Abstract P116: Neurologic Recovery after 15 Minutes of Normothermic Cardiac Arrest by Pressure and Flow-controlled Circulation Using a Peripheral Extracorporal Circuit
Background Cardiopulmonary resuscitation (CPR) after cardiac arrest (CA) can only restore cerebral and myocardial function if employed within 3–5 minutes after CA. Sharply increasing mortality rates and absent neurologic recovery. follow later CPR efforts. While state of the art CPR may restore the circulation, inconstant blood-flow and pressure control enhances whole body organ damage that includes the brain. We tested how peripheral extracorporal circulation (ECC) with a pressure and flow-controlled circulation can improve survival and neurologic recovery after 15 minutes of normothermic CA.
Methods Ten anesthetized Pigs (54.9±4.5 KG BW) underwent normothermic ischemia for 15 min. following ventricular fibrillation (VF) induction. After 15 minute CA a conventional CPR (control group, n=4) and peripheral extracorporal circulation (ECC) (experimental group, n=6) was evaluated. ECC yielded 70 – 80 mmHg arterial pressure and 70 – 80 ml/kgBW/min systemic flow for 60 minutes.and subsequent survival and neurologic recovery determined. Neurologic assessment used a scoring system (Neurologic Deficit Score (NDS): 0=normal; 500= brain death), and MRI and brain histology was evaluated at the end of the experiment (up to day 7).
Results No animal (n=4) of the control group could be resuscitated successfully after 20 min of continuous CPR. Conversely, 4 out of 6 experimental group animals survived, regaining complete functional neurologic recovery at intervals ranging from 48 hours to 7 days (NDS=0±0). Of these survivors (n=4), MRI showed mild changes in ischemia-sensitive brain-areas that were confirmed by brain histology on day 7. Of non survivors (n=2) in experimental group, had to intractable ventricular fibrillation despite ECC, and one animal (n=1) had incomplete recovery (24hour-NDS=145) and underwent euthanasia after 30 hours.
Conclusion This pilot study of 15 min. normothermic cardiac arrest demonstrates complete functional neurologic recovery in 4 out of 6 surviving animals, if death of a carefully contolled ECC is employed., whereas CPR alone resulted in all 4 control animals. Application of a constant blood-flow and pressure with ECC after CA is superior to conventional CPR using manual chest compression and drug support.