Release of adenylate kinase into cerebrospinal fluid during open-heart surgery and its relation to postoperative intellectual function.

In 33 of 36 patients having open-heart surgery, the levels of adenylate kinase in cerebrospinal fluid (CSF-AK) were raised. No such increase was seen in 8 patients who had had lung operations without cardiopulmonary bypass. A significant increase in CSF-AK was recorded in 18 patients whose CSF was examined both preoperatively and postoperatively, and this increase was correlated with change in an index of intellectual function. Since there was no evidence of damage to the blood-brain barrier, these findings point to a causal relation between brain-cell injury during cardiopulmonary bypass and release of AK into CSF. Measurement of CSF-AK may therefore prove useful in research to improve the quality of open-heart surgery.