To avoid the drawbacks of systemic anticoagulation during prolonged extracorporeal circulation in patients with adult respiratory distress syndrome (ARDS) a heparinization technique has been developed by which partially degraded heparin can be covalently end-point attached to the surface of the equipment constituting the extracorporeal circuit (Carmeda Bio-Active Surface, CBAS) thereby localizing the anticoagulatory effert. Since 1986 we have used extracorporeal circuits and membrane lungs coated with the CBAS for extracorporeal lung assistance (ECLA) in 14 patients suffering from ARDS. The patients were on ECLA for 3 to 55 days with a survival rate of43%. Our experience so far is that by using equipment coated with CBAS it is possible to perform long-term extracorporeal circulation with a minimum of intravenously administered heparin, thus avoiding the risk of major coagulation defects.
42 ASE JOLIN AND LARS BJERlNIES EXTRACELLULAR r Ca++ (POC/ROC) Blockers Potentiators r W i Halogenated inhalation anesthetics cause pertubation of cell membrane lnhal anesth ANGIOTENSIN I1 Endotheline M Receptor I 8-recep to r u-recep to r CAMP A.ACID A.ACID phospholipid , ithstract). Federation PTOC 1984: 43: 923. Respiratory failure, in the series Lung Biology in Health and 50. Sckar M C, Hokin L E. The role of phosphoinositides in signal Disease. New York: Marcel Dekker, 1985: 23-160. transduction. J Membrane Bid 1986: 89: 193-210. 51, (:arlsson A J, Bindslrv L, Hedenstierna G , Hypoxia-induced 69.
In isolated rat lungs subjected to fat emulsion damage, a model simulating adult respiratory distress syndrome, we have previously reported that adenosine (ADO) reduces pulmonary vascular resistance (PVR) and the fluid filtration rate (FFR). In the present study the aim was to examine morphologically this effect of ADO. Two groups of isolated rat lungs were subjected to the injury. Marked and significant differences were found between the groups; in lungs not given ADO, FFR and airway pressure were higher and, as evaluated by electron microscopy, the endothelial lining was thin and partly disrupted. The epithelial cells of the alveolar walls were also partly disrupted and the alveolar septa were split enclosing interstitial edema. In lungs receiving ADO from the onset of exposure to fat emulsion, FFR was lower and ultrastructure did not differ from non-injured non-treated controls perfused for the same length of time.
In adult respiratory distress syndrome, a major concern is to reduce increments in pulmonary vascular resistance (PVR) and maintain the patency of lung microvessels. We have investigated the effects of adenosine, a potent systemic vasodilator, on PVR and fluid filtration rate (FFR) in isolated blood-perfused rat lungs. The preparations were undamaged or subjected to fat emulsion-induced injury simulating ARDS. In undamaged lungs adenosine caused a significant dose-dependent reduction of hypoxia-induced increases in PVR. Furthermore, the increase in FFR upon elevation of left atrial pressure by 0.77 kPa was significantly hampered by adenosine, 24 nmol.ml-1.min-1. Employing the same rate of infusion, adenosine, in a group of injured preparations, significantly reduced the rise in PVR towards baseline and completely abolished the further increase upon a superimposed injection of serotonin. In another series of preparations with lung injury randomly assigned to an adenosine group and a control group, adenosine significantly reduced FFR. Thus, adenosine, even when infused at low rates, reduced increments in PVR and fluid filtration, both in undamaged and in fat emulsion-injured isolated lungs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.