Platelet damage and haemolysis during bubble oxygenator perfusion with and without arterial line filter, compared to membrane oxygenator perfusion

Abstract

We determined to what extent a 27 micron depth filter (Bentley Polyfilter bypass blood filter PF427, Bentley Lab., Irvine, California, USA) in the arterial line of a bubble oxygenator (BO) system is responsible for the difference in haemocompatibility between this BO system and a membrane oxygenator (MO) system in which no arterial line filter is used. We studied three groups of patients subjected to long perfusions of approximately three hours: BO perfusion with ( n = 8) and without ( n = 8) the arterial line filter and MO perfusion ( n = 10) without filter. Platelet and erythrocyte damage were evaluated at seven sampling points during perfusion. Also pre-and postoperative bleeding times and postoperative blood loss and blood transfusions up to 18 hours after perfusion were determined.We found that the 27 micron depth filter in the arterial line impairs the haemocompatibility of the BO only to a small extent; the MO remains haematologically superior over the BO even when the arterial line filter is absent from the BO circuit. I ntroductionAn arterial line filter is recommended for cardiopulmonary bypasses with a bubble oxygenator (BO), because a BO system produces a considerable amount of microemboli.1-5 However, an arterial line filter induces turbulences and high shear stresses by the microfenestrations, by which platelets and erythrocytes are damaged. 1. 2. 5-8 Furthermore this effect of the arterial line filter is in particular pronounced during long perfusions of over two hours and during high flow rates.' Therefore it might add to the impaired haemocompatibility of the BO system. Because a membrane oxygenator (MO) produces much fewer microemboli than a BO, 1.2,5 s one might argue that the haematological superiority of the MO system is supported by the fact that the BO system requires an arterial line filter which may have haematological side effects.