The Effect of Atrial Septal Defect in the Treatment of ARDS with Left Ventricular Dysfunction Simulating Severe COVID-19

To explore the effect of atrial septal defect (ASD) and venoarterial extracorporeal membrane oxygenation (VA-ECMO) in the treatment of ARDS combined with left ventricular dysfunction (LVD) to find a new effective method for treating severe COVID-19 patients. Five large animal ARDS models of sheep were established by intravenous injection of Lipopolysaccharide. ASD was made under general anesthesia and VA-ECMO was simulated by extracorporeal circulation machine. The oxygenation of peripheral blood, systemic circulation, and cardiac function were observed under conditions of closed and opened ASD, and the significance of ASD shunt in improving cardiopulmonary function was evaluated. With ASD closed, the atrial shunts disappeared, the peripheral artery pressure of oxygen(PaO2): 141.2±21.4mmHg, the oxygenation index (PaO2/FiO2): 353.0±53.5, the mean blood pressure (MAP): 49.3±13.5 mmHg, the heart was full; with ASD opened, the left-to-right shunt was observed, PaO2: 169.3±18.9mmHg, PaO2/FiO2: 423.3±47.3, MAP: 68.2±16.1 mmHg, the range of cardiac motion significantly increased, heart beat was powerful, and systemic circulation significantly improved. Statistical analysis showed that there were significant differences between opened and closed ASD (P < .01). ASD plus VA-ECMO is an effective method for the treatment of ARDS combined with LVD, which is the main cause of death in severe COVID-19 patients. However, further clinical validation is needed.