Antithrombin III in Cardiac Surgery: An Outcome Study

A retrospective study examined the impact, in heparin resistant patients (HRP), of lyophilized antithrombin III (ATIII) upon five patient outcomes: intensive care unit stay (ICU-S), 24 hour chest tube drainage (CTD in ml), blood and blood product usage (BPU), development of post-operative coagulopathy (PO-Coag), and reoperation for bleeding (Re-Op). Data was collected from the medical records of 311 patients admitted to the hospital between 12/15/95 and 10/24/96. Subjects were divided into three groups based upon heparin resistance and hemostasis medication. Group 1 (n=l09) were HRP treated with increased heparin, Group 2 (n=100) were HRP receiving ATIII, and Group 3 (n=102) were non-HRP and served as controls. Group 2 was also subdivided by use of aminocaproic acid and time of ATIII administration. No significant differences were found between the groups for PO-Coag. and Re-Op. However, significant reduction in CTD (p=0.05) was seen in the aminocaproic acid patients who were treated with ATIII pre-CPB or within the first 20 minutes of CPB. The CTD in this group was (419.37, ± 72.96) as compared to Group 1 (782.88, ± 360.94) and Group 3 (766.67, ± 407.56). Other Group 2 subgroups showed significant differences in BPU, ICU-S and CTD. The results of this study support the notion that early identification and treatment of HRP with ATIII and aminocaproic acid may decrease postoperative blood loss