Techniques to Prevent Lung Injury in Premature Infants Less Effective than Expected

A neonatologist at The Children’s Hospital of Philadelphia led a new study showing current non-invasive techniques for respiratory support are less effective than previously thought in reducing severe lung injury in very premature infants.

Neonatologists commonly use non-invasive nasal ventilation instead of mechanical ventilation via a breathing tube in hopes of avoiding bronchopulmonary dysplasia (BPD). Frequently a by-product of intubation, BPD — scarring and inflammation of the lungs — is a leading cause of death or neurological injury in extremely-low-birth-weight infants.

This trial, led by Haresh Kirpalani, MD, compared two common forms of non-invasive ventilation used in extremely-low-birth-weight premature infants. Both techniques make breathing easier for the infant by stopping the lungs from collapsing, which over time causes lung inflammation and injury.

The current standard of care, nasal continuous positive airway pressure (CPAP), delivers slightly pressurized air throughout the breathing cycle. In contrast, nasal intermittent positive-pressure ventilation (IPPV), which has become widespread, provides an additional spike of positive pressure when the infant inhales. While more complicated, the hope had been that IPPV was more effective than standard CPAP.

With this study, the researchers tested the idea that the extra pressure delivered via IPPV would be more beneficial than CPAP in preventing bronchopulmonary dysplasia. The study team randomly assigned 1009 infants with a birth weight under 1000 grams (2.2 pounds) and gestational age under 30 weeks to either nasal CPAP or nasal IPPV. The infants were from 34 neonatal intensive care units in 10 countries.

Dr. Kirpalani and his team found no significant difference in the primary outcome of either death or survival with BPD when the babies reached 36 weeks old. They also found no significant difference in rates of other neonatal complications between the two treatment groups.

“Although somewhat discouraging, this research is significant as it refutes the common assumption that the non-invasive therapies being used are reducing severe lung injury in these tiny babies,” said Dr. Kirpalani. “The study alerts us that we still need to develop new therapies for babies to avoid lung injury and BPD.”

The study was published recently in the New England Journal of Medicine. To learn more about the study, visit the Research Institute’s website. For details on CHOP’s newborn care and research, see the Division of Neonatology.