Experimental extracorporeal membrane oxygenation reduces central venous pressure: an adjunct to control of venous hemorrhage?

BACKGROUND: Venoarterial ECMO has been utilized in trauma patients to improve oxygenation, particularly in the setting of pulmonary contusions and ARDS. We hypothesized that venoarterial ECMO could reduce the central venous pressure in the trauma scenario, thus, alleviating major venous hemorrhage. METHODS: Ten swine were cannulated for venoarterial ECMO. Central venous pressure, mean arterial pressure, portal vein pressure and portal vein flow were recorded at three different flow rates in both a hemodynamic normal state and a setting of increased central venous pressure and right ventricular load, mimicking acute lung injury. RESULTS: Venoarterial ECMO reduced the central venous pressure (CVP( sup)) from 9.4+/-0.8 to 7.3+/-0.7 mmHg (p<0.01) and increased the mean arterial pressure from 103+/-8 to 119+/-10 mmHg (p<0.01) in the normal hemodynamic state. In the state of increased right ventricular load, the CVP(sup) declined from 14.3+/-0.4 to 11.0+/-0.7mmHg (p<0.01) and the mean arterial pressure (MAP) increased from 66+/-6 to 113 +/-5 mmHg (p<0.01). CONCLUSION: Venoarterial ECMO reduces systemic venous pressure while maintaining or improving systemic perfusion in both a normal circulatory state and in the setting of increased right ventricular load associated with acute lung injury. ECMO may be a useful tool in reducing blood loss during major venous hemorrhage in both trauma and selected elective surgery.