Early Respiratory Response to Bovine Lipid Extract Surfactant Can Predict Failure of Minimally Invasive Surfactant Therapy

Minimally invasive surfactant therapy (MIST) techniques for instillation of surfactant via a thin intratracheal catheter in a spontaneously breathing neonate with respiratory distress syndrome are being increasingly adopted worldwide. We designed this study to describe the short-term respiratory outcomes in neonates who received high-volume bovine lipid extract surfactant (BLES) at 5 mL/kg via MIST and analyze predictors of MIST failure. This was a retrospective, observational cohort study that included all neonates who received BLES via MIST between January 1, 2018 and December 31, 2023. Baseline demographic characteristics, immediate- and short-term respiratory outcomes were compared between patients with MIST success and MIST failure (defined as the need for mechanical ventilation within 7 days of procedure). Predictors of MIST failure were examined using logistic regression models. Of a total of 213 neonates, 41 (19.2%) were deemed MIST failure. Neonates with MIST failure compared with MIST success had lower mean (standard deviation [SD]) gestational age in weeks (29.0 [2.8] vs. 31.3 [3.4], p < 0.001) and lower mean birthweight (SD) (1247.2 [602] vs. 1654.1 [747] g, p <0.001). Neonates with MIST failure had higher preprocedural positive end expiratory pressures and higher oxygen needs than neonates with MIST success. On regression analysis, fraction of inspired oxygen (FiO2) at 1 hour (p = 0.049) and FiO2 at 6 hours (p = 0.03) post-MIST was identified as independent predictors of MIST failure after accounting for differences in baseline characteristics. Successful administration of high-volume surfactant via MIST, without any need of mechanical ventilation within 7 days of procedure was achieved in 80.8% of the cohort with a low MIST failure rate of 19.2%. Oxygen requirements measured at 1- and 6-hour post-MIST serve as independent predictors of MIST failure.