Lung Recruitment

Babies born early (under 32 weeks) are at risk of developing lung problems after birth. A major reason for this is that the lungs are not fully developed. Lungs of preterm babies will often collapse in between breathing due to lung immaturity. Applying gentle pressure, using nasal device through their nostril or through the breathing tube helps to prevent this lung collapse. This would help in air-oxygen going to lungs and also makes the babies breathing more comfortable. This gentle pressure is medically called as PEEP/CPAP and could be delivered by breathing machine (ventilator) and CPAP machine, collectively called as "continuous distending pressure (CDP)". Those babies breathing on their own and receiving inadequate CDP would need more breathing support by placing them on breathing machine (ventilator). The longer the baby receives breathing machine support, higher chance of lung injury . Preterm infants who are already on breathing machine, providing sub optimal PEEP/CPAP could also lead to lung damage. Providing optimal PEEP/CPAP could prevent these negative outcomes. Currently there is not enough evidence to suggest optimal PEEP/CPAP in preterm infants. Neonatal units all around the world uses PEEP/CPAP ranging from 4 to 10cm H20 based on their unit practice. Currently available investigations provide limited one time information (e.g. Chest X-ray) regarding whether baby is receiving optimal PEEP/CPAP. Electrical Impedance Tomography (EIT) is a new technology which could provide better information regarding the pressure delivered. Also, this device would provide continuous information as if the clinicians are doing continuous chest X-ray but without any radiation. In this study, the team will assess the effect of different levels of PEEP/CPAP (4 to 10cm H20) on prevention of lung collapse using EIT. This would be studied in premature infants who are on breathing machine support and CPAP machine support.

The primary aim of this work is to evaluate the role of high frequency oscillatory ventilation (HFOV) in recruitment of lung in preterm newborns 32 to 37 weeks gestational age with moderate to severe respiratory distress. The secondary aim is to evaluate the role of chest ultrasound in monitoring of lung recruitment in comparison to routine chest x ray in those babies. Also cardiac hemodynamics will be assesed using functional echocardiography.