Mechanical ventilation used to support the sick newborn infant is associated with many complications including the development of chronic lung disease. Limiting prolonged invasive ventilation remains an important strategy to decrease lung injury and prevent chronic lung disease. Currently, there is no objective measure available to predict readiness for removal of the endotracheal tube ("extubation") and discontinuing mechanical ventilation in this fragile population.

The investigators propose to predict extubation success by evaluating the electrical activity of the diaphragm (Edi), which provides important information about the "drive" to breathing coming from the brain and the function of the diaphragm, two essential factors determining extubation readiness and success.

In this observational study, very low birth weight preterm infants with RDS who require mechanical ventilation in first 24 hour of life will be recruited. A size appropriate nasogastric tube with multiple array of electrodes (Edi catheter) will be inserted in each eligible infant. The average EdI (Edi_avg) will be measured during mechanical ventilation just before extubation. All infants will be extubated to non-invasive positive pressure ventilation (NIPPV or CPAP) delivered through nasal cannula

The specific aim is to determine whether there is a relationship between Edi_avg before extubation and the extubation success in a sample of preterm infants with respiratory distress syndrome (RDS). We hypothesize that Edi-avg of infants with successful extubation will be significantly different from the infants who fail extubation

Inclusion Criteria:

Preterm infants less than 35 week gestation, requiring intubation and mechanical ventilation for respiratory distress in the first 24 hours of life

Exclusion Criteria:

Infants with a non-intact esophagus (e.g tracheal-esophageal fistula or atresia), a non-functional diaphragm (e.g. phrenic nerve palsy), severe intracranial hemorrhage or structural CNS abnormality, severe birth asphyxia and critically sick infant needing paralysis or deep sedation.

A convenience sample of forty(40) preterm infants less than 35 week gestation admitted in the ICN with the need for intubation and mechanical ventilation for respiratory distress in the first 24 hours of life will be recruited for this study.