Merja Kallio1, Anne-Sea van der Zwaag2,3, Andreas D Waldmann3,4, Marika Rahtu5, Martijn Miedema6, Thalia Papadouri7, Anton H van Kaam6, Peter C Rimensberger8, Richard Bayford9, Inéz Frerichs10. 1. PEDEGO Research Unit, Department of Children and Adolescents, Oulu University Hospital, University of Oulu, Oulu, Finland, merja.kallio@oulu.fi. 2. Department of Mechanical Engineering, Delft University of Technology, Delft, The Netherlands. 3. SenTec AG, EIT Branch, Landquart, Switzerland. 4. Department of Anesthesiology and Intensive Care Medicine, Rostock University Medical Center, Rostock, Germany. 5. PEDEGO Research Unit, Department of Children and Adolescents, Oulu University Hospital, University of Oulu, Oulu, Finland. 6. Department of Neonatology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands. 7. Neonatal Intensive Care Unit, Archbishop Makarios III Hospital, Nicosia, Cyprus. 8. Division of Neonatology and Pediatric Intensive Care, University Hospital of Geneva, University of Geneva, Geneva, Switzerland. 9. Department of Natural Sciences, Middlesex University, London, United Kingdom. 10. Department of Anesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Kiel, Germany.
Abstract
BACKGROUND: Exogenous surfactant administration is an essential part of respiratory distress syndrome treatment in preterm infants. Current guidelines recommend the first dose to be given as early as possible, followed by an additional dose if symptoms persist. The effect of additional dosing on regional ventilation and lung volume has not been investigated so far. OBJECTIVES: The aim of this study was to assess changes in ventilation distribution, lung volume, and gas exchange following repeated surfactant dosing in invasively ventilated neonates. METHOD: Preterm infants requiring invasive ventilation and repeated surfactant treatment, and participating in the prospective observational multicenter trial "Continuous Regional Analysis Device for neonate Lung (CRADL)" were included in this analysis. Ventilation distribution, end-expiratory lung impedance (EELZ), and tidal impedance variation were determined by electrical impedance tomography together with clinical parameters before and after repeat endotracheal surfactant treatment. RESULTS: Nine neonates (gestational age 32.7 ± 2.7 weeks, weight 1,724 ± 691 g) received an additional dose of surfactant at a median postnatal age of 33.5 h (IQR 9.1-46.6). One patient was excluded from the analysis due to simultaneous interventions confounding data analysis. Repeated surfactant dose did not significantly affect ventilation distribution. There were no significant changes in EELZ or tidal impedance variation. SpO2/FiO2 increased from 248 ± 104 to 367 ± 92 (p = 0.001), while FiO2 was reduced from 0.41 ± 0.20 to 0.27 ± 0.10 (p = 0.004). Expiratory tidal volume fell from 4.3 ± 0.6 to 3.0 ± 1.2 mL/kg (p = 0.03), while other ventilator and clinical parameters remained stable. CONCLUSIONS: Repeated surfactant dose during invasive ventilation improves oxygenation without measurable changes in EELZ or ventilation distribution.
BACKGROUND: Exogenous surfactant administration is an essential part of respiratory distress syndrome treatment in preterm infants. Current guidelines recommend the first dose to be given as early as possible, followed by an additional dose if symptoms persist. The effect of additional dosing on regional ventilation and lung volume has not been investigated so far. OBJECTIVES: The aim of this study was to assess changes in ventilation distribution, lung volume, and gas exchange following repeated surfactant dosing in invasively ventilated neonates. METHOD: Preterm infants requiring invasive ventilation and repeated surfactant treatment, and participating in the prospective observational multicenter trial "Continuous Regional Analysis Device for neonate Lung (CRADL)" were included in this analysis. Ventilation distribution, end-expiratory lung impedance (EELZ), and tidal impedance variation were determined by electrical impedance tomography together with clinical parameters before and after repeat endotracheal surfactant treatment. RESULTS: Nine neonates (gestational age 32.7 ± 2.7 weeks, weight 1,724 ± 691 g) received an additional dose of surfactant at a median postnatal age of 33.5 h (IQR 9.1-46.6). One patient was excluded from the analysis due to simultaneous interventions confounding data analysis. Repeated surfactant dose did not significantly affect ventilation distribution. There were no significant changes in EELZ or tidal impedance variation. SpO2/FiO2 increased from 248 ± 104 to 367 ± 92 (p = 0.001), while FiO2 was reduced from 0.41 ± 0.20 to 0.27 ± 0.10 (p = 0.004). Expiratory tidal volume fell from 4.3 ± 0.6 to 3.0 ± 1.2 mL/kg (p = 0.03), while other ventilator and clinical parameters remained stable. CONCLUSIONS: Repeated surfactant dose during invasive ventilation improves oxygenation without measurable changes in EELZ or ventilation distribution.