Assessment of cerebral damage during open-heart surgery. A new experimental model.

A new experimental technique for the assessment of cerebral cellular damage during extracorporeal circulation is described. It is based upon the direct measurement of the enzyme creatine phosphokinase (CPK) and the brain-specific isoenzyme CPK-B in cerebrospinal fluid of dogs submitted to conventional techniques of cardiopulmonary bypass (CPB). Highly significant elevations occur during a 60 min period of CPB in CSF levels of total CPK and CPK-B isoenzyme. These elevated levels persist at 24 hours postoperation, despite full clinical recovery in the dogs. In a comparative study of the effects of introducing a 40 micrometer arterial line screen filter during the period of CPB, there was a highly significant reduction in total CPK and CPK-B levels in the filtered group (p < 0.005).