Evaluation of Semi-rigid and Flexible Catheters for Less Invasive Surfactant Administration in Preterm Infants

Inclusion Criteria: * Preterm infants born less than 37 weeks of gestation * Treating physician in charge of admission decides to administer intratracheal surfactant via standardized institution- LISA protocol (regardless of this study) (see Supplement file 1) * Written informed consent signed by caregivers or legal representative to participate Exclusion Criteria: * Refusal to participate in study or not providing written informed consent by caregivers/parents * Treating physician decides to use different route of surfactant administration or does not adhere to LISA protocol. * Rupture of membranes (ROM) at less than 22 weeks of gestation or more than 6 weeks before birth * Estimated birth weight \< 3rd percentile using 2013 Fenton growth trajectories * Twins with feto-fetal transfusion syndrome (FFTS) and FFTS being the cause of premature delivery * Contraindications listed in the LISAcath® or Nasogastric Tube manual (esophageal/pharyngeal varices or other vascular lesions, esophageal/pharyngeal tumor, nasal fracture, skull fracture, known allergy to material)