Addition of acetylsalicylic acid to heparin for anticoagulation management during pumpless extracorporeal lung assist.

Pump-driven extracorporeal membrane oxygenation (ECMO) or pumpless arterio-venous interventional lung assist (iLA) is associated with possible complications, mainly consisting of bleeding or thrombosis/clotting by cellular deposits on the membrane or extracorporeal circuit surfaces, which may reduce gas-exchange capacity. In this study, we report our experiences with the addition of low-dose acetylsalicylic acid (ASA 1.5 mg/kg body weight/d) to heparin for anticoagulation of a pumpless low-resistance gas-exchange membrane (Novalung GmbH, Talheim, Germany). We assessed changes in coagulation parameters and the demand for transfusion of blood components. Furthermore, we compared the function of the artificial membranes (oxygen transfer and capacity of CO2 removal) of the ASA group (n = 15) with that of a matched-pair control group treated with heparin alone. The mean duration of iLA treatment was 6.6 ± 3.7 days. The addition of ASA did not increase bleeding activity or the demand for transfusion. Relative changes of CO2 removal on day 3 expressed as a percentage in the ASA group were (mean value) -11.8% in comparison with control (-3.0%, p = 0.266), but the relative amount of oxygen transfer tended to be increased in the ASA group (+3.9%) and to be decreased in the control group (-14.7%, p = 0.214). PaO2/FiO2 ratio was significantly improved in the ASA group compared with the control group at day 5. The use of membranes per patient (membrane/patient ratio) tended to be decreased in patients treated with ASA (1.12 ± 0.34) in comparison with control (1.33 ± 0.62, p = 0.157). In the ASA group, one patient died due to multiple organ failure, whereas in the control group, five patients died. We conclude that supplementation of low-dose ASA during pumpless extracorporeal lung support is safe and might preserve the function of oxygen transfer.