Gethin Boyle St Thomas’ Hospital A comparison of haemostatic biomarkers in low-risk patients undergoing cardiopulmonary bypass using either conventional centrifugal cell salvage or the HemoSep device

Conventional cell saver vs. HemoSep during cardiopulmonary bypass. Background Approximately 1600 CPB cases/year 100+ ECMO RPB processing in the UK Pro’s Raise Hb & Hct Reduces allogenic blood usage Cost saving Plasma proteins, clotting factors & platelets (Issitt & Sheppard 2011) Con’s Potential of fluid overload Inflammatory mediators Surgical debris Bacteriological contamination

HemoSep Device Advancis Surgical Orbital agitator (120cpm) Suction aspiration unit Collection reservoir and pump Processing and transfusion bags Polyvinyl chloride blood bag Polycarbonate control membrane filter (1μm) 12g Superadsorber pad (240mL/g)

HemoSep Device (Gunaydin & Gourlay, 2013)

Methods RCT Sorin Xtra (control group) HemoSep (study group) 54 patients (n = 28 control, n = 26 study) 1st time CABG & AVR Granted full R&D, NRES and REC approval Bloods taken Pre operatively during anaesthesia Prior to weaning from CPB Post re-transfusion of cell saved blood 3hrs post operatively FBC (RBC, WBC, Hb, Hct, Plt, MPV & PDW) Clotting screen (PT, aPTT & Fibrinogen) D Dimers Platelet function Endogenous Thrombin Potential (ETP)

Results Surgical data

Results FBC’s

Results Clotting screens

Results ETP

Conclusion Returning whole blood is of little benefit in terms of coagulation with low risk CPB cases. In larger volumes of blood, the HemoSep device could be beneficial as shown by the shorter prothrombin time, ETP and D- dimer levels suggesting there is less activation of coagulation and fibrinolysis. Further work is needed to confirm this. It remains to be determined whether conventional centrifugal cell salvage removes more cytokines, plasma-free haemoglobin, surgical debris and bacteriological contamination. More vigilant approach in measuring ACT post-transfusion may be required. In large volumes, centrifugation may not only cause a dilutional coagulopathy, but also instigate a consumption coagulopathy.