Abstracts

Rationale: Impaired thermoregulation has been described in animal models of status epilepticus. The proposed mechanism for temperature dysregulation is interference with neurons in the anterior hypothalamus. It is well established that the mortality rate of refractory non-convulsive status epilepticus (RNCSE) is high. Factors influencing mortality in RNCSE may include etiology, patient age, duration, and diagnostic delay. Of the intravenous anesthetic agents used in the management of NCSE, the preferred agents at our institution are propofol and ketamine. The purpose of this study was to investigate: 1) the frequency of spontaneous hypothermia (SH)(core body temperature < 35 ° C) in patients with RNCSE 2) the mortality and control rates of patients who develop spontaneous hypothermia relative to patients who remain normothermic (NT) 3) relationship between SH and anesthetic infusions.Methods: After IRB approval, we reviewed the charts of patients admitted to the Neurological ICU for management of RNCSE between the years of 2012 and 2014 at Ochsner Medical Center treated with propofol and ketamine. This is a single center, retrospective analysis of cases of RNCSE, looking at the occurrence of spontaneous hypothermia and the associated mortality and seizure control rate.Results: We identified 67 patients in RNCSE treated with propofol and ketamine. (1) Of these, 14 patients were treated post-cardiac arrest with therapeutic hypothermia and were excluded from this analysis. Patient demographics were 40 females and 13 males. Ages ranged from 8 to 85 years (average 58 years, median 63). SH occurred in 33/53 (62%) and categorized as mild (temp 32 – 34.9 °C) in 32, and moderate (temp 28 – 32°C) in 1. RNCSE control rates were 94% in the SH group and 100% in the NT group. Mortality rates were 39% (13/33) in the SH group and 24% (5/21) in the NT group. Anesthetic infusions at time of lowest spontaneous body temperature were recorded, 18/33 (55%) were receiving a combination of ketamine and propofol, 10/33 (30%) were receiving propofol only, and 5/33 (15%) were receiving ketamine only.Conclusions: This study demonstrated that SH occurred in over 60% of patients being treated for RNCSE. While status control rates remained similar across both groups, the SH group had a higher mortality rate than that of the NT group, although this failed to reach significance (p = 0.3749). These findings may suggest that the inability to regulate body temperature is a poor prognostic indicator. The simultaneous combination of propofol and ketamine was most frequently associated with SH, and suggests that this may, in part, be secondary to a medication effect.