Determinants and predictors of outcome in super refractory status epilepticus--a developing country perspective

Abstract

Importance: Super refractory status epilepticus (SRSE) is a recent entity. There is limited information about the etiology and outcome of SRSE from developing countries.

Objective: We evaluated determinants and predictors of outcome in patients with convulsive SRSE in Indian population.

Methods: In this open cohort study, data of patients with convulsive SE admitted in neurointensive care unit (NICU) from 2005 to 2013 was retrospectively analyzed. Regression and survival analysis was done for outcome of patients divided into non refractory SE (NRSE), refractory SE (RSE), and SRSE groups.

Main outcome measure: The primary outcome for analysis was in hospital mortality. Also functional outcome at 6 months was graded according to the Glasgow outcome scale (GOS), and classified as good (GOS 4 and 5) and poor (GOS 1, 2 and 3) outcome groups.

Results: Out of 177 patients with SE, 105 (59.3%) had NRSE; 72 (40.7%) had RSE of which 30 (16.9% of 177) were sub-classified as SRSE. SRSE was frequent (39%) in children (p<0.01), elderly (21.7%; p<0.003), and in incident SE (82.1%, p=0.05). Encephalitis was the commonest etiology in RSE (30.9%, p=0.015), SRSE (66.7%, p<0.001) than NRSE (12.3%). Encephalitis (β=8.250 (1.8-37.82); p=0.007) was the determinant of the progression of SE to SRSE. Overall mortality was 19.2%, highest in SRSE (40.0%) followed by RSE (35.7%), both significantly (p<0.001) higher than NRSE (6.7%). Mortality was high in patients with encephalitis than other etiologies (39.1% vs. 12.1%; p=0.001). Acidosis predicted mortality in the entire cohort (β=7.313 (1.6-32.58); p=0.009); however none of the variables predicted mortality in SRSE patients. At 6 months follow up only 33.3% of patients with SRSE were in GOS good outcome group when compared to RSE (33.3% vs. 57.1%; p=0.055), and NRSE (33.3% vs. 79.1%; p<0.0001).

Conclusions and relevance: SRSE is common in children, elderly, and incident SE. Encephalitis was the determinant of progression of SE to SRSE. None of the variables predicted mortality in SRSE patients. Sixty percent of patients with SRSE survived and one third had good outcome. Therefore one should continue the care inspite of weeks of SE.

Keywords: Acidosis; Encephalitis; Mortality; Status epilepticus; Super refractory status epilepticus.