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 children and to determine whether these levels correlated with preoperative variables, intraoperative bypass management, or postoperative course.
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 times: at induction of anesthesia, after 15 minutes of CPB, at the end of CPB, and 1, 6, 18, and 42 hours after CPB. Preoperative, intraoperative, and postoperative data were prospectively recorded. All soluble adhesion molecule levels fell markedly at the initiation of CPB as a result 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 after 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 elevated throughout the 42 hours. Peak soluble P-selectin levels were associated with total support time (P=.04) and preoperative cyanosis (P=.003). Soluble L-selectin levels were inversely associated with longer total support time (P=.002), longer circulatory arrest time (P=.004), 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 children undergoing CPB. The soluble adhesion molecule levels after CPB change most significantly in patients with the highest potential for vascular injury: younger, cyanotic patients with longer pump times and longer postoperative courses. These data may be useful in the assessment of new therapies.