Amplitude-Integrated EEG in Infants at Risk of Hypoxic-Ischemic Encephalopathy: A Feasibility Study in Road and Air Transport in Western Australia
Summary
Here, we present a feasibility study to assess a portable amplitude-integrated electroencephalogram (aEEG) recording system during the transport of infants with suspected hypoxic ischemic encephalopathy (HIE).
Abstract
Infants at risk of HIE require early identification and initiation of therapeutic hypothermia (TH). Earlier treatment with TH is associated with better outcomes. aEEG is frequently used when making the decision whether to commence TH. As this is often limited to tertiary centers, TH may be delayed if the infant requires transport to a center that provides it. We aimed to provide a method for the application of amplitude-integrated electroencephalogram (aEEG) and to determine the feasibility of acquiring clinically meaningful information during transport. All infants ≥35 weeks, at risk of HIE at referral, were eligible for inclusion. Scalp electrodes were placed in the C3-C4; P3-P4 position on the infant's scalp and connected to the aEEG amplifier. The aEEG amplifier was, in turn, connected to a clinical tablet computer with EEG software to collect and analyze aEEG information. Recordings were reviewed by the chief principal investigator and two independent reviewers (blinded) for background trace and artifact. Predefined criteria for data quality were set to movement artifacts and software impedance notifications. Surveys were completed by healthcare staff and parents for acceptability and ease of use.
Introduction
Impaired oxygen delivery or blood flow to the brain around the time of birth can cause brain injury (hypoxic ischemic encephalopathy; HIE). This is a leading cause of death and disability in full-term babies1. HIE is reported to have a worldwide incidence of 2 per 1000 deliveries, which is likely to be higher in low to middle-income countries. In Western Australia, approximately 50 babies are born each year who have a clinical diagnosis of HIE (32308 live births in 2022, an incidence of approximately 1.5 per 10002).
HIE is diagnosed with criteria based on the circumstances of birth, changes in the infant's blood acid balance (from umbilical cord or baby after birth), and changes in neurological status3. The treatment for moderate or severe HIE is whole-body hypothermia of 33-34 °C. The earlier this is commenced, the likely greater the benefit to the baby's neurological outcome3,4,5. Amplitude-integrated EEG (aEEG) is an essential part of assessment and monitoring, which in many regions is only available in tertiary centers. Electrodes (EEG safety DIN connector or DIN 42802 with 1.5 mm diameter pin) are inserted into the scalp to measure and record brain electrical activity. Electrodes are then connected to an amplifier, which is in turn connected to a clinical tablet computer to display and record brainwave activity. aEEG can provide information on brain wave activity and be used to assist with the diagnosis of HIE6. The combination of neurological examination and aEEG may enhance the ability to identify infants with moderate or severe HIE7,8,9.
The Newborn Emergency Transport Service of Western Australia (NETS WA) provides intensive care transport to approximately 1100 sick babies per year. Healthcare staff in local hospitals can contact NETS WA through a free phone number and are immediately connected via a conference call with a neonatal specialist doctor and nurse to request a transfer. The NETS team travels either by specialized road ambulance or fixed-wing aircraft with a purpose-built intensive care transport equipment cot. On arrival of the transport team to the referring hospital, the baby is assessed, and treatment is continued or escalated. The team then transfers the infant to a tertiary neonatal intensive care unit (NICU) in the state capital (Perth). In Western Australia, owing to the often-large distances between referring hospitals and centralized specialist services10 (a maximum distance of 1381 miles), aEEG may not applied for up to many hours after birth, leading to a delay in treatment.
Many monitoring systems have been designed for the intensive care unit but owing to their size and power requirement, they are impractical for the transport environment. Ward-based equipment is prone to movement artifacts, which may record insufficient quality data in the transport environment. Ambulatory EEG amplifier technology, designed primarily to be worn by patients at home, can connect to a computer tablet with EEG detection software and be applied to a newborn during transport11. This can be carried by the neonatal transport team to a baby with suspected HIE. The software is capable of being viewed remotely via a portable internet uplink and web-based viewer. Currently, there are no reports on the suitability or readability of aEEG in the transport environment.
Applying and monitoring aEEG in the transport of infants with HIE has not been previously reported, and there are no existing protocols for its use. There is no evidence to support feasibility or utility in the transport environment. We present a protocol for aEEG use in neonatal transport. It aims to assess whether aEEG in babies with HIE who require transport after birth is feasible and can provide readable clinical information.
Protocol
Representative Results
Discussion
This novel study describes the application and early data acquisition of aEEG in infants with suspected HIE who require transport soon after birth. aEEG application during neonatal transport has not been reported previously. aEEG has been used under novel circumstances, such as remote monitoring under telehealth neurocritical care consultation in Brazil and the Paediatric ED15,16.
The aEEG needle application is similar to that used …
Disclosures
The authors have nothing to disclose.
Acknowledgements
We thank the Perth Children’s Hospital Foundation for their generous support in purchasing the EEG equipment used in this project. We thank Gardar Thorvardsson (Kvikna) and Ieesha Sparks (Temple Medical and Scientific) for their support in the technical aspects of the study project.
Materials
| Stratus EEG Centrum, Acquire Pro Software for Microsoft Windows |
Stratus Software Solutions LLC Kvikna Medical Lyngháls 9 110 Reykjavik Iceland |
Version 4.2 | |
| Trackit T4PCU24+8 | Lifelines Neuro 7 Clarendon Court Over Wallop StockBridge Hants, UK |
SN: T4-170046 Issue: 4 C169 |
|
| Ultra Subdermal Needle Electrode | Natus 3150 Pleasant View Road Middleton WI 53562 USA |
019-476600 | 14 mm x 0.38 mm SST Needle DIN 42802 connector |
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