Soluble selectins in the pulmonary and systemic circulation in acute cardiogenic and non-cardiogenic pulmonary failure

Objective: Pulmonary endothelial activation caused by high pulmonary capillary pressures may be involved in the pathogenesis of cardiogenic pulmonary edema (CPE). We studied soluble selectins and soluble ICAM-1 as markers of cell activation in the systemic and pulmonary circulation of patients with respiratory failure (RF) due to CPE (RFCPE) as compared to patients with RF due to pulmonary infection (RFPI). Setting: Cardiovascular Intensive Care Unit at a university hospital. Patients: Twenty patients with RFCPE, 20 patients with RFPI and 17 critically ill patients without RE. Interventions: Blood samples were obtained from the arterial and the pulmonary capillary circulation and sE-, sL-, and sP-selectin as well as sICAM-1 were determined. To distinguish between systemic and pulmonary endothelial activation, transpulmonary gradients (concentration(arterial blood) - concentration(pulmonary) (capillary blood)) were calculated. Results: Systemic concentration of sL-selectin was lower in patients with RFCPE and RFPI than in patients without RF (RFCPE: 719.0 +/- 243.9 ng/ml, RFPI: 528.5 +/- 220.8 ng/ml, no RF: 882.4 +/- 222.6 ng/ml; P < 0.001). Systemic concentrations of ICAM-1, sE- and sP-selectin were not significantly different between the three groups. Transpulmonary gradients in sE- and sl-selectin were predominantly negative in patients with RFCPE (-3.2 <plus/minus> 7.8 ng/ml and -55.4 +/- 116.1 ng/ml, respectively) and RFPI (-2.3 +/- 5.8 ng/ml and -17.6 +/- 40.3 ng/ml, respectively) but were predominantly positive in patients without RF (11.6 +/- 7.2 ng/ml and 66.6 +/- 69.6 ng/ml, respectively), which suggests trapping of sE-and sl-selectin in the pulmonary circulation in the majority of patients with RFPI as well as in the majority of patients with RFCPE. Conclusion: Pulmonary endothelial activation occurs during both RFCPE and RFPI. This adds evidence that, besides hydrostatic mechanisms, cell activation occurs during CPE.