Abstract
Background
Extracorporeal membrane oxygenation (ECMO) is rapidly becoming a mainstream technology for lung or heart/lung support. Current ECMO devices mostly consist of a power-driven centrifugal pump and a dedicated oxygenator. We studied the safety and efficacy of a novel, fully pneumatically driven ECMO device, which could be used in both venovenous or venoarterial mode in an animal model.
Methods
Six healthy, awake sheep were treated with the Mobybox ECMO device (Hemovent, Aachen, Germany) over a 7-day period in a venovenous mode. Gas exchange, coagulation parameters, and safety were assessed.
Results
Using a blood flow rate of 2 L/min and a low sweep gas flow rate of 0.3 L/min, the PCO2 ranged from 38 to 44 mm Hg pre oxygenator and dropped to 32 to 36 mm Hg post oxygenator, whereas the PaO2 post oxygenator increased to 600 mm Hg. Higher levels of sweep gas flow resulted in cessation of spontaneous breathing in some animals, consistent with high-efficiency carbon dioxide removal; thus, the sweep gas flow rate was maintained at a low level. Platelets dropped from 177 ± 53/μL to 107 ± 28/μL on day 2, while returning to baseline by day 7 (180 ± 51/μL). Plasma-free hemoglobin remained low (2-9 mg/dL), whereas fibrinogen slightly increased, and then remained stable throughout the period. Neither the pump nor the oxygenator showed any visible clotting after 7 days.
Conclusions
The pneumatically driven ECMO device provided excellent safety and physiologic efficacy in a 7-day sheep experiment without visible clotting, hemolysis, or sustained reductions in fibrinogen or platelets.