The purpose of this study is to determine whether Nasal intermittent positive pressure ventilation (NIPPV) non synchronized is better than continuous positive airway pressure (NCPAP)in preventing extubation failure within 72 h, after extubation of very low birth weight infants at the NEOCOSUR Network.

Is a Randomized trial to preterms infants <1500g and less than 34 weeks with RDS requiring machanical ventilation in the extubation period, randomized to receive NIPPV or NCPAP once extubation criteria were met. Parental written informed consent is required previous extubation. The failure rate is defined as the need for re-intubation and mechanical ventilation).

Exclusion criteria are: major congenital anomalies; presence of cardiovascular instability;intubation less than 2 hours; mechanical ventilation more than 14 days, using muscle relaxant, airway anomalies, consent not provided or refused.

Outcome measures:

The primary outcome was to assess the need for re-intubation within the first 72 hours after extubation in the 2 groups.

The criteria for failure were met by at least 1 of the following:

pH < 7.25 and PaCO2 > 65 mmHg; recurrent apnea more than 2 episodes per hour associated with bradycardia; during 4 hour continuous; 2 episodes of apnea that required bagand-mask ventilation in any time during the study; or a PaO2 < 50 mm Hg with a fraction of inspired oxygen > 0.6. The secondary outcomes concerning respiratory support were total duration on ETT ventilation, total duration on NCPAP, total duration on supplemental oxygen, incidence of pneumothorax,BPD and dead. Other outcomes included incidence of patent ductus arteriosus (PDA), necrotizing enterocolitis, intraventricular hemorrhage grades 3 and 4, retinopathy of prematurity stage 3, time to full feeds, and length of hospital stay.

Sample size calculations for the primary outcome: We estimated that there would be a more than 80% chance of detecting 43% difference between the groups (alpha 0.05) when samplesize (n) is 110 patients for each mode of treatment.

Inclusion Criteria:

• Preterm with a weight less than 1501 g
• Gestational age less or equal to 34 weeks
• Preterm that meets extubation criteria after at least 2 hours and less than 14 days connected to mechanical ventilation
• Patient receiving methylxanthynes

Exclusion Criteria:

• Patient more than 14 days in mechanical ventilation
• Newborn with congenital cardiopathy
• Newborn with congenital malformation
• Newborn wirh chromosomopathy or genopathic disease
• Newborn with suspected gastrointestinal disease
• Newborn with neuromuscular disease or receiving muscle relaxants
• Lack or informed consent signed by parents or legal representative