Scoring System Validity for Short-term Outcomes of Coronary Artery Bypass Surgery in Indigenous Australians

tion. A better understanding of the withdrawal period, DCDheart physiology andEVP science is required to improve outcomes. We aimed to define the derangements following withdrawal, noting their impact on donor blood use in EVP. Methodology: In a clinically relevant porcine asphyxia model (n=24) and initial human trials, haemodynamic (MAP, CVP, intra-ventricular pressures(IVP)), electrical/circulatory arrest times, metabolic (pH, O2, lactate, trop-T), biochemical (K+) and endocrine changes (noradrenaline & adrenaline measured in coronary sinus and systemic sites) duringwithdrawal periods (20-40 min) were analysed. Blood collection methods for EVP, and perfusion strategies (pressure vs. flow) were tested. Results: From pre-withdrawal to post-arrest, IVP increased in the RV, while LV IVP fell (PV loop studies). Early rapid O2 desaturations were noted (14 mmHg +/-1 at 5 min post withdrawal). By 30 min post-withdrawal, pHwas 10mmol/L, troponin-T >200 mg/L and K+ >10mmol/L. Adrenaline and noradrenaline (NA) surges were noted at 4 min post withdrawal (assoc. HR increase) with ongoing amine release (NA) in the coronary sinus, but no further increase systemically (p<0.05). Conclusion: Dramatic changes occurred during the withdrawal period, notably RV distension, profound acidosis, myocardial ischaemia & hyperkalaemia all of which have important implications for clinical cardiac transplantation/ EVP. A greater understanding of these processes provides insight for post-mortem interventions to limit impact and optimise EVP perfusate.