Abstracts

Patient safety is of increasing concern in epilepsy centres. Various devices for detetction of epileptic seizures are available on the market. We decided to test the clinical value of bed alarms and pulse oxymeters in the Danish Epilepsy Centre, Dianalund., In-patients at increased risk of generalized convulsive seizures were supervised by video-cameras during the time spent in bed. The signals from the video-cameras were transmitted to a central supervision unit where a nurse was watching the screens with patients under supervision. In case of seizure, the supervising nurse notified the ward with the patient. The patient under supervision in bed carried a pulse oxymeter, and the bed was equipped with a seizure alarm. The staff in the ward registered alarms and compared with the messages from the nurse watching the patient on the screen. The sensitivity of the alarm (probability of alarming in case of seizure) and the occurrence of false alarms were registered. Patients were included from April 2004 to September 2005. In a second inclusion period from October 2005 to April 2006 we tried to improve the use of bed alarms by adjustment of alarm parameters., In the first period 83 patients, aged 1-63 years, had 1332 epileptic seizures. The sensitivity of bed alarms was 18.7% in case of tonic-clonic seizures, 1.2% with tonic seizures, and 3.6% with focal motor seizures. The sensitivity of pulse oxymeters was 22.5% in tonic-clonic seizures, and 9.2% in tonic seizures. The sensitivity of both alarms were lower for other seizure types. The combined sensitivity of pulse oxymeters and bed alarms was 26% for tonic-clonic seizures and smaller for other seizure types. In average, there were 0.75 false alarms from the bed alarm per 24 hours, and 2.19 false alarms from the pulse oxymeters per 24 hours. In the second inclusion period it was not possible to improve the sensitivity or specificity of either alarm type., In our hands the combined use of bed alarms and pulse oxymeters detects a quarter of tonic-clonic seizures in epilepsy patients at increased seizure risk and a smaller fraction of other seizure types. There is a need for development of better technology for the provision of safety for epilepsy patients.,