ORIGINAL RESEARCH
An Audit of Continuous EEG Monitoring in the Neurological–Neurosurgical Intensive Care Unit Nitin K. Sethi, Beth S. Rapaport, and Gail E. Solomon
Purpose: The use of long-term continuous EEG (cEEG) monitoring in neurological–neurosurgical intensive care units (NSICU) has witnessed an exponential increase. We decided to do an audit of the long-term cEEG monitoring in our NSICU over the past 7 years (2005–2011). The study was performed to determine technical and staffing consideration for the future. Methods: An audit of all long-term cEEG monitoring studies in our NSICU from 2005 through 2011. Results: We found a dramatic increase in the use of the cEEG monitoring in our NSICU over the 7-year period. Conclusions: The use of long-term cEEG monitoring in the NSICU is expected to further increase in the coming years. Stricter clinical criteria for undertaking cEEG recordings are likely to increase the role and usefulness of this procedure. Key Words: Long-term continuous EEG monitoring, Neurological ICU, Audit, Utility. (J Clin Neurophysiol 2014;31: 416–417)
T
he use of long-term cEEG monitoring in neurosurgical intensive care units (NSICUs) has witnessed a dramatic increase in hospitals across the country where such facilities are available. The singular reason for this increase has been a growing body of work indicating subclinical (electrographic) seizures in a large number of critically ill neurological and neurosurgical patients. These seizures are likely to be missed if only 30-minute EEG studies are performed. Continuous digital EEG provides dynamic and real time information about cerebral function and is especially useful in critically ill neurological and neurosurgical patients in whom neurological examination is limited due to disorders of consciousness. Importantly, it can be carried out in a timely fashion bedside and thus is of help when an acute intracerebral process such as sudden hemorrhagic conversion of an ischemic stroke or vasospasm in a patient with acute subarachnoid hemorrhage is suspected. These patients are frequently too unstable to be transported for a computed tomography let alone MRI of the brain. Quantitative EEG software is now commercially available, which makes it feasible for caregivers not formally trained in EEG interpretation to analyze the data. A growing body of work attesting to the above utilities of cEEG monitoring has fueled an increase in its use in NSICUs across the country where such facility is available. Whether this has resulted in
From the Department of Neurology, New York-Presbyterian Hospital, Weill Cornell Medical Center, New York, NY, U.S.A. Address correspondence and reprint requests to Nitin K. Sethi, MD, Comprehensive Epilepsy Center, New York-Presbyterian Hospital, Weill Cornell Medical Center, 525 East, 68th Street, New York, NY 10065, U.S.A.; e-mail: [email protected]. Copyright Ó 2014 by the American Clinical Neurophysiology Society
ISSN: 0736-0258/14/3105-0416
416
improved patient outcomes and should be the standard of care remains open to debate. We decided to do an audit of the long-term cEEG monitoring in our NSICU over the past 7 years (2005–2011). There was substantial increase in the number of long-term EEG monitoring in our NSICU over the past 7 years. Patients were more likely to undergo long-term cEEG monitoring as compared with an emergent 30minutes EEG study whenever a change in their sensorium or neurological examination was documented. This increase in the utility of long-term cEEG monitoring forced us to restructure the EEG services of our hospital.
METHODS We did an audit of all long-term cEEG monitoring studies in our NSICU from 2005 through 2011. Our hospital has an 11-bed NSICU, which serves critically ill neurological and neurosurgical patients. A closed ICU model of care is followed in which patients admitted to the ICU are transferred under the care of an intensivist assigned to the ICU on a full-time basis. Patients admitted to the ICU are cared for by the critical care team led by the intensivist. In reality, a mixed model of care is followed and comanagement by the primary neurologist or neurosurgeon on record occurs to varying degrees. Majority of the beds are hardwired for long-term cEEG recording and an EEG technician is available around the clock during the week and from 9 AM through 9 PM on Saturday and Sunday. A decision to initiate long-term cEEG monitoring is usually made by the neurointensivist or members of the critical care team (neurology critical care fellows, neurology, and anesthesia residents) when a clinical suspicion for seizures is raised or a change in the patient’s neurological examination especially level of consciousness is documented. All EEGs are recorded on a 21-channel digital EEG system (XLTEK; Natus Medical Incorporated, San Carlos, CA). Studies can be reviewed at the bedside by logging into the EEG machine unit, which is mounted on the wall in the patient’s room. They can also be reviewed from a remote location by logging on to a secure EEG server maintained by the information technology services of the hospital with a user specific password and username. Ethics approval for the study and informed patient consent were deemed not necessary as only an audit of the total number of recordings was carried out. All patient identifying data were removed at the time of the audit.
RESULTS The results are tabulated in a spreadsheet (Fig. 1). Whereas in 2005, there were in total 32 patients monitored (total number of days ¼ 104), in 2011, there were in total 171 patients monitored
Journal of Clinical Neurophysiology Volume 31, Number 5, October 2014
Journal of Clinical Neurophysiology Volume 31, Number 5, October 2014
FIG. 1. Bar graph showing yearly census for total number of patients monitored and total days of monitoring in the neurosurgical intensive care unit. (total number of days ¼ 285). This represents a more than 5-fold increase in the number of long-term cEEG studies.
DISCUSSION We found a dramatic increase in the use of the cEEG monitoring in our NSICU. Our data indicate that more critically ill neurological and neurosurgical patients are getting monitored and at times for a longer length of time. Studies from large academic centers in and outside the country all indicate a high prevalence of subclinical (electrographic) seizures in critically ill patients in the neurological–neurosurgical ICU (Claassen et al., 2004; Nuwer and Jordan, 2000). This body of work is hard to ignore and likely the main cause for increased utilization of cEEG monitoring in our NSICU. Since most of the patient rooms are hardwired for cEEG monitoring, studies can be initiated in a timely fashion. An added advantage is that patients do not need to be transported for EEG studies to the neurophysiology laboratory. Neither does the technician need to bring a portable EEG unit to the patient’s bedside. The studies can be read at bedside and also remotely so timely interpretation of studies is available. But the availability of this service 24/7 created its own unique set of problems. We found that residents and attending physicians started using cEEG monitoring as a substitute for a portable 30minutes emergent electroencephalogram. Studies were frequently ordered for indications where a 30-minutes emergent EEG would suffice such as sudden change in the sensorium of a patient, sudden change in neurological examination, patient not waking up after recent neurosurgical intervention and patient admitted after a single seizure who then became encephalopathic after receiving intravenous lorazepam in the emergency room. We feel that the decision to initiate cEEG monitoring in favor of a portable 30-minute emergent electroencephalogram has to be made on a case-to-case basis because there are some “postictal” encephalopathic patients who exhibit subclinical focal seizures a few hours after receiving the initial lorazepam dose in the emergency room.
Copyright Ó 2014 by the American Clinical Neurophysiology Society
cEEG Monitoring in NSICU
We further found that in many cases cEEG monitoring was not used in the long-term continuous form. Patients were connected to the monitor, disconnected for other tests, and again reconnected after short intervals. This burdened the EEG services to a tremendous degree, and we were forced to hire more technicians (Kull and Emerson, 2005). Patients were getting connected at odd hours throughout the night and the critical care team started calling for frequent reads sometimes on an hourly basis. This increased the work load of the neurophysiology attending or fellow on call, and we were forced to call a meeting with the critical care team to reorganize the service. In-service training was carried out to educate residents, critical care fellows, and intensivists on appropriate indications for cEEG monitoring. A decision was made that no new patient studies would be initiated between the hours of 10 PM through 7 AM. Studies would be reviewed three times a day (once in the morning around 9 AM, second at around 4 PM, and finally at night around 10 PM), and results were communicated to the ICU team. More “active” EEG studies (such as a patient with ongoing electrographic or electroclinical seizures) would be reviewed more frequently as per the discretion of the neurophysiology attending or fellow on call. A significant weakness of our study is that we did not address the question of whether cEEG monitoring helped in the management of these critically ill patients in our NSICU. Future large studies addressing questions such as how many patients were determined to be in nonconvulsive status or to have rhythmic periodic patterns thought currently to be in the continuum between interictal and ictal such as periodic lateralized discharges, generalized periodic discharges, stimulus induced rhythmic periodic or ictal discharges by cEEG monitoring, and in how many patients the monitoring led to a change in the management plan such as either initiation or withholding of aggressive anticonvulsant therapy are critical to determine whether the increased cost and labor of cEEG in NSICHs is justified. The general consensus is that the use of cEEG monitoring in NSICUs shall continue to increase in the years to come. Continuous EEG monitoring is indeed ready for prime time, but its true potential and utility in the neurological ICU remains to be explored (Kurtz et al., 2009).
CONCLUSIONS The availability of long-term digital cEEG monitoring is a powerful armament with the potential to improve care of neurological and neurosurgical patients admitted to the ICU. Its true potential and utility in the NSICU remains to be explored. Like any new technology, we expect a learning curve with the long-term EEG monitoring units in the ICU. Initially the use would be less, then more use at times for improper indications and finally rational use for appropriate indications. Stricter clinical criteria for undertaking cEEG recordings are likely to increase the role and usefulness of this procedure in the future. REFERENCES Claassen J, Mayer SA, Kowalski RG, et al. Detection of electrographic seizures with continuous EEG monitoring in critically ill patients. Neurology 2004;62:1743–1748. Kull LL, Emerson RG. Continuous EEG monitoring in the intensive care unit: technical and staffing considerations. J Clin Neurophysiol 2005;22:107–118. Kurtz P, Hanafy KA, Claassen J. Continuous EEG monitoring: is it ready for prime time? Curr Opin Crit Care 2009;15:99–109. Nuwer MR, Jordan KG. Continuous ICU EEG monitoring. Suppl Clin Neurophysiol 2000;53:72–75.
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An Audit of Continuous EEG Monitoring in the Neurological–Neurosurgical Intensive Care Unit Nitin K. Sethi, Beth S. Rapaport, and Gail E. Solomon
Purpose: The use of long-term continuous EEG (cEEG) monitoring in neurological–neurosurgical intensive care units (NSICU) has witnessed an exponential increase. We decided to do an audit of the long-term cEEG monitoring in our NSICU over the past 7 years (2005–2011). The study was performed to determine technical and staffing consideration for the future. Methods: An audit of all long-term cEEG monitoring studies in our NSICU from 2005 through 2011. Results: We found a dramatic increase in the use of the cEEG monitoring in our NSICU over the 7-year period. Conclusions: The use of long-term cEEG monitoring in the NSICU is expected to further increase in the coming years. Stricter clinical criteria for undertaking cEEG recordings are likely to increase the role and usefulness of this procedure. Key Words: Long-term continuous EEG monitoring, Neurological ICU, Audit, Utility. (J Clin Neurophysiol 2014;31: 416–417)
T
he use of long-term cEEG monitoring in neurosurgical intensive care units (NSICUs) has witnessed a dramatic increase in hospitals across the country where such facilities are available. The singular reason for this increase has been a growing body of work indicating subclinical (electrographic) seizures in a large number of critically ill neurological and neurosurgical patients. These seizures are likely to be missed if only 30-minute EEG studies are performed. Continuous digital EEG provides dynamic and real time information about cerebral function and is especially useful in critically ill neurological and neurosurgical patients in whom neurological examination is limited due to disorders of consciousness. Importantly, it can be carried out in a timely fashion bedside and thus is of help when an acute intracerebral process such as sudden hemorrhagic conversion of an ischemic stroke or vasospasm in a patient with acute subarachnoid hemorrhage is suspected. These patients are frequently too unstable to be transported for a computed tomography let alone MRI of the brain. Quantitative EEG software is now commercially available, which makes it feasible for caregivers not formally trained in EEG interpretation to analyze the data. A growing body of work attesting to the above utilities of cEEG monitoring has fueled an increase in its use in NSICUs across the country where such facility is available. Whether this has resulted in
From the Department of Neurology, New York-Presbyterian Hospital, Weill Cornell Medical Center, New York, NY, U.S.A. Address correspondence and reprint requests to Nitin K. Sethi, MD, Comprehensive Epilepsy Center, New York-Presbyterian Hospital, Weill Cornell Medical Center, 525 East, 68th Street, New York, NY 10065, U.S.A.; e-mail: [email protected]. Copyright Ó 2014 by the American Clinical Neurophysiology Society
ISSN: 0736-0258/14/3105-0416
416
improved patient outcomes and should be the standard of care remains open to debate. We decided to do an audit of the long-term cEEG monitoring in our NSICU over the past 7 years (2005–2011). There was substantial increase in the number of long-term EEG monitoring in our NSICU over the past 7 years. Patients were more likely to undergo long-term cEEG monitoring as compared with an emergent 30minutes EEG study whenever a change in their sensorium or neurological examination was documented. This increase in the utility of long-term cEEG monitoring forced us to restructure the EEG services of our hospital.
METHODS We did an audit of all long-term cEEG monitoring studies in our NSICU from 2005 through 2011. Our hospital has an 11-bed NSICU, which serves critically ill neurological and neurosurgical patients. A closed ICU model of care is followed in which patients admitted to the ICU are transferred under the care of an intensivist assigned to the ICU on a full-time basis. Patients admitted to the ICU are cared for by the critical care team led by the intensivist. In reality, a mixed model of care is followed and comanagement by the primary neurologist or neurosurgeon on record occurs to varying degrees. Majority of the beds are hardwired for long-term cEEG recording and an EEG technician is available around the clock during the week and from 9 AM through 9 PM on Saturday and Sunday. A decision to initiate long-term cEEG monitoring is usually made by the neurointensivist or members of the critical care team (neurology critical care fellows, neurology, and anesthesia residents) when a clinical suspicion for seizures is raised or a change in the patient’s neurological examination especially level of consciousness is documented. All EEGs are recorded on a 21-channel digital EEG system (XLTEK; Natus Medical Incorporated, San Carlos, CA). Studies can be reviewed at the bedside by logging into the EEG machine unit, which is mounted on the wall in the patient’s room. They can also be reviewed from a remote location by logging on to a secure EEG server maintained by the information technology services of the hospital with a user specific password and username. Ethics approval for the study and informed patient consent were deemed not necessary as only an audit of the total number of recordings was carried out. All patient identifying data were removed at the time of the audit.
RESULTS The results are tabulated in a spreadsheet (Fig. 1). Whereas in 2005, there were in total 32 patients monitored (total number of days ¼ 104), in 2011, there were in total 171 patients monitored
Journal of Clinical Neurophysiology Volume 31, Number 5, October 2014
Journal of Clinical Neurophysiology Volume 31, Number 5, October 2014
FIG. 1. Bar graph showing yearly census for total number of patients monitored and total days of monitoring in the neurosurgical intensive care unit. (total number of days ¼ 285). This represents a more than 5-fold increase in the number of long-term cEEG studies.
DISCUSSION We found a dramatic increase in the use of the cEEG monitoring in our NSICU. Our data indicate that more critically ill neurological and neurosurgical patients are getting monitored and at times for a longer length of time. Studies from large academic centers in and outside the country all indicate a high prevalence of subclinical (electrographic) seizures in critically ill patients in the neurological–neurosurgical ICU (Claassen et al., 2004; Nuwer and Jordan, 2000). This body of work is hard to ignore and likely the main cause for increased utilization of cEEG monitoring in our NSICU. Since most of the patient rooms are hardwired for cEEG monitoring, studies can be initiated in a timely fashion. An added advantage is that patients do not need to be transported for EEG studies to the neurophysiology laboratory. Neither does the technician need to bring a portable EEG unit to the patient’s bedside. The studies can be read at bedside and also remotely so timely interpretation of studies is available. But the availability of this service 24/7 created its own unique set of problems. We found that residents and attending physicians started using cEEG monitoring as a substitute for a portable 30minutes emergent electroencephalogram. Studies were frequently ordered for indications where a 30-minutes emergent EEG would suffice such as sudden change in the sensorium of a patient, sudden change in neurological examination, patient not waking up after recent neurosurgical intervention and patient admitted after a single seizure who then became encephalopathic after receiving intravenous lorazepam in the emergency room. We feel that the decision to initiate cEEG monitoring in favor of a portable 30-minute emergent electroencephalogram has to be made on a case-to-case basis because there are some “postictal” encephalopathic patients who exhibit subclinical focal seizures a few hours after receiving the initial lorazepam dose in the emergency room.
Copyright Ó 2014 by the American Clinical Neurophysiology Society
cEEG Monitoring in NSICU
We further found that in many cases cEEG monitoring was not used in the long-term continuous form. Patients were connected to the monitor, disconnected for other tests, and again reconnected after short intervals. This burdened the EEG services to a tremendous degree, and we were forced to hire more technicians (Kull and Emerson, 2005). Patients were getting connected at odd hours throughout the night and the critical care team started calling for frequent reads sometimes on an hourly basis. This increased the work load of the neurophysiology attending or fellow on call, and we were forced to call a meeting with the critical care team to reorganize the service. In-service training was carried out to educate residents, critical care fellows, and intensivists on appropriate indications for cEEG monitoring. A decision was made that no new patient studies would be initiated between the hours of 10 PM through 7 AM. Studies would be reviewed three times a day (once in the morning around 9 AM, second at around 4 PM, and finally at night around 10 PM), and results were communicated to the ICU team. More “active” EEG studies (such as a patient with ongoing electrographic or electroclinical seizures) would be reviewed more frequently as per the discretion of the neurophysiology attending or fellow on call. A significant weakness of our study is that we did not address the question of whether cEEG monitoring helped in the management of these critically ill patients in our NSICU. Future large studies addressing questions such as how many patients were determined to be in nonconvulsive status or to have rhythmic periodic patterns thought currently to be in the continuum between interictal and ictal such as periodic lateralized discharges, generalized periodic discharges, stimulus induced rhythmic periodic or ictal discharges by cEEG monitoring, and in how many patients the monitoring led to a change in the management plan such as either initiation or withholding of aggressive anticonvulsant therapy are critical to determine whether the increased cost and labor of cEEG in NSICHs is justified. The general consensus is that the use of cEEG monitoring in NSICUs shall continue to increase in the years to come. Continuous EEG monitoring is indeed ready for prime time, but its true potential and utility in the neurological ICU remains to be explored (Kurtz et al., 2009).
CONCLUSIONS The availability of long-term digital cEEG monitoring is a powerful armament with the potential to improve care of neurological and neurosurgical patients admitted to the ICU. Its true potential and utility in the NSICU remains to be explored. Like any new technology, we expect a learning curve with the long-term EEG monitoring units in the ICU. Initially the use would be less, then more use at times for improper indications and finally rational use for appropriate indications. Stricter clinical criteria for undertaking cEEG recordings are likely to increase the role and usefulness of this procedure in the future. REFERENCES Claassen J, Mayer SA, Kowalski RG, et al. Detection of electrographic seizures with continuous EEG monitoring in critically ill patients. Neurology 2004;62:1743–1748. Kull LL, Emerson RG. Continuous EEG monitoring in the intensive care unit: technical and staffing considerations. J Clin Neurophysiol 2005;22:107–118. Kurtz P, Hanafy KA, Claassen J. Continuous EEG monitoring: is it ready for prime time? Curr Opin Crit Care 2009;15:99–109. Nuwer MR, Jordan KG. Continuous ICU EEG monitoring. Suppl Clin Neurophysiol 2000;53:72–75.
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