Digital Trend Analysis in the Pediatric and Neonatal Intensive Care Units

Multimodal neuromonitoring in the pediatric intensive care unit

Neuromonitoring is used to assess the central nervous system in the intensive care unit. The purpose of neuromonitoring is to detect neurologic deterioration and intervene to prevent irreversible nervous system dysfunction. Neuromonitoring starts with the standard neurologic examination, which may lag behind the pathophysiologic changes. Additional modalities including continuous electroencephalography (CEEG), multiple physiologic parameters, and structural neuroimaging may detect changes earlier. Multimodal neuromonitoring now refers to an integrated combination and display of non-invasive and invasive modalities, permitting tailored treatment for the individual patient. This chapter reviews the non-invasive and invasive modalities used in pediatric neurocritical care.

Utilization of quantitative electroencephalogram in China: an online questionnaire survey

Background

Quantitative electroencephalogram (QEEG) is a tool that uses a computer to analyze brain activity monitored by electroencephalogram (EEG) according to measurements such as frequency, amplitude, and slope. The purpose of this study was to understand the current situation of QEEG utilization in China and further compare the situations among different regions and different levels of hospitals.

Methods

An online questionnaire comprising 14 questions was designed. Statistical description and analysis were made for the results of the questionnaire survey.

Results

A total of 158 people from 134 medical institutions participated in the survey. The participants came from 21 provinces, accounting for 61.76% (21/34) of the 34 provincial administrative regions in China. The Eastern China region accounted for 66.42% (89/134) of all the medical institutions that participated in this survey. Among the institutions surveyed, QEEG was routinely used in only 23.88% (32/134) of them. Among the medical institutions in which QEEG was routinely used, 87.50% (28/32) of them were 3A-grade hospitals. Among the institutions with routine use of QEEG, 56.25% (18/32) were affiliated hospitals of medical schools. There was a significant difference in the utilization of QEEG between the 3A-grade and non-3A-grade hospitals (P = 0.040) and between the hospitals affiliated to medical schools and those non-affiliated to medical schools (P = 0.020).

Conclusions

The utilization of QEEG is still limited in China. There are differences in the use of QEEG among different hospitals and regions.

Spectrograms for Seizure Detection in Critically Ill Children

SUMMARY

Electrographic seizures are common in critically ill children and a significant proportion of these seizures are nonconvulsive. There is an association between electrographic seizures and neurophysiological disturbances, worse short- and long-term neurologic outcomes, and mortality in critically ill patients. In this context, timely diagnosis and treatment of electrographic seizures in critically ill children becomes important. However, most institutions lack the resources to support round-the-clock or frequent review of continuous EEG recordings causing significant delays in seizure diagnosis. Given the current gaps in review of continuous EEG across institutions globally, use of visually simplified, time-compressed quantitative EEG trends such as spectrograms has the potential to enhance timeliness of seizure diagnosis and treatment in critically ill children.

Neurocritical Care and Brain Monitoring

The goal of neurocritical care (NCC) is to improve the outcome of patients with neurologic insults. NCC includes the management of the primary brain injury and prevention of secondary brain injury; this is achieved with standardized clinical care for specific disorders along with neuromonitoring. Neuromonitoring uses multiple modalities, with certain modalities better suited to certain disorders. The term "multimodality monitoring" refers to using multiple modalities at the same time. This article reviews pediatric NCC, the various physiologic parameters used, especially continuous electroencephalographic monitoring.

Monitoring of newborns at high risk for brain injury

Due to the increasing number of surviving preterm newborns and to the recognition of therapeutic hypothermia as the current gold standard in newborns with hypoxic-ischaemic encephalopathy, there has been a growing interest in the implementation of brain monitoring tools in newborns at high risk for neurological disorders.Among the most frequent neurological conditions and presentations in the neonatal period, neonatal seizures and neonatal status epilepticus, paroxysmal non-epileptic motor phenomena, hypoxic-ischaemic encephalopathy, white matter injury of prematurity and stroke require specific approaches to diagnosis. In this review we will describe the characteristics, aims, indications and limitations of routinely available diagnostic techniques such as conventional and amplitude-integrated EEG, evoked potentials, cranial ultrasound and brain MRI. We will conclude by briefly outlining potential future perspectives from research studies.

Continuous EEG monitoring in children in the intensive care unit (ICU)

Pediatric EEG in the intensive care unit (ICU) requires specific technical requirements in order to yield relevant data depending upon clinical scenario: diagnosis of electroclinical or subclinical seizures, their quantification before and after therapeutic changes and sometimes evaluation of severity of cortical dysfunction. The urgent nature of these indications implies the rapid set-up of the EEG system by qualified staff and possibility of maintaining the electrodes in place during long periods of time. Various techniques are available today for EEG monitoring, the interpretation of which depends on the contribution of an experienced physician. Among recent techniques, those most commonly used are trend curves obtained via signal analysis such as amplitude EEG (a-EEG) and density spectral array (DSA) or compressed spectral array (CSA). Trend curves enable the digital creation of a display graph containing several hours of transformed and compressed EEG recorded data. Visualized on one sole display graph, these trend curves can facilitate the identification of very slow changes in EEG background activity and their variation (alertness cycles, changes linked to treatment administrations) as well as seizure patterns and their quantification. In this chapter, we propose a brief overview of monitoring techniques, followed by a review of the various data yielded by EEG monitoring as well as the relevance of this type of management; finally, detailed clinical indications will be discussed after thorough analysis of the literature.

Application of envelope trend to analyze early EEG changes in the frontal regions during intracarotid amobarbital procedure in children

BACKGROUND

Intracarotid amobarbital procedure (IAP) is acknowledged as the gold standard test for language lateralization. EEG is performed routinely during IAP to monitor the anesthetization of a brain hemisphere. Here, we studied the correlation between the early EEG changes using envelope trend and the clinical outcome of IAP.

METHOD

Fifty consecutive patients underwent IAP at Texas Children's Hospital (2004-2009). Intracarotid amobarbital procedure was considered "complete" or "incomplete" based on the outcome if the procedure was completed or aborted due to behavior changes. Envelope trend was used to calculate the median EEG amplitude changes within the first 60s of IAP. Statistical analysis was performed to determine the role of EEG changes and clinical features on the procedure outcome.

RESULTS

Only 30 IAP-EEG files were available for review. Amobarbital was administered at the dose of 60-150mg (mean: 110±20). The intracarotid amobarbital procedure was recorded as complete in 23 patients and incomplete in 7 patients. EEG changes occurred within the first few seconds following amobarbital injection. Following amobarbital injection, focal slowing was present in the ipsilateral frontal region or both ipsilateral and contralateral frontal regions. Elapsed time to the first EEG change or duration and change in median EEG amplitude in the ipsilateral frontal regions were indifferent between the complete and incomplete groups (p>0.05). However, the median amplitude changes between the ipsilateral and contralateral frontal regions within each group were found significant only in the complete group (p<0.05), suggesting ipsilateral without contralateral frontal slowing. Other than age at the time of IAP (p=0.03), none of the other clinical features correlated with the clinical outcome of IAP (p>0.05).

CONCLUSION

Early EEG changes during IAP using envelope trend may predict successful completion of the IAP test. Younger children are at risk of behavioral changes during IAP.

Multimodal monitoring in the pediatric intensive care unit: new modalities and informatics challenges

We review several newer modalities to monitor the brain in children with acute neurologic disease in the pediatric intensive care unit, such as partial brain tissue oxygen tension (PbtO2), jugular venous oxygen saturation (SjvO2), near infrared spectroscopy (NIRS), thermal diffusion measurement of cerebral blood flow, cerebral microdialysis, and EEG. We then discuss the informatics challenges to acquire, consolidate, analyze, and display the data. Acquisition includes multiple data types: discrete, waveform, and continuous. Consolidation requires device interoperability and time synchronization. Analysis could include pressure reactivity index and quantitative EEG. Displays should communicate the patient's current status, longitudinal and trend information, and critical alarms.

[French guidelines on electroencephalogram]

Electroencephalography allows the functional analysis of electrical brain cortical activity and is the gold standard for analyzing electrophysiological processes involved in epilepsy but also in several other dysfunctions of the central nervous system. Morphological imaging yields complementary data, yet it cannot replace the essential functional analysis tool that is EEG. Furthermore, EEG has the great advantage of being non-invasive, easy to perform and allows control tests when follow-up is necessary, even at the patient's bedside. Faced with the advances in knowledge, techniques and indications, the Société de Neurophysiologie Clinique de Langue Française (SNCLF) and the Ligue Française Contre l'Épilepsie (LFCE) found it necessary to provide an update on EEG recommendations. This article will review the methodology applied to this work, refine the various topics detailed in the following chapters. It will go over the summary of recommendations for each of these chapters and underline proposals for writing an EEG report. Some questions could not be answered by the review of the literature; in those cases, an expert advice was given by the working and reading groups in addition to the guidelines.

Electroencephalographic monitoring in the pediatric intensive care unit

Continuous electroencephalographic (CEEG) monitoring is used with increasing frequency in critically ill children to provide insight into brain function and to identify electrographic seizures. CEEG monitoring use often impacts clinical management, most often by identifying electrographic seizures and status epilepticus. Most electrographic seizures have no clinical correlate, and thus would not be identified without CEEG monitoring. There are increasing data showing that electrographic seizures and electrographic status epilepticus are associated with worse outcome. Seizure identification efficiency may be improved by further development of quantitative electroencephalography trends. This review describes the clinical impact of CEEG data, the epidemiology of electrographic seizures and status epilepticus, the impact of electrographic seizures on outcome, the utility of quantitative electroencephalographic trends for seizure identification, and practical considerations regarding CEEG monitoring.