A prospective observational study of seizures after cardiac surgery using continuous EEG monitoring.
BACKGROUND
Recently, there have been several retrospective reports suggesting an increased frequency in seizures after cardiopulmonary bypass, associated with increased patient morbidity. We sought to prospectively investigate the incidence of electrographic seizures without clear convulsive clinical correlates and subsequent neurologic injury following cardiac surgery.


METHODS
This single-center, prospective, observational study used continuous subhairline electroencephalographic (cEEG) monitoring in the intensive care unit following routine cardiac surgery, ranging from coronary bypass surgery to complex aortic arch reconstruction. The primary outcome was the proportion of patients developing postoperative seizures, as confirmed on cEEG monitoring. Secondary outcomes included neurologic injury, post-operative complications, mortality, and ICU and hospital lengths of stay.


RESULTS
101 consenting patients were included and 3 patients had seizures (2 focal and convulsive, 1 generalized and electrographic). All three patients with seizures were ≥65 years old, had "open-chamber" procedures, and had cardiopulmonary bypass times >120 min. One of the 3 patients with seizures was exposed to higher doses of tranexamic acid. None of the patients with seizures had permanent neurologic sequelae and all were doing well at 1-year follow-up. There was no increased morbidity or mortality in patients with seizures.


CONCLUSIONS
Electrographic seizures occur infrequently after cardiac surgery and are generally associated with a good prognosis. Prophylactic cEEG monitoring is unlikely to be cost-effective in this population. (ClinicalTrials.gov Identifier: NCT01291992).
Department of Clinical Neurological Sciences, London Health Sciences Centre, University of Western Ontario, 339 Windermere Road, London, ON, N6A 5A5, Canada, teneille.gofton@lhsc.on.ca.
Teneille E
TE
Gofton
Michael W A
MW
Chu
Loretta
L
Norton
Stephanie A
SA
Fox
Lindsay
L
Chase
John M
JM
Murkin
G Bryan
GB
Young
D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000933:Antifibrinolytic Agents / Q000009:adverse effects; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D004569:Electroencephalography / Q000379:methods; D005500:Follow-Up Studies; D015994:Incidence; D008991:Monitoring, Physiologic; D011446:Prospective Studies; D012640:Seizures / Q000139:chemically induced / Q000175:diagnosis / Q000209:etiology; D014148:Tranexamic Acid / Q000009:adverse effects; D016896:Treatment Outcome
D000933:Antifibrinolytic Agents; D014148:Tranexamic Acid