Use Of Amplitude-integrated Electroencephalography Research Articles

Use of amplitude-integrated electroencephalography in decision-making for extracorporeal membrane oxygenation in comatose cardiac arrest patients whose eventual neurologic recovery is uncertain.

Comatose cardiac arrest patients frequently experience cardiogenic shock or recurrent arrest. Extracorporeal membrane oxygenation (ECMO) can be used to salvage patients with cardiogenic shock or cardiac arrest refractory to conventional therapies. However, in comatose cardiac arrest patients whose neurologic recovery is uncertain, the use of ECMO is restricted because it requires considerable financial and human resources. Amplitude-integrated electroencephalography is an easily applicable, real-time electroencephalography monitoring tool that has been increasingly used to monitor brain activity in comatose cardiac arrest patients. We describe our experience of using amplitude-integrated electroencephalography in decision-making to place ECMO for comatose cardiac arrest patients whose eventual neurologic recovery appeared uncertain at the time of ECMO placement.

Использование амплитудно-интегрированной электроэнцефалографии у глубоконедоношенных новорожденных

Использование амплитудно-интегрированной электроэнцефалографии у глубоконедоношенных новорожденных

Prediction of Outcome in Neonates with Hypoxic-Ischemic Encephalopathy II: Role of Amplitude-Integrated Electroencephalography and Cerebral Oxygen Saturation Measured by Near-Infrared Spectroscopy

Background: Few data have been published on the combined use of amplitude-integrated electroencephalography (aEEG) and near-infrared spectroscopy (NIRS) for outcome prediction in neonates cooled for hypoxic-ischemic encephalopathy (HIE). Objective: Our aim was to evaluate the predictive values and the most powerful predictive combinations of single aEEG and NIRS parameters and the respective cut-off values with regard to short-term outcomes in HIE II. Methods: aEEG and NIRS were prospectively studied at the Medical University of Vienna in the first 102 h of life with regard to magnetic resonance imaging (MRI). Thirty-two neonates diagnosed with HIE II treated with hypothermia were investigated. The measurement period was divided into 6-h epochs. According to MRI, 2 outcome groups were defined and predictive values of aEEG parameters, regional cerebral oxygen saturation (rScO₂), and the additional value of both methods combined were studied. Receiver operating curves (ROC) were obtained and area under the curve (AUC) values were calculated. ROC were then used to detect the optimal cut-off points, sensitivity, specificity, positive predictive values, and negative predictive values. Results: At all time epochs, combined parameter scores were more predictive than single parameter scores. The highest AUC were observed between 18 and 60 h of cooling for the aEEG summation score (0.72-0.84) and for (background pattern + seizures) × rScO₂ (0.79-0.85). At 42-60 h sensitivity was similar between those 2 scores (87.5-90.0%), but the addition of NIRS to aEEG led to an increase in specificity (from 52.4-59.1% to 72.7-90.5%). Conclusions: In HIE II, aEEG and NIRS are important predictors of short-term outcome. The combination of both methods improves prognostication. The highest predictive abilities were observed between 18 and 60 h of cooling.

Neonatal somatosensory evoked potentials persist during hypothermia.

Treatment with therapeutic hypothermia has challenged the use of amplitude-integrated electroencephalography in predicting outcomes after perinatal asphyxia. In this study, we assessed the feasibility and gain of somatosensory evoked potentials (SEP) during hypothermia. This retrospective study comprised neonates from 35+6 to 42+2 gestational weeks and treated for asphyxia or hypoxic-ischaemic encephalopathy at Helsinki University Hospital between 14 February 2007 and 23 December 2009. This period was partly before the introduction of routine therapeutic hypothermia, which enabled us to include normothermic neonates who would these days receive hypothermia treatment. We analysed SEPs from 47 asphyxiated neonates and compared the results between 23 normothermic and 24 hypothermic neonates. Our data showed that hypothermia led to SEP latencies lengthening by a few milliseconds, but the essential gain for predicting outcomes by SEPs was preserved during hypothermia. Of the 24 hypothermic neonates, bilaterally absent SEPs were associated with poor outcome in 2/2 neonates, normal SEPs were associated with good outcomes in 13/15 neonates and 5/7 neonates with unilaterally absent or grossly delayed SEPs had a poor outcome. Our findings indicated that SEPs were a reliable tool for evaluating the somatosensory system in asphyxiated neonates in both normothermic and hypothermic conditions.

Use of Amplitude-integrated electroencephalography in neonates with special emphasis on Hypoxic-ischemic encephalopathy and therapeutic hypothermia

Recognizing the need for neurological monitoring in critically ill neonates such as the other vital parameters, neonatologists, and neurologists is becoming more familiar and comfortable with the use of amplitude-integrated electroencephalography (aEEG) in the neonatal intensive care unit, with minimal training and can be interpreted by care providers without neurophysiology backgrounds. In its simplest form, aEEG is a processed single-channel electroencephalogram that is filtered and time compressed. Current evidence demonstrates that aEEG is useful to monitor cerebral background activity, diagnose and treat seizures, and predict neurodevelopmental outcomes for preterm and term infants. This review aims to explain the fundamentals behind aEEG and its clinical applications specially referring to neonatal hypoxic-ischemic encephalopathy and hypothermia.

The use of amplitude-integrated electroencephalography combined with continuous conventional electroencephalography during therapeutic hypothermia for an infant with postnatal cardiac arrest.

IntroductionAmplitude-integrated electroencephalography (aEEG) has been employed in therapeutic hypothermia (TH) trials of neonates after perinatal hypoxic-ischemic encephalopathy (HIE). We present a case report involving the use of aEEG during TH with continuous conventional electroencephalography (cEEG) for an infant who experienced postnatal intraoperative cardiac arrest.Case descriptionA five-month-old infant developed cardiac arrest during operation. Return of spontaneous circulation was achieved after one hour of cardiopulmonary resuscitation. Therapeutic hypothermia was applied with neuromuscular blockades. During the TH, the brain function and seizures were monitored with aEEG, which can also display continuous cEEG. Intermittent and discrete seizures were detected on aEEG and confirmed with raw cEEG during the TH and rewarming periods. Several kinds of antiepileptic drugs (AEDs) were administered to manage seizures according to the findings of aEEG with cEEG. Seizures were controlled by the treatments, and she showed no clinical seizures after TH and AED discontinuation.Discussion and evaluation, conclusionsThis case indicated the possibility that the use of aEEG with continuous cEEG for a postnatal infant after cardiac arrest was feasible to detect and assess seizures and the effects of antiepileptic therapy while undergoing TH.

Use of amplitude-integrated electroencephalography (aEEG) and near infrared spectroscopy findings in neonates with asphyxia during selective head cooling

BackgroundAmplitude-integrated electroencephalogram (aEEG) at <6h is the best single outcome predictor in term infants with perinatal asphyxia at normothermia. Hypothermia treatment has changed the cutoff values for outcome prediction by using time at onset of normal trace and SWC. Cerebral hemodynamics and oxygenation changes detected by near infrared spectroscopy (NIRS) during hypothermia treatment in aphyxiated neonates are not a well known issue. AimThe aim of this study was to investigate the correlations between brain monitoring (amplitude integrated EEG and NIRS) and outcome in asphyxiated full-term infants with moderate/severe hypoxic–ischemic encephalopathy before, during and after hypothermia treatment. MethodTen neonates were recruited for hypothermia treatment by using the cool cap entry criteria. aEEG and NIRS were applied in 10 and 8 patients, respectively with moderate and severe hypoxic–ischemic encephalopathy before, just after brain cooling and rewarming periods. Patterns and voltages of aEEG backgrounds sleep–wake cycles (SWC) and NIRS values (TOI% and FTOE) were recorded. During the follow up their outcomes were assessed by using the Bayley Scales of Infant Development II. ConclusionHypothermia changes the predictive value of early aEEG. Normalization of a baby’s aEEG and the appearance of SWCs while being cooled occurs later. In our study one patient had normal aEEG background pattern at 80 and imminent SWC at 90h after birth and still had normal Bayley scores at 24months. Time to normal aEEG and SWC appearance should be carefully evaluated during the cooling period. NIRS values were different due to the clinical presentations of the patients.

Effects of Postnatal Age and Aminophylline on the Maturation of Amplitude-Integrated Electroencephalography Activity in Preterm Infants

Background: The use of amplitude-integrated electroencephalography (aEEG) is increasing during the neonatal intensive care of preterm infants. Objective: This prospective study was designed to assess factors that affect the maturation of aEEG activity in preterm infants with a gestational age (GA) of <32 weeks. Methods: aEEGs with cerebral function monitoring were performed weekly in preterm infants, and the recordings were evaluated and scored to assess the degree of continuity, the degree of sleep-wake cycling, and the amplitude of the lower border. Subjects with any of the following conditions were excluded: intraventricular hemorrhage or periventricular leukomalacia on cranial ultrasonography, sedation, hypotension, or respiratory instability (FiO₂ >50%). Results: The authors analyzed 207 recordings in 35 infants (GA 24–31 weeks, birth weight 440–1,980 g, postmenstrual age 25–38 weeks). At postmenstrual age 34–36 weeks, the aEEG total score was higher in preterm infants with a GA from 24 to 28 weeks than in less premature infants with a GA from 29 to 31 weeks (aEEG total score 12 vs. 10, p < 0.05). Logistic regression analysis revealed that the sleep-wake cycling was more prominent in infants with higher postnatal age (OR 3.32, 95% CI 2.40–4.59) or those receiving aminophylline (OR 3.28, 95% CI 1.06–10.08). Conclusions: The maturation of aEEG activity was found to be significantly correlated with postnatal age and with aminophylline use in clinically stable preterm infants. Most notably, aminophylline was found to be significantly associated with the degree of sleep-wake cycling as indicated by aEEG activity.

Amplitude-Integrated Electroencephalography in the Newborn: A Valuable Tool

The use of amplitude-integrated electroencephalography (aEEG) for research and clinical use in the newborn infant has increased over the last 2 decades. However, with this increased use, concerns have been expressed about (1) the accuracy and reliability of the interpretation of aEEG by neonatal clinicians and (2) the lack of evidence of benefit from aEEG monitoring for the infant.1 As early as 1994, Greisen2 noted that lack of knowledge of whether and when to act on the information obtained with aEEG, rather than the technology itself, limited the usefulness of this technique in the newborn. The aims of this commentary are to address these concerns by first reviewing the historical context in which the aEEG was developed and then summarizing current evidence on the use of aEEG in the newborn. aEEG is not a new technology. The cerebral function monitor (CFM) was devised by Dr Douglas Maynard and its clinical potential was explored by Dr Pamela Prior in the 1960s as a means of monitoring cerebral function in adults undergoing bypass surgery and after resuscitation.3,4 With its time-compressed output, the CFM provided a simpler and cheaper means of following trends in cerebral function in the ICU and the operating room without the need for experienced technicians for application, voluminous recordings, and expertise in interpretation for the, then, analog conventional EEG systems. The electrode placement over the parietal areas (P3–P4 in the 10–20 system) was designed so as to be in close proximity to the vulnerable “watershed” regions of the brain in the border zones of arterial blood supply from all 3 cerebral arteries. This position also minimized artifacts from sweating, muscle activity, and eyelid … Address correspondence to Divyen K. Shah, MB, ChB, Washington University, Department of Pediatrics, 8th Floor, NW Tower, 1 Children's Place, St Louis, MO 63110. E-mail: shah_d{at}kids.wustl.edu

Accuracy of Bedside Electroencephalographic Monitoring in Comparison With Simultaneous Continuous Conventional Electroencephalography for Seizure Detection in Term Infants

Our goals were to compare (1) single-channel amplitude-integrated electroencephalography alone, (2) 2-channel amplitude-integrated electroencephalography alone, and (3) amplitude-integrated electroencephalography plus 2-channel electroencephalography with simultaneous continuous conventional electroencephalography for seizure detection in term infants to check the accuracy of limited channels and compare the different modalities of bedside electroencephalography monitoring. Infants referred to a tertiary center with clinical seizures underwent simultaneous continuous conventional electroencephalography and 2-channel (C3-P3 and C4-P4) bedside monitoring. Off-line analysis of the continuous conventional electroencephalographic results was performed independently by 2 neurologists. Two experienced neonatal readers reviewed results obtained with amplitude-integrated electroencephalography and 2-channel electroencephalography combined and single-channel and 2-channel amplitude-integrated electroencephalography. All readings were performed independently and then compared. Twenty-one term newborns were monitored. Seizures were detected in 7 patients who had up to 12 electrical seizures, with 1 infant in status epilepticus. Seizures were identified correctly in 6 of 7 patients with amplitude-integrated electroencephalography plus 2-channel electroencephalography. The missed infant had an isolated 12-second seizure. With amplitude-integrated electroencephalography plus 2-channel electroencephalography, 31 of 41 non-status epilepticus seizures were correctly identified (sensitivity, 76%; specificity, 78%; positive predictive value, 78%; negative predictive value, 78%), with a substantial level of interrater agreement. The seizures missed were predominantly slow sharp waves of occipital origin from a single patient (7 of 10 seizures). Nine false-positive results were obtained in 351 hours of recording (1 false-positive result per 39 hours). These were thought to be related to muscle, electrode, and patting artifacts. Use of amplitude-integrated electroencephalography alone (1 or 2 channel) provided low sensitivity (27%-56%) and low interobserver agreement. Limited-channel bedside electroencephalography combining amplitude-integrated electroencephalography with 2-channel electroencephalography, interpreted by experienced neonatal readers, detected the majority of electrical seizures in at-risk newborn infants.

The Use of Amplitude-Integrated Electroencephalography: Beware of Its Unintended Consequences

In the preface to the 2006 issue on brain monitoring in the neonate, White and Spitzer1 stated that continuous electroencephalogram monitoring “will substantially enhance our understanding of neonatal neurologic injury and markedly improve outcomes for all hospitalized newborn infants.” However, they caution that “access to information often precedes the ability to use it wisely.” In light of the experience of the obstetrical community with electronic fetal monitoring (EFM),2 widespread use of the new amplitude-integrated electroencephalography (aEEG) to diagnose and manage neonatal seizures should be implemented cautiously. EFM was introduced into widespread clinical practice in the early 1960s in an effort to identify a fetus undergoing stress or distress who might develop hypoxic-ischemic encephalopathy and subsequent cerebral palsy.3,4 At the time of its introduction, there were no controlled studies to show that it was preferable to auscultation. Subsequent studies and meta-analyses have shown that although the cesarean-section rate has increased by 40% since the introduction of EFM, the perinatal morbidity and mortality rates have not changed, nor has the incidence of subsequent cerebral palsy.5–7 However, EFM has resulted in a marked increase in maternal morbidity associated with the cesarean sections. Nelson7 noted that three fourths of children who developed cerebral palsy showed no abnormalities on fetal monitoring, and monitoring … Address correspondence to John M. Freeman, MD, 1026 Rolandvue Rd, Towson, MD 21204. E-mail: jfreeman{at}jhmi.edu

Amplitude-Integrated Electroencephalography: A Tool for Monitoring Silent Seizures in Neonates

The clinical use of amplitude-integrated electroencephalography in the diagnosis of seizures in high-risk newborn infants with suspected central nervous system insult is evaluated with emphasis on silent seizures. Recordings from 93 infants with suspected central nervous system insults over a period of 7 years were retrospectively analyzed for the presence of electrical seizures and for their correlation with clinical events. Thirty infants (32%) had overt clinical seizures; 29 (97%) of these manifested clear seizure patterns in their tracings, and the remaining one infant had a suspected tracing. Eleven infants (12%) had subtle clinical seizures; of these 7 (59%) had clear electrical seizures, 3 (31%) had suspected tracing, and one had a normal tracing. Fifty-two infants (56%) had no clinical events indicative of seizures; of these 8 (15%) had clear electrical seizures, 17 (33%) had suspected tracings, and 27 (52%) had normal tracings. Electroencephalographic seizures are common in sick newborn infants. Amplitude-integrated electroencephalography can provide important information concerning their neurologic status and help to confirm or refute the presence of seizures in clinically suspected cases and detect infants with silent seizures.