Lung Neutrophils in the Adult Respiratory Distress Syndrome

Abstract

Although neutrophils are of pathogenetic importance in various animal models of acute lung injury, their role in the adult respiratory distress syndrome (ARDS) is unclear. To study the significance of lung neutrophils in this disorder, patients with ARDS (n=11) were evaluated by bronchoalveolar lavage within 24 h of admission to the intensive care unit. Patients with non-ARDS respiratory failure requiring mechanical ventilation (n=4) and normal volunteers (n=12) were also studied. Neutrophils constituted 67.6 ± 9.8% of recovered lavage cells in patients with ARDS compared with only 4.0 ± 2.4% of cells in mechanically ventilated control patients and 0.8 ± 0.2% in normal volunteers (p < 0.005, both comparisons). Furthermore, in patients with ARDS (n=6) evaluated serially by bronchoalveolar lavage at 72−h intervals, neutrophil percentages decreased from 91 ± 3.2% (initial lavage) to 42.8 ± 12% (final lavage) (p < 0.005). Lung neutrophils also predicted the severity of abnormalities in gas exchange and lung p...