Plasma endotoxin levels and functions of peripheral granulocytes in surgical patients with respiratory distress syndrome.

Plasma endotoxin levels and granulocyte functions (chemiluminescence and chemotaxis) were determined in fifty-two patients with postoperative sepsis. Seventeen had concurrent respiratory distress syndrome (RDS group) and the remaining thirty-five were free of the syndrome (non-RDS group). The plasma endotoxin concentrations were higher in the RDS group than in the non-RDS group (p less than 0.001). All nine patients with particularly high levels (greater than 80 pg) belonged to the RDS group. We noted a positive correlation in chemiluminescence (p less than 0.001, r = 0.67) and a negative correlation in chemotactic activity (p less than 0.001, r = 0.69). To determine whether endotoxin alters normal granulocyte functions in vitro, healthy granulocytes were treated by the endotoxin (E. coli 0111:B4). There was an increase in chemiluminescence and a decrease in chemotactic activity, as observed in vivo. Furthermore, normal granulocytes chemiluminescence was increased by pretreatment of RDS plasma showing high endotoxin levels in vitro (n = 4, p less than 0.05). Thus, endotoxin in the plasma probably plays an important role in marked changes in peripheral granulocyte functions in patients with respiratory distress syndrome.