S100 blood concentrations in children subjected to cardiopulmonary by-pass.

S100 is a member of a family of calcium-binding proteins present primarily in nervous tissue, where it is mainly concentrated in glial cells (1)(2). Although the role of this protein in brain function and disease has not yet been conclusively elucidated, it has been ascertained that the appearance of this protein constituent of neural cells in biological fluids is a reliable indicator of active cell damage in the nervous system in different pathological conditions (3)(4)(5)(6). Open heart surgery is known to be associated with brain cell injury. It was diagnosed previously using rather crude psychometric tests and clinical observations in seemingly healthy patients (7), and measurements of S100 in the blood have recently been successfully used to monitor cerebral damage after cardiac surgery (8)(9)(10). The present study is aimed at investigating the potential use of measurements of S100 in the blood to monitor possible cerebral distress during extracorporeal circulation in children (0–9 years), when hemodynamic adaptive phenomena in the brain show peculiarities linked to the age of the patient (11). The data presented indicate significantly higher blood concentrations of this nervous tissue constituent during cardiopulmonary by-pass (CPB), together with a direct relationship with the duration of CPB. Blood samples were taken from 13 patients (6 males and 7 females), ages from <1 year to 9 years (two patients <1 year of age, one 1 year of age, six 3 years of age, one 4 years of age, one 5 years of age, and two 9 years of age), with no preexisting neurological disorders or other co-morbidities, who were undergoing cardiac …