Twelve Hours In Vitro Biocompatibility Testing of Membrane Oxygenators.
In vitro test systems for extracorporeal membrane oxygenation (mock loop) represent an interesting alternative to complex and expensive in vivo test systems to analyze the pathomechanisms leading to insufficient biocompatibility. Data on mock loop systems are limited, and operation times are constricted to a maximum duration of 6 hr. This study aims at a 12 hr operation time and frequent monitoring of markers for insufficient biocompatibility in two experimental settings. Porcine blood circulated in a mock loop without any modifications, or the circuit was operated with a CO2-enhanced gas (5% CO2/21% O2/74% N2) in combination with a nutrient solution (phosphate-adenine-glucose-guanosine-saline-mannitol). Coagulation parameters changed over time without differences between the two groups. In the unmodified test setting, a pH increase was detected after 1 hr, followed by significantly increased levels of free hemoglobin as a marker for hemolysis and elevated numbers of activated platelets, which correlate with detected von Willebrand factor, microparticles, and interleukin-β. Proinflammatory cytokine levels were significantly increased after 12 hr. In contrast, these parameters remained constant in the modified test setting providing proof of a stable operating in vitro mock loop system with an extended/prolonged operation time.
From the *Department of Anesthesiology and †Department of Intensive Care, University Hospital RWTH Aachen University, Aachen, Germany; and ‡Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute Aachen, RWTH Aachen University, Germany.
Christian
C
Bleilevens
Oliver
O
Grottke
Sabine
S
Tillmann
Markus
M
Honickel
Rüedger
R
Kopp
Jutta
J
Arens
Rolf
R
Rossaint
D000818:Animals; D001775:Blood Circulation / Q000502:physiology*; D015199:Extracorporeal Membrane Oxygenation / Q000009:adverse effects; D005260:Female; D005434:Flow Cytometry; D006403:Hematologic Tests; D006461:Hemolysis; D066298:In Vitro Techniques; D008297:Male; D008422:Materials Testing; D008955:Models, Cardiovascular; D010107:Oxygenators, Membrane / Q000009:adverse effects; D013552:Swine; D013916:Thrombelastography; D013997:Time Factors