title: Surfactant and partial liquid ventilation via conventional and high-frequency techniques in an animal model of respiratory distress syndrome.
abstract: OBJECTIVE: To compare the physiologic and pathologic effects of conventional ventilation (CV) and high-frequency ventilation (HFV) during partial liquid ventilation (PLV) with perflubron after surfactant treatment with the results of HFV plus surfactant in an animal lung-injury model created by saline lavage. We also studied the dose effects of perflubron during HFV. DESIGN: Randomized experimental study. SETTING: Research animal laboratory. SUBJECTS: A total of 32 newborn piglets. INTERVENTIONS: After lung injury was induced, the animals were randomized to one of four groups: a) CV + surfactant + perflubron to functional residual capacity (FRC); b) HFV + surfactant + perflubron to FRC; c) HFV + surfactant + 10 mL/kg perflubron; and d) HFV + surfactant. All then received intratracheal surfactant. After 30 mins, perflubron was administered to the PLV groups. The animals underwent ventilation for 20 hrs. MEASUREMENTS AND MAIN RESULTS: Arterial blood gases and hemodynamic variables were continuously monitored. Pulmonary histologic and morphometric analyses were performed after death or euthanasia at 20 hrs. All animals had sustained improvements in arterial/alveolar oxygen ratios, and no differences were observed among groups. All HFV groups required higher mean airway pressures to maintain oxygenation (p <.05). Hemodynamics did not differ among groups. Pathologic analysis demonstrated decreased lung injury in both cranial-dorsal (nondependent) and caudal-ventral (dependent) lobes of all animals treated with PLV when compared with those treated with HFV + surfactant (p <.05). CONCLUSIONS: After surfactant treatment, physiologic support over 20 hrs was similar during HFV with or without perflubron and CV with perflubron. All PLV modalities improved lung pathologic factors uniformly to a greater degree than did HFV + surfactant. A lower treatment volume of perflubron during HFV produced physiologic and pathologic results similar to those produced by perflubron with respect to FRC during either CV or HFV.
authors.affiliation: Infant Pulmonary Research Center, Children's Hospital of St. Paul, St. Paul, Minnesota (Drs. Manaligod, Bendel-Stenzel, Smith, Simonton, Connett, and Mammel; Mr. Bing; and Ms. Meyers); the departments of Pediatrics (Drs. Manaligod, Bendel-Stenzel, and Mammel) and Biostatistics (Dr. Connett), University of Minnesota, Minneapolis, Minnesota; and Alliance Pharmaceutical Corporation, San Diego, California (Dr. Smith).
authors.forename: Ellen M.
authors.initials: EM
authors.lastname: Bendel-Stenzel
authors.forename: Kendra M.
authors.initials: KM
authors.lastname: Smith
authors.forename: Susan C.
authors.initials: SC
authors.lastname: Simonton
authors.forename: Dennis R.
authors.initials: DR
authors.lastname: Bing
authors.forename: Pat A.
authors.initials: PA
authors.lastname: Meyers
authors.forename: John E.
authors.initials: JE
authors.lastname: Connett
authors.forename: Mark C.
authors.initials: MC
authors.lastname: Mammel