Electrographic Seizures in Children and Neonates Undergoing Extracorporeal Membrane Oxygenation

Ictal-Interictal Continuum in the Pediatric Intensive Care Unit

BACKGROUND

The ictal-interictal continuum (IIC) consists of several electroencephalogram (EEG) patterns that are common in critically ill adults. Studies focused on the IIC are limited in critically ill children and have focused primarily on associations with electrographic seizures (ESs). We report the incidence of the IIC in the pediatric intensive care unit (PICU). We then compare IIC patterns to rhythmic and periodic patterns (RPP) not meeting IIC criteria looking for associations with acute cerebral abnormalities, ES, and in-hospital mortality.

METHODS

This was a retrospective review of prospectively collected data for patients admitted to the PICU at Children's National Hospital from July 2021 to January 2023 with continuous EEG. We excluded patients with known epilepsy and cerebral injury prior to presentation. All patients were screened for RPP. The American Clinical Neurophysiology Society standardized Critical Care EEG terminology for the IIC was applied to each RPP. Associations between IIC and RPP not meeting IIC criteria, with clinical and EEG variables, were calculated using odds ratios (ORs).

RESULTS

Of 201 patients, 21% (42/201) had RPP and 12% (24/201) met IIC criteria. Among patients with an IIC pattern, the median age was 3.4 years (interquartile range (IQR) 0.6-12 years). Sixty-seven percent (16/24) of patients met a single IIC criterion, whereas the remainder met two criteria. ESs were identified in 83% (20/24) of patients and cerebral injury was identified in 96% (23/24) of patients with IIC patterns. When comparing patients with IIC patterns with those with RPP not qualifying as an IIC pattern, both patterns were associated with acute cerebral abnormalities (IIC OR 26 [95% confidence interval {CI} 3.4-197], p = 0.0016 vs. RPP OR 3.5 [95% CI 1.1-11], p = 0.03), however, only the IIC was associated with ES (OR 121 [95% CI 33-451], p < 0.0001) versus RPP (OR 1.3 [0.4-5], p = 0.7).

CONCLUSIONS

Rhythmic and periodic patterns and subsequently the IIC are commonly seen in the PICU and carry a high association with cerebral injury. Additionally, the IIC, seen in more than 10% of critically ill children, is associated with ES. The independent impact of RPP and IIC patterns on secondary brain injury and need for treatment of these patterns independent of ES requires further study.

Neurophysiologic Features Reflecting Brain Injury During Pediatric ECMO Support

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) provides lifesaving support to critically ill patients who experience refractory cardiopulmonary failure but carries a high risk for acute brain injury. We aimed to identify characteristics reflecting acute brain injury in children requiring ECMO support.

METHODS

This is a prospective observational study from 2019 to 2022 of pediatric ECMO patients undergoing neuromonitoring, including continuous electroencephalography, cerebral oximetry, and transcranial Doppler ultrasound (TCD). The primary outcome was acute brain injury. Clinical and neuromonitoring characteristics were collected. Multivariate logistic regression was implemented to model odds ratios (ORs) and identify the combined characteristics that best discriminate risk of acute brain injury using the area under the receiver operating characteristic curve.

RESULTS

Seventy-five pediatric patients requiring ECMO support were enrolled in this study, and 62 underwent neuroimaging or autopsy evaluations. Of these 62 patients, 19 experienced acute brain injury (30.6%), including seven (36.8%) with arterial ischemic stroke, four (21.1%) with hemorrhagic stroke, seven with hypoxic-ischemic brain injury (36.8%), and one (5.3%) with both arterial ischemic stroke and hypoxic-ischemic brain injury. A univariate analysis demonstrated acute brain injury to be associated with maximum hourly seizure burden (p = 0.021), electroencephalographic suppression percentage (p = 0.022), increased interhemispheric differences in electroencephalographic total power (p = 0.023) and amplitude (p = 0.017), and increased differences in TCD Thrombolysis in Brain Ischemia (TIBI) scores between bilateral middle cerebral arteries (p = 0.023). Best subset model selection identified increased seizure burden (OR = 2.07, partial R2 = 0.48, p = 0.013), increased quantitative electroencephalographic interhemispheric amplitude differences (OR = 2.41, partial R2 = 0.48, p = 0.013), and increased interhemispheric TCD TIBI score differences (OR = 4.66, partial R2 = 0.49, p = 0.006) to be independently associated with acute brain injury (area under the receiver operating characteristic curve = 0.92).

CONCLUSIONS

Increased seizure burden and increased interhemispheric differences in both quantitative electroencephalographic amplitude and TCD MCA TIBI scores are independently associated with acute brain injury in children undergoing ECMO support.

Fifteen-minute consultation: When to consider extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a form of organ support which is used for severe, potentially reversible respiratory, cardiac or cardiorespiratory failure. While it is associated with significant risk of intracerebral injury in neonates and children, outcomes can be excellent, and timely referral is associated with improved survival and reduced morbidity. This article provides a concise summary of the technical aspects of ECMO support, indications for referral, complications, outcomes and important considerations for follow-up.

Neonatal seizures during extra corporeal membrane oxygenation support

To evaluate EEG monitoring during neonatal ECMO and to identify any correlations between seizure detection to abnormal neuroimaging. Eight-year, service evaluation of neonates who received at least one continuous EEG (cEEG) whilst on ECMO at Great Ormond Street Hospital. Pearson's chi-square test and multivariate logistic regression analysis were used to assess clinical and EEG variables association with seizures and neuroimaging findings. Fifty-seven neonates were studied; 57 cEEG recordings were reviewed. The incidence of seizures was 33% (19/57); of these 74% (14/19) were electrographic-only. The incidence of status epilepticus was 42%, (8/19 with 6 neonates having electrographic-only status and 2 electro-clinical status. Seizures were detected within an hour of recording in 84%, (16/19). The overall mortality rate was 39% (22/57). Seizure detection was strongly associated with female gender (OR 4.8, 95% CI: 1.1-20.4, p = 0.03), abnormal EEG background activity (OR 2.8, 95% CI: 1.1-7.4, p = 0.03) and abnormal EEG focal features (OR 23.6, 95% CI: 5.4-103.9, p = 0.001). There was a strong association between the presence of seizures and abnormal neuroimaging findings (OR 10.9, 95% CI: 2.8-41.9, p = 0.001). Neonates were highly likely to have abnormal neuroimaging findings in the presence of severely abnormal background EEG (OR 9.5, 95% CI 1.7-52.02, p = 0.01) and focal EEG abnormalities (OR 6.35, 95% CI 1.97-20.5, p = 0.002)Conclusion: The study highlights the importance of cEEG in neonates undergoing ECMO. An association between seizure detection and abnormal neuroimaging findings was described. What is Known: • Patients on ECMO are at a higher risk of seiures. • Continuous EEG monitoring is recommended by the ACNS for high risk and ECMO patients. What is New: • In this cohort, neonates with sezirues were 11 times more likely of having abnromal neuroimaging findings. • Neonates with burst suppressed or suppressed EEG background were 9.5 times more likely to have abnormal neuroimaging findings. What does this study add? • This study reports a 33% incidence of neonatal seizures during ECMO. • Neonates with seizures were 11 times more likely to have an abnormal brain scan. • The study captures the real-time approach of EEG monitoring. • Recommended cEEG monitoring should last at least 24 h for ECMO patients. • This is the first study to assess this in neonates only.

Neuromonitoring of Pediatric and Adult Extracorporeal Membrane Oxygenation Patients: The Importance of Continuous Bedside Tools in Driving Neuroprotective Clinical Care

Extracorporeal membrane oxygenation (ECMO) is a form of temporary cardiopulmonary bypass for patients with acute respiratory or cardiac failure refractory to conventional therapy. Its usage has become increasingly widespread and while reported survival after ECMO has increased in the past 25 years, the incidence of neurological injury has not declined, leading to the pressing question of how to improve time-to-detection and diagnosis of neurological injury. The neurological status of patients on ECMO is clinically difficult to evaluate due to multiple factors including illness, sedation, and pharmacological paralysis. Thus, increasing attention has been focused on developing tools and techniques to measure and monitor the brain of ECMO patients to identify dynamic risk factors and monitor patients' neurophysiological state as a function in time. Such tools may guide neuroprotective interventions and thus prevent or mitigate brain injury. Current means to continuously monitor and prevent neurological injury in ECMO patients are rather limited; most techniques provide indirect or postinsult recognition of irreversible brain injury. This review will explore the indications, advantages, and disadvantages of standard-of-care, emerging, and investigational technologies for neurological monitoring on ECMO, focusing on bedside techniques that provide continuous assessment of neurological health.

Recovery and Survival of Patients After Out-of-Hospital Cardiac Arrest: A Literature Review Showcasing the Big Picture of Intensive Care Unit-Related Factors

As an important public health issue, out-of-hospital cardiac arrest (OHCA) requires several stages of high quality medical care, both on-field and after hospital admission. Post-cardiac arrest shock can lead to severe neurological injury, resulting in poor recovery outcome and increased risk of death. These characteristics make this condition one of the most important issues to deal with in post-OHCA patients hospitalized in intensive care units (ICUs). Also, the majority of initial post-resuscitation survivors have underlying coronary diseases making revascularization procedure another crucial step in early management of these patients. Besides keeping myocardial blood flow at a satisfactory level, other tissues must not be neglected as well, and maintaining mean arterial pressure within optimal range is also preferable. All these procedures can be simplified to a certain level along with using targeted temperature management methods in order to decrease metabolic demands in ICU-hospitalized post-OHCA patients. Additionally, withdrawal of life-sustaining therapy as a controversial ethical topic is under constant re-evaluation due to its possible influence on overall mortality rates in patients initially surviving OHCA. Focusing on all of these important points in process of managing ICU patients is an imperative towards better survival and complete recovery rates.

Amplitude Integrated Electroencephalography: Simulated Assessment of Neonatal Seizure Detection in PICU Patients

OBJECTIVES

Amplitude integrated electroencephalography (aEEG) is a mainstay of care in neonatal ICUs; however, knowledge gaps exist in relation to its accuracy for identifying seizures in older children. We aimed to review the diagnostic accuracy of existing neonatal seizure detection criteria for seizure detection in older children in hospital.

DESIGN

Retrospective study.

SETTING

PICU/Neurophysiology Department in Dublin.

PATIENTS

One hundred twenty patients (2 mo to 16 yr old) were chosen from a database of formal 10-20 system, 21-lead electroencephalography recordings (2012-2020), comprising 30 studies with seizures, 90 without.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Electroencephalography studies containing electrographic seizures (ESzs) were annotated to describe number, duration, distribution, and spread. Two-channel aEEG (using leads C3-P3, C4-P4) recordings were generated and independently reviewed by a professional specialist in clinical neurophysiology blinded to outcome and without reference to the raw electroencephalography trace. Logistic regression was used to identify factors associated with correct seizure identification on aEEG. Median patient age was 6.1 years. Abnormal recordings featured 123 seizures. Status epilepticus (SE) was evident by electroencephalography in 10 cases. Using neonatal criteria, aEEG had a sensitivity of 70% and negative predictive value of 90% for identifying any ESz. Accurate detection of individual seizures was diminished when seizures were very short or occurred during waking. Sensitivity for individual seizures was 81% when seizures less than 1 minute were excluded. aEEG correctly identified SE in 70% of the 10 cases, although ESz were confirmed to be present in 80% of this subpopulation.

CONCLUSIONS

aEEG criteria for neonatal seizure identification can be applied with caution to older children and should be supplemented by formal electroencephalography. Seizure identification is better for longer seizures and those arising from sleep. SE is not always recognized by aEEG among older children.

Continuous Electroencephalography (EEG) Protocol Improves Seizure Detection in Children on Extracorporeal Membrane Oxygenation

BACKGROUND / OBJECTIVE

Seizures are a complication for pediatric patients requiring extracorporeal membrane oxygenation (ECMO). There are no standardized guidelines regarding continuous electroencephalography (EEG) monitoring to detect seizures in these patients, and the impact of protocolized monitoring has not been evaluated. Here we examined the effects of continuous EEG protocol implementation in our pediatric ECMO population.

METHODS

Retrospective chart reviews were conducted on 57 patients who underwent extracorporeal membrane oxygenation and concurrent continuous EEG out of 165 patients supported on extracorporeal membrane oxygenation. Timing of continuous EEG initiation and seizures detected by continuous EEG was determined for 5 years prior to and 15 months after protocol implementation.

RESULTS

Protocol implementation was associated with increased ECMO-supported patients who were concurrently monitored by continuous EEG. Time from ECMO cannulation to continuous EEG initiation was shorter (median 7 hours after versus 16.2 hours before; P < .001). Patients who had ongoing seizures at the start of continuous EEG recording decreased from 64% preprotocol to 0% postprotocol (P < .001), and there was an associated earlier time to break in status epilepticus postprotocol. Seizures were detected past 48 hours after cannulation in 50% of patients in the postprotocol group.

CONCLUSIONS

Protocol implementation resulted in earlier continuous EEG initiation and more EEGs initiated before seizure onset with evidence of altered seizure dynamics. Although current recommendations suggest that continuous EEG duration of 24-48 hours results in seizure detection for >90% of critically ill adults, longer monitoring may be needed to reliably detect seizures in children supported with ECMO, particularly if monitoring is initiated earlier in the post-cannulation period.

Clinical Guidelines for Routine Neuromonitoring in Neonatal and Pediatric Patients Supported on Extracorporeal Membrane Oxygenation

DISCLAIMER

These guidelines for routine neuromonitoring in neonatal and pediatric patients supported on extracorporeal membrane oxygenation (ECMO) are intended for educational use to build the knowledge of physicians and other health professionals in assessing the conditions and managing the treatment of patients undergoing extracorporeal life support (ECLS)/ECMO and describe what are believed to be useful and safe practice for ECLS and ECMO but these are not necessarily consensus recommendations. The aim of clinical guidelines was to help clinicians to make informed decisions about their patients. However, adherence to a guideline does not guarantee a successful outcome. Healthcare professionals must make their own treatment decisions about care on a case-by-case basis, after consultation with their patients, using their clinical judgment, knowledge, and expertise. These guidelines do not take the place of physicians' and other health professionals' judgment in diagnosing and treatment of patients. These guidelines are not intended to and should not be interpreted as setting a standard of care or being deemed inclusive of all proper methods of care nor exclusive of other methods of care directed at obtaining the same results. The ultimate judgment must be made by the physician and other health professionals and the patient considering all the circumstances presented by the individual patient, and the known variability and biologic behavior of the clinical condition. These guidelines reflect the data at the time the guidelines were prepared; the results of subsequent studies or other information may cause revisions to the recommendations in these guidelines to be prudent to reflect new data, but ELSO is under no obligation to provide updates. In no event will ELSO be liable for any decision made or action taken in reliance upon the information provided through these guidelines.

Subtypes and Mechanistic Advances of Extracorporeal Membrane Oxygenation-Related Acute Brain Injury

Extracorporeal membrane oxygenation (ECMO) is a frequently used mechanical cardiopulmonary support for rescuing critically ill patients for whom conventional medical therapies have failed. However, ECMO is associated with several complications, such as acute kidney injury, hemorrhage, thromboembolism, and acute brain injury (ABI). Among these, ABI, particularly intracranial hemorrhage (ICH) and infarction, is recognized as the primary cause of mortality during ECMO support. Furthermore, survivors often suffer significant long-term morbidities, including neurocognitive impairments, motor disturbances, and behavioral problems. This review provides a comprehensive overview of the different subtypes of ECMO-related ABI and the updated advance mechanisms, which could be helpful for the early diagnosis and potential neuromonitoring of ECMO-related ABI.

Continuous Amplitude-Integrated Electroencephalography During Neonatal and Pediatric Extracorporeal Membrane Oxygenation

PURPOSE

Early prognostication of neurologic outcome in neonates and children supported with extra-corporeal membrane oxygenation (ECMO) is challenging. Amplitude-integrated EEG (aEEG) offers the advantages of continuous monitoring and 24-hours availability at the bedside for intensive care unit providers. The objective of this study was to describe the early electrophysiological background patterns of neonates and children undergoing ECMO and their association with neurologic outcomes.

METHODS

This was a retrospective review of neonates and children undergoing ECMO and monitored with aEEG. Amplitude-integrated EEG was summarized as an aEEG background score determined within the first 24 hours of ECMO and divided in 3-hour periods. Screening for electrical seizures was performed throughout the full ECMO duration. Neurologic outcome was defined by the Pediatric Cerebral Performance Category score at hospital discharge.

RESULTS

Seventy-three patients (median age 79 days [8-660], median weight 4.78 kg [3.24-10.02]) were included in the analysis. Thirty-two patients had a favorable neurologic outcome and 41 had an unfavorable neurologic outcome group at hospital discharge. A 24-hour aEEG background score >17 was associated with an unfavorable outcome with a sensitivity of 44%, a specificity of 97%, a positive predictive value of 95%, and a negative predictive value of 57%. In multivariate analysis, 24-hour aEEG background score was associated with unfavorable outcome (hazard ratio, 6.1; p = 0.001; 95% confidence interval, 2.31-16.24). The presence of seizures was not associated with neurologic outcome at hospital discharge.

CONCLUSIONS

Continuous aEEG provides accurate neurologic prognostication in neonates and children supported with ECMO. Early aEEG monitoring may help intensive care unit providers to guide clinical care and family counseling.

Extracorporeal Membrane Oxygenation for Neonates With Congenital Diaphragmatic Hernia: Prevalence of Seizures and Outcomes

OBJECTIVES

We aimed to determine the prevalence of electrographic seizures and associated odds of adverse outcomes of electrographic seizures in neonates with congenital diaphragmatic hernia (CDH) receiving extracorporeal membrane oxygenation (ECMO).

DESIGN

Retrospective, descriptive case series.

SETTING

Neonatal ICU (NICU) in a quaternary care institution.

PATIENTS

All neonates with CDH receiving ECMO undergoing continuous electroencephalographic monitoring (CEEG) and follow-up between January 2012 and December 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All eligible neonates with CDH receiving ECMO underwent CEEG (n = 75). Electrographic seizures occurred in 14 of 75 (19%): they were exclusively electrographic-only in nine of 14, both electrographic-only and electroclinical in three of 14, and electroclinical only in two of 14. Two neonates developed status epilepticus. We identified an association between presence of seizures, rather than not, and longer duration of initial session of CEEG monitoring (55.7 hr [48.2-87.3 hr] vs 48.0 hr [43.0-48.3 hr]; p = 0.001). We also found an association between presence of seizures, rather than not, and greater odds of use of a second CEEG monitoring (12/14 vs 21/61; odds ratio [OR], 11.43 [95% CI, 2.34-55.90; p = 0.0026). Most neonates with seizures (10/14), experienced their onset of seizures more than 96 hours after the start of ECMO. Overall, the presence of electrographic seizures, compared with not, was associated with lower odds of survival to NICU discharge (4/14 vs 49/61; OR 0.10 [95% CI 0.03 to 0.37], p = 0.0006). Also, the presence of seizures-rather than not-was associated with greater odds of a composite of death and all abnormal outcomes on follow-up (13/14 vs 26/61; OR, 17.5; 95% CI, 2.15-142.39; p = 0.0074).

CONCLUSIONS

Nearly one in five neonates with CDH receiving ECMO developed seizures during the ECMO course. Seizures were predominantly electrographic-only and when present were associated with great odds of adverse outcomes. The current study provides evidence to support standardized CEEG in this population.

Feasibility of non-invasive neuro-monitoring during extracorporeal membrane oxygenation in children

INTRODUCTION

Detection of neurological complications during extracorporeal membrane oxygenation (ECMO) may be enhanced with non-invasive neuro-monitoring. We investigated the feasibility of non-invasive neuro-monitoring in a paediatric intensive care (PIC) setting.

METHODS

In a single centre, prospective cohort study we assessed feasibility of recruitment, and neuro-monitoring via somatosensory evoked potentials (SSEP), electroencephalography (EEG) and near infrared spectroscopy (NIRS) during venoarterial (VA) ECMO in paediatric patients (0-15 years). Measures were obtained within 24h of cannulation, during an intermediate period, and finally at decannulation or echo stress testing. SSEP/EEG/NIRS measures were correlated with neuro-radiology findings, and clinical outcome assessed via the Pediatric cerebral performance category (PCPC) scale 30 days post ECMO cannulation.

RESULTS

We recruited 14/20 (70%) eligible patients (median age: 9 months; IQR:4-54, 57% male) over an 18-month period, resulting in a total of 42 possible SSEP/EEG/NIRS measurements. Of these, 32/42 (76%) were completed. Missed recordings were due to lack of access/consent within 24 h of cannulation (5/42, 12%) or PIC death/discharge (5/42, 12%). In each patient, the majority of SSEP (8/14, 57%), EEG (8/14, 57%) and NIRS (11/14, 79%) test results were within normal limits. All patients with abnormal neuroradiology (4/10, 40%), and 6/7 (86%) with poor outcome (PCPC ≥4) developed indirect SSEP, EEG or NIRS measures of neurological complications prior to decannulation. No study-related adverse events or neuro-monitoring data interpreting issues were experienced.

CONCLUSION

Non-invasive neuro-monitoring (SSEP/EEG/NIRS) during ECMO is feasible and may provide early indication of neurological complications in this high-risk population.

International survey of neuromonitoring and neurodevelopmental outcome in children and adults supported on extracorporeal membrane oxygenation in Europe

BACKGROUND

Adverse neurological events during extracorporeal membrane oxygenation (ECMO) are common and may be associated with devastating consequences. Close monitoring, early identification and prompt intervention can mitigate early and late neurological morbidity. Neuromonitoring and neurocognitive/neurodevelopmental follow-up are critically important to optimize outcomes in both adults and children.

OBJECTIVE

To assess current practice of neuromonitoring during ECMO and neurocognitive/neurodevelopmental follow-up after ECMO across Europe and to inform the development of neuromonitoring and follow-up guidelines.

METHODS

The EuroELSO Neurological Monitoring and Outcome Working Group conducted an electronic, web-based, multi-institutional, multinational survey in Europe.

RESULTS

Of the 211 European ECMO centres (including non-ELSO centres) identified and approached in 23 countries, 133 (63%) responded. Of these, 43% reported routine neuromonitoring during ECMO for all patients, 35% indicated selective use, and 22% practiced bedside clinical examination alone. The reported neuromonitoring modalities were NIRS (n = 88, 66.2%), electroencephalography (n = 52, 39.1%), transcranial Doppler (n = 38, 28.5%) and brain injury biomarkers (n = 33, 24.8%). Paediatric centres (67%) reported using cranial ultrasound, though the frequency of monitoring varied widely. Before hospital discharge following ECMO, 50 (37.6%) reported routine neurological assessment and 22 (16.5%) routinely performed neuroimaging with more paediatric centres offering neurological assessment (65%) as compared to adult centres (20%). Only 15 (11.2%) had a structured longitudinal follow-up pathway (defined followup at regular intervals), while 99 (74.4%) had no follow-up programme. The majority (n = 96, 72.2%) agreed that there should be a longitudinal structured follow-up for ECMO survivors.

CONCLUSIONS

This survey demonstrated significant variability in the use of different neuromonitoring modalities during and after ECMO. The perceived importance of neuromonitoring and follow-up was noted to be very high with agreement for a longitudinal structured follow-up programme, particularly in paediatric patients. Scientific society endorsed guidelines and minimum standards should be developed to inform local protocols.

Seizures in children undergoing extracorporeal membrane oxygenation: a systematic review and meta-analysis

OBJECTIVES

To investigate the incidence of seizures and short-term mortality associated with seizures in children undergoing extracorporeal membrane oxygenation (ECMO).

METHODS

PubMed, Embase, and Web of Science were searched from inception to September 2021. Study quality was assessed using the Newcastle-Ottawa Scale. Random effects meta-analysis was conducted.

RESULTS

Fourteen studies met the inclusion criteria for quantitative meta-analysis. The cumulative estimate of seizure incidence was 15% (95% CI: 12-17%). Studies using electroencephalography reported a higher incidence of seizures compared with those using electro-clinical criteria (19% vs. 9%, P = 0.034). Furthermore, 75% of seizures were subclinical. Children receiving extracorporeal cardiopulmonary resuscitation (ECPR) exhibited a higher incidence of seizures compared to children with respiratory and cardiac indications. Seizure incidence was higher in patients undergoing venoarterial (VA) ECMO compared with venovenous (VV) ECMO. The pooled odds ratio of mortality was 2.58 (95% CI: 2.25-2.95) in those developed seizures.

CONCLUSION

The incidence of seizures in children requiring ECMO was 15% and majority of seizures were subclinical. The incidence of seizures was higher in patients receiving ECPR than in those with respiratory and cardiac indications. Seizures were more frequent in patients undergoing VA ECMO than VV ECMO. Seizures were associated with increased short-term mortality.

IMPACT

The incidence of seizures in children undergoing extracorporeal membrane oxygenation (ECMO) was ~15% and majority of the seizures were subclinical. Seizures were associated with increased short-term mortality. Risk factors for seizures were extracorporeal cardiopulmonary resuscitation and venoarterial ECMO. Electroencephalography (EEG) monitoring is recommended in children undergoing ECMO and further studies on the optimal protocol for EEG monitoring are necessary.

Sporadic and Periodic Interictal Discharges in Critically Ill Children: Seizure Associations and Time to Seizure Identification

PURPOSE

We evaluated interictal discharges (IEDs) as a biomarker for the time to development of electrographic seizures (ES).

METHODS

Prospective observational study of 254 critically ill children who underwent continuous electroencephalography (cEEG) monitoring. We excluded neonates and patients with known epilepsy or the sole cEEG indication to characterize events. Interictal discharges included sporadic epileptiform discharges and periodic and rhythmic patterns. Sporadic epileptiform discharges were categorized as low frequency (rare [<1/hour] and occasional [≥1/hour but <1/minute]) and high frequency (frequent, [≥1/minute] and abundant [≥1/10 seconds]). Time variables included time from cEEG start to first IED and time between first IED and ES.

RESULTS

Interictal discharges were present in 33% (83/254) of patients. We identified ES in 20% (50/254), and 86% (43/50) had IEDs. High-frequency sporadic epileptiform discharges (odds ratio [OR], 35; 95% confidence interval [CI], 14.5-88; P < 0.0001) and lateralized periodic discharges (OR, 27; 95% CI, 7.3-100; P < 0.0001) were associated with ES. Mildly abnormal EEG background without IEDs or background asymmetry was associated with the absence of seizures (OR, 0.1; 95% CI, 0.04-0.3; P < 0.0001). Time from cEEG start to first IED was 36 minutes (interquartile range, 3-131 minutes), and time between first IED and ES was 9.6 minutes (interquartile range, 0.6-165 minutes).

CONCLUSIONS

Interictal discharges are associated with ES and are identified in the first 3 hours of cEEG. High-frequency sporadic epileptiform discharges and periodic patterns have the highest risk of ES. Our findings define a window of high seizure risk after the identification of IEDs in which to allocate resources to improve seizure identification and subsequent treatment.

Variation in electroencephalography and neuroimaging for children receiving extracorporeal membrane oxygenation

BACKGROUND

Seizures, strokes, and intracranial hemorrhage are common and feared complications in children receiving extracorporeal membrane oxygenation (ECMO) support. Researchers and clinicians have proposed and deployed methods for monitoring and detecting neurologic injury, but best practices are unknown. We sought to characterize clinicians' approach to electroencephalography (EEG) and brain imaging modalities in children supported by ECMO.

METHODS

We performed a retrospective observational cohort study among US Children's Hospitals participating in the Pediatric Health Information System (PHIS) from 2016 to 2021. We identified hospitalizations containing ECMO support. We stratified these admissions by pediatric, neonatal, cardiac surgery, and non-cardiac surgery. We characterized the frequency of EEG, cranial ultrasound, brain computed tomography (CT), magnetic resonance imaging (MRI), and transcranial Doppler during ECMO hospitalizations. We reported key diagnoses (stroke and seizures) and the prescription of antiseizure medication. To assess hospital variation, we created multilevel logistic regression models.

RESULTS

We identified 8746 ECMO hospitalizations. Nearly all children under 1 year of age (5389/5582) received a cranial ultrasound. Sixty-two percent of the cohort received an EEG, and use increased from 2016 to 2021 (52-72% of hospitalizations). There was marked variation between hospitals in rates of EEG use. Rates of antiseizure medication use (37% of hospitalizations) and seizure diagnoses (20% of hospitalizations) were similar across hospitals, including high and low EEG utilization hospitals. Overall, 37% of the cohort received a CT and 36% received an MRI (46% of neonatal patients). Stroke diagnoses (16% of hospitalizations) were similar between high- and low-MRI utilization hospitals (15% vs 17%, respectively). Transcranial Doppler (TCD) was performed in just 8% of hospitalizations, and 77% of the patients who received a TCD were cared for at one of five centers.

CONCLUSIONS

In this cohort of children at high risk of neurologic injury, there was significant variation in the approach to EEG and neuroimaging in children on ECMO. Despite the variation in monitoring and imaging, diagnoses of seizures and strokes were similar across hospitals. Future work needs to identify a management strategy that appropriately screens and monitors this high-risk population without overuse of resource-intensive modalities.

The effect of extracorporeal membrane oxygenation on neurodevelopmental outcomes in children after repair of congenital heart disease: A pilot study from Turkey

Background

Extracorporeal membrane oxygenation (ECMO) is widely used after congenital heart surgery. The purpose of this study is to analyze the neurodevelopmental (ND) outcomes in patients who receivedECMO support after congenital cardiac surgery.

Methods

Between January 2014 and January 2021, 111 patients (5.8%) receivedECMO support after congenital heart operations, and 29 (26,1%) of these patients were discharged. Fifteen patients who met the inclusion criteria were included. A propensity score matching (PSM) analysis model was established using eight variables (age, weight, sex, Modified Aristotle Comprehensive Complexityscores, seizures, cardiopulmonary bypass duration, number of operations, and repair method) with 1:1 matching. According to the PSM model, 15 patients who underwent congenital heart operations were selected as the non-ECMO group. The Ages & Stages Questionnaire Third Edition (ASQ-3) was used for ND screening;it includes communication, physical skills (gross and fine motor), problem-solving, and personal-social skills domains.

Results

There were no statistically significant differences between the patients' preoperative and postoperative characteristics. All patients were followed up for a median of 29 months (9-56 months). The ASQ-3 results revealed that communication, fine motor, and personal-social skills assessments were not statistically different between the groups. Gross motor skills (40 vs. 60), problem-solving skills (40 vs. 50), and overall scores (200 vs. 250) were better in the non-ECMO patients (P = 0.01, P = 0.03, and P = 0.03, respectively). Nine patients (%60) in the ECMO group and 3 patients (%20) in the non-ECMO group were with neurodevelopmental delay (P = 0,03).

Conclusion

ND delay may occur in congenital heart surgery patients who receivedECMO support. We recommend ND screening in all patients with congenital heart disease, especially those who receivedECMO support.

Optimal neuromonitoring techniques in neonates with hypoxic ischemic encephalopathy

Neonates with hypoxic ischemic encephalopathy (HIE) are at significant risk for adverse outcomes including death and neurodevelopmental impairment. Neuromonitoring provides critical diagnostic and prognostic information for these infants. Modalities providing continuous monitoring include continuous electroencephalography (cEEG), amplitude-integrated electroencephalography (aEEG), near-infrared spectroscopy (NIRS), and heart rate variability. Serial bedside neuromonitoring techniques include cranial ultrasound and somatic and visual evoked potentials but may be limited by discrete time points of assessment. EEG, aEEG, and NIRS provide distinct and complementary information about cerebral function and oxygen utilization. Integrated use of these neuromonitoring modalities in addition to other potential techniques such as heart rate variability may best predict imaging outcomes and longer-term neurodevelopment. This review examines available bedside neuromonitoring techniques for the neonate with HIE in the context of therapeutic hypothermia.

Neuromonitoring in neonatal critical care part II: extremely premature infants and critically ill neonates

Neonatal intensive care has expanded from cardiorespiratory care to a holistic approach emphasizing brain health. To best understand and monitor brain function and physiology in the neonatal intensive care unit (NICU), the most commonly used tools are amplitude-integrated EEG, full multichannel continuous EEG, and near-infrared spectroscopy. Each of these modalities has unique characteristics and functions. While some of these tools have been the subject of expert consensus statements or guidelines, there is no overarching agreement on the optimal approach to neuromonitoring in the NICU. This work reviews current evidence to assist decision making for the best utilization of these neuromonitoring tools to promote neuroprotective care in extremely premature infants and in critically ill neonates. Neuromonitoring approaches in neonatal encephalopathy and neonates with possible seizures are discussed separately in the companion paper. IMPACT: For extremely premature infants, NIRS monitoring has a potential role in individualized brain-oriented care, and selective use of aEEG and cEEG can assist in seizure detection and prognostication. For critically ill neonates, NIRS can monitor cerebral perfusion, oxygen delivery, and extraction associated with disease processes as well as respiratory and hypodynamic management. Selective use of aEEG and cEEG is important in those with a high risk of seizures and brain injury. Continuous multimodal monitoring as well as monitoring of sleep, sleep-wake cycling, and autonomic nervous system have a promising role in neonatal neurocritical care.

Development of a Model for the Pediatric Survival After Veno-Arterial Extracorporeal Membrane Oxygenation Score: The Pedi-SAVE Score

Pediatric cardiac extracorporeal membrane oxygenation (ECMO) patients have high mortality rates. The purpose of our study was to develop and validate the Pediatric Survival After Veno-arterial ECMO (Pedi-SAVE) score for predicting survival at hospital discharge after pediatric cardiac veno-arterial (VA) ECMO. We used data for pediatric cardiac VA-ECMO patients from the Extracorporeal Life Support Organization registry (1/1/2001-12/31/2015). Development and validation cohorts were created using 2:1 random sampling. Predictors of survival to develop pre- and postcannulation models were selected using multivariable logistic regression and random forest models. ß-coefficients were standardized to create the Pedi-SAVE score. Of 10,091 pediatric cardiac VA-ECMO patients, 4,996 (50%) survived to hospital discharge. Pre- and postcannulation Pedi-SAVE scores predicted that the lowest risk patients have a 65% and 74% chance of survival at hospital discharge, respectively, compared to 33% and 22% in the highest risk patients. In the validation cohort, pre- and postcannulation Pedi-SAVE scores had c-statistics of 0.64 and 0.71, respectively. Precannulation factors associated with survival included: nonsingle ventricle congenital heart disease, older age, white race, lower STAT mortality category, higher pH, not requiring acid-buffer administration, <2 cardiac procedures, and indication for VA-ECMO other than failure to wean from cardiopulmonary bypass. Postcannulation, additional factors associated with survival included: lower ECMO pump flows at 24 hours and lack of complications. The Pedi-SAVE score is a novel validated tool to predict survival at hospital discharge for pediatric cardiac VA-ECMO patients, and is an important advancement in risk adjustment and benchmarking for this population.

The Role of Electroencephalography in the Prognostication of Clinical Outcomes in Critically Ill Children: A Review

Electroencephalography (EEG) is a neurologic monitoring modality that allows for the identification of seizures and the understanding of cerebral function. Not only can EEG data provide real-time information about a patient’s clinical status, but providers are increasingly using these results to understand short and long-term prognosis in critical illnesses. Adult studies have explored these associations for many years, and now the focus has turned to applying these concepts to the pediatric literature. The aim of this review is to characterize how EEG can be utilized clinically in pediatric intensive care settings and to highlight the current data available to understand EEG features in association with functional outcomes in children after critical illness. In the evaluation of seizures and seizure burden in children, there is abundant data to suggest that the presence of status epilepticus during illness is associated with poorer outcomes and a higher risk of mortality. There is also emerging evidence indicating that poorly organized EEG backgrounds, lack of normal sleep features and lack of electrographic reactivity to clinical exams portend worse outcomes in this population. Prognostication in pediatric critical illness must be informed by the comprehensive evaluation of a patient’s clinical status but the utilization of EEG may help contribute to this assessment in a meaningful way.

Electrographic Seizures in Neonates with a High Risk of Encephalopathy

Background: Neonatal encephalopathy is caused by a wide variety of acute brain insults in newborns and presents with a spectrum of neurologic dysfunction, such as consciousness disturbance, seizures, and coma. The increased excitability in the neonatal brain appears to be highly susceptible to seizures after a variety of insults, and seizures may be the first clinical sign of a serious neurologic disorder. Subtle seizures are common in the neonatal period, and abnormal clinical paroxysmal events may raise the suspicion of neonatal seizures. Continuous video electroencephalographic (EEG) monitoring is the gold standard for the diagnosis of neonatal seizures. The aim of this study was to identify the prevalence of electrographic seizures and the impact of monitoring in neonates with a high risk of encephalopathy. Methods: We conducted this prospective cohort study in a tertiary neonatal intensive care unit over a 4-year period. Neonates with a high risk of encephalopathy who were receiving continuous video EEG monitoring were eligible. The patients were divided into 2 groups: (1) acute neonatal encephalopathy (ANE) and (2) other high-risk encephalopathy conditions (OHRs). The neonates’ demographic characteristics, etiologies, EEG background feature, presence of electrographic seizures and the impact of monitoring were analyzed. Results: A total of 71 neonates with a high risk of encephalopathy who received continuous video EEG monitoring were enrolled. In this consecutive cohort, 42 (59.2%) were monitored for ANE and 29 (40.8%) were monitored for OHRs. At the time of starting EEG monitoring, 54 (76.1%) of the neonates were term infants. The median gestational age at monitoring was 39 weeks (interquartile range, 37−41 weeks). The median total EEG monitoring duration was 64.7 h (interquartile range, 22.2−72.4 h). Electrographic seizures were captured in 25 of the 71 (35.2%) neonates, of whom 20 (80%) had electrographic-only seizures without clinical correlation. Furthermore, of these 20 neonates, 13 (65%) developed electrographic status epilepticus. Electrographic seizures were most commonly found in the ANE group (17, 40.5%) than in the OHRs group (8, 27.6%) (p = 0.013). Besides, normal/mild abnormality and inactive EEG background were less electrographic seizure than moderate and major abnormality EEG background (2 of 30, 6.7% vs. 23 of 41, 56.1%, p < 0.001). Finally, continuous video EEG monitoring excluded the diagnosis of electrographic seizures in two-thirds of the monitored neonates who had paroxysmal events mimicking seizures and led to a change in clinical management in 39.4% of the neonates. Conclusions: Our findings showed that monitoring could accurately detect seizures, and that it could be used to guide seizure medication management. Therefore, continuous video EEG monitoring has important clinical management implications in neonates with a high risk of encephalopathy.

Characteristics of Neonates with Cardiopulmonary Disease Who Experience Seizures: A Multicenter Study

OBJECTIVE

To compare key seizure and outcome characteristics between neonates with and without cardiopulmonary disease.

STUDY DESIGN

The Neonatal Seizure Registry is a multicenter, prospectively acquired cohort of neonates with clinical or electroencephalographic (EEG)-confirmed seizures. Cardiopulmonary disease was defined as congenital heart disease, congenital diaphragmatic hernia, and exposure to extracorporeal membrane oxygenation. We assessed continuous EEG monitoring strategy, seizure characteristics, seizure management, and outcomes for neonates with and without cardiopulmonary disease.

RESULTS

We evaluated 83 neonates with cardiopulmonary disease and 271 neonates without cardiopulmonary disease. Neonates with cardiopulmonary disease were more likely to have EEG-only seizures (40% vs 21%, P < .001) and experience their first seizure later than those without cardiopulmonary disease (174 vs 21 hours of age, P < .001), but they had similar seizure exposure (many-recurrent electrographic seizures 39% vs 43%, P = .27). Phenobarbital was the primary initial antiseizure medication for both groups (90%), and both groups had similarly high rates of incomplete response to initial antiseizure medication administration (66% vs 68%, P = .75). Neonates with cardiopulmonary disease were discharged from the hospital later (hazard ratio 0.34, 95% CI 0.25-0.45, P < .001), although rates of in-hospital mortality were similar between the groups (hazard ratio 1.13, 95% CI 0.66-1.94, P = .64).

CONCLUSION

Neonates with and without cardiopulmonary disease had a similarly high seizure exposure, but neonates with cardiopulmonary disease were more likely to experience EEG-only seizures and had seizure onset later in the clinical course. Phenobarbital was the most common seizure treatment, but seizures were often refractory to initial antiseizure medication. These data support guidelines recommending continuous EEG in neonates with cardiopulmonary disease and indicate a need for optimized therapeutic strategies.

Seizures in Children with Cardiac Disease on Extracorporeal Membrane Oxygenation

BACKGROUND

Children supported with extracorporeal membrane oxygenation (ECMO) have been shown to be at risk for developing seizures. However, previous studies have consisted of heterogeneous patient populations. We aimed to describe the rate of seizures in pediatric patients receiving ECMO for cardiac indications and to identify risk factors for the occurrence of this complication.

METHODS

This is a retrospective cohort study of consecutive pediatric patients on ECMO for congenital or acquired cardiac disease between 2014 and 2018 at a tertiary care pediatric hospital.

RESULTS

We reviewed 110 children, of whom 104 (95%) received continuous electroencephalogram for at least 48 h after ECMO initiation. Seizures were observed in 20 (18%) children. Seizures were subclinical only in 13 (65%) patients, and 8 (40%) developed status epilepticus. The median time from ECMO initiation to first seizure was 34 h (25%, 75%: 19, 44). Children with seizures were more likely to have suffered pre-ECMO cardiac arrest (odds ratio 5.7, 95% confidence interval 2.0-16.1, p < 0.001), require extracorporeal cardiopulmonary resuscitation (odds ratio 5.2, 95% confidence interval 1.9-14.7, p < 0.001), and have been cannulated via the cervical vessels (p = 0.029). Children with seizures also had lower pH nadir prior to ECMO (p = 0.015) and had higher peak lactate prior to ECMO (p = 0.002). Patients with seizures had significantly a longer median intensive care unit length of stay, (43 versus 32 days, p = 0.02), had a significantly worse pediatric cerebral performance score (2 versus 1, p = 0.03), and tended to have worse survival to hospital discharge (50% versus 71%, p = 0.069).

CONCLUSIONS

Seizures in pediatric patients on ECMO for cardiac indications are common, occurring in nearly one in five patients. Seizures are frequently subclinical only and often progress to status epilepticus. Continuous electroencephalogram is therefore warranted for this patient population, especially in the setting of cardiac arrest, extracorporeal cardiopulmonary resuscitation, or severe metabolic acidosis.

EEG in the Pediatric Intensive Care Unit: An Irish Experience

INTRODUCTION

Evidence for continuous EEG monitoring in the pediatric intensive care unit (PICU) is increasing. However, 24/7 access to EEG is not routinely available in most centers, and clinical management is often informed by more limited EEG resources. The experience of EEG was reviewed in a tertiary PICU where 24/7 EEG cover is unavailable.

METHODS

Retrospective EEG and clinical review of 108 PICU patients. Correlations were carried out between EEG and clinical variables including mortality. The role of EEG in clinical decision making was documented.

RESULTS

One hundred ninety-six EEGs were carried out in 108 PICU patients over 2.5 years (434 hours of recording). After exclusion of 1 outlying patient with epileptic encephalopathy, 136 EEGs (median duration, 65 minutes; range, 20 minutes to 4 hours 40 minutes) were included. Sixty-two patients (57%) were less than 12 months old. Seizures were detected in 18 of 107 patients (17%); 74% of seizures were subclinical; 72% occurred within the first 30 minutes of recording. Adverse EEG findings were associated with high mortality. Antiepileptic drug use was high in the studied population irrespective of EEG seizure detection. Prevalence of epileptiform discharges and EEG seizures diminished with increasing levels of sedation.

CONCLUSIONS

EEG provides important diagnostic information in a large proportion of PICU patients. In the absence of 24/7 EEG availability, empirical antiepileptic drug utilization is high.

Extracorporeal Life Support Organization (ELSO): Guidelines for Pediatric Cardiac Failure

These guidelines are applicable to neonates and children with cardiac failure as indication for extracorporeal life support. These guidelines address patient selection, management during extracorporeal membrane oxygenation, and pathways for weaning support or bridging to other therapies. Equally important issues, such as personnel, training, credentialing, resources, follow-up, reporting, and quality assurance, are addressed in other Extracorporeal Life Support Organization documents or are center-specific.

Noninvasive neurocritical care monitoring for neonates on extracorporeal membrane oxygenation: where do we stand?

OBJECTIVE

To determine practice variation in the utilization of neuromonitoring modalities in neonatal extracorporeal membrane oxygenation (ECMO) patients across Level IV neonatal intensive care units (NICUs).

STUDY DESIGN

Cross-sectional survey design using electronic surveys sent to site sponsors of a multicenter collaborative of 34 Level IV NICUs of the Children's Hospitals Neonatal Consortium (CHNC) from June to August 2018.

RESULTS

We had 22 survey respondents from CHNC ECMO centers. Twenty-seven percent of respondents routinely monitored for seizures using electroencephalogram. Cerebral near infrared spectroscopy was used by 50%. Head ultrasound was performed by 95% but the frequency, duration, and type of views varied. Post ECMO screening brain MRI prior to hospital discharge was routinely performed by 77% of respondents. A majority of centers (95%) performed neurodevelopmental follow-up after hospital discharge.

CONCLUSIONS

There is variation in neuromonitoring practices in Level IV NICUs performing ECMO. Lack of evidence and clear outcome benefits has contributed to practice variation across institutions.

Seizures Are Associated With Brain Injury in Infants Undergoing Extracorporeal Membrane Oxygenation

OBJECTIVE

Determine seizure frequency and association with neurologic outcomes in infants undergoing extracorporeal membrane oxygenation. Identify patient or clinical factors associated with seizures or brain injury on imaging.

METHODS

Retrospective, single-center study including infants less than 1 year of age, who underwent extracorporeal membrane oxygenation between 2012 and 2017.

RESULTS

A total of 104 infants met study criteria including 45 patients with continuous electroencephalographic (EEG) monitoring during their extracorporeal membrane oxygenation run and 59 infants without EEG. Seizures (electrographic-only or electro-clinical) were identified in 18 of the 45 (40%). Among the 18 infants with seizures, 14 (78%) had moderate to severe brain injury, whereas only 44% of those without seizures (12 of 27) on EEG had moderate to severe brain injury (P = .03). Cardiopulmonary resuscitation prior to extracorporeal membrane oxygenation (ECPR), mode of extracorporeal membrane oxygenation, length of stay, survival to discharge, and congenital heart disease were not associated with seizures. One of 10 patients with cyanotic congenital heart disease due to hypoplastic left heart syndrome had seizures compared with 7 of 10 patients with non-hypoplastic left heart syndrome lesions (P = .02). Seizures were associated with moderate to severe brain injury, after adjusting for ECPR and congenital heart disease (P = .04).

CONCLUSIONS

Electrographic seizures were common in patients undergoing extracorporeal membrane oxygenation and higher than previously reported. Seizures were associated with moderate to severe abnormalities on imaging, after adjusting for ECPR and congenital heart disease. This study adds to recent literature describing the risk of seizures in patients on extracorporeal membrane oxygenation and highlights the presence of brain injuries that may be identified by routine EEG surveillance.

EEG Monitoring After Convulsive Status Epilepticus

After convulsive status epilepticus, patients of all ages may have ongoing EEG seizures identified by continuous EEG monitoring. Furthermore, high EEG seizure exposure has been associated with unfavorable neurobehavioral outcomes. Thus, recent guidelines and consensus statements recommend many patients with persisting altered mental status after convulsive status epilepticus undergo continuous EEG monitoring. This review summarizes the available epidemiologic data and related recommendations provided by recent guidelines and consensus statements.

Prevalence of Seizures and Risk Factors for Mortality in a Continuous Cohort of Pediatric Extracorporeal Membrane Oxygenation Patients

OBJECTIVES

To evaluate the risk factors for mortality in pediatric extracorporeal membrane oxygenation patients.

DESIGN

Retrospective, single-center study.

SETTING

PICU and Pediatric cardiothoracic ICU in an urban, quaternary care center.

PATIENTS

All neonatal and pediatric patients requiring extracorporeal membrane oxygenation at our institution between January 2014 and December 2018, who underwent a standardized continuous electroencephalogram neuromonitoring protocol during most of the duration of extracorporeal membrane oxygenation support. We excluded patients who had extracorporeal membrane oxygenation initiated at another institution.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Sixty-six children required extracorporeal membrane oxygenation support during this period. Four patients were excluded, three due to lack of electroencephalogram data, one with extracorporeal membrane oxygenation initiated at other institution. In the remaining 62, 11 patients (17%) had seizures, of which 5 (45%) had status epilepticus. Eight of 11 patients (72%) had exclusively electrographic seizures. A total of 33 patients (53.2%) died, of which 22 died during extracorporeal membrane oxygenation course, and one died 3 years after hospital discharge. Mean survival from extracorporeal membrane oxygenation initiation was 766.9 days (standard deviation, 691.7; median, 546.5; interquartile range 1-3, 97.7-1255.0). In multivariate analysis, increased risk of mortality was associated with the use of extracorporeal cardiopulmonary resuscitation (hazard ratio, 4.33; 95% CI, 1.75-10.72; p = 0.002), imaging findings of cerebral edema (hazard ratio, 14.31; 95% CI, 5.18-39.54; p < 0.001), high lactate level (> 100 mg/dL within 2 hr preextracorporeal membrane oxygenation) (hazard ratio, 1.22; 95% CI, 1.03-1.44; p = 0.022), and prolonged deep hypothermic circulatory arrest (hazard ratio, 3.43; 95% CI, 1.65-7.13; p < 0.001). Presence of seizures was associated with imaging findings of cerebral edema (hazard ratio, 4.16; 95% CI, 1.04-16.58; p = 0.04).

CONCLUSIONS

Seizures are common in children requiring extracorporeal membrane oxygenation support, with a high rate of electrographic seizures and status epilepticus, as in prior studies. Presence of cerebral edema is both risk factor for mortality and seizures. Other risk factors for mortality include extracorporeal cardiopulmonary resuscitation, high lactate levels, and prolonged deep hypothermic circulatory arrest.

EEG is A Predictor of Neuroimaging Abnormalities in Pediatric Extracorporeal Membrane Oxygenation

The goal of this project was to evaluate if severity of electroencephalogram (EEG) during or shortly after being placed on extracorporeal membrane oxygenation (ECMO) would correlate with neuroimaging abnormalities, and if that could be used as an early indicator of neurologic injury. This was a retrospective chart review spanning November 2009 to May 2018. Patients who had an EEG recording during ECMO or within 48 hours after being decannulated (early group) or within 3 months of being on ECMO (late group) were included if they also had ECMO-related neuroimaging. In the early EEG group, severity of the EEG findings of mild, moderate, and severe EEG correlated to mild, moderate, and severe neuroimaging scores. Patients on venoarterial (VA) ECMO were noted to have higher EEG and neuroimaging severity; this was statistically significant. There was no association in the late EEG group to neuroimaging abnormalities. Our study highlights that EEG severity can be an early predictor for neuroimaging abnormalities that can be identified by computed tomography (CT) and or magnetic resonance imaging (MRI). This can provide guidance for both the medical team and families, allowing for a better understanding of overall prognosis.

Development and Validation of a Seizure Prediction Model in Neonates After Cardiac Surgery

BACKGROUND

Electroencephalographic seizures (ESs) after neonatal cardiac surgery are often subclinical and have been associated with poor outcomes. An accurate ES prediction model could allow targeted continuous electroencephalographic monitoring (CEEG) for high-risk neonates.

METHODS

ES prediction models were developed and validated in a multicenter prospective cohort where all postoperative neonates who underwent cardiopulmonary bypass (CPB) also underwent CEEG.

RESULTS

ESs occurred in 7.4% of neonates (78 of 1053). Model predictors included gestational age, head circumference, single-ventricle defect, deep hypothermic circulatory arrest duration, cardiac arrest, nitric oxide, extracorporeal membrane oxygenation, and delayed sternal closure. The model performed well in the derivation cohort (c-statistic, 0.77; Hosmer-Lemeshow, P = .56), with a net benefit (NB) over monitoring all and none over a threshold probability of 2% in decision curve analysis (DCA). The model had good calibration in the validation cohort (Hosmer-Lemeshow, P = .60); however, discrimination was poor (c-statistic, 0.61), and in DCA there was no NB of the prediction model between the threshold probabilities of 8% and 18%. By using a cut point that emphasized negative predictive value in the derivation cohort, 32% (236 of 737) of neonates would not undergo CEEG, including 3.5% (2 of 58) of neonates with ESs (negative predictive value, 99%; sensitivity, 97%).

CONCLUSIONS

In this large prospective cohort, a prediction model of ESs in neonates after CPB had good performance in the derivation cohort, with an NB in DCA. However, performance in the validation cohort was weak, with poor discrimination, poor calibration, and no NB in DCA. These findings support CEEG of all neonates after CPB.

EEG features of brain injury during extracorporeal membrane oxygenation in children

OBJECTIVE

To examine EEG features of major pathophysiology in children undergoing extracorporeal membrane oxygenation (ECMO).

METHODS

This was a single-center, retrospective study of 201 pediatric patients on ECMO, using the first 24 hours of continuous EEG (cEEG) monitoring, collating background activity and electrographic seizures (ES) with imaging, ECMO type, and outcome.

RESULTS

Severely abnormal cEEG background occurred in 12% (25/201), and was associated with death (sensitivity 0.23, specificity 0.97). ES occurred in 16% (33/201) within 3.2 (0.6-20.3) hours (median [interquartile range]) of cEEG commencement, and higher ES burden was associated with death. ES was always associated with ipsilateral injury (p = 0.006), but occurred in only one-third of cases with abnormal imaging. In 28 patients with isolated hemisphere lesion, type of arterial ECMO cannulation was associated with side of injury: right carotid cannulation was associated with right hemisphere lesions, and ascending aorta cannulation with left hemisphere lesions (odds ratio, 0.29 [95% confidence interval, 0.08-0.98], p = 0.03).

CONCLUSIONS

After starting ECMO, cEEG background activity has the potential to inform prognosis. Type of arterial (carotid vs aortic) ECMO correlates with side of focal cerebral injury, which in ≈33% is associated with presence of ES. We hypothesize that the differential distribution reflects abnormal flow dynamics or embolic injury.

Neurological Monitoring and Complications of Pediatric Extracorporeal Membrane Oxygenation Support

Extracorporeal membrane oxygenation is extracorporeal life support for life-threatening cardiopulmonary failure. Since its introduction, the use of extracorporeal membrane oxygenation has expanded to patients with more complex comorbidities without change in patient mortality rates. Although many patients survive, significant neurological complications like seizures, ischemic strokes, and intracranial hemorrhage can occur during extracorporeal membrane oxygenation care. The risks of these complications often add to the complexity of decision-making surrounding extracorporeal membrane oxygenation support. In this review, we discuss the pathophysiology and incidence of neurological complications in children supported on extracorporeal membrane oxygenation, factors influencing the incidence of these complications, commonly used neurological monitoring modalities, and outcomes for this complex patient population. We discuss the current literature on the use of electroencephalography for both seizure detection and monitoring of background electroencephalographic changes, in addition to the use of less commonly used imaging modalities like transcranial Doppler. We summarize the knowledge gaps and the lack of clinical consensus guidelines for managing these potentially life-changing neurological complications. Finally, we discuss future work to further understand the pathophysiology of extracorporeal membrane oxygenation-related neurological complications.

Continuous Electroencephalography Monitoring in Critically Ill Infants and Children

Continuous video electroencephalography (CEEG) monitoring of critically ill infants and children has expanded rapidly in recent years. Indications for CEEG include evaluation of patients with altered mental status, characterization of paroxysmal events, and detection of electrographic seizures, including monitoring of patients with limited neurological examination or conditions that put them at high risk for electrographic seizures (e.g., cardiac arrest or extracorporeal membrane oxygenation cannulation). Depending on the inclusion criteria and clinical characteristics of the population studied, the percentage of pediatric patients with electrographic seizures varies from 7% to 46% and with electrographic status epilepticus from 1% to 23%. There is also evidence that epileptiform and background CEEG patterns may provide important information about prognosis in certain clinical populations. Quantitative EEG techniques are emerging as a tool to enhance the value of CEEG to provide real-time bedside data for management and prognosis. Continued research is needed to understand the clinical value of seizure detection and identification of other CEEG patterns on the outcomes of critically ill infants and children.

Electrographic Seizures and Brain Injury in Children Requiring Extracorporeal Membrane Oxygenation

BACKGROUND

Single-center studies suggest that up to 30% of children undergoing extracorporeal membrane oxygenation have electrographic seizures. The aim of this study was to characterize seizure prevalence, seizure risk factors, and brain injury prevalence in the pediatric extracorporeal membrane oxygenation population at a tertiary care children's hospital.

METHODS

We performed a retrospective systematic review of medical records for 86 consecutive children (neonates to age 21 years) who received Neurology consults and continuous video electroencephalography while undergoing extracorporeal membrane oxygenation from November 2015 to September 2018.

RESULTS

Continuous video electroencephalography was initiated in 86 of 170 children who required extracorporeal membrane oxygenation (51%); median duration of continuous vodeo electroencephalography was four days. Nineteen of 86 had electroencephalography-confirmed seizures (22%). Sixteen of 19 had seizures within the first 48 hours on continuous video electroencephalography. Interictal epileptiform discharges were a significant risk factor for seizures; 89% of those with seizures versus 46% of those without had interictal epileptiform discharges (P < 0.001, Fisher's exact test). Children with seizures also had higher pericannulation lactate (median 6.7, interquartile range of 4.3 to 19.0 for those with, and median 4.0, interquartile range of 2.0 to 7.3 for those without; P = 0.02, Mann-Whitney U test). Seizures were associated with hemorrhage on neuroimaging (68% of children with seizures had intracranial hemorrhage versus 34% of those without, P = 0.01, chi-square test).

CONCLUSION

Approximately half the children undergoing extracorporeal membrane oxygenation received continuous video electroencephalography during the study period, and 22% had seizures. Interictal epileptiform discharges and elevated pre-extracorporeal membrane oxygenation lactate levels were risk factors for seizures; seizures were associated with intracranial hemorrhage.

A retrospective comparison of phenobarbital and levetiracetam for the treatment of seizures following cardiac surgery in neonates

OBJECTIVE

To compare the safety and efficacy of phenobarbital and levetiracetam in a cohort of neonates with seizures following cardiac surgery.

METHODS

We performed a retrospective single-center study of consecutive neonates with electrographically confirmed seizures managed with antiseizure medication after cardiac surgery from June 15, 2012 to December 31, 2018. We compared the safety and efficacy of phenobarbital and levetiracetam as first-line therapy.

RESULTS

First-line therapy was phenobarbital in 31 neonates and levetiracetam in 22 neonates. Phenobarbital was associated with more adverse events (P = .006). Eight neonates (14%) experienced an adverse event related to phenobarbital use, including seven with hypotension and one with respiratory depression. No adverse events were reported with levetiracetam use. The cessation of electrographic seizures was similar in both groups, including 18 neonates (58%) with seizure cessation after phenobarbital and 12 neonates (55%) with seizure cessation after levetiracetam (P = 1.0). The combined cessation rates of phenobarbital and levetiracetam when used as first- or second-line therapy were 58% and 47%, respectively (P = .47).

SIGNIFICANCE

Phenobarbital was associated with more adverse events than levetiracetam, and the two drugs were equally but incompletely effective in treating electrographically confirmed seizures in neonates following cardiac surgery. Given its more acceptable safety profile and potential noninferiority, levetiracetam may be a reasonable option for first-line therapy for treatment of seizures in this population. Further prospective studies are needed to confirm these results.

Association of Cerebral Oximetry with Outcomes after Extracorporeal Membrane Oxygenation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is associated with neurologic morbidity and mortality. We investigated whether cerebral regional oxygen saturation (rSO₂) is associated with neurologic outcomes and survival in children on ECMO.

METHODS

This was a retrospective observational study of children aged 1 day to 20 years who underwent ECMO with routine cerebral rSO₂ monitoring in the pediatric intensive care unit at a single academic center between February 2008 and September 2014. We collected all serial rSO₂ values recorded in the electronic medical record during the ECMO course. Favorable outcome was defined as survival with Pediatric Cerebral Performance Category (PCPC) ≤ 2 at hospital discharge or no decline from baseline PCPC.

RESULTS

We reviewed data from 153 patients who underwent 156 ECMO runs. The median age was 12.5 days (interquartile range [IQR], 2 days-15 months). Ninety-nine (64%) patients survived to hospital discharge, and 82/99 (83%) survivors had favorable neurologic outcome by discharge PCPC. Neuroimaging studies were obtained in 135 (87%) patients, 59 (44%) of which showed abnormal findings. Ninety-two (59%) patients had any rSO₂ ≤ 50%, 60 (38%) had any rSO₂ decline > 20% from baseline, and 26 (17%) had any rSO₂ decline > 20% from the reading 1 h prior. Any rSO₂ ≤ 50% and any rSO₂ decline > 20% from baseline were each associated with unfavorable outcome at hospital discharge (multivariable-adjusted odds ratio [OR], 2.82 [95% CI 1.10-7.25] and 4.52 [95% CI 1.76-11.58], respectively). rSO₂ decline > 20% from the reading 1 h prior was not significantly associated with the outcomes.

CONCLUSION

Among children in one institution who underwent routine clinical rSO₂ monitoring during ECMO, rSO₂ decline was associated with unfavorable short-term neurologic outcome and death after adjusting for potential confounders. The effectiveness of initiating early preventative measures in these high-risk patients needs further study.

Electroencephalographic Reporting for Refractory Status Epilepticus

PURPOSE

We aimed to determine whether clinical EEG reports obtained from children in the intensive care unit with refractory status epilepticus could provide data for comparative effectiveness research studies.

METHODS

We conducted a retrospective descriptive study to assess the documentation of key variables within clinical continuous EEG monitoring reports based on the American Clinical Neurophysiology Society's standardized EEG terminology for children with refractory status epilepticus from 10 academic centers. Two pediatric electroencephalographers reviewed the EEG reports. We compared reports generated using free text or templates.

RESULTS

We reviewed 191 EEG reports. Agreement between the electroencephalographers regarding whether a variable was described in the report ranged from fair to very good. The presence of electrographic seizures (ES) was documented in 46% (87/191) of reports, and these reports documented the time of first ES in 64% (56/87), ES duration in 72% (63/85), and ES frequency in 68% (59/87). Reactivity was documented in 16% (31/191) of reports, and it was more often documented in template than in free-text reports (40% vs. 14%, P = 0.006). Other variables were not differentially reported in template versus free-text reports.

CONCLUSIONS

Many key EEG features are not documented consistently in clinical continuous EEG monitoring reports, including ES characteristics and reactivity assessment. Standardization may be needed for clinical EEG reports to provide informative data for large multicenter observational studies.

Artifact Mimicking Ictal Epileptiform Activity in EEG

Although the EEG is designed to record cerebral activity, it also frequently records activity from extracerebral sources, leading to artifact. Differentiating rhythmical artifact from true electrographic ictal activity remains a substantial challenge to even experienced electroencephalographers because the sources of artifact able to mimic ictal activity on EEG have continued to increase with the advent of technology. Knowledge of the characteristics of the polarity and physiologic electrical fields of the brain, as opposed to those generated by the eyes, heart, and muscles, allows the electroencephalographer to intuitively recognize noncerebrally generated waveforms. In this review, we provide practical guidelines for the EEG interpreter to correctly identify physiologic and nonphysiologic artifacts capable of mimicking electrographic seizures. In addition, we further elucidate the common pitfalls in artifact interpretation and the costly impact of epilepsy misdiagnosis due to artifact.

Standards for Studies of Neurological Prognostication in Comatose Survivors of Cardiac Arrest: A Scientific Statement From the American Heart Association

Significant improvements have been achieved in cardiac arrest resuscitation and postarrest resuscitation care, but mortality remains high. Most of the poor outcomes and deaths of cardiac arrest survivors have been attributed to widespread brain injury. This brain injury, commonly manifested as a comatose state, is a marker of poor outcome and a major basis for unfavorable neurological prognostication. Accurate prognostication is important to avoid pursuing futile treatments when poor outcome is inevitable but also to avoid an inappropriate withdrawal of life-sustaining treatment in patients who may otherwise have a chance of achieving meaningful neurological recovery. Inaccurate neurological prognostication leading to withdrawal of life-sustaining treatment and deaths may significantly bias clinical studies, leading to failure in detecting the true study outcomes. The American Heart Association Emergency Cardiovascular Care Science Subcommittee organized a writing group composed of adult and pediatric experts from neurology, cardiology, emergency medicine, intensive care medicine, and nursing to review existing neurological prognostication studies, the practice of neurological prognostication, and withdrawal of life-sustaining treatment. The writing group determined that the overall quality of existing neurological prognostication studies is low. As a consequence, the degree of confidence in the predictors and the subsequent outcomes is also low. Therefore, the writing group suggests that neurological prognostication parameters need to be approached as index tests based on relevant neurological functions that are directly related to the functional outcome and contribute to the quality of life of cardiac arrest survivors. Suggestions to improve the quality of adult and pediatric neurological prognostication studies are provided.

Prevalence of Seizures in Pediatric Extracorporeal Membrane Oxygenation Patients as Measured by Continuous Electroencephalography

OBJECTIVES

Standards for neuromonitoring during extracorporeal membrane oxygenation support do not currently exist, and there is wide variability in practice. We present our institutional experience at an academic children's hospital since establishment of a continuous electroencephalography monitoring protocol for extracorporeal membrane oxygenation patients.

DESIGN

Retrospective, single-center study.

SETTING

Neonatal ICU and PICU in an urban, quaternary care center.

PATIENTS

All neonatal and pediatric patients requiring extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

During the study period, 70 patients were cannulated for extracorporeal membrane oxygenation and had continuous electroencephalography monitoring for greater than 24 hours. Electroencephalographic seizures were observed in 16 of 70 patients (23%), including five patients (7%) who were in status epilepticus. Among patients with continuous electroencephalography seizures, nine (56%) had subclinical nonconvulsive status epilepticus and eight (50%) had seizures in the initial 24 hours of extracorporeal membrane oxygenation support. Survival to hospital discharge was significantly greater for extracorporeal membrane oxygenation patients without seizures (74% vs 44%; p = 0.02).

CONCLUSIONS

Seizures occur in a significant proportion of pediatric and neonatal extracorporeal membrane oxygenation patients, frequently in the initial 24 hours after extracorporeal membrane oxygenation cannulation. Because seizures are associated with significantly decreased survival, neuromonitoring early in the extracorporeal membrane oxygenation course is important and useful. Further studies are needed to correlate electroencephalography findings with neurologic outcome.

Neuromonitoring in the neonatal ECMO patient

Utilization of extraocorporeal membrane oxygenation (ECMO) has become increasingly widespread as a bridging therapy for neonates with severe, reversible respiratory or cardiac diseases. While significant risks remain, due to advances in medical and surgical management, overall mortality has decreased. However, short and long-term neurological morbidity has remained high. Therefore, increasing attention has been focused on multimodal neuromonitoring to track and optimally, minimize or prevent intracranial injury. This review will explore the the indications, advantages, disadvantages, timing, frequency, duration, and any known correlation with neurodevelopmental outcomes of common types of neuromonitoring in the neonatal ECMO population. Investigational monitoring techniques such as NIRS will be briefly reviewed.

Improving Long-Term Outcomes After Extracorporeal Membrane Oxygenation: From Observational Follow-Up Programs Toward Risk Stratification

Since the introduction of extracorporeal membrane oxygenation (ECMO), more neonates and children with cardiorespiratory failure survive. Interest has therefore shifted from reduction of mortality toward evaluation of long-term outcomes and prevention of morbidity. This review addresses the changes in ECMO population and the ECMO-treatment that may affect long-term outcomes, the diagnostic modalities to evaluate neurological morbidities and their contributions to prognostication of long-term outcomes. Most follow-up data have only become available from observational follow-up programs in neonatal ECMO-survivors. The main topics are discussed in this review. Recommendations for long-term follow up depend on the presence of neurological comorbidity, the nature and extent of the underlying disease, and the indication for ECMO. Follow up should preferably be offered as standard of care, and in an interdisciplinary, structured and standardized way. This permits evaluation of outcome data and effect of interventions. We propose a standardized approach and recommend that multiple domains should be evaluated during long-term follow up of neonates and children who needed extracorporeal life support.

Patterns of Head Computed Tomography Abnormalities During Pediatric Extracorporeal Membrane Oxygenation and Association With Outcomes

BACKGROUND

We sought to classify type and distribution of acute infarction and hemorrhage on head computed tomography (CT) during pediatric extracorporeal membrane oxygenation (ECMO). We also analyzed the occurrence of seizures on electroencephalography and outcomes between those with and without CT abnormalities.

METHODS

We conducted a single center observational study in pediatric intensive care units. The medical records of 179 children who underwent ECMO between 2009 and 2013 were reviewed. No interventions were done.

RESULTS

A total of 46% (82/179) of children underwent CT. Of these, 60% (49/82) had acute pathology. Cerebral infarction occurred in 55% (27/49) and hemorrhage in 41% (20/49). Infarction was arterial in 67% (18/27) with a preponderance in the middle cerebral artery territory (17 patients). Infarction was bilateral in 41% (11/27) and not specific to the side of cannulation in the rest. Sensitivity and specificity for head ultrasound in predicting infarction on CT were 100% and 53%, respectively. A total of 36% (65/179) underwent continuous encephalography monitoring; 22% (14/65) of these had electrographic seizures. Electrographic seizures were increased in those with infarction (odds ratio [OR], 6.81; 95% confidence interval [CI], 1.98 to 23.43). Survival was reduced with both infarction (OR, 0.22; 95% CI, 0.09 to 0.54) and hemorrhage (OR, 0.31; 95% CI, 0.13 to 0.72). Children with CT abnormalities had more unfavorable outcomes (P = 0.01).

CONCLUSIONS

Head ultrasound is insufficient to rule out infarction. Infarction is middle cerebral artery predominant and associated with an increased risk of electrographic seizures.