Background: An increase of S100beta in serum during cardiopulmonary bypass (CPB) has been interpreted as a sign of brain injury. Cardiotomy suction may cause fat embolization, and its role in the S100beta increase was examined.
Methods: Twenty coronary artery operation patients were randomly assigned to two groups, 10 with suction during CPB to cardiotomy reservoir (CR), 10 to cell saving device (CS). S100beta was measured (immunoassay) in blood from the patients and from cell saving device after processing. In 7 additional patients S100beta was measured in the cell saving device before processing and directly from the wound at sternotomy.
Results: Before anesthesia, serum S100beta was 0.03+/-0.06 microg/L. At the end of CPB it was 2.47+/-1.31 microg/L and 0.44+/-0.27 microg/L (CR vs CS; p < 0.001). S100beta was 33+/-12 microg/L in CS reservoir and 42+/-18 microg/L in blood from the wound.
Conclusions: Most serum S100beta after CPB with cardiotomy suction may be of extracerebral origin. S100beta after CPB with cell saving device was the same as after off-pump operation. The interpretation that an increase in S100beta during CPB in patients reflects cerebral injury must be questioned.