AEEG MONITORING IN NEWBORN INFANTS GCNC …Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in...

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Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in Newborn Infants - GCNC - CHW This document reflects what is currently regarded as safe practice. However, as in any clinical situation, there may be factors which cannot be covered by a single set of guidelines. This document does not replace the need for the application of clinical judgement to each individual presentation. Approved by: SCHN Policy, Procedure and Guideline Committee Date Effective: 1 st September 2017 Review Period: 3 years Team Leader: Clinical Nurse Consultant Area/Dept: Grace Centre for Newborn Care Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 1 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time. AEEG MONITORING IN NEWBORN INFANTS - GCNC - CHW PRACTICE GUIDELINE © KEY POINTS aEEG provides information about the functional integrity of the brain and can be interpreted immediately. The application of the electrodes is undertaken by staff who have been trained in the technique. Key performance indicators: Electrodes remain in situ for at least 4 hours Traces are interpreted and reported upon by a review group Procedure documented in patient’s medical record CHANGE SUMMARY References updated Images updated to reflect new equipment Equipment start up and troubleshooting section revised READ ACKNOWLEDGEMENT All clinicians working in Grace Centre for Newborn Care e.g. Registered Nurses, Clinical Nurse Specialists, Nursing Unit Managers, Clinical Nurse Educators, Registrars, Fellows and Neonatologists are to read and acknowledge they understand the contents of this document. Training and education: Regular in-services are provided and bedside teaching sessions.

Transcript of AEEG MONITORING IN NEWBORN INFANTS GCNC …Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in...

Page 1: AEEG MONITORING IN NEWBORN INFANTS GCNC …Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in Newborn Infants -GCNC - CHW This document reflects what is currently regarded as

Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in Newborn Infants - GCNC - CHW

This document reflects what is currently regarded as safe practice. However, as in any clinical situation, there may be factors which cannot be covered by a single set of guidelines. This document does not replace the need for the application of clinical judgement to each individual presentation. Approved by: SCHN Policy, Procedure and Guideline Committee Date Effective: 1st September 2017 Review Period: 3 years Team Leader: Clinical Nurse Consultant Area/Dept: Grace Centre for Newborn Care

Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 1 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

AEEG MONITORING IN NEWBORN INFANTS - GCNC - CHW

PRACTICE GUIDELINE ©

KEY POINTS • aEEG provides information about the functional integrity of the brain and can be

interpreted immediately.

• The application of the electrodes is undertaken by staff who have been trained in the technique.

Key performance indicators:

• Electrodes remain in situ for at least 4 hours

• Traces are interpreted and reported upon by a review group

• Procedure documented in patient’s medical record

CHANGE SUMMARY • References updated

• Images updated to reflect new equipment

• Equipment start up and troubleshooting section revised

READ ACKNOWLEDGEMENT • All clinicians working in Grace Centre for Newborn Care e.g. Registered Nurses, Clinical

Nurse Specialists, Nursing Unit Managers, Clinical Nurse Educators, Registrars, Fellows and Neonatologists are to read and acknowledge they understand the contents of this document.

• Training and education: Regular in-services are provided and bedside teaching sessions.

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Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in Newborn Infants - GCNC - CHW

Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 2 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

TABLE OF CONTENTS Background ............................................................................................................................ 3 Indications .............................................................................................................................. 3 Consent ................................................................................................................................... 3 Principles of aEEG Monitoring .............................................................................................. 3 Definitions ................................................................................................................................. 4 Trace Interpretation ................................................................................................................ 4 Background Pattern .................................................................................................................. 4

1. Continuous Normal Voltage ............................................................................................. 4 2. Discontinuous Normal Voltage ........................................................................................ 5 3. Burst Suppression ........................................................................................................... 6 4. Continuous Low Voltage .................................................................................................. 8 5. Isoelectric (flat) ................................................................................................................ 8

Classification Table: Voltage Values and pattern recognition ................................................ 10 Sleep Wake Cycle .................................................................................................................. 10 Seizures ................................................................................................................................. 11 Status Epilepticus ................................................................................................................... 12 RecogniZe © .......................................................................................................................... 12 Gestational Differences ....................................................................................................... 13

Term infant......................................................................................................................... 13 Preterm Infant .................................................................................................................... 14

Medications Administration and Background Trace ........................................................ 14 Artifact ................................................................................................................................... 15

Common factors that impact the aEEG trace .................................................................... 15 Tips to insure quality aEEG trace(s) .................................................................................. 15

Application and duration of use ......................................................................................... 16 Application Process ............................................................................................................. 16 Low Impedance Needle Electrode Application ....................................................................... 17 Nursing Care ......................................................................................................................... 18 Marking Events ....................................................................................................................... 18 Documentation ..................................................................................................................... 18 Daily Trace Interpretation ....................................................................................................... 19 Use of the Monitor ................................................................................................................ 19

To commence recording .................................................................................................... 19 Checking Signal Quality ..................................................................................................... 19 Pausing and ending a session ........................................................................................... 20 Powering down the system ................................................................................................ 20 Commonly used icons and screen management ............................................................... 20

Cleaning ................................................................................................................................. 21 Audit Process ....................................................................................................................... 21 References ............................................................................................................................ 22

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Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in Newborn Infants - GCNC - CHW

Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 3 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

Background

Amplitude-integrated electroencephalography (aEEG) is a method for continuous monitoring of brain function that is used in the Grace Centre for Newborn Care (GCNC). Single-channel aEEG has been shown to be predictive of neurodevelopmental outcome in term infants with hypoxic-ischaemic encephalopathy. Two-channel bedside monitoring provides both raw EEG and quantitative measures of EEG trace from the cerebral cortex of each hemisphere. aEEG provides information about the functional integrity of the brain and can be used immediately after admission of the infant to the GCNC1.

Indications

aEEG monitoring should be used on the following infants.2

• Infant’s ≥35/40 and ≤ 44/40 with: o Definite or questionable seizures o Neonatal encephalopathy (with or without seizures) o Unexplained apnoea o Brain injury or suspected brain injury o Metabolic Disorders o Meningoencephalitis

Monitoring should be negotiated with the attending Neonatologist.

Limitations

aEEG monitoring can be used for seizure detection in preterm infants and in cases of large IVH however background trace interpretation is difficult.

aEEG monitoring lacks the detail of a formal multichannel EEG, but is a valuable means of continuously monitoring cerebral activity at the bedside. It is recommended for any neonate with suspected seizures or cerebral dysfunction a formal EEG is obtained.

Consent

Nil formal consent required, a thorough explanation to parents must be provided.

Principles of aEEG Monitoring

The term amplitude integrated EEG (aEEG) denotes a method for encephalographic monitoring. The aEEG provides information about brain function and may detect epileptic discharges and signs of hypoxia–ischaemia2. The method is based upon filtered and compressed EEG that enables evaluation of long-term changes and trends in electrocortical background activity by relatively simple pattern recognition3.

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The aEEG trace is extracted from a limited number of channels of the conventional EEG and is both time compressed and filtered before display4. The leads are placed on a single pair of biparietal locations and the monitor displays the aEEG bandwidth, which reflects the trend of maximum and minimum amplitudes at a speed of 6 cmh. One raw EEG tracing is displayed as a second tracing3. The band width in the output reflects variations in minimum and maximum EEG amplitude, both of which depend on the maturity and severity of illness of the newborn infant. Due to the semi logarithmic scale used to plot the output, changes in background activity of very low amplitude (5 μV) are enhanced2,4.

Definitions Amplitude – is a measurement of the level of electrical brain activity detected it is measured in microvolts from peak to peak Artifact - is any electrical signal detected by an aEEG machine from an extracerebral source, including electrode or cable movement, AC supply noise, ventilator noise. Frequency – is the number of complete cycles of repetitive waves in one second measured in hertz (Hz)

Trace Interpretation

It is recommended that aEEG traces are assessed both visually based on pattern recognition and with consideration of the upper and lower amplitude margins2. When interpreting traces revision of the background activity, sleep wake cycling and seizure recognition is required3. There is a notable difference between term and preterm infant aEEG background patterns which is addressed at the end of this section.

Background Pattern The background pattern describes the dominating type of electro-cortical activity in the aEEG trace. It is classified into five trace patterns which are outlined below:

1. Continuous Normal Voltage

o Continuous activity with lower (minimum) amplitude around (5 to) 7 to 10 mcV and maximum amplitude of 10 to 25 (to 50) mcV.

In a healthy term infant there will be continuous electrical activity at a fairly high level. This will generate an upper margin of the aEEG in the range of 20-50 µV and a lower margin in the range of 10 to 20 µV. In general, if the upper margin is above 10 µV and the lower margin is above 5 µV, it is considered a Continuous Normal Voltage trace. There will also be limited variability which is displayed as a narrow pattern and is indicative of organized brain activity.

If the pattern is narrow (limited variability), wavy (sleep wake cycling SWC), the upper margin is > 10 µV, and the lower margin is > 5 µV, it is considered a Continuous Normal Voltage trace.

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Picture 1a. Example of CNV compressed aEEG trace

Picture 1b. Example of CNV raw EEG trace

The CNV trace is a narrow, wavy trace meeting the defined μV criteria.

• Lower margin > 5 μV (generally between 5-10 μV)

• Upper margin > 10 μV (generally between 10-25 μV)

• SWC present

• Bandwidth variability is limited – generally between 5-15 μV

• Lower margin variability is present – the lower margin is wavy5

2. Discontinuous Normal Voltage

o Discontinuous background with minimum amplitude variable, but below 5 mcV, and maximum amplitude above 10 mcV.

Increased bandwidth variability is also referred to as discontinuous activity, indicating low brain activity levels. Where the Continuous Normal Voltage trace was narrow with evidence of SWC, the Discontinuous Normal Voltage trace bandwidth has widened out indicating increased bandwidth variability. The lower margin has dropped below 5 µV however there continues to be variability in the lower margin of the trace in that it is not a straight line.

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Picture 2a. Example of DNV compressed aEEG trace Picture 2b. Example of DNV raw EEG trace

The DNV trace is a wide banded pattern that appears universally gray. The widened trace indicates increased variability in background brain activity due to intermittent levels of lower activity.

• Lower margin < 5 μV

• Upper margin > 10 μV

• SWC absent

• Bandwidth variability is increased – generally > 25 μV

• Lower margin variability is present – the lower margin is wavy5

3. Burst Suppression

o Discontinuous background with minimum amplitude without variability at 0 to 1 (2) mcV and bursts with amplitude >25 mcV. Can either be classified as High Burst density >100 bursts/h or Low Burst Density <100 bursts/h.

Burst Suppression is very similar in appearance to a Discontinuous Normal Voltage trace. Burst Suppression is abnormal in both the term and preterm baby. The raw EEG displays brief bursts of activity lasting ~1-3 seconds followed by prolonged periods of very low voltage background activity. The upper margin is > 10 μV due to high voltage bursts, and the lower margin is < 5 μV. There is increased variability in the bandwidth, but, there is limited

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variability of the lower margin it is a straight line. In the aEEG, it is this straight line that separates Burst Suppression from a Discontinuous Normal Voltage trace. No SWC.

Burst suppression can either present in a high or low density form:

- Low density BS: more time is spent in a low voltage background activity <25 μV. Presents as a ‘wide tooth comb’ with longer inter burst interval.

- High Density BS: there is a cluster of spikes with minimal gaps in between them with the upper margin >25 μV. Presents as a ‘fine tooth comb’ with short inter burst interval.

Picture 3a. Example of High Density BS compressed aEEG trace

Picture 3b. Example of High Density BS raw EEG trace

The BS pattern is indicative of the brain going through bursts of brain activity followed by periods of suppression which can be referred to as the interburst interval (IBI – the time between bursts of activity).

• Lower margin < 5 μV • Upper margin > 10 μV • SWC absent • Bandwidth variability is increased – generally > 25 μV • Lower margin variability is absent – the lower margin is flat • As the interburst interval (IBI) increases, the trace takes the shape of a fine tooth comb • A dark band appears on the lower portion of the trace between 0 μV and 3-4 μV

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4. Continuous Low Voltage

o Continuous background pattern of very low voltage (around or below 5 mcV).

Continuous Low Voltage is severely abnormal in both the term and preterm baby. The raw EEG waveforms are low in amplitude (<5 μV). There is no SWC, both margins have dropped and the upper margin is < 10 μV and the lower margin is <5 μV. There is a thicker bandwidth indicating some variability in activity, but it is at very low, abnormal voltage.

Picture 4a. CLV compressed aEEG data Picture 4b. Example of CLV raw EEG trace

The CLV pattern is indicative of the brain spending the majority of its activity in the very low voltage range.

• Lower margin < 5 μV

• Upper margin < 10 μV

• SWC absent

• Bandwidth variability is limited – generally between 4-8 μV

• Lower margin variability is absent – the lower margin is flat5

5. Isoelectric (flat)

o Primarily inactive (isoelectric tracing) background below 5mcV.

Isoelectric or Flat aEEG traces are severely abnormal in both the term and preterm baby. The raw EEG is a flat trace and the waveform is difficult to see. The aEEG has no sleep wake cycling, and both the upper and lower margin are <5 μV. The traces below demonstrate the very narrow dark bandwidth indicating greatly reduced variability; the intermittent burst spikes are associated movement or environmental artifact.

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Picture 5a. Isoelectric compressed aEEG data Picture 5b. Example of Isoelectric raw EEG trace

The FT pattern could be indicative of the brain spending nearly all of its time with extremely low or no μV activity.

• Lower margin < 5 μV

• Upper margin < 5 μV

• SWC absent

• Bandwidth variability is greatly reduced – generally between 1-2 μV

• Lower margin variability is absent – the lower margin is flat5

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Classification Table: Voltage Values and pattern recognition

Classification category

EEG characteristics Lower Margin μV

Upper Margin μV

aEEG Commonly seen with

Continuous Normal Voltage CNV

+/- 50 μV Continuously variable Absence of excessive spikes, sharp, waves, seizures Reactive to stimulation

>5

<10

SWC with duration >20 minutes Alternating wide & narrow trace

Infants >36 weeks

Discontinuous Normal Voltage DNV

Periods of lower amplitude, interspersed with periods of high amplitude

<5

>10

Wide depressed aEEG trace Variability in lower margin

Indicative of mild cerebral injury, anticonvulsant therapy or prematurity

Burst suppression High Density

Periods of abnormally high amplitude (bursts) lasting 1-3 seconds Separated by prolonged periods of markedly suppressed amplitude <5 μV

<5

>10 Due to high voltage bursts

Flat lower aEEG margin Spikes in upper margin represent bursts

If prolonged high there is probability of severe brain damage

Burst suppression Low Density

Space between spikes indicates length of suppression

Continuous Low Voltage CLV

Continuous low amplitude All waveforms <5 μV

<5 <10 Narrow aEEG trace with greatly reduced margins

Severe brain damage

Isoelectric-inactive-flat trace

Very low amplitude Flat trace/difficult to see any electrical waveform Often see ECG artifact

<5

<5

Low amplitude narrow trace May have low amplitude spikes

Severe brain damage, brain injury or brain death

Sleep Wake Cycle Sleep-wake cycling (SWC) in the aEEG is characterized by smooth sinusoidal variations, mostly in the minimum amplitude. The broader bandwidth represents discontinuous background activity during quiet sleep, and the narrower bandwidth corresponds to the more continuous activity during wakefulness and active sleep.3 SWC is categorised into three categories:

1. No SWC: No cyclic variation of the aEEG background.

2. Imminent/immature SWC: Some, but not fully developed, cyclic variation of the lower amplitude, but not developed as compared with normative gestational age representative data.

3. Developed SWC: Clearly identifiable sinusoidal variations between discontinuous and more continuous background activity, with cycle duration >20 min.3

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Seizures

Epileptic seizure activity in the aEEG usually is seen as an abrupt rise in the minimum amplitude and a simultaneous rise in the maximum amplitude, often followed by a short period of decreased amplitude. The raw EEG should show simultaneous seizure activity, with a gradual build-up and then decline in frequency and amplitude of repetitive spikes or sharp-wave or activity with duration of at least 5 to 10 sec.3 Seizures are classified as:

• Single seizure: A solitary seizure.

• Repetitive seizures: Single seizures appearing more frequently than at 30-minute intervals.

• Status epilepticus: Continuously ongoing seizure activity for >30 minutes.

Picture 6a. Example of recurrent bilateral seizures in compressed aEEG data

Picture 6b. Example of seizure activity in raw EEG data

Categorized by a sudden rise in the lower margin sometimes accompanied by a rise in the upper margin

• Often appear as rhythmic discharges on the raw EEG

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Status Epilepticus • Continuous unremitting seizures > 30 minutes in duration

• Recurrent seizures, without regaining consciousness between seizures for > 30 minutes

• Often appears as a saw tooth pattern on aEEG

Picture 7. Compressed and raw EEG image of status epilepticus

RecogniZe © Is an automated event detection system for use with the BrainZ BRM 2 (Olympic) monitor. RecogniZe identifies events that may be seizures and clinically significant by identifying regularity in the EEG waveform which may correspond to seizure activity. 5 Patterns identified by the software based upon length, amplitude and trace as potential seizures are highlighted with a visual alarm highlighted as a flashing red highlight on the ‘clinical’ button, and the top of the compressed aEEG data as an orange bar, and the raw aEEG screen is highlighted with a red line. Clinicians are required to assess the visual alarm and determine the appropriate clinical response in consultation with the medical officer. There have been reported instances of false seizure detection from RecogniZe that can be associated with artefact or poor electrode contact, review of suspicious traces with a neonatologist is recommended prior to commencing pharmacotherapy.

Since the increased use of continuous aEEG monitoring it has become apparent that subclinical seizures are common. Debate continues regarding the treatment of subclinical seizures and their impact upon long term neurodevelopmental outcomes.2

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Picture 8a. Example of RecogniZe software in compressed aEEG data

Picture 8b. Example of RecogniZe software in raw aEEG trace

Gestational Differences

Term infant

In term infants, aEEG is an excellent method for evaluating cerebral function and cerebral recovery after hypoxic-ischemic insults such as perinatal asphyxia and apparent life-threatening events (ALTE)7. Clinical symptoms of cerebral dysfunction can be difficult to detect due to the illness itself or because sedatives or analgesics have been administered. In such infants, electrocortical background activity usually remains unaffected or only moderately depressed unless high doses of antiepileptic medicines or sedatives have been administered7. A continuous aEEG with amplitudes between 10 and 25 mcV, some smooth or cyclic variation, or fully developed SWC is usually a reassuring sign of non-compromised brain function.3 Poor prognostic indicators include burst suppression, continuous low voltage or flat/isoelectric tracing.4

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Preterm Infant

Although the aEEG has not been evaluated in preterm infants as extensively as in term infants, several studies have shown its utility in this population3, especially in preterm infants with large intraventricular haemorrhages7. Compared with term infants, the background pattern of less mature infants is more discontinuous. There are more frequent ‘bursts’, and the raw tracing of the EEG signal may show periods of relatively low voltage with sudden but infrequent bursts of high activity.4

The following table summarises aEEG features in Newborns at different gestational/post-conceptual ages:

Gestational age

or Post conceptual age

(wk)

Dominating Background pattern SWC

Minimum Amplitude

(mcV)

Maximum Amplitude

(mcV) Burst/h

24 through 25 Discontinuous Imminent/immature 2 to 5 25 to 50 (to 100)

>100

26 through 27 Discontinuous Imminent/immature 2 to 5 25 to 50 (to 100)

>100

28 through 29 Discontinuous/ Continuous

Imminent/immature + some developed

2 to 5 25 to 30 >100

30 through 31 Continuous/ Discontinuous

Developed 2 to 6 20 to 30 >100

32 through 33 Continuous/ Discontinuous in QS

Developed 2 to 6 20 to 30 >100

34 through 35 Continuous/ Discontinuous in QS

Developed 3 to 7 15 to 25 >100

36 through 37 Continuous/ Discontinuous in QS

Developed 4 to 17 to 25 >100

38+ Continuous/ Discontinuous in QS

Developed 15 to 25 >100

Table 2. Gestational aEEG changes Modified from Hellstrom-Westas et al (2006). QS = Quiet Sleep

Medications Administration and Background Trace

Many of the medications used in GCNC may affect the aEEG tracing. Antiepileptic drugs and opioids generally cause a transient depression in the overall activity of the aEEG.4, 8 Phenobarbital causes decreased cerebral activity, generalized voltage suppression and increased interburst interval9-11. Morphine and midazolam have been shown to exert similar effects on aEEG 8, 9, 12,13.

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Artifact

The difficulty in interpreting and applying aEEG in clinical practice rests heavily on the distinction between artifact and activity4. The range of recorded artifact varies anywhere between 12 and 60% among published values14. Electrocardiogram activity, patient movement, high-frequency oscillator ventilation and electrode placement are a few of the variables that may influence the presence of artifact. One of the more common signs seen from electrocardiographic artifact is the ‘drift of the baseline’, in which the baseline tracing becomes falsely elevated in the setting of severely suppressed background activity4. A baseline level above 5 mV may be mistaken for a more reassuring pattern. Owing to these apparent difficulties with interpretation, non-experts with only a small amount of exposure may over- or under-analyse certain events14, further training is thus necessary and advocated.15

ECG and other causes of artifact may elevate the lower margin beyond the level of the actual brain activity. In the example above, the aEEG is elevated due to the peak to peak voltage of the electricity/contractility of the heart (ECG artifact).

Common factors that impact the aEEG trace

Background pattern appears erratic or extremely elevated – Possible causes:

• ECG artifact (lower margin appears elevated)

• Handling/patting

• Muscle activity/infant movement

• High-frequency ventilation

• Status epilepticus

• Gasp artifact Background pattern appears unusually dampened or depressed – among possible causes:

• Severe scalp oedema

• Electrodes placed significantly too close together

• Significant sedation

Tips to insure quality aEEG trace(s)

• Carefully prepare skin and place electrodes according to positioning guide and always check impedance levels

• Properly place and label markers for any care/procedures, concerning movements and specific medications

• Review the raw EEG display to evaluate for artifact that may falsely elevate the aEEG baseline and help in positively identifying seizure activity

• Ensure DAB box is placed at foot of bed or at point away from electrodes to prevent artifact

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Application and duration of use

• It is recommended that monitoring stays insitu ideally for a minimum of 8 hours.

• Sucrose 25% is administered prior to electrode placement.

• Low Impedance Needle electrodes are routinely used for all neonates requiring aEEG monitoring.

• The literature reports needle electrodes in place for up to 5 days without infection.16

• Consideration should be given at the time of application to other scheduled diagnostic imaging e.g. EEG, MRI, Head Ultrasounds.

• After application of electrodes complete documentation in the electronic medical record including application time.

Application Process

• Electrodes are to be applied by staff who have been trained in the application of needle electrodes.

• Equipment required:

o aEEG monitor

o Adaptor set with positioning aid

o Marker pen

o Wrap hat

o Needle electrodes (x4 plus 1 hydrogel for reference site)

o Antiseptic alcohol

o KY Jelly (assists to part hair)

o Steri-strips

o Tape

Caution: when removing needle electrodes make sure the needle is encased in the

blue protective sheath to avoid an accidental injury

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Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in Newborn Infants - GCNC - CHW

Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 17 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

Low Impedance Needle Electrode Application Step Action

1 Position infant supine

2 Using sensor positioning strip, measure from the sagittal suture to the tragus of the ear. Align so each end point has the same letter (A,B etc)

3 Mark the site for electrode placement.

4 Open packet of needle electrodes (3 per packet). Squeezing the distal end of the blue safety

cover open ‘protective shield’ will allow the needle and black hub to glide out in one pass. Pull plastic housing to the end of the cable wire (away from the needle)

5 Hold skin taut and insert needle electrodes at 30o angle or less (sub-dermal)

6 Insert the first sub-dermal needle electrode with the sensor wire upwards. Ensure that all the metal is under the dermal layer or else it will pick up interference and have a fuzzy signal.

7 Secure the subdermal needle in place with a chevron using steri-

strips For babies with a lot of hair, after inserting needle electrode apply a small amount of lubricating gel (eg KY jelly) on the hair where you want to tape the electrode. After jelly dries it creates a surface for the tape to stick. The gel is easily washed out.

8 Site electrodes in the following manner. • All leads to be directed to the top of the head • Black electrode placed at the back • Purple electrode placed in front • Ensure electrodes do not touch

Needles should not be pointing towards each other to ensure adequate distance is maintained for good quality signal.

9 Gently turn infants head over and repeat process.

10 Apply head wrap with adequate tension to support electrodes. To avoid tension on the needles, create a strain relief loop using brown tape near the electrodes.

11 Site the green reference electrode, either on the neck, shoulder, or back. Choose a site with no hair

12 Plug blue connector into the data acquisition unit (DAU)

13 Note: Needle electrodes may be left in-site for up to 96 hours. If electrodes need re-siting. Do Not stop the machine. Continue monitoring, making a note on the trace, of the event.

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Guideline No: 2008-0018 v4 Guideline: aEEG Monitoring in Newborn Infants - GCNC - CHW

Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 18 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

Nursing Care

Nursing care of the infant with aEEG monitoring includes:

• Maintenance of sensors and troubleshooting impedance if poor signal or artifact

• Navigation of the monitor interface including admission, marking of events, suspension and/or stopping recording

• Interpretation of the aEEG pattern within scope of role and training

• Notification of abnormal or evolving background pattern including suspected seizures to the medical officer

• Documentation in electronic medical record

Marking Events To mark an event:

Open the Markers/Add overlay, and press one of the preset markers. A marker is inserted at the timeline cursor position (the red vertical line in the aEEG display).

1. To add a marker at a different place in the session, use the navigation controls to move back and forth through the session, or touch the aEEG display to reposition the timeline cursor at the new location.

2. To add a custom marker, touch the custom marker field on the Markers/Add overlay. Use the on-screen keyboard to type the custom marker Event name, and press Add.

Documentation

• Application of sensors and discontinuation of trace to be entered in electronic medical record

• At present: Procedures, Imaging enter as free text

• Consistency of terminology used eg aEEG

• Specific entry heading under review for each shift using the 7 S’s of systematic review

1. Story/situation: reason for monitoring

2. Signal quality: green/yellow/red (If the aEEG trace is of a poor quality it is difficult to reliably interpret the results)

3. Strength of brain activity (background pattern CNV, DNV, CLV, BS, I)

4. Sleep-wake cycles: describe as imminent/immature, present or absent

5. Symmetry: Trace correlation

6. Suspicious: Seizure activity or other events

7. Stability: trend changes over time

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Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 19 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

Daily Trace Interpretation Daily ‘‘aEEG review’’ sessions will be completed and documented by an identified aEEG superuser to support clinical staff in recognising common patterns, artifacts, and to review challenging tracings/cases.

Use of the Monitor

1. Set up the aEEG monitor close to the patient and check that the connections are correct.

2. Hang the data acquisition box (DAB) from a convenient hook or handle on the incubator or cot.

3. Switch on the power switch and wait for the system to power up to the main display.

4. Apply the neonatal sensor set (see previous instructions). Use the Electrode impedance view to check impedance levels of the individual sensors.

5. Check the impedance levels of the first two sensors before applying the remaining sensors.

To commence recording To begin live monitoring of the patient:

1. Press the record button.

2. Optionally, enter patient information, and press Next.

3. Select the electrode configuration (we always use 5 electrode – two channel monitoring)

4. Touch the record button, enter patient details (optional), and then press Next.

5. Press Start Recording. The CFM starts live monitoring mode.

Checking Signal Quality

During live monitoring, ensure the Electrode Impedance View is selected.

Note: Keep an eye on the Electrode Impedance View while securing the wrap hat, making sure contact quality is maintained.

To start Electrode Impedance View:

1. Press the impedance selector button.

2. The Electrode Impedance View displays the individual impedance values of each electrode measured in kΩ.

• OK (Green) = Values below 10 kΩ.

• Marginal (Amber) = Values above 10-20 kΩ (generating a Signal Quality Alert).

• Extremely Poor (Red) = Values above 20 kΩ (generating a Signal Quality Alert).

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Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 20 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

Picture 9. Image identifying impedance display in monitor

Pausing and ending a session

To pause a session:

1. Press the Record button to stop recording.

2. Press Stop Recording.

The session is paused (live monitoring and recording of data is suspended).

To resume live monitoring and recording:

1. Press the Record button.

2. Press Resume Recording. To end a session:

1. Press the Record button to stop recording, and press Stop Recording.

2. Open the Patient/Close overlay, and press Close Session.

The session unloads from system memory and a watermark appears in the aEEG display.

Powering down the system

Before you power down the CFM, you must stop recording and close the current session.

To power down the CFM:

• In the Tools/System/Exit overlay, press Shutdown.

• Confirm Shutdown.

The system powers down within 15-20 seconds.

Commonly used icons and screen management Open sessions Create new sessions Online help

Home Add markers Record

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Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 21 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

On/off Indicates Indicates needle issue seizures

Channel selector

Compress-ed data

Scroll

Artifact

Cleaning • Monitor and DAU to be wiped down with soft cloth dampened with water and detergent

after use

• Monitors stored in Store room.

• Restock gauze, sensor sets etc. after each use

Audit Process

aEEG traces will be reviewed and reported on in a regular audit meeting by a group of superusers including a Neonataologist, Clinical Fellow, Transitional Nurse Practitioner, Clinical Nurse Consultant and Nurse Educator. A daily aEEG review report is completed by a superuser and documented every 24 hours for the duration of monitoring in electronic medical record. The final aEEG report endorsed in the audit meeting will be documented in Powerchart.

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Date of Publishing: 25 August 2017 3:45 PM Date of Printing: Page 22 of 22 K:\CHW P&P\ePolicy\Aug 17\aEEG Monitoring in Newborn Infants - GCNC - CHW.docx This Guideline may be varied, withdrawn or replaced at any time.

References 1. de Vries, LS. & Hellstrom-Westas, L. The role of cerebral function monitoring in the newborn. Arch.Dis.

Child. Fetal Neonatal Ed.2005;90;201-207. 2. Toet, MC. & Lemmers, PMA. Brain monitoring in neonates. Early Human Development 85 (2009) 77–84 3. Hellstrom-Westas, L., Rosen, I., de Vries, LS. & Greisen. Amplitude Integrated EEG Classification and

Interpretation in Preterm and Term Infants. NeoReviews. 2006: 7(5):e76-e87 4. Tao, JD & Mathur, AM. Using amplitude-integrated EEG in neonatal intensive care. Journal of

Perinatology (2010) 30, S73–S81 5. Scanmedics Product manual 6. Natus, (2016) A cerebral function monitor pattern recognition: quick reference guide. www.natus.com 7. Hellstrom-Westas L, Klette H, Thorngren-Jerneck K, Rosen I. Early prediction of outcome with aEEG in

preterm infants with large intraventricular hemorrhages. Neuropediatrics. 2001;32:319–324. 8. Bjerre I, Hellstro¨m-Westas L, Rose´n I, Svenningsen NW. Monitoring of cerebral function after severe

birth asphyxia in infancy. Arch Dis Child. 1983;58:997–1002 9. Lavery, SV, & Randall KS. Cerebral Monitoring of the Term Infant. Neonatal Network. 2008: 27(5):329-

337 10. Herbertz S, Pulzer F, Gebauer C, Panhofer M, Robel-Tillig E, Knupfer M. The effect of maturation and

sedation on amplitude-integrated electroencephalogram of the preterm neonate: results of a prospective study. Acta Paediatr 2006; 95:1394–1399.

11. Bell AH, Greisen G, Pryds O. Comparison of the effects of phenobarbitone and morphine administration on EEG activity in preterm babies. Acta Paediatr 1993; 82: 35–39.

12. Shany E. The influence of phenobarbital overdose on aEEG recording. Eur J Paediatr Neurol 2004; 8: 323–325.

13. Niemarkt HJ, Halbertsma FJ, Andriessen P, Bambang Oetomo S. Amplitude-integrated electroencephalographic changes in a newborn induced by overdose of morphine and corrected with naloxone. Acta Paediatr 2008; 97: 132–134.

14. van Leuven K, Groenendaal F, Toet MC, Schobben AF, Bos SA, de Vries LS et al. Midazolam and amplitude-integrated EEG in asphyxiated full-term neonates. Acta Paediatr 2004; 93: 1221–1227.

15. Hagmann CF, Robertson NJ, Azzopardi D. Artifacts on electroencephalograms may influence the amplitude-integrated EEG classification: a qualitative analysis in neonatal encephalopathy. Pediatrics 2006; 118: 2552–2554.

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17. Whitelaw, A & White, R. Training neonatal staff in recording and reporting continuous electroencephalography. Clin Perinatol. 2006;33;667-677.

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