Non-invasive Ventilation in Preterm Infants

This is a prospective, observational cohort study. For the study part on noninvasive neurally adjusted ventilatory assist (NIV-NAVA) the design is interventional. For all participants prospective data collection will be conducted by chart review and by downloading ventilatory data from the ventilator. A registration of respiratory severity score will be done by a caregiver during the weaning period. This consists of a visual assessment of the work of breathing every 2 hours. For participants on NIV-NAVA consenting to the interventional part of the study a titration procedure will be conducted, afterwards serial electrical impedance tomography and lung and diaphragm ultrasound measurements will be done.

All infants on non-invasive respiratory support will be studied. Only infants on NIV-NAVA, will undergo an intervention.

The NAVA level will be reduced to 0,5 cmH2O/microvolt (µV) for 3 minutes as a starting point. Limit peak pressure will be set to 35 cmH2O (the maxi-mum pressure that can be delivered to the patient is cut off at 30 cmH2O). Other ventilator settings will be left unchanged and are as clinically indicated. Starting from a NAVA level of 0,5 cmH20/µV the level will be increased by 0,5 cmH2O/µV every 3 minutes until reaching a maximum NAVA level of 2,5 cmH2O/µV.

This is a non-invasive technique consisting of the application of a non-adhesive single-use patient belt to monitor regional changes in lung aeration at the bedside.

Lung ultrasound is a non-invasive technique used to diagnose lung pathology and to monitor lung condition. This technique is part of the standard of care for preterm infants in our neonatal unit. Lung ultrasound scores are calculated at each time an ultrasound is performed. Ultrasound of the diaphragm consists of a short additional measurement of diaphragm thickness and thickening fraction and will be done at the same time of the lung ultrasound following a standardized procedure.

Definition of the breakpoint for patients of NIV-NAVA after following a prespecified titration protocol

Parts (in % of global lung volume) of the lung that are not ventilated as measured with electrical impedance tomography (EIT)

At inclusion, day 3, day 7 and weekly thereafter as long as supported with NIV-NAVA as long as supported with NIV-NAVA, up to 10 weeks

Percentage of TV per 'Region of Interest' (ROI) as measured with electrical impedance tomography (EIT)

At inclusion, day 3, day 7 and weekly thereafter as long as supported with NIV-NAVA as long as supported with NIV-NAVA, up to 10 weeks

At inclusion, day 3, day 7 and weekly thereafter as long as supported with NIV-NAVA as long as supported with NIV-NAVA, up to 10 weeks

Inclusion Criteria: Preterm infants (< 37 weeks GA) supported with non-invasive respiratory support. Non-invasive respiratory support can consist of non-invasive NAVA, nasal continuous positive airway pressure (nCPAP) or high flow nasal canula (flow > 2 liters/min).The support can be given as primary respiratory support or as respiratory support after weaning from invasive ventilation (= after extubation). Infants can only be enrolled after written and signed informed consent by the parents. Exclusion Criteria: Infant born after a gestational age of 37 weeks or more. Infants with major congenital malformations or chromosomal abnormalities (eg trisomy 18, congenital diaphragmatic hernia…)

Database on non-invasive ventilation has the potential to be shared but no concrete plan for sharing individual patient data is made.

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