Abstract

We have used a rapid induction of profound hypothermia (<10 degrees C) with delayed resuscitation using cardiopulmonary bypass (CPB) as a novel approach for resuscitation from exsanguination cardiac arrest (ExCA). We have defined this approach as emergency preservation and resuscitation (EPR). We observed that 2 h but not 3 h of preservation could be achieved with favorable outcome using ice-cold normal saline flush to induce profound hypothermia. We tested the hypothesis that adding energy substrates to saline during induction of EPR would allow intact recovery after 3 h CA. Dogs underwent rapid ExCA. Two minutes after CA, EPR was induced with arterial ice-cold flush. Four treatments (n=6/group) were defined by a flush solution with or without 2.5% glucose (G+ or G-) and with either oxygen or nitrogen (O+ or O-) rapidly targeting tympanic temperature of 8 degrees C. At 3 h after CA onset, delayed resuscitation was initiated with CPB, followed by intensive care to 72 h. At 72 h, all dogs in the O+G+ group regained consciousness, and the group had better neurological deficit scores and overall performance categories than the O-groups (both P<0.05). In the O+G- group, four of the six dogs regained consciousness. All but one dog in the O-groups remained comatose. Brain histopathology in the O-G+ was worse than the other three groups (P<0.05). We conclude that EPR induced with a flush solution containing oxygen and glucose allowed satisfactory recovery of neurological function after a 3 h of CA, suggesting benefit from substrate delivery during induction or maintenance of a profound hypothermic CA.