Predictors of outcome in refractory status epilepticus

To further characterize the demographics, outcomes, and prognostic factors for refractory status epilepticus (RSE).

Retrospective analysis of all the episodes of RSE treated between January 1, 1999, and August 30, 2011.

Neurointensive care unit within a tertiary referral center, Mayo Clinic, Rochester, Minnesota.

Refractory status epilepticus was defined as generalized convulsive or nonconvulsive status epilepticus (SE) that continued despite initial first- and second-line therapies. Exclusion criteria were aged younger than 18 years, anoxic/myoclonic SE, psychogenic SE, simple partial SE, and absence SE.

Functional outcome was defined by modified Rankin scale (mRS) dichotomized into good (mRS, 0-3) and poor (mRS, 4-6). Functional decline was defined as a change in mRS greater than 1 from hospital admission to discharge.

We identified 63 consecutive episodes of non-anoxic RSE in 54 patients. Anesthetic agents were used in 55 episodes (87.30%), and duration of drug-induced coma was (mean [SD]) 11.0 (17.9) days. In-hospital mortality was 31.75% (20 of 63 episodes). Poor functional outcome at discharge occurred in 48 of 63 episodes (76.19%). Hospital length of stay was (mean [SD]) 27.7 (37.3) days. Duration of drug-induced coma (P=.03), arrhythmias requiring intervention (P=.01), and pneumonia (P=.01) were associated with poor functional outcome. Prolonged mechanical ventilation was associated with mortality (P=.04). Seizure control without suppression-burst or isoelectric electroencephalogram predicted good functional recovery (P=.01). Age, history of epilepsy, previous SE, type of SE, and anesthetic drug used were not associated with functional outcome.

Three-quarters of patients with RSE have a poor outcome. Achieving control of the SE without requiring prolonged drug-induced coma or severe electroencephalographic suppression portends better prognosis.