Figure 3. Changes in velocity of platelet aggregation induced by five randomized incremental concentrations of nitric oxide administered to six patients with acute respiratory distress syndrome. Changes are expressed in percentage of variation from the first control value (C1), which is by definition equal to 0%. Inhaled nitric oxide induced a significant and non-dose-dependent decrease in velocity of platelet aggregation induced by three aggregating agents: 5 micro Meter adenosine diphosphate (ADP), ristocetin, and collagen (P < 0.01).