Abstracts

Rationale: Tranexamic acid (TXA) is an antifibrinolytic commonly in use for hemostasis during cardiac surgery. An association between tranexamic acid (TXA) and postoperative seizures has been suggested. To further explore this association, we reviewed the incidence of clinical and electrographic seizures in ICU patients following cardiac surgery.Methods: A total of 87 patients who underwent cardiac surgery between 1/2008-8/2010 and had either routine (n=24) or continuous EEG monitoring (n=63) were retrospectively reviewed. The incidence of clinical and electrographic seizures was compared between patients receiving TXA (n=69) and those who did not (n=18). Patients were further divided into groups based on the dose of TXA received (none, low, medium and high). Secondary outcome analysis included a comparison of functional outcome using the Glasgow Outcome Scale between patients with and without seizures as well as with and without TXA exposure. Results: There was a significant difference in the incidence of clinical seizures in the patients exposed to TXA 50/69(72.5%) compared to those who were not 8/18 (44.4%, p = 0.047). The highest incidence of clinical seizures was seen in the high dose TXA group (18/22, 81.8%). There was no difference in the incidence of electrographic seizures between the TXA exposure groups 12/69(17.4%) vs. 3/18 (16.7%). However, there was a trend toward higher incidence of electrographic seizures in the high dose TXA group (6/22, 27.3%). There was no difference in functional outcome between TXA exposure groups (p = 0.11) but there was a significant difference in the incidence of death at discharge in patients who had electrographic seizures 7/15 (53.8%) vs. 13/72 (18.0%, p = 0.038).Conclusions: Patients who have undergone cardiac surgery and exposed to TXA are at risk for clinical and electrographic seizures, particularly those receiving high dose TXA. The risk of electrographic seizures in this population is comparable to the incidence of seizures seen in critically ill patients with acute neurological disease and may be responsible for worse outcome. Therefore, cEEG is recommended for post surgical cardiac patients with prolonged encephalopathy particularly if there is a history of a prior witnessed clinical seizure or high dose TXA exposure. Although poor functional outcome in patients exposed to TXA only approached statistical significance, this may have been due to small sample size and warrants further investigation.