): NHFOV is used as the noninvasive mode after extubation
• NCPAP (Device): NCPAP is used as the noninvasive mode after extubation

Primary outcomes

• intubation rate [3 days]: the baby was re-intubated due to respiratory failure
• total time of hospitalization [100 days]: the duration of baby in hospital
• bronchopulmonary dysplasia(BPD) [at 28 days after birth or 36 weeks'gestational age or at discharge]: bronchopulmonary dysplasia was diagnosed after extubation BPD was defined according to the National Institutes of Health consensus definition

Secondary outcomes

• airleaks [3 days]: airleaks was diagnosed after extubation
• Retinopathy of prematurity [100 days]: Retinopathy of prematurity was diagnosed after extubation
• Neonatal necrotizing enterocolitis [3 days]: Neonatal necrotizing enterocolitis was diagnosed after extubation
• Intraventricular hemorrhage [3 days]: Intraventricular hemorrhage was diagnosed after extubation
• mortality rate [100 days]: the baby died in hospital
• patent ductus arteriosus (PDA) [100 days]: patent ductus arteriosus (PDA) was diagnosed

Sex: All, ages: 30 Minutes to 1 Month

Inclusion Criteria:

* The gestational age was less than 37 weeks;
* These neonates were diagnosed with RDS and supported by invasive ventilation with synchronized intermittent mandatory ventilation (SIMV. The diagnosis of RDS was based on clinical manifestations and chest X-ray findings. The clinical signs and symptoms of RDS were respiratory distress, tachypnea, nasal flaring, groan, and cyanosis after birth. The typical X-ray picture of RDS showed a grain shadow, air bronchogram or white lung;
* The neonates were ready to be extubated for the first time and subsequent noninvasive ventilation.

Exclusion Criteria:

* parents' decision not to participate;
* major congenital anomalies;
* died or left the NICU within 24 hour.

Eligibility criteria for extubation:

Besides the improved symptoms, X-rays and sufficient spontaneous breathing efforts, the eligibility criteria for extubation were peak inspiratory pressure (PIP) of 15-20 cm H2O, positive end expiratory pressure (PEEP) of 4-6 cm H2O, respiratory rate of 15 to 30, FiO2 from 0.21 to 0.30, hematocrit more than 35%. and arterialized capillary blood gas analysis need to meet the following criteria: pH>7.20, PaCO2<=55 mmHg.

• Results publication: Chen L, Wang L, Ma J, Feng Z, Li J, Shi Y. Nasal High-Frequency Oscillatory Ventilation in Preterm Infants With Respiratory Distress Syndrome and ARDS After Extubation: A Randomized Controlled Trial. Chest. 2019 Apr;155(4):740-748. doi: 10.1016/j.chest.2019.01.014. PMID 30955572

• Shi Yuan, PhD,MD, Study director, Daping Hospital and the Research Institute of Surgery of the Third Military Medical University