To analyze factors related to the development of seizures (S) and non-convulsive status epilepticus (NCSE) after cardiovascular surgery (CVS).

Although an unexpected complication, seizures in the postoperative period (Post-op) following CVS are known to negatively impact on morbidity and mortality outcomes.

Retrospective analysis of medical records of patients who presented S or NCSE during the 30 days post-op of CVS between the years 2008 and 2018. Medical history, type of surgery, pre- intra and post-op conditions were evaluated. Categorical variables were analyzed with X2 and quantitative variables with parametric methods.

6055 CVS were done, from which 56 (0.9%) had S/NCSE during Post-op.  Female 45%, mean age 66.7 y.o. Aortic valve replacement (AVR, 20%), coronary artery bypass grafting (CABG, 18%) and AVR+CABG (14%) were the most frequent types of CVS. Of those who presented epilepsy, the majority had S (39%), followed by NCSE (29%) with no significant differences regarding aetiology. Concerning NCSE, 100% had haemodynamic instability, 75% received multiple blood transfusions, 57% had associated infections and 45% suffered a stroke (CVA). Nonetheless, CVA was the only aetiology presenting statistical differences when analyzing prognostic variables such as length of hospital stay (51.3 vs 28.3 days;p=.02), days in critical care units (32.2 vs 18.2 days;p=.03), infection rate (79% vs 48%;p=.02), need of reintervention (45.8% vs 14.8%;p=.01) and death (37.5% vs 11.1%;p=.03). Time to NCSE diagnosis was significantly longer than in the other types of S.

Seizures/NCSE in Post-op after CVS are complications not frequently analyzed. In our case series they were presented more frequently after AVR and CABG. Associated factors were haemodynamic instability, infections and CVA, the latter being present in less than half of patients in spite of being the most reported complication after CVS. NCSE was present in one third of patients, showing the importance of its suspicion.