Duration of surfactant administration and its impact on stabilisation of vital parameters in very preterm neonates <28 weeks of gestational age (SurfStab): 1 min versus 5 min—study protocol for a prospective randomised-controlled phase IV trial

Background Respiratory distress syndrome remains one of the leading causes of morbidity and mortality in extremely preterm neonates. Surfactant replacement therapy substantially improves survival. Current European Consensus Guidelines recommend the less invasive surfactant administration (LISA) technique. However, no evidence exists on whether the duration of administration affects physiological stability. Rapid surfactant administration may provoke transient hypoxia or bradycardia due to airway obstruction, whereas slower delivery could potentially reduce such fluctuations. Methods/design The SurfStab Trial is a single-centre, randomised, controlled phase IV clinical trial conducted at the Division of Neonatology, Medical University of Graz, Austria. Extremely preterm neonates (< 28 weeks of gestation) requiring surfactant via LISA will be randomly allocated (1:1) to receive surfactant administration over either 1 min (“1-min group”) or 5 min (“5-min group”). The primary outcome is the maximum change in cerebral oxygen saturation (crSO 2 ), measured continuously using near-infrared spectroscopy (NIRS) from 5 min before LISA catheter insertion (baseline) to 15 min after completion of the procedure. Secondary outcomes include changes in arterial oxygen saturation (SpO 2 ), heart rate (HR), arterial blood pressure (ABP), thoracic electrical impedance tomography (EIT), lung ultrasound, and the need for repeat surfactant administration, invasive ventilation, or supplemental oxygen up to three and up to 48 h after study intervention, as well as short-term outcomes at hospital discharge. The planned sample size is 76 neonates. Discussion This trial will address a crucial gap in neonatal care by determining whether the duration of surfactant administration influences cerebral and systemic oxygen stability in extremely preterm neonates. The findings may refine evidence-based recommendations for optimal LISA procedure and may contribute to improved outcomes. Clinical Trial Registration ClinicalTrials.gov , Identifier: NCT NCT07261787. Registered 02/12/2025. Eu CT number 2025-522754-39-00. Registered 01/12/2025.