Circulating Adhesion Molecules in Pediatric Cardiac Surgery

Abstract

Cardiopulmonary bypass (CPB) may be associated with the risk of a "whole body inflammation." Adhesion molecules, such as endothelial leukocyte adhesion molecule (ELAM-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1), seem to play a pivotal role in the inflammatory response. Soluble forms of these adhesion molecules may serve as markers of endothelial activation or damage. To elucidate whether plasma levels of soluble adhesion molecules differ between pediatric and adult cardiac surgery patients, 15 consecutive children younger than 5 yr undergoing CPB were prospectively studied and compared with adults scheduled for elective coronary artery bypass grafting and valve replacement. Plasma levels of circulating (soluble) adhesion molecules (sELAM-1, sICAM-1, sVCAM-1) were measured from arterial blood samples using enzyme-linked immunosorbent assays after induction of anesthesia (= "baseline"), during CPB, at the end of surgery, and on postoperative days 1 and 2. At baseline, plasma levels of all three soluble adhesion molecules were significantly higher in children than in adults. sELAM-1 and sICAM-1 plasma concentrations were even beyond normal in the children (sELAM-1: 88.8 +/- 13.8 ng/mL; sICAM-1: 349 +/- 27 ng/mL). During CPB and until the end of surgery, plasma levels of all adhesion molecules decreased in the children and remained almost unchanged in the adults. In the children, sELAM-1 remained lower than baseline values until the second postoperative day (45.2 +/- 12.2 ng/mL), whereas sICAM-1 increased in the postbypass period without, however, reaching baseline values (254 +/- 40 ng/mL). Postoperatively, sVCAM-1 plasma levels were lower than baseline value (postoperative day 2: 450 +/- 33 ng/mL) and did not differ between the two groups. At baseline, PaO_2/FIO2 was significantly lower in the children than in the adults and inversely related to plasma levels of all adhesion molecules. Neutrophil count was higher in the children only on postoperative day 2, whereas rectal temperature did not differ and never exceeded 38.5 degrees C in either group. Plasma levels of circulating adhesion molecules were significantly different between pediatric and adult cardiac surgery patients at baseline. Alterations in microcirculation and/or oxygenation may directly or indirectly affect endothelium, thus resulting in higher plasma levels of sELAM-1, sICAM-1, and sVCAM-1 in children scheduled for cardiac surgery. CBP did not result in a significant increase in soluble adhesion molecules in either group, indicating no marked endothelial damage in this situation.

(Anesth Analg 1995;81:1129-35)