title: Effects of less-invasive surfactant administration on oxygenation, pulmonary surfactant distribution, and lung compliance in spontaneously breathing preterm lambs.
abstract: BACKGROUND
  A new technique was proposed to administer surfactant to spontaneous breathing preterm infants by placing a thin catheter through the vocal cords. This technique was not studied with respect to oxygenation, gas exchange, surfactant distribution, and lung mechanics. We tested the technique of less-invasive surfactant administration (LISA) in a spontaneous breathing preterm lamb model.
  
  
  METHODS
  Preterm lambs (n = 12) of 133-134 d gestational age were randomized to the following three groups: (i) continuous positive airway pressure (CPAP) only, (ii) CPAP + LISA, and (iii) intubation and mechanical ventilation with surfactant administration. Surfactant was labeled with samarium oxide. During the next 180 min, blood gas analyses were performed. Postmortem, lungs were removed and surfactant distribution was assessed, and pressure-volume curves were performed.
  
  
  RESULTS
  Pao2 in the LISA-treated lambs was significantly higher than in the lambs that exclusively received CPAP. Moreover, Pao2 values were similar between the LISA-treated and the intubated lambs. Overall, surfactant deposition was less in the LISA lambs, with significantly less surfactant distributed to the right upper lobe. Lung compliance was better in the intubated lambs compared with the LISA-treated lambs, although this did not reach significance.
  
  
  CONCLUSIONS
  LISA improved oxygenation, similar to conventional surfactant application techniques, despite lower surfactant deposition and lung compliance.
authors.affiliation: Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Hendrik J
authors.initials: HJ
authors.lastname: Niemarkt
authors.affiliation: Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Elke
authors.initials: E
authors.lastname: Kuypers
authors.affiliation: Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Reint
authors.initials: R
authors.lastname: Jellema
authors.affiliation: Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Daan
authors.initials: D
authors.lastname: Ophelders
authors.affiliation: 1] Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands [2] Section of Neonatology, Department of Pediatric and Adolescent Medicine, University Hospital RWTH Aachen, Aachen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Hütten
authors.affiliation: Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Maria
authors.initials: M
authors.lastname: Nikiforou
authors.affiliation: Neonatology, Department of Pediatric and Adolescent Medicine, University Hospital, University Köln, Köln, Germany.
authors.forename: Angela
authors.initials: A
authors.lastname: Kribs
authors.affiliation: Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Boris W
authors.initials: BW
authors.lastname: Kramer
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002406:Catheterization, Peripheral / Q000379:methods*; D045422:Continuous Positive Airway Pressure / Q000379:methods; D008170:Lung Compliance / Q000187:drug effects*; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D010087:Oxides; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure; D011663:Pulmonary Surfactants / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology*; D012493:Samarium; D012756:Sheep; D014827:Vocal Cords / Q000601:surgery
chemical_list: D010087:Oxides; D011663:Pulmonary Surfactants; D012493:Samarium; C120592:samarium oxide; D010100:Oxygen