Introduction: Based on
extracorporeal circulation, targeted reperfusion strategies have been developed to improve survival and neurologic recovery in refractory
cardiac arrest: Controlled Automated Reperfusion of the whoLe Body (CARL). Furthermore, animal and human cadaver studies have shown beneficial effects on cerebral pressure due to head elevation during conventional
cardiopulmonary resuscitation. Our aim was to evaluate the impact of head elevation on survival, neurologic recovery and histopathologic outcome in addition to CARL in an animal model. Methods: After 20 min of
ventricular fibrillation, 46 domestic pigs underwent CARL, including high, pulsatile extracorporeal blood flow, pH-stat
acid-base management, priming with a
colloid,
mannitol and
citrate, targeted
oxygen,
carbon dioxide and blood pressure management, rapid cooling and slow
rewarming. N = 25 were head-up (HUP) during CARL, and N = 21 were supine (SUP). After weaning from ECC, the pigs were extubated and followed up in the animal care facility for up to seven days. Neuronal density was evaluated in neurohistopathology. Results: More animals in the HUP group survived and achieved a favorable neurological recovery, 21/25 (84%) versus 6/21 (29%) in the SUP group. Head positioning was an independent factor in neurologically favorable survival (p < 0.00012). Neurohistopathology showed no significant structural differences between HUP and SUP. Distinct, partly transient clinical
neurologic deficits were
blindness and
ataxia. Conclusions: Head elevation during CARL after 20 min of
cardiac arrest independently improved survival and neurologic outcome in pigs. Clinical follow-up revealed transient
neurologic deficits potentially attributable to functions localized in the posterior perfusion area, whereas histopathologic findings did not show corresponding differences between the groups. A possible explanation of our findings may be
venous congestion and
edema as modifiable contributing factors of neurologic injury following prolonged
cardiac arrest.