[Adrenomedullary epinephrine excretion and myocardial norepinephrine release during cardiopulmonary bypass]

It has long been known that shock or surgical stress promotes an epinephrine (E) excretion from the adrenomedullary glands. In fourteen adult cardiac patients, plasma E values in both superior vena cava (SVC) cannula and inferior vena cava (IVC) cannula during total cardiopulmonary bypass (CPB) are studied at three stages, before aortic cross clamp (pre AXC), after release of aortic cross clamp (post AXC) and at 34 degrees C rectal temperature in rewarming (34 degrees C RT). Although E values in both SVC and IVC are slightly higher values than normal in pre AXC, they increase sharply to peaked values at post AXC and decline uniformly close to normal at 34 degrees C RT. IVC-E is constantly significantly higher (statistically) than SVC-E at each of all three stages. It is strongly suggested that E response to CPB is mainly originated from the adrenomedullary glands, and cardiac reflex which has sympathetic efferent limbs triggered by myocardial ischemia can indicate the increase in E during AXC. Myocardial norepinephrine (NE) release in heart ischemia such as acute myocardial infarction has been generally accepted. To examine whether myocardial NE release occurs during AXC, if there is the association of NE release with any clinical parameters, the second investigation is done in twenty-six adult cardiac patients. Plasma NE values in both the radial artery (A) and the coronary sinus (CS) are measured at six stages, pre AXC (stage 1), post AXC (stage 2), post CPB (stage 3), three hours after off CPB (stage 4), six hours off CPB (stage 5) and twelve hours off CPB (stage 6).(ABSTRACT TRUNCATED AT 250 WORDS)