Experimental models of the respiratory distress syndrome : lavage and oleic acid

textabstractSo far the existing animal models have a lack of long lasting stability. Hardly any attention was paid to standardization of the induction of respiratory distress. We aimed at models in which the individual animals have a comparable respiratory distress for several hours to obtain the opportunity of comparative studies on interventions. We have chosen for two models in pigs: one model implied damage of the alveolar part of the alveolar-capillary membrane, and the other implied damage of the endothelial part. The first model was induced with alveolar lavage as an analogy of primary depletion of surfactant; the second was induced by intravenous administration of oleic acid as an analogy of fat embolism. We developed both models under guidance of the most commonly used criteria of ARDS (72,84; Table 1.1). The lavage model is described in the chapters II to V. In chapter II literature on the lavage model is reviewed. The development and the pathophysiological characteristics of our lavage model are presented in chapter III. In chapter IV the nature and distribution of pulmonary vasoconstriction in lavage induced respiratory distress is analyzed by morphometry. Chapter V contains the hemodynamic and gas exchange effects of PEEP in the lavage model. The oleic acid model is described in chapters VI to IX with the same order of chapters as the lavage model: a literature review in chapter VI, the development of the model in chapter VII, the morphometry of the muscular pulmonary arteries in chapter VIII and the PEEP study in chapter IX. In chapter X the results of our studies with the lavage and oleic acid model are compared and considered. The thesis is summarized in chapters XI and XII in English and Dutch language respectively. Chapters III to V and VII to IX are submitted for publication as independent papers, implying an overlap in method description. Parts in method description, which overlap with a former chapter are printed in smaller characters