http://repub.eur.nl/res/aut/13711/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/13310/ 2004-01-01T00:00:00Z Besides being one of the mechanisms responsible for ventilator-induced lung injury, atelectasis also seems to aggravate the course of experimental pneumonia. In this study, we examined the effect of reducing the degree of atelectasis by natural modified surfactant and/or open lung ventilation on bacterial growth and translocation in a piglet model of Group B streptococcal pneumonia. After creating surfactant deficiency by whole lung lavage, intratracheal instillation of bacteria induced severe pneumonia with bacterial translocation into the blood stream, resulting in a mortality rate of almost 80%. Treatment with 300 mg/kg of exogenous surfactant before instillation of streptococci attenuated both bacterial growth and translocation and prevented clinical deterioration. This goal was also achieved by reversing atelectasis in lavaged animals via open lung ventilation. Combining both exogenous surfactant and open lung ventilation prevented bacterial translocation completely, comparable to Group B streptococci instillation into healthy animals. We conclude that exogenous surfactant and open lung ventilation attenuate bacterial growth and translocation in experimental pneumonia and that this attenuation is at least in part mediated by a reduction in atelectasis. These findings suggest that minimizing alveolar collapse by exogenous surfactant and open lung ventilation may reduce the risk of pneumonia and subsequent sepsis in ventilated patients. http://repub.eur.nl/res/pub/9198/ 1999-01-01T00:00:00Z The aim of this study was to compare high-frequency oscillatory ventilation (HFOV) with conventional mechanical ventilation (CMV) with and without surfactant in the treatment of surfactant-deficient rabbits. A previously described saline lung lavage model of lung injury in adult rabbits was used. The efficacy of each therapy was assessed by evaluating gas exchange, lung deflation stability and lung histopathology. Arterial oxygenation did not improve in the CMV group without surfactant but increased rapidly to prelavage values in the other three study groups. During deflation stability, arterial oxygenation decreased to postlavage values in the group that received HFOV alone, but not in both surfactant-treated groups (HFOV and CMV). The HFOV group without surfactant showed more cellular infiltration and epithelial damage compared with both surfactant-treated groups. There was no difference in gas exchange, lung deflation stability and lung injury between HFOV and CMV after surfactant therapy. It is concluded that the use of surfactant therapy in combination with high-frequency oscillatory ventilation is not superior to conventional mechanical ventilation in improving gas exchange, lung deflation stability and in the prevention of lung injury, if lungs are kept expanded. This indicates that achieving and maintaining alveolar expansion (i.e. open lung) is of more importance than the type of ventilator. http://repub.eur.nl/res/pub/8932/ 1998-01-01T00:00:00Z Does endotracheal instilled prostacyclin (epoprostenol) improve oxygenation in preterm infants with persistent pulmonary hypertension? Four preterm infants were studied. Prostacyclin (50 ng x kg(-1)) was injected as an endotracheal bolus. In two patients the prostacyclin bolus was repeated and in one patient prostacyclin was administered continuously. Oxygenation was evaluated through the oxygenation index and the ratio of arterial oxygen tension to the fraction of inspired oxygen. The mean arterial blood pressure was used to evaluate systemic circulation. The oxygenation index (+/-SD) decreased significantly from 39 (+/-13.3) to 7 (+/-2.5) and the ratio of arterial oxygen tension to the fraction of inspired oxygen (+/-SD) increased significantly from 47 (+/-13) to 218 (+/-67), most likely related to a reduction of the pulmonary vascular resistance with a reversal of the extrapulmonary shunting at the ductus arteriosus and atrial level. The blood pressure did not change. All effects were reversed on drug withdrawal. Repeated or continuous endotracheal administration of prostacyclin in three children demonstrated a sustained response without tachyphylaxis, and without overt side-effects. Endotracheal instillation of prostacyclin resulted in an improved oxygenation without systemic vascular repercussions in four preterm infants with persistent pulmonary hypertension. Repeated or continuous administration showed a sustained response and no overt side-effects were noticed.