Abstracts

Rationale: Although epilepsy monitoring units (EMUs) are relatively safe (Noe KH, Drazkowski JF, 2009; Dobesberger J, et al., 2011), adverse events do occur during these elective admissions (hafer PO, et. al, 2011). Interest in EMU safety intensified after a highly publicized death (Maass B, 2008) was captured on video EEG, however, there is little consensus regarding the critical safety measures to prevent harm. We sought to determine whether the safety signals (SS) triggered during EMU events differed by seizure type, and to determine the efficiency of each of the different SS. Methods: We screened 468 consecutive elective EMU admissions from January 2008 until April 2011 for definitive events to evaluate the first 50 events for each of the following seizure types: complex partial seizures (CPS), generalized tonic clonic seizures (GTC), and psychogenic non-epileptic seizures (PNES). In patients with more than one seizure type, the first event of each type with archived intact video, audio, and EEG data was used. LTM data with the corresponding report and electronic medical record were reviewed for all events. A total of 150 events from 129 unique patients were included. Demographics, seizure type, the specific SS alerting the response team, and response times were extracted. Telemetry signals included alarms for cardiac and/or oxygen desaturations. This study was approved by the institutional review board. Statistical analyses were performed using either ANOVA, fisher exact, or chi-square tests.Results: There was no group difference in patient age or number of anti-epileptic drugs (AEDs) at time of admission. Patients with PNES were older at disease onset, had shorter length of illness, longer seizure duration (P<0.0005), and were more likely female (P<0.0002). There was no difference in overall mean response time to the different seizure types (Table 1). However, response time to push button (PB) was faster than telemetry signals for all groups (p<0.0001). Type of SS alerting the responder varied by event type: PNES were more likely signaled by PB, whereas CPS and GTC were signaled equally by telemetry and push button (Figure 1). Fifteen out of 150 events were missed. CPS (11) were more likely missed than GTC (4) and PNES (0) (p< 0.001). For these missed events, SS telemetry alarms were activated in 6/11 CPS and 3/4 GTC; the remainder had no SS triggered.Conclusions: In this retrospective study, we found overall response time to SS for the first EMU event does not differ by seizure type. Response time to PB is faster in alerting responders and a higher proportion of PNES were triggered by PB and not telemetry. Not all events trigger an SS, and a greater percentage of epileptic seizures are missed compared with PNES, which is cause for concern. Future studies investigating more effective techniques to trigger every event are critical, as 24/7 monitoring by health care professionals is not practical in many settings, especially in light of continued reductions in inpatient healthcare workers.