Priming with Gelatin Polysuccinate or Human Albumin Does Not Affect the Neurologic Outcome Using Controlled Automated Reperfusion of the Whole Body after 20 Minutes of Cardiac Arrest

Objectives: The probability of a favorable neurological survival after cardiac arrest (CA) decreases with prolonged duration of resuscitation. In our experiments on pigs, a survival rate of over 90% was achieved by application of controlled automated reperfusion of the whole body (CARL) after 20 minutes of CA. Over 80% of the surviving animals showed little to no neurological deficits. One element of CARL, which entails a therapy bundle based on extracorporeal circulation, is the composition of the priming solution. This study focused on the comparison of human albumin 20% and gelatin polysuccinate 4% as components of the CARL priming solution.

Methods: Sixteen pigs (German hybrid pigs) were treated using CARL after 20 minutes of normothermic CA, induced by ventricular fibrillation, and followed up for up to 7 days. Eight animals underwent CARL using human albumin 20% (group HA, N = 8) and another eight animals using gelatin polysuccinate 4% (group GP, N = 8). The neurological deficit was assessed daily and rated employing a species-specific neurological deficit score (NDS). The NDS scale ranges from 0 (representing an animal without a neurological deficit) to 500 (indicating brain death). Animals with an NDS of less than 50 are capable of standing independently, walking unsupported, eating on their own and display a species-specific behavior. Therefore, NDS of less than 50 on day 7 was considered to be a favorable neurological outcome.

Results: Sixteen pigs (100%) were successfully weaned off the extracorporeal circulation after 60 minutes. Two (2/8, 25%) pigs of each group were euthanized in accordance with the approved experimental protocol due to insufficient recovery. In either group, six (6/8, 75%) reached the seventh postoperative day with an NDS of less than 50. In group HA, five (5/8, 62.5%) animals and in group GP four (4/8, 50%) pigs displayed no neurological deficit on day 7 (NDS 0).

Conclusions: Gelatin polysuccinate 4% can be used as an alternative to human albumin 20% in the CARL priming solution. In this chronic animal model undergoing 20 minutes of CA, no differences regarding lethality and neurological recovery were found.