Longevity of ECMO circuit in Covid-19 patients and site of heparin administration

ABSTRACT

Objective: We measured transmembrane pressure gradient (ΔP) and membrane lung resistance (RML) in Covid-19 patients supported by ECMO when unfractionated heparin (UFH) was administered systemically via a central venous catheter or administered immediately before the membrane lung. Methods: Daily changes in ΔP and RML were recorded during ECMO support (Cardiohelp, Getinge, Germany) in 2 patients where UFH was administered systemically (Sys UFH) and in 2 additional patients where UFH was administered pre-membrane lung (pre-ML UFH). The ECMO cannulation strategy was similar in all patients (bi-femoral cannulation with 25F multistage drainage and 21F return cannulae). Results: There was no difference in the daily APTT and CRP between the two groups (Table 1). The ECMO circuit was changed on day 6 and 7 in Sys UFH patients because of increased ΔP and RML. In pre- ML UFH patients, ΔP and RML remained stable with an unchanged ECMO circuit for 26 and 32 days respectively (Figure 1+2). Conclusions: Although many Covid-19 related factors increase the risk of thrombosis, the pre-ML administration of UFH may contribute to prolonged circuit function.