Comparison of a phospholipid-based protein-free surfactant and a natural bovine surfactant (SURVANTA) during pressure and volume-controlled ventilation in an improved rabbit fetus model.
During pressure- or volume-controlled ventilation different surfactant preparations were compared in an improved rabbit fetus model. Based on a self-designed software program, this model enables on-line registration of lung mechanics and heart rate in up to ten fetuses. Using a commercially available bovine lung surfactant (SURVANTA) as standard, we compared animals treated with a protein-free surfactant preparation containing only phospholipids, PL (dipalmitoylphosphatidylcholine:palmitoyloleoylphosphatidylglycerol++ +, DPPC:POPG 70:30) plus palmitic acid (PA) with an untreated ventilated control group. During pressure-controlled ventilation the insufflation pressure (IP) was decreased and increased stepwise with and without positive end-expiratory pressure (PEEP). SURVANTA was significantly more potent than PL plus PA and both differed significantly from the untreated controls. With additional PEEP the differences between SURVANTA and PL+PA disappeared but the differences to the controls were still present. We found that, with additional PEEP, active natural surfactants lead to ECG-irregularities, which indicates that PEEP influences pulmonary and cardiovascular function and compromises the benefits of surfactant therapy. Also during volume-controlled ventilation SURVANTA was superior to PL+PA and the untreated controls. In order to raise the level of activity of pure PL mixtures to that of natural bovine surfactants, we suggest that a surface active protein (probably SP-C) must be added to such mixtures.
Häfner
D
D
Byk Gulden Lomberg Chemische Fabrik GmbH, Department of Respiratory Pharmacology, Konstanz, Germany.
Kilian
U
U
Bühler
R
R
Beume
R
R
Habel
R
R
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000494:pharmacology; D000399:Air Pressure; D000818:Animals; D001688:Biological Products; D002417:Cattle; D004562:Electrocardiography; D005260:Female; D005333:Fetus / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D008168:Lung / Q000502:physiology; D008954:Models, Biological; D010715:Phosphatidylglycerols / Q000494:pharmacology; D010991:Plethysmography; D011175:Positive-Pressure Respiration; D011247:Pregnancy; D011663:Pulmonary Surfactants / Q000008:administration & dosage / Q000494:pharmacology*; D011817:Rabbits; D013501:Surface-Active Agents / Q000494:pharmacology*; D013990:Tidal Volume / Q000502:physiology
D001688:Biological Products; D010715:Phosphatidylglycerols; D011663:Pulmonary Surfactants; D013501:Surface-Active Agents; D015060:1,2-Dipalmitoylphosphatidylcholine; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol; C072197:beractant