During 1998–1999 inhaled nitric oxide (NO) was tested in 23 ARDS patients (13 in Pilsen centre, 10 in Brno centre) with the mean age of 48 years (range 20– 74 years). Oxygenation index (OI = paO2/FiO2) before the NO test (10–20 ppm for 30 minutes) was 100± 46 mmHg and 11 patients (48%) responded to inhaled NO with a significant OI increase (³ 20%). Responders had lower APACHE II on admission (16.9 ± 5.4 vs. 26.3 ± 10.1; p < 0.05), SOFA score on NO-test day (8.9 ± 3.5 vs. 12.6 ± 3.7; p < 0.05) and a markedly higher survival (6 out of 11 patients) compared to nonresponders (1 out of 12 patients) (p < 0.05). In responders NO-test was performed earlier after ICU admission (90 ± 71 vs. 226 ± 210 hrs; p = 0.05) and initiation of mechanical ventilation (35 ± 47 vs. 122 ± 95 hrs; p < 0.05). A trend to better NO response was seen in patients with higher baseline OI value (118 ± 57 mmHg in responders and 83 ± 26 mmHg in nonresponders; p = 0.08). Responders did not differ in age, baseline mean pulmonary artery pressure, and ARDS aetiology (primary vs. secondary) from nonresponders. No correlation was found between response in pulmonary pressures and oxygenation. We conclude that ARDS patients may profit from inhaled NO in the early phase of the disease bef ore critical hypoxemia develops.

        Key words: nitric oxide - ARDS - respiratory failure - mechanical ventilation - intensive care