Postconditioning in cardiopulmonary resuscitation: a better protocol for cardiopulmonary resuscitation

Although current cardiopulmonary resuscitation (CPR) performance can increase the rates of restoration of spontaneous circulation (ROSC) and survival to hospital admission, the discharge rates of patients remain disappointing. The high mortality rate is attributed to post-cardiac arrest brain injury. The discovery of the postconditioning phenomenon opens a door to endogenous neuroprotection. The protection mechanisms of postconditioning include attenuating mitochondrial calcium overload and reducing oxidative stress, recruiting the reperfusion injury salvage kinase (RISK) pathway, and preventing from the mitochondrial permeability transition pore (mPTP) opening at the time of reperfusion. An advantage of postconditioning lies in the potentially clinical application in the unexpected ischemic situation. Prior laboratory researches indicate that postconditioning may lessen the reperfusion/ischemia-induced injury in unexpected coronary occlusion, acute myocardial infarction and stroke. Because cardiac arrest, stroke and acute myocardial infarction have a similar pathophysiological process, we hypothesize that postconditioning could be used in the clinical practice of CPR to treat patients with post-cardiac arrest brain injury. We propose a novel protocol of "Postconditioning cardiocerebral resuscitation (Post-CCR)". The Post-CCR includes applying three cycles of 18s chest compression and 10s interruption for ventilation first, and then executing chest compression only CPR until the patients return spontaneous circulation. Post-CCR can not only provide vital blood flow to the heart and brain but also activate endogenous protective mechanism to lessen post-cardiac arrest brain injury. We consider that it would become a feasible, safe and efficient cerebralprotective intervention in the prevention and alleviation of post-cardiac arrest brain injury, which would also improve the outcome after cardiac arrest.