Abstracts

Rationale: SIRPIDS were first described by Hirsch (2004) as a common pattern observed in comatose patients in the neurological ICU with different brain injuries and metabolic derangements. It was reported then to be present in 22% of the study group. To our knowledge there are no prospective studies involving continuous EEG to study the actual incidence of this phenomenon. We believe the incidence might be higher because typically the EEG reader does not check the video for stimulation either by ICU staff or environmental factors (e.g., alarms) and no prior study has specifically evaluated EEG changes induced by stimulation in a rigorous fashion. For example, no prior publications have examined in detail the type of stimulation required to elicit SIRPIDS, how consistent the stimulation response is, and what kind of protocol should be employed for comparing stimulated versus non-stimulated states in an individual patients.Methods: We prospectively studied adult patients 18 years or older admitted to the NSICU at the University of Cincinnati Medical Center (UCMC) and being monitored on cvEEG as part of standard clinical care. Only unresponsive patients who requires frequent neurological examination including applying painful stimulation to elicit a motor response as part of standard clinical care for monitoring were included. The neurological examination performed by applying different stimulating maneuvers like sternal rub or axillary pinching to evaluate the patient’s response. All included patients were stimulated off sedation by applying verbal, tactile and then painful stimulation in a sequential pattern after recording EEG for a period up to 2 minutes with no stimulation and minimal noise in the patient room with the doors closed. EEG segments were independently reviewed by 2 epilepsy attendings (DF, MP). A third reader reviewed studies when there was disagreement between the 2 EEG readers.Results: 145 patients were screened; 50 patients were included and underwent stimulation protocol. Traumatic brain injury, intracerebral hemorrhage, subarachnoid hemorrhage, stroke, encephalopathy NOS were the most common pathologies. Status epilepticus patients were excluded as they were maintained on sedating medication drips. The ability of following commands was the most common reason for exclusion. Other common reasons for exclusion were status epilepticus or frequent seizures maintained on a sedating drip, and the inability to wean sedation due to the concern of harming the patient with frequent stimulation i.e refractory intracranial hypertension. Further results including the incidence and the characteristics of stimulation producing SIRPIDS are still under evaluation.Conclusions: Pending final data analysis. Will mainly focus on the incidence of SIRPIDS in this prospective patient cohort, and the inter-rater agreement. Also it will be compared to the incidence of SIRPIDS reported in the excluded patient as mentioned in their EEG reports.