Latency to treatment of status epilepticus is associated with mortality and functional status

Abstract

Introduction: Status epilepticus (SE) is a life-threatening neurologic emergency. Despite advances in management, in-hospital mortality remains unchanged. This is partly due to the pharmacoresistance which develops the longer that seizures persist. Therefore, rapid antiseizure medication (ASM) administration may represent a beneficial treatment option. The purpose of this study was to determine: 1) whether in-hospital mortality is reduced with shorter latencies to initial treatment of SE with an ASM (LTSE); and 2) the critical time frame during which LTSE is associated with reduced in-hospital mortality.

Materials and methods: This was a retrospective, single-center study of adults diagnosed with SE between 1/1/2005 and 10/31/2012. Demographic characteristics included seizure history, etiology, semiology, and duration. Subjects were assigned to LTSE groups at the time frames of 5, 10, 30 and 60min. The primary outcome was in-hospital mortality, with poor functional status (mRS 3-6) as a secondary measure. Pearson's chi-square, Mann-Whitney-U, two-sample-t-tests, and binary logistic regression analysis were used as appropriate, with p<0.05.

Results: In unadjusted analysis, LTSE>30min demonstrated increased risk of mortality (OR 2.06, CI 1.01-4.17, p=0.046) and poor functional status (OR 2.48, CI 1.05-5.85, p=0.038) compared to LTSE≤30min. Increased mortality risk remained after adjusting for SE duration (OR 2.07, CI 1.01-4.26, p=0.047) and nonconvulsive seizures (OR 2.28, CI 1.08-4.80, p=0.03). Compared to subjects treated within 60min, those treated after 60min were at increased risk of poor functional status, regardless of the presence of nonconvulsive seizures (OR 2.96, CI 1.14-7.73, p=0.026). In addition, when acute symptomatic SE was stratified by cardiac versus non-cardiac etiologies, subjects with non-cardiac acute symptomatic SE demonstrated worse functional outcome when treated after 60min (OR 7.20, CI 1.13-46.07, p=0.037).

Conclusions: Treatment of SE within 30min of onset is associated with reduced risk of in-hospital mortality and poor functional status, although this may be attenuated by acute symptomatic seizures related to cardiac arrest. This represents a therapeutic option which has the potential to benefit patient outcomes.

Keywords: Antiepileptic drugs; Epilepsy; Morbidity; Prognosis; Seizures; Status epilepticus.