Affiliations: Department of Cardiac Surgery, University Hospital Munich, Ludwig-Maximilian-University, Munich, Germany
Correspondence:
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Corresponding author: Dr Sabina Guenther, Department of Cardiac Surgery, University Hospital Munich, Ludwig-Maximilian-University, Marchioninistr. 15, 81377 Munich, Germany. Tel.: +49 089 4400 73457; Fax: +49 089 4400 78873; E-mail:sabina.guenther@med.uni-muenchen.de
Abstract: BACKGROUND: Air embolism is a potentially fatal but underrecognized
complication in Extracorporeal Life Support (ECLS). Oxygenators containing
venous air traps have been developed to minimize the risk of air embolism in
daily care. OBJECTIVE: We reproduced air embolism as occurring via a central
venous catheter in an experimental setting to test the potential of
oxygenators with and without venous bubble trap (VBT) to withhold air. METHODS: An in vitro ECLS circuit was created and a central venous
catheter with a 3-way stopcock and a perforated male luer cap was inserted
into the inflow line. Three different oxygenators with and without VBT and
their capability to withhold air were examined. After 60 seconds of stable
ECLS flow, the stopcock was opened towards the atmosphere for 3 minutes.
Afterwards, air accumulation within the oxygenator was determined. RESULTS: Comparison of the total air entrapment showed a
significant superiority of the oxygenators with VBT (p < 0.001). All
oxygenators were able to partly withhold macro air boli, however, the
capacity of oxygenators with VBT was higher. Passing through the oxygenator resulted
in a reduction of microbubbles in all cases. CONCLUSIONS: Macro air emboli can be substantially reduced by usage
of oxygenators that contain a VBT, whereas the capability to withhold
microbubbles to a vast extent seems to depend on the intrinsic oxygenator's
membrane.
Keywords: Air embolism, extracorporeal life support, oxygenator, venous bubble trap
