Admission patterns and survival from Status Epilepticus in Critical Care in the United Kingdom: An analysis of the Intensive Care National Audit & Research Centre (ICNARC) Case Mix Programme database

BackgroundThe factors influencing outcome after Critical Care Unit (CCU) for patients with status epilepticus (SE) are poorly understood. We examined survival for these patients to establish (a) whether the risk of mortality has changed over time and (b) whether admission to different unit types affects mortality risk over and above other risk factors.
MethodsWe analysed the Intensive Care National Audit & Research Centre (ICNARC) database and the Case Mix Programme Database (CMPD) (January 2001 - December 2016). Units were defined as neuro-CCU (NCCU), general CCUs with 24-hr neurological support (GCCU-N) or general CCU with limited neurological support (GCCU-L). 
ResultsThere were 35,595 CCU cases of SE with a threefold increase over time (4,739 in 2001-2004 to 14,166 in 2013-2016). More recent admissions were older and were more often unsedated on admission. Mortality declined for all units though this was more marked for NCCUs (8·1% in 2001-2004 to 4.4% in 2013-2016 compared to 5.1% and 4.1% for GCCU-L). Acute hospital mortality was 2-3 times higher than CCU mortality although this has also declined with time. GCCU-L appeared to have lower mortality that NCCUs (OR 0.84, 95% CI 0.72, 0.98) but after post-hoc adjustment for case mix there were no differences. Older age and markers of morbidity of seriousness were all associated with increased mortality risk.
ConclusionsThe number of patients admitted to CCU for SE is rising but critical care and acute hospital mortality is decreasing. Patients treated in NCCU have higher mortality but this is explicable by more severe underlying disease.