Researchers at the Mayo Clinic, Rochester, MN studied the outcome and identified prognostic factors for refractory status epilepticus (RSE) in 54 adult patients, median age 52 years [range 18-93]. RSE was defined as generalized convulsive or nonconvulsive status epilepticus that continued despite initial first and second-line therapies. Patients younger than 18 years, anoxic/myoclonic, psychogenic, simple partial, and absence SE were excluded. Of 63 consecutive episodes of RSE, anesthetic agents were used in 55 (87.3%). Duration of drug-induced coma was a mean of 11 days (SD 17.9 days). Cardiac arrhythmias occurred in 21 of 60 episodes (35%) and required intervention in 14 of 21 cases (66.67%). In hospital mortality was 31.75%, in 20 of 63 episodes. Functional outcome at discharge was poor in 48 (76.19%) episodes. Hospital length of stay was a mean of 27.7 days (SD 37.3 days). Poor functional outcome was associated with drug-induced coma (p=0.03), cardiac arrhythmias requiring intervention (p=0.01), and pneumonia (p=0.01). Prolonged mechanical ventilation was associated with mortality (p=0.04). Good functional recovery (p=0.01) followed seizure control without suppression-burst or isoelectric EEG. Functional outcome was not related to age, history of epilepsy, previous SE, type of SE, and anesthetic drug used. [1]

COMMENT. In adults with refractory status epilepticus, risk factors for a poor prognosis include the severity of the SE, the need for drug-induced coma, cardiopulmonary complications requiring prolonged mechanical ventilation, and pneumonia. Aggressive EEG suppression does not improve outcome of RSE. Three-quarters of adult RSE patients have a poor outcome.

A review of studies of status epilepticus published from 1990-2009 shows that children have a better prognosis than adults, and age and depth of coma are the strongest predictors of outcome of SE [2]. In otherwise normal children with focal epilepsy, SE has no significant effect on long-term intellectual and seizure outcome. [3]