Menu Search Donate
Guideline identity image

Hypoxic Ischaemic Encephalopathy (HIE) - management

This document is only valid for the day on which it is accessed. Please read our disclaimer.

Definition

Brain injury secondary to inadequate oxygen delivery. Cardiac arrest is the most common cause, but HIE may also be caused by prolonged seizures, drowning, asphyxia, infectious/metabolic encephalopathy and low cardiac output states.

Principles of management

Avoidance of secondary injury (hypoperfusion, hypoglycaemia, hypoxia) while the brain recovers from the primary insult.

PICU Guidelines

Airway

  • All children with severe HIE require intubation for airway protection and to ensure adequate ventilation

Ventilation & Oxygenation

  • Volume Control mode to prioritise CO2 control
  • ParterialCO2 4.7- 5.3 kPa (note correlation to end tidal CO2 and set EtCO2 aims accordingly)
  • Titrate oxygen to keep PaO2 12-15 kPa

Monitoring

  • All children should receive invasive blood pressure monitoring
  • Invasive ICP monitoring is not recommended

Head Position

  • Head of Bed elevated to 30°
  • Avoid hip flexion
  • Keep head in midline

C-Spine

  • Children with HIE secondary to drowning, hanging1 or other traumatic etiology: remove hard collar. Use sandbags alongside manual stabilisation for log rolls
  • Continue c-spine stabilisation and log rolls until formally cleared

Circulation

  • Worse survival and neurological outcomes occur with MAP <5th centile for age
  • Treat hypotension aggressively with IV fluid bolus +/- inotropes/vasopressors
  • Goal is to maintain MAP in upper range for age (i.e. 50-95th centile)
Age Goal MAP mmHg
< 2 years ≥55
2 - 6 years ≥60
>6 years ≥70
  • Use crystalloid to maintain CVP 4-8 mmHg
  • Noradrenaline may be required to achieve blood pressure targets

Therapeutic Temperature Management2

  • There is no evidence to support the use of moderate hypothermia (32 -33°C); however fever is associated with worse outcomes
  • Post Cardiac Arrest management:
    See Targeted Temperature Management Guideline
    Maintain core temperature 36°C for the first 36hrs then 36.5°C until 72hrs post injury/arrest.
    Use oesophageal or bladder temperature - not rectal probe

Sedation

  • Sedation reduces intracranial pressure by reducing brain metabolism and energy expenditure
  • Refer to the PICU Sedation and Analgesia guideline appropriate to the age and weight of the child
  • Goal is deep sedation and analgesia during first 72 hours
  • Muscle relaxation will be required to prevent shivering for duration of Targeted Temperature Management

Fluids, Glucose & Nutrition

  • 70% maintenance fluid as isotonic saline ± potassium
  • Establish enteral feeding as tolerated
  • Maintain serum glucose 3.5 - 5.5 as hypoglycaemia can result in secondary brain injury
  • If blood glucose > 11mmol on two occasions - consider insulin infusion on consultant order

Sodium control

  • Maintain serum sodium >140mmol
  • If < 140 restrict to 50% maintenance fluid
  • 3% Hypertonic saline (dose = 3ml/kg over 1 hour) may be administered via central line3

Anticonvulsants

  • Children receiving muscle relaxants should receive seizure prophylaxis regardless of EEG findings
  • Phenytoin: loading dose 20mg/kg followed by maintenance dose 3 mg/kg 8 hourly

Imaging & Neurophysiology

  • Perform an EEG within the first 24 hours to detect non convulsive status epilepticus which is common in HIE
  • Consider ongoing continuous/intermittent EEG monitoring

Notes

  1. Hanging injuries may result in vascular injury with a risk of subsequent stroke and require a CT angiogram to exclude this
  2. Refer to PICU Targeted Temperature Management Guideline
  3. Expect serum Na to rise by ~4mmol/L with 3ml/kg 3% saline

References

  • Abend NS, Licht DJ. Predicting outcome in children with hypoxic ischemic encephalopathy. Ped Crit Care Med. 2008 9:32-39
  • Moler FW, Sliverstein MD, Holubkov R et al. Therapeutic Hypothermia after Out-of-Hospital Cardiac Arrest in Children. N Engl J Med. 2015 May 14:372(20):1898-1908
  • Nielsen N, Wetterslev J, Cronberg T et al. Targeted Temperature Management at 33oC versus 36oC after Cardiac Arrest. N Engl J Med. 2013 369(23):2197-2206

Did you find this information helpful?

Document Control

  • Date last published: 03 October 2016
  • Document type: Clinical Guideline
  • Services responsible: Paediatric Intensive Care Unit
  • Author(s): Anusha Guneshalingham, Jean Strock
  • Owner: Anusha Guneshalingham
  • Editor: John Beca
  • Review frequency: 2 years