SOLUBLE ADHESION MOLECULES IN INFANTS AND CHILDREN UNDERGOING CARDIOPULMONARY BYPASS

Background The vascular injury and tissue damage after cardiopulmonary bypass (CPB) involves leukocyte-endothelial interactions mediated by cell adhesion molecules. This study was designed to determine the time course of soluble adhesion molecule levels after CPB in infants and c hildren and to determine whether these levels correlated with preopera tive variables, intraoperative bypass management, or postoperative cou rse. Methods and Results In 56 patients undergoing CPB (median age 1.0 year, range 2 days to 19 years), plasma concentrations of soluble E-, P-, and L-selection, soluble ICAM-1, and soluble VCAM-1 were measured using sandwich enzyme-linked immunosorbent assays at the following ti mes: at induction of anesthesia. after 15 minutes of CPB, at the end o f CPB, and 1, 6, 18, and 42 hours after CPB. Preoperative, intraoperat ive, and postoperative data were prospectively recorded. All soluble a dhesion molecule levels fell markedly at the initiation of CPB as a re sult of a combination of dilution and bypass circuit uptake. The time course of soluble selectins (P, E, and L), normalized to end of bypass levels, all rose significantly (P < .001) in the initial 6 hours afte r CPB and then returned to end bypass levels at 42 hours. Soluble ICAM -1 and VCAM rose 63% and 89% in the first 6 hours and remained elevate d throughout the 42 hours. Peak soluble beta-selectin levels were asso ciated with total support lime (P = .04) and preoperative cyanosis (P = .003). Soluble L-selectin levels were inversely associated with long er total support time (P = .002), longer circulatory arrest time (P = .003), longer length of intubation (P = .0009), preoperative cyanosis (P = .002), and younger age at surgery (P = .01). Conclusions Soluble adhesion molecules have a characteristic time course in infants and ch ildren undergoing CPB. The soluble adhesion molecule levels after CPB change most significantly in patients with the highest potential for v ascular injury: younger, cyanotic patients with longer pump times and longer postoperative courses. These data may be useful in the assessme nt of new therapies.