RESUMO
Background: Ongoing or recurrent seizure activity without prominent motor features is a common burden in neurological critical care patients and people with epilepsy during ICU stays. Continuous EEG (CEEG) is the gold standard for detecting ongoing ictal EEG patterns and monitoring functional brain activity. However CEEG review is very demanding and time consuming. The purpose of the present multirater, EEG expert reviewer study, is to test and assess the clinical feasibility of an automatic EEG pattern detection method (Neurotrend). Methods: Four board certified EEG reviewers used Neurotrend to annotate 76 CEEG datasets à 6 h (in total 456 h of EEG) for rhythmic and periodic EEG patterns (RPP), unequivocal ictal EEG patterns and burst suppression. All reviewers had a predefined time limit of 5 min (± 2 min) per CEEG dataset and were compared to a predefined gold standard (conventional EEG review with unlimited time). Subanalysis of specific features of RPP was conducted as well. We used Gwet's AC1 and AC2 coefficients to calculate interrater agreement (IRA) and multirater agreement (MRA). Also, we determined individual performance measures for unequivocal ictal EEG patterns and burst suppression. Bonferroni-Holmes correction for multiple testing was applied to all statistical tests. Results: Mean review time was 3.3 min (± 1.9 min) per CEEG dataset. We found substantial IRA for unequivocal ictal EEG patterns (0.61-0.79; mean sensitivity 86.8%; mean specificity 82.2%, p < 0.001) and burst suppression (0.68-0.71; mean sensitivity 96.7%; mean specificity 76.9% p < 0.001). Two reviewers showed substantial IRA for RPP (0.68-0.72), whereas the other two showed moderate agreement (0.45-0.54), compared to the gold standard (p < 0.001). MRA showed almost perfect agreement for burst suppression (0.86) and moderate agreement for RPP (0.54) and unequivocal ictal EEG patterns (0.57). Conclusions: We demonstrated the clinical feasibility of an automatic critical care EEG pattern detection method on two levels: (1) reasonable high agreement compared to the gold standard, (2) reasonable short review times compared to previously reported EEG review times with conventional EEG analysis.
RESUMO
BACKGROUND AND PURPOSE: Acute stroke management requires minimization of prehospital time. This study addresses the value of helicopter transport compared with other means of transportation to a stroke unit and compares their rates of thrombolysis on a nationwide basis. METHODS: Prospective data collection and prespecified evaluation of data from 32 stroke units between 2003 and 2009 were used. We distinguished between patients transported either directly to a stroke unit or transferred indirectly via a peripheral hospital. Thus, there were 6 transport groups: helicopter emergency service (HEMS) direct and indirect, ambulance accompanied by an emergency physician direct and indirect, and ambulance without physician direct and indirect. Demographic and clinical factors, time delays, and rates of thrombolysis of patients transported by helicopter were compared with factors of patients transported otherwise. RESULTS: Of 21 712 ischemic stroke patients, 905 patients (4.1%) were transported by helicopter. Of these, 752 patients (3.4%) were transported by direct HEMS, and 153 patients (0.7%) were transported by indirect HEMS. Thrombolysis rates were highest for HEMS (24% direct, 29% indirect) transport, followed by ambulance accompanied by an emergency physician (18% direct, 15% indirect). The probability of receiving thrombolysis was highest for indirect HEMS transport (OR 3.6, 2.2-6.0), followed by indirect ambulance accompanied by an emergency physician transport (OR 1.5, 1.1-1.9). The shortest times, 90 minutes or less from stroke onset to hospital arrival, were achieved with direct AMBP and direct HEMS transport. CONCLUSIONS: The shortest hospital arrival times and highest thrombolysis rates were seen in ischemic stroke patients transported by helicopter.
