title: Acute and sustained effects of aerosolized vs. bolus surfactant therapy in premature lambs with respiratory distress syndrome.
abstract: BACKGROUND
  Surfactant (SF) instillation may produce acute deleterious effects on gas exchange and both systemic and cerebral hemodynamics. Our aim was to compare the effects of aerosolized SF (SF-aero) with those of bolus SF (SF-bolus) administration on gas exchange, lung mechanics, and cardiovascular function in premature lambs with respiratory distress syndrome (RDS).
  
  
  METHODS
  Fourteen preterm lambs (85% gestation) were randomly assigned to receive SF-aero or SF-bolus. Oxygenation index (OI), PaCO2, cardiovascular parameters, carotid blood flow (CBF), lung compliance (mean dynamic compliance), and tidal volume (VT) were measured every 30 min for 6 h. Biochemical and histological analyses were performed.
  
  
  RESULTS
  After delivery, lambs developed severe RDS (inspiratory fraction of oxygen: 1; pH < 7.15; PaCO2 > 80 mm Hg; PaO2 < 30 mm Hg, mean dynamic compliance < 0.08 ml/cm H2O/kg). By 60 min after treatment, both groups showed an improvement in OI, PaCO2, mean dynamic compliance, and VT that was maintained until the end of the experiment. PaCO2 and CBF increased significantly in the SF-bolus group during the first 15-30 min, without concomitant changes in cardiovascular parameters, whereas in the SF-aero group, PaCO2 and CBF decreased gradually. SF-aero induced less alveolar hemorrhage and inflammation.
  
  
  CONCLUSIONS
  SF-aero produced improvements in gas exchange and lung mechanics similar to those produced by bolus administration but with less lung injury and fewer cerebral hemodynamic changes.
authors: Research Unit for Experimental Neonatal Respiratory Physiology, Cruces University Hospital, Barakaldo, Spain. macarmen.reysantano@osakidetza.net
authors: Carmen
authors: C
authors: Rey-Santano
authors: Victoria E
authors: VE
authors: Mielgo
authors: Leire
authors: L
authors: Andres
authors: Estibaliz
authors: E
authors: Ruiz-del-Yerro
authors: Adolfo
authors: A
authors: Valls-i-Soler
authors: Xabier
authors: X
authors: Murgia
mesh_terms: D000336:Aerosols; D000818:Animals; D000831:Animals, Newborn; D006801:Humans; D007231:Infant, Newborn; D011663:Pulmonary Surfactants / Q000008:administration & dosage*; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy*; D012756:Sheep
chemical_list: D000336:Aerosols; D011663:Pulmonary Surfactants