Adhesion molecules appear to play a central role in tissue damage secondary to inflammatory response. Besides various neutrophil- and endothelial-bound adhesion molecules, soluble forms of endothelial-derived adhesion molecules have been detected in the circulating blood in recent years. They seem to be good markers of endothelial damage, but their importance in the critically ill has not been definitely elucidated yet. Plasma levels of circulating (soluble) adhesion molecules (endothelial leucocyte adhesion molecules [sELAM-1], vascular cell adhesion molecule 1 [sVCAM-1], intercellular adhesion molecule 1 [sICAM-1]) were serially measured from arterial blood samples using enzyme-linked immunosorbent assays (ELISA) in 50 consecutive patients suffering from severe trauma (injury severity score [ISS] >25 points) or postoperative complications. Measurements were carried out on the day of admission on the intensive care unit (ICU) (''baseline'' value) and during the next 5 days. Survival was defined as survival throughout the study period. The survivor group (n=30) consisted of more patients who had sustained trauma (53%), whereas in the nonsurvivors (n=20) more patients with postoperative complications were found (65%). On admission to ICU, septic shock was more often seen in the nonsurvivors (30%) than in the survivors (13%) and the nonsurvivors showed a slightly higher APACHE II score at baseline. At baseline, plasma levels of all three adhesion molecules were elevated beyond normal range in both groups. The sICAM-1 and sELAM-1 plasma concentrations were significantly higher in the nonsurvivors than in the survivors already at baseline. The sELAM-1 and sICAM-1 values significantly decreased in the survivors without reaching normal values. At the end of the investigation period, sVCAM-1 plasma level was within normal range in the survivors. In the nonsurvivors, all three adhesion molecules increased significantly throughout the study period (sELAM-1, from 115 +/- 31 to 158 +/- 3 ng/mL; sICAM-1, from 830 +/- 210 to 1,536 +/- 199 ng/mL; sVCAM-1, from 861 +/- 168 to 1,249 +/- 151 ng/mL). None of the other hemodynamic or laboratory variables could be correlated with the time course of adhesion molecules, except for PaO2/PaO2 ratio, which was negatively correlated with plasma levels of soluble adhesion molecules in the nonsurvivors (analysis of covariance). It is concluded that plasma levels of soluble adhesion molecules were markedly higher in nonsurviving than in surviving critically ill patients. They may possibly serve as markers of the extent of inflammatory response, of the endothelial damage in patients at risk of multiple-organ failure or both. Their role in critical illness, however, is not definitely clarified. Thus, it has to be elucidated whether preventing an increase in soluble adhesion molecules is of benefit for the patient's organ function or even outcome.
