[Antithrombin III behavior in open heart operations in infancy and early childhood].

Antithrombin III activity was evaluated preoperatively, intraoperatively and postoperatively in the plasma of 54 children with congenital heart disease undergoing open heart surgery. The patients were divided into an acyanotic and a cyanotic group. A comparison of these two groups indicated a significantly decreased AT III activity in cyanotic children as compared to acyanotic children throughout the perioperative phase. AT III levels decreased in the cyanotic group from 71.9 +/- 3.77% preoperatively to 61.5 +/- 2.15% (p less than 0.01) postoperatively and rose to 69.6 +/- 2.36% (p less than 0.01) on the first and to 78.9 +/- 2.24% (p less than 0.01) on the second postoperative day. In the acyanotic group AT III levels decreased from 84.3 +/- 1.98% to 73 +/- 2.97% (p less than 0.01) postoperatively and increased to 78.5 +/- 2.96% (p less than 0.01) on the first and to 90.2 +/- 3.06% on the second postoperative day. A few acyanotic patients, too, showed decreased values of AT III. However, they were never found to be as low as in the cyanotic group. Preoperative AT III values as well as the severity of underlying disease, the success of corrective surgical treatment and postoperative complications proved to be the predominant influencing factors of AT III activity.