Behaviour of the contact phase of blood coagulation in the adult respiratory distress syndrome (ARDS).

In order to assess the role of the kallikrein-kinin (K-K) system in the pathogenesis of the adult respiratory distress syndrome (ARDS) we have prospectively determined coagulation contact phase, blood gas and hemodynamic parameters in patients with ARDS at 0, 36 and 72 h from diagnosis. Compared to normal values, significantly lower mean levels of factor XII (71.4 +/- 9.8%, p less than 0.0005), prekallikrein (PPK) (52 +/- 5.7%, p less than 0.0005), high molecular weight kininogen (HMWK) (73 +/- 2%, p less than 0.0005) and alpha 2-macroglobulin (alpha 2-M) (51 +/- 7.1%, p less than 0.0005) were found in ARDS patients. The functional kallikrein inhibitory activity (KKI) and C1-esterase inhibitor antigenic (CIINH) were significantly higher in these patients (113.2 +/- 5, p less than 0.005 and 124.7 +/- 7.6, p less than 0.0005 respectively) compared with normal values during the entire study period. The KKI/CIINH ratio decreased significantly in our ARDS patients at 0, 36 and 72 h (p less than 0.025; p less than 0.05 and p less than 0.005 respectively). We found a significant correlation between PPK levels and oxygenation index (r = 0.69, p less than 0.001), PPK and the static thoracic compliance values (r = 0.64, p less than 0.001). There was also a significant correlation between PPK levels and Qs/Qt (r = -0.89, p less than 0.001). ARDS patients that survived presented a stability in the PPK values in successive tests. Nevertheless non-survivors showed a progressive decrease in PPK levels during the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)