Glasgow Coma Scale Scores and Impact of Delirium on Intubated Seizure Patients Treated with Phenytoin and Lacosamide: Retrospective Analysis and Literature Review

Studies have shown that decrease in time intubated is associated with better prognosis. Delirium is associated with increased duration of mechanical ventilation and Intensive Care Unit (ICU) length of stay. However, there is limited report on delirium in intubated seizure patients. As per report, low Glasgow Coma Scale (GCS) increased the risk of delirium and thus increasing ICU length of stay. Information on delirium and outcome in intubated seizure patients receiving lacosamide versus phenytoin is limited. Our retrospective pilot study aimed to assess the GCS scores and impact of delirium in intubated seizure patients who were treated with phenytoin and lacosamide. In this retrospective pilot study, review was conducted via chart review of hospitalized, intubated seizure patients on Phenytoin or Lacosamide at Loyola University Medical Center Neurology ICU from 2018 to 2020. Endotracheal intubation was identified by ICD 10, ICD-10-PCS 0BH17EZ, (Z99.11), and Delirium diagnosis was identified using delirium ICD codes 10 F05, R41. 82 R41.0, ICD 9: 293, 780.97, and 298.2. Hospital and ICU patient admit and discharge dates and Glasgow Coma Scale scores were extracted. This pilot study investigated qualitative variables. The patient age at admission was an average of 65 years. A total of 20 charts were included in the final analysis. 50% of phenytoin group experienced delirium (4/8), 50% of the lacosamide group also experienced delirium (6/12). Number of Days Intubated in Delirium: 2.0 days, no delirium: 1.5 days, number of Days in ICU in Delirium: 5.6 days, no delirium: 3.3 days, number of days in hospital in delirium: 13.7 days, no delirium: 8.5 day. Patients with delirium had longer ICU stays (5.6 days vs. 3.3) and hospital stays (13.7 days vs. 8.5). Patients with GCS less than 10 were much more likely to experience delirium, with 8 out of 11 (73%) patients experiencing delirium versus 2 out of 9 (22%) for patients with GCS greater than 10. Low GCS score at ICU admission could predict emerging delirium in intubated seizure patients. Studies are required to see if early treatment of delirium can decrease the ICU length of stay. Our pilot study highlighted that GCS scores are a key component of assessment of functioning over hospital admission. Prospective and larger studies are required to determine the impact of delirium and relationship between GCS scores and delirium in intubated seizure patients. KeywordsStatus epilepticus; intubation; seizure; delirium; anticonvulsants; Glasgow Coma Scale score