Limiting calcium overload after cardiac arrest: The role of human albumin in controlled automated reperfusion of the whole body

Background Regarding the overall inadequate results after cardiopulmonary resuscitation, the development of new treatment concepts is urgently needed. Controlled Automated Reperfusion of the whoLe body (CARL) represents a therapy bundle to control the conditions of reperfusion and the composition of the reperfusate after cardiac arrest (CA). The aim of this study was to investigate the plasma expander’s role in the CARL priming solution and examine its mechanism of action. Methods Viscosity, osmolality, colloid osmotic pressure (COP), pH and calcium binding of different priming solutions were measured in vitro and compared to in vivo data. N = 16 pigs were allocated to receive CARL following 20 min of untreated CA with either human albumin 20% (HA, N = 8) or gelatin polysuccinate 4% (GP, N = 8). Blood gas analyses were performed during the first hour of reperfusion and catecholamine and fluid requirements were recorded. Neurological outcome was assessed by neurological deficit scoring (NDS) on the seventh day. Results In vitro, addition of HA to the CARL priming solution resulted in higher COP and higher calcium-binding than GP. In vivo, treatment with HA led to greater reduction of ionized calcium and higher extracorporeal flows within the first 30 min of reperfusion with no difference in catecholamine support and fluid requirement. Seven-day survival of 75% with no difference in NDS was observed in both groups. Conclusions Our data show that the plasma expander in the CARL priming solution has a significant effect on the initial reperfusate and can potentially influence the course of resuscitation. However, seven-day survival and NDS did not differ between groups.