Influence of Respiratory Rate Settings on CO2 Levels During Nasal Intermittent Positive Pressure Ventilation (NIPPV).

"NIPPV will be administered using Leoni (Heinen\&Löwenstein, Bad Ems, Germany) and RAM cannula (Neotech, Valencia, CA).~After initial setting and before routine blood gas testing, tcCO2 will be connected and calibrated. We will use SenTec digital monitor (SenTec AG, Therwil, Switzerland). Correlation/agreement between the tcCO2 and PCO2 will be assessed and documented in each infant.~For Each infant we will get 2 set of data: Change in measurements when changing from 30 bpm to 10 bpm, and change in measurements when changing from 10 bpm to 30 bpm At the end of each hour, before rate change, we will document the following measurements:TcCO2, FiO2, saturation, the infant's respiratory rate (as measured in the monitor), number of apneas, bradycardia (heart rate\<100 bpm), saturation\<90% and\>94% episodes (as measured in the monitor), 1-hour saturation histogram clasification."