- Email: [email protected]
P476: Sleep and biorhythm in the ICU
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Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339
0.865–1.494, 0.824–2.357, and 0.831–1.437, respectively. Four patients had quantitative reactivity in one or more bands. RR in the alpha band was increased in one patient (CPC 2-3), in the theta band in two patients (CPC 1-2 and 2-3), and in the delta band in one patient (CPC 3-4). One patient had a decrease in RR in the delta band and had a CPC of 5. Of the three patients who showed no reactivity one had a CPC of 3 and two had a CPC of 5. Five patients were partly sedated, one of which had a CPC of 5. Conclusion: It seems possible to achieve a quantitative measure of reactivity. In this study we found no obvious systematic correlation with outcome but larger studies are required.
P475 Face validity of IDOS, an ICU depth of sleep index from a single channel of EEG L. Reinke 1 , H. van der Hoeven 2 , W. Dieperink 1 , J. Tulleken 1 University Medical Center Groningen, Department of Critical Care, Groningen, Netherlands; 2 University Medical Center Groningen, Department of Neurophysiology, Groningen, Netherlands 1
Question: The measurement and analysis of sleep in the intensive care unit (ICU) is notoriously complex and time-consuming. This is reflected by the variable and often poor interrater agreement between R&K raters in previous studies (Ambrogio, Koebnick, Quan, Ranieri, & Parthasarathy, 2008; Elliott, McKinley, Cistulli, & Fien, 2013). To evaluate the face validity of a new index for depth of sleep in ICU patients, we compared it to manual scoring by R&K criteria in outpatient and ICU polysomnographic (PSG) recordings. Methods: The ICU depth of sleep index (IDOS index) was constructed from the ratio of gamma and delta band power spectral density (PSD) of a single channel of EEG. PSG recordings of five ICU patients (24-72 hours each) and 15 healthy outpatient recordings (18 hours each) were analyzed with both methods. Manual selection of thresholds was used to classify the IDOS index as either wake, sleep or slow wave sleep (SWS). This classification was compared to manual scoring by R&K criteria. Results: When reduced to 3 classes, the obtained overall agreement between R&K and the IDOS index, as quantified by Cohen’s kappa statistic, was 0.82 for the outpatient recordings. Sensitivity and specificity were highest for the wake state (91% and 97%, respectively) and lowest for SWS (91% and 67%, respectively). For ICU recordings, the average agreement was good, with kappa=0.68, but varied between individual recordings.
P476 Sleep and biorhythm in the ICU L. Reinke 1 , H. van der Hoeven 2 , W. Dieperink 1 , J. Tulleken 1 University Medical Center Groningen, Department of Critical Care, Groningen, Netherlands; 2 University Medical Center Groningen, Department of Neurophysiology, Groningen, Netherlands
1
Question: Sleep deprivation is among the most common stressors experienced during critical illness (Watson, 2007), and there are strong indications that delirium and sleep deprivation are closely intertwined (Bellapart & Boots, 2012; Boyko et al., 2012). Sleep is important to the recovery of the critically ill, but may be hampered by disturbances in biorhythm (Mundigler et al., 2002; Paul & Lemmer, 2007; Figueroa-Ramos et al., 2009). Recent findings contradict the assumption that biorhythm is disturbed in all ICU patients, warranting further investigation (Gehlbach et al., 2012). ICU patients could potentially benefit from interventions to optimize biorhythm and consequently sleep. To this end, a protocol to monitor sleep and biorhythm was designed, and tested in the ICU. Methods: Critically ill patients (n=5) were subjected to 24-72 hour polysomnographic (PSG) recording followed by R&K analysis. Bihourly serum-melatonin samples were analyzed with tandem mass-spectrometry. Results: Of the 5 included critically ill patients, three showed severe frag-
Figure 1. Hypnogram after R&K classification of ICU patients’ PSG recording. Of the shown 8 days of PSG, only 1 day could be classified as ’normal’; the second day of patient A. Patient B and C experience severely fragmented sleep, with little to no contrast between day and night.
Figure 1. Hypnogram of ICU sleep recording (1A) versus IDOS index, calculated from a single channel of EEG (1B). To facilitate calculation of agreement between both methods, 30 second epochs were classified into three possible classes; wake (blue), sleep (red) and slow wave sleep (SWS, green). Average agreement for outpatient recordings was excellent, with Cohen’s Kappa =0.82 (n=15). For ICU recordings the average agreement was good, with Kappa =0.68 (n=5).
Conclusions: The IDOS index shows striking resemblance with manually scored outpatient recordings, with excellent agreement. With the established face-validity, the IDOS index could be useful in real-time, automated, single channel visualization of depth of sleep in ICU patients. Figure 2. Melatonin secretion and best fit curves of ICU patients. Severe fragmentation of sleep in patient B seems to coinicide with low contrast in melatonin secretion between day and night. During intubation (day 3) there is no melatonin peak. Other patients (A, C and D) show remarkably robust biorhythms, with increasing phase-delay and lower peaks as quality of sleep worsens.
Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339
mentation of sleep. Melatonin secretion was lower for patients with worse sleep, although biorhythm was visible in all but one patient. PSG with R&K analysis proved to be time-consuming and cumbersome, while the use of tandem mass spectrometry resulted in high throughput with excellent accuracy. Conclusions: Taking the limited scope of this pilot into account, worsening characteristics of sleep seem to coincide with loss of circadian rhythm. Currently, the availability of materials and the time-consuming analysis of PSG recordings are the main limiting factors of the study of sleep in the ICU. Automated, objective measures of quality and quantity of sleep are currently being validated in ICU and non-ICU patients, using only single channel EEG data.
P478 Prediction of good and poor outcome in comatose patients after cardiac arrest: the utility of early EEG/SEP recordings during therapeutic hypothermia M. Spalletti 1 , R. Carrai 1,2 , A. Comanducci 1 , C. Cossu 1 , S. Gabbanini 1 , A. Peris 3 , G. Gensini 2,4 , A. Grippo 1,2 , A. Amantini 1,2 1 AOU Careggi, Neurophysiopathology, Florence, Italy; 2 IRCCS Don Gnocchi, Neurologic Rehabilitation Unit, Florence, Italy; 3 AOU Careggi, ICU Emergency, Florence, Italy; 4 AOU Careggi, Heart-Vessels, Florence, Italy Question: Somatosensory evoked potentials (SEPs) are a reliable predictor of poor outcome in comatose patients after cardiac arrest (CA) treated with therapeutic hypotermia (TH). The role of EEG has been recently emphasized during early phase after CA. Our aim is to evaluate the prognostic value of EEG and SEPs in post-anoxic comatose patients within 12hs and 24hs from cardiac arrest (CA). Methods: Comatose patients after CA treated with TH were included. EEG and SEPs were recorded within 12hs and 24hs after CA. EEG was classified into discontinous (low voltage, isoelectric, burst suppression) and continuous (other patterns except epileptiform). SEPs were dicotomized into “bilaterally absent” (BA) and “present”. Neurologic outcome was evaluated at 6 months by GOS: “awakening” (GOS 3-5) was considered good outcome. Results: EEG and SEPs were recorded in 72 patients: 25 of these were studied within 12hs from CA. All patients with a continuous EEG pattern at 12hs awakened. The same EEG pattern recorded at 24 hs was not always predictive of awakening. BA SEPs at 12hs predicted poor outcome and were associated to discontinuous EEG patterns. Continuous EEG pattern was always associated with present SEPs. Conclusion: Combined early EEG/SEPs recordings are a useful tool for reliable prognostication both of good and poor outcome in comatose patients treated with TH.
P479 Continuous EEG monitoring in neurointensive care. Organisation and assessment of impact M. Fabricius 1 , A. Sabers 2 , H. Hoegenhaven 1 , J. Brennum 3 , K. Moeller 4 , K. Hansen 2 , T.W. Kjaer 1 1 Rigshospitalet, Clinical neurophysiology, Copenhagen, Denmark; 2 Rigshospitalet, Neurology, Copenhagen, Denmark; 3 Rigshospitalet, Neurosurgery, Copenhagen, Denmark; 4 Rigshospitalet, Neuroanaesthesiology, Copenhagen, Denmark Background: Continuous EEG (cEEG) is an emerging discipline for assessment of acute changes in cerebral function in the intensive care unit (ICU). A number of publications demonstrate that non-convulsive status epilepticus is a common complication in both neurological and non-neurological ICU patients and that cEEG is superior to conventional 30 minute standard EEG in capturing these patients. Yet establishing cEEG as part of daily routine is resource demanding and raises a number of treatment-related issues. Furthermore cEEG as a daily routine must be carefully introduced to assure that the most relevant patients are monitored, and that neurophysiologists and clinicians communicate in an efficient way. Methods: At Rigshospitalet, cEEG for suspected non-convulsive status epilepticus has been offered as a 24/7 service since april 2013. Recordings are assessed by senior clinical neurophysiologists at no more than eight hours interval, and a report is written directly into the patients electronic records. Clinicians may phone the neurophysiologist around the clock for discussion or referral. After six month, a total of 67 patients had
S177
been monitored with cEEG. At this time, an anonymous web-based survey was performed addressing 168 clinicians within paediatrics, neurology, neurosurgery and neuroanaesthesiology. Results: We obtained 51 responses. Of these 74% were senior/consultants and 26% trainees/researchers. 48 (94%) found that cEEG was an important investigation in neurocritical care. 50% of the clinicians had been involved in patients monitored with cEEG. Of those, 88% found that the logistics and communication with the neurophysiologist worked optimally or quite well in the best case, and 76-80% on average. cEEG had an impact on clinical decision-making that was optimal in 76% (best) and 44% (average) of cases and quite good in 20% (best) and 52% (average) of cases. Only one clinician found cEEG suboptimal for clinical decision-making in the actual case. When additional indications for cEEG were asked for, monitoring of patients with subarachnoid hemorrhage for delayed ischemia was the most prevalent suggestion. Conclusion: In this survey cEEG is highly demanded and supports clinical decision-making in the vast majority of cases where non-convulsive status epilepticus is suspected.
P480 Treatment of electroencephalographic status epilepticus after cardiac arrest – retrospective analysis and notification of a multicenter randomized controlled trial J. Hofmeijer 1,2 , M. Tjepkema-Cloostermans 1 , M.J. Blans 3 , A. Beishuizen 4 , M.J.A. van Putten 1,5 1 University Twente, Clinical Neurophysiology, Enschede, Netherlands; 2 Rijnstate Hospital, Neurology, Arnhem, Netherlands; 3 Rijnstate Hospital, Intensive Care, Arnhem, Netherlands; 4 Medical Spectrum Twente, Intensive Care, Enschede, Netherlands; 5 Medical Spectrum Twente, Clinical Neurophysiology, Enschede, Netherlands Question: Electroencephalographic seizures, including status epilepticus, occur in 9-35% of comatose patients after cardiac arrest. Mortality is 90-100% [1]. It is unclear whether (some) seizure patterns represent a condition in which treatment improves outcome, or severe ischemic damage, in which treatment is futile. Methods: In two teaching hospitals, we retrospectively identified patients that were treated with anti-epileptic drugs from our prospective cohort study on the prognostic value of continuous EEG monitoring in comatose patients after cardiac arrest. Outcome at six months after cardiac arrest was dichotomized between “good” (CPC 1 or 2) and “poor” (CPC 3, 4, or 5). EEG analyses were done at 24 hours after cardiac arrest and during anti-epileptic treatment, blinded for outcome. Results: Thirty-one (22%) of 139 patients were treated with anti-epileptic drugs (fenytoin, levetiracetam, valproate, clonazepam, propofol, midazolam): two with one, nine with two, thirteen with three, five with four, one with five, and one with six different drugs. This treatment improved epileptic EEG patterns temporarily (<6h). However, all but one patients with electroencephalographic status epilepticus died. In patients with seizures or GPDs at 24 hours, there was no difference in outcome between those treated with and without anti-epileptic drugs. Conclusion: In comatose patients after cardiac arrest with electroencephalographic status epilepticus, the general practice of treatment with conventional anti-epileptic drugs does not improve patients’ outcome. A multicenter randomized controlled trial to estimate the effect of early and aggressive treatment, directed at complete suppression of epileptiform activity during at least 24 hours, is in preparation. Reference: [1] Cloostermans 2012.
P482 Reliable monitoring of respiration rate with reflectance-mode photoplethysmography R. Paamand 1 , H.B.D. Sorensen 2 , D.B. Saadi 2 , H. Aydin 1 , P. Jennum 1 1 DCSM, Glostrup Hospital, Dept. of Clin. Neurophysiology, Glostrup, Denmark; 2 Technical University of Denmark, DTU Electro, Biomedical Signal Processing, Copenhagen, Denmark Problem: Recent innovations in embedded, networked sensors have en-
Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339
0.865–1.494, 0.824–2.357, and 0.831–1.437, respectively. Four patients had quantitative reactivity in one or more bands. RR in the alpha band was increased in one patient (CPC 2-3), in the theta band in two patients (CPC 1-2 and 2-3), and in the delta band in one patient (CPC 3-4). One patient had a decrease in RR in the delta band and had a CPC of 5. Of the three patients who showed no reactivity one had a CPC of 3 and two had a CPC of 5. Five patients were partly sedated, one of which had a CPC of 5. Conclusion: It seems possible to achieve a quantitative measure of reactivity. In this study we found no obvious systematic correlation with outcome but larger studies are required.
P475 Face validity of IDOS, an ICU depth of sleep index from a single channel of EEG L. Reinke 1 , H. van der Hoeven 2 , W. Dieperink 1 , J. Tulleken 1 University Medical Center Groningen, Department of Critical Care, Groningen, Netherlands; 2 University Medical Center Groningen, Department of Neurophysiology, Groningen, Netherlands 1
Question: The measurement and analysis of sleep in the intensive care unit (ICU) is notoriously complex and time-consuming. This is reflected by the variable and often poor interrater agreement between R&K raters in previous studies (Ambrogio, Koebnick, Quan, Ranieri, & Parthasarathy, 2008; Elliott, McKinley, Cistulli, & Fien, 2013). To evaluate the face validity of a new index for depth of sleep in ICU patients, we compared it to manual scoring by R&K criteria in outpatient and ICU polysomnographic (PSG) recordings. Methods: The ICU depth of sleep index (IDOS index) was constructed from the ratio of gamma and delta band power spectral density (PSD) of a single channel of EEG. PSG recordings of five ICU patients (24-72 hours each) and 15 healthy outpatient recordings (18 hours each) were analyzed with both methods. Manual selection of thresholds was used to classify the IDOS index as either wake, sleep or slow wave sleep (SWS). This classification was compared to manual scoring by R&K criteria. Results: When reduced to 3 classes, the obtained overall agreement between R&K and the IDOS index, as quantified by Cohen’s kappa statistic, was 0.82 for the outpatient recordings. Sensitivity and specificity were highest for the wake state (91% and 97%, respectively) and lowest for SWS (91% and 67%, respectively). For ICU recordings, the average agreement was good, with kappa=0.68, but varied between individual recordings.
P476 Sleep and biorhythm in the ICU L. Reinke 1 , H. van der Hoeven 2 , W. Dieperink 1 , J. Tulleken 1 University Medical Center Groningen, Department of Critical Care, Groningen, Netherlands; 2 University Medical Center Groningen, Department of Neurophysiology, Groningen, Netherlands
1
Question: Sleep deprivation is among the most common stressors experienced during critical illness (Watson, 2007), and there are strong indications that delirium and sleep deprivation are closely intertwined (Bellapart & Boots, 2012; Boyko et al., 2012). Sleep is important to the recovery of the critically ill, but may be hampered by disturbances in biorhythm (Mundigler et al., 2002; Paul & Lemmer, 2007; Figueroa-Ramos et al., 2009). Recent findings contradict the assumption that biorhythm is disturbed in all ICU patients, warranting further investigation (Gehlbach et al., 2012). ICU patients could potentially benefit from interventions to optimize biorhythm and consequently sleep. To this end, a protocol to monitor sleep and biorhythm was designed, and tested in the ICU. Methods: Critically ill patients (n=5) were subjected to 24-72 hour polysomnographic (PSG) recording followed by R&K analysis. Bihourly serum-melatonin samples were analyzed with tandem mass-spectrometry. Results: Of the 5 included critically ill patients, three showed severe frag-
Figure 1. Hypnogram after R&K classification of ICU patients’ PSG recording. Of the shown 8 days of PSG, only 1 day could be classified as ’normal’; the second day of patient A. Patient B and C experience severely fragmented sleep, with little to no contrast between day and night.
Figure 1. Hypnogram of ICU sleep recording (1A) versus IDOS index, calculated from a single channel of EEG (1B). To facilitate calculation of agreement between both methods, 30 second epochs were classified into three possible classes; wake (blue), sleep (red) and slow wave sleep (SWS, green). Average agreement for outpatient recordings was excellent, with Cohen’s Kappa =0.82 (n=15). For ICU recordings the average agreement was good, with Kappa =0.68 (n=5).
Conclusions: The IDOS index shows striking resemblance with manually scored outpatient recordings, with excellent agreement. With the established face-validity, the IDOS index could be useful in real-time, automated, single channel visualization of depth of sleep in ICU patients. Figure 2. Melatonin secretion and best fit curves of ICU patients. Severe fragmentation of sleep in patient B seems to coinicide with low contrast in melatonin secretion between day and night. During intubation (day 3) there is no melatonin peak. Other patients (A, C and D) show remarkably robust biorhythms, with increasing phase-delay and lower peaks as quality of sleep worsens.
Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339
mentation of sleep. Melatonin secretion was lower for patients with worse sleep, although biorhythm was visible in all but one patient. PSG with R&K analysis proved to be time-consuming and cumbersome, while the use of tandem mass spectrometry resulted in high throughput with excellent accuracy. Conclusions: Taking the limited scope of this pilot into account, worsening characteristics of sleep seem to coincide with loss of circadian rhythm. Currently, the availability of materials and the time-consuming analysis of PSG recordings are the main limiting factors of the study of sleep in the ICU. Automated, objective measures of quality and quantity of sleep are currently being validated in ICU and non-ICU patients, using only single channel EEG data.
P478 Prediction of good and poor outcome in comatose patients after cardiac arrest: the utility of early EEG/SEP recordings during therapeutic hypothermia M. Spalletti 1 , R. Carrai 1,2 , A. Comanducci 1 , C. Cossu 1 , S. Gabbanini 1 , A. Peris 3 , G. Gensini 2,4 , A. Grippo 1,2 , A. Amantini 1,2 1 AOU Careggi, Neurophysiopathology, Florence, Italy; 2 IRCCS Don Gnocchi, Neurologic Rehabilitation Unit, Florence, Italy; 3 AOU Careggi, ICU Emergency, Florence, Italy; 4 AOU Careggi, Heart-Vessels, Florence, Italy Question: Somatosensory evoked potentials (SEPs) are a reliable predictor of poor outcome in comatose patients after cardiac arrest (CA) treated with therapeutic hypotermia (TH). The role of EEG has been recently emphasized during early phase after CA. Our aim is to evaluate the prognostic value of EEG and SEPs in post-anoxic comatose patients within 12hs and 24hs from cardiac arrest (CA). Methods: Comatose patients after CA treated with TH were included. EEG and SEPs were recorded within 12hs and 24hs after CA. EEG was classified into discontinous (low voltage, isoelectric, burst suppression) and continuous (other patterns except epileptiform). SEPs were dicotomized into “bilaterally absent” (BA) and “present”. Neurologic outcome was evaluated at 6 months by GOS: “awakening” (GOS 3-5) was considered good outcome. Results: EEG and SEPs were recorded in 72 patients: 25 of these were studied within 12hs from CA. All patients with a continuous EEG pattern at 12hs awakened. The same EEG pattern recorded at 24 hs was not always predictive of awakening. BA SEPs at 12hs predicted poor outcome and were associated to discontinuous EEG patterns. Continuous EEG pattern was always associated with present SEPs. Conclusion: Combined early EEG/SEPs recordings are a useful tool for reliable prognostication both of good and poor outcome in comatose patients treated with TH.
P479 Continuous EEG monitoring in neurointensive care. Organisation and assessment of impact M. Fabricius 1 , A. Sabers 2 , H. Hoegenhaven 1 , J. Brennum 3 , K. Moeller 4 , K. Hansen 2 , T.W. Kjaer 1 1 Rigshospitalet, Clinical neurophysiology, Copenhagen, Denmark; 2 Rigshospitalet, Neurology, Copenhagen, Denmark; 3 Rigshospitalet, Neurosurgery, Copenhagen, Denmark; 4 Rigshospitalet, Neuroanaesthesiology, Copenhagen, Denmark Background: Continuous EEG (cEEG) is an emerging discipline for assessment of acute changes in cerebral function in the intensive care unit (ICU). A number of publications demonstrate that non-convulsive status epilepticus is a common complication in both neurological and non-neurological ICU patients and that cEEG is superior to conventional 30 minute standard EEG in capturing these patients. Yet establishing cEEG as part of daily routine is resource demanding and raises a number of treatment-related issues. Furthermore cEEG as a daily routine must be carefully introduced to assure that the most relevant patients are monitored, and that neurophysiologists and clinicians communicate in an efficient way. Methods: At Rigshospitalet, cEEG for suspected non-convulsive status epilepticus has been offered as a 24/7 service since april 2013. Recordings are assessed by senior clinical neurophysiologists at no more than eight hours interval, and a report is written directly into the patients electronic records. Clinicians may phone the neurophysiologist around the clock for discussion or referral. After six month, a total of 67 patients had
S177
been monitored with cEEG. At this time, an anonymous web-based survey was performed addressing 168 clinicians within paediatrics, neurology, neurosurgery and neuroanaesthesiology. Results: We obtained 51 responses. Of these 74% were senior/consultants and 26% trainees/researchers. 48 (94%) found that cEEG was an important investigation in neurocritical care. 50% of the clinicians had been involved in patients monitored with cEEG. Of those, 88% found that the logistics and communication with the neurophysiologist worked optimally or quite well in the best case, and 76-80% on average. cEEG had an impact on clinical decision-making that was optimal in 76% (best) and 44% (average) of cases and quite good in 20% (best) and 52% (average) of cases. Only one clinician found cEEG suboptimal for clinical decision-making in the actual case. When additional indications for cEEG were asked for, monitoring of patients with subarachnoid hemorrhage for delayed ischemia was the most prevalent suggestion. Conclusion: In this survey cEEG is highly demanded and supports clinical decision-making in the vast majority of cases where non-convulsive status epilepticus is suspected.
P480 Treatment of electroencephalographic status epilepticus after cardiac arrest – retrospective analysis and notification of a multicenter randomized controlled trial J. Hofmeijer 1,2 , M. Tjepkema-Cloostermans 1 , M.J. Blans 3 , A. Beishuizen 4 , M.J.A. van Putten 1,5 1 University Twente, Clinical Neurophysiology, Enschede, Netherlands; 2 Rijnstate Hospital, Neurology, Arnhem, Netherlands; 3 Rijnstate Hospital, Intensive Care, Arnhem, Netherlands; 4 Medical Spectrum Twente, Intensive Care, Enschede, Netherlands; 5 Medical Spectrum Twente, Clinical Neurophysiology, Enschede, Netherlands Question: Electroencephalographic seizures, including status epilepticus, occur in 9-35% of comatose patients after cardiac arrest. Mortality is 90-100% [1]. It is unclear whether (some) seizure patterns represent a condition in which treatment improves outcome, or severe ischemic damage, in which treatment is futile. Methods: In two teaching hospitals, we retrospectively identified patients that were treated with anti-epileptic drugs from our prospective cohort study on the prognostic value of continuous EEG monitoring in comatose patients after cardiac arrest. Outcome at six months after cardiac arrest was dichotomized between “good” (CPC 1 or 2) and “poor” (CPC 3, 4, or 5). EEG analyses were done at 24 hours after cardiac arrest and during anti-epileptic treatment, blinded for outcome. Results: Thirty-one (22%) of 139 patients were treated with anti-epileptic drugs (fenytoin, levetiracetam, valproate, clonazepam, propofol, midazolam): two with one, nine with two, thirteen with three, five with four, one with five, and one with six different drugs. This treatment improved epileptic EEG patterns temporarily (<6h). However, all but one patients with electroencephalographic status epilepticus died. In patients with seizures or GPDs at 24 hours, there was no difference in outcome between those treated with and without anti-epileptic drugs. Conclusion: In comatose patients after cardiac arrest with electroencephalographic status epilepticus, the general practice of treatment with conventional anti-epileptic drugs does not improve patients’ outcome. A multicenter randomized controlled trial to estimate the effect of early and aggressive treatment, directed at complete suppression of epileptiform activity during at least 24 hours, is in preparation. Reference: [1] Cloostermans 2012.
P482 Reliable monitoring of respiration rate with reflectance-mode photoplethysmography R. Paamand 1 , H.B.D. Sorensen 2 , D.B. Saadi 2 , H. Aydin 1 , P. Jennum 1 1 DCSM, Glostrup Hospital, Dept. of Clin. Neurophysiology, Glostrup, Denmark; 2 Technical University of Denmark, DTU Electro, Biomedical Signal Processing, Copenhagen, Denmark Problem: Recent innovations in embedded, networked sensors have en-