What are the determinants of vital organ perfusion during CPR?
Cerebral blood flow is dependent on the gradient between the carotid artery and the intracranial pressure during systole (thoracic compression). Myocardial blood flow is dependent on the gradient between the aorta and right atrium during diastole (release phase of thoracic compression). During conventional CPR, cerebral and myocardial flow are less than 5% of prearrest values. Below the diaphagm, renal and hepatic blood flow during CPR is 1% to 5% of prearrest values. 8. What are the determinants of improved vital organ perfusion during CPR? Force, rate, and duration of chest compression during CPR will determine the effectiveness of organ perfusion during CPR. Irrespective of the mechanism of forward blood flow during CPR, increasing the force of chest compressions increases arterial pressures. At pressures >400 newtons (about 40 Kg), bone and tissue trauma are more likely. Increasing the rate of chest compressions will significantly increase the arterial pressure. GENERAL GUIDELINES
