High-dose tranexamic acid is an independent predictor of early seizure after cardiopulmonary bypass.

BACKGROUND: Risk factors associated with early seizure after cardiopulmonary bypass (CPB) were examined. The role of tranexamic acid in seizure development was evaluated.
METHODS: Early seizure was defined as a seizure occurring within 24 hours of CPB, without neurologic deficit or new lesion on brain imaging. Independent determinants of early seizure were examined by multivariate logistic regression modelling.
RESULTS: Between 2004 and 2009, early seizure occurred in 119 of 8,929 patients (1.3%). A significant increase in the yearly rate of early seizure was observed in 2004 (0.73%) vs 2009 (1.97%; p<0.0001). Multivariate analysis showed the following variables were independent predictors of early seizure: age older than 75 years (adjusted odds ratio [OR], 2.1; p=0.0001), open heart procedure (OR, 12.0; p<0.0001), preoperative renal failure (OR, 3.2; p<0.0001), peripheral vascular disease (OR, 1.8; p=0.02), and total tranexamic acid dose of 100 mg/kg or more (OR, 2.6; p<0.0001). Risk of seizure was related to tranexamic acid in a dose-dependent fashion, with higher doses associated with increased risk of seizure. The use of CO2 in a subset of patients undergoing open heart procedures did not decrease the incidence of early seizure (4.8% vs 2.5% for no CO2; p=0.27). Postoperative chest tube drainage and blood product use were similar between patients receiving low-dose and high-dose tranexamic acid.
CONCLUSIONS: High-dose tranexamic acid (≥100 mg/kg) is independently associated with an increased risk of early seizure. Future tranexamic acid trials should assess the blood-conserving effect of tranexamic acid at a lower dosage and specifically monitor for seizure occurrence.