Inadequate enrollment

Positive end-expiratory pressure (PEEP) is used in premature infants receiving mechanical ventilation to maintain lungs open and facilitate gas exchange. When ventilation/perfusion mismatch is present, areas of the lung that are open for gas exchange do not match up with areas of the lung that are receiving blood for gas exchange. This study measures the feasibility of enrolling and completing study maneuvers in premature infants for a prospective study measuring the responsiveness of V/Q mismatch to changes in the amount (or level) of PEEP.

Inclusion Criteria:

1. Preterm birth before 32 weeks gestational age by best obstetric estimate, determined by the clinical obstetric team during antepartum admission
2. Birth weight less than 1500 grams, as measured by the clinical team at neonatal admission.
3. Presence of endotracheal intubation and invasive mechanical ventilation
4. Less than or equal to 28 days chronologic age
5. Supplemental oxygen requirement, with a fraction of inspired oxygen (FiO2) equal to or greater than 0.25 as documented on the bedside infant flow sheet.

Exclusion Criteria:

1. Congenital anomalies, as determined by the clinical supervising physician
2. Current of prior air leak syndrome, as determined by the clinical supervising physician.
3. Non-English speaking parents
4. Non-viable birth, as determined by the clinical supervising physician