Paediatric Acute care Guidelines PMH Emergency Department

Background

General

  • Electrocution occurs when current passes through a person and disrupts normal electrical function of cells
  • Most electrical injuries occur in the home, usually associated with electrical cords (60-70%) and wall outlets (10-15%)
  • If a healthy child is exposed to common household electric current, is asymptomatic and no evidence of arrhythmia/ cardiac arrest, they can be discharged safely

 

The extent of damage done is determined by:

Amount of electrical current flow:

  • High voltage (>1000V) vs low (<1000V)
Type of current (AC v DC):

  • AC (most common in Australian homes), is more dangerous, causes tetanic muscle contraction and ‘lock-on’ effect
  • DC is less dangerous, patient tends to be thrown away from source
Current path:

  • Trans-thoracic (hand to hand), has a high mortality (>60%) due to increased spinal cord and myocardial damage
  • Vertical (hand to foot), mortality >20% due to cardiac arrhythmias
  • Straddle (foot to foot) low mortality <5%
Which tissues did it flow through?

  • Moist tissue (mouth) or wet skin increases conduction and therefore results in a more severe injury
  • Thin skin increases susceptibility to severe injuries
Duration:

  • Prolonged contact increases severity of injury

 

Three Main Electrical  Injury Patterns:

  • Direct trauma from electric current (direct tissue damage, e.g. cardiac ischaemia/ arrhythmia, compartment syndromes, rhabdomyolysis, peripheral nerve injury)
  • Trauma from conversion of electrical energy to thermal energy (burns)
  • Mechanical effects of electric current (violent muscle contraction which may lead to fractures/dislocations, falls resulting in possible trauma)

 

Lightning Injuries:

  • Results in an instantaneous massive unidirectional current (DC) and thus a different pattern of injury to electrical injury
  • Rarely causes burns/soft tissue destruction as it is too quick and  no ’lock on’
  • Likely to cause asystolic cardiac arrest (depolarised entire myocardium) or respiratory arrest (thoracic muscle spasm/ central respiratory depression)
  • Relatively high (up to 50% chance of survival) if CPR commenced early and continued  
  • Asystole may spontaneously recover therefore management of apnoea and respiratory arrest is imperative
  • Cardiac:
    • VF likely secondary to hypoxia not lightning shock induced
  • Neurologic:
    • Immediate transient (LOC, confusion, anterograde amnesia, weakness, paraesthesia)
    • Immediate persistent (hypoxic encephalopathy, intracranial haemorrhage)
    • Delayed (motor neuron disease, movement disorders)
  • Traumatic: fall resulting in spinal cord injury, epidural or subdural haematoma
  • Autonomic instability:
    • Keraunoparalysis (transient paralysis and appearance of acute arterial insufficiency of limb)

Assessment

History

  • Electrical source, voltage, duration of contact, environmental factors at scene, resuscitative measures already provided
  • Previous medical history (especially cardiac)
  • Tetanus immunisation status

Examination

General:
Consider whether critically unwell or not, if so take ABCDE approach, in particular:

  • Airway- burns or soft tissue swelling to mouth, face, anterior neck (children may have oral burns from chewing electric cord)
  • Cervical spine- consider need for immobilisation if thrown from source
  • Circulation- VF commonest arrhythmia in arrested patients. Asystole common in high voltage and lightning strikes. Other arrhythmias are also possible.
Specific:

Skin:

  • Size, location of burns:
  • Entry and exit wounds- may be deceptively small, with extensive underlying soft tissue damage
  • Wound location give information about the pathway of the current through the body, if far apart increase tissues exposed for internal injuries to have occurred
  • Low voltage – small, well-demarcated contact burns at entry and exit sites
  • High voltage – serious burns, painless, yellow-grey charred craters with central necrosis, or skin sparing with damage to underlying soft tissue and bone
  • Kissing burn – occurs at flexor crease when current arcs across both flexor surfaces, associated with extensive underlying tissue damage

Neurological exam:

  • Most common CNS symptom is loss of consciousness
  • Other CNS symptoms may include acute peripheral neuropathy, transient paralysis/paraesthesia
  • Incidence of spinal cord damage is 2-27% following high voltage injury when the current travels arm to arm or arm to leg
  • May resemble lower motor neuron disease, amyotrophic lateral sclerosis or transverse myelitis

Eyes:

  • Visual acuity and fundoscopy due to risk of direct trauma and cataract

Ears:

  • Hearing and examination of tympanic membrane as risk of tympanic membrane rupture
Limbs:

  • Check range of movement and for bony tenderness
  • Neurovascular obs to extremities to assess for vascular damage/ delayed onset compartment syndrome

 

Investigations

Initial ECG for all:

  • Looking for arrhythmia or cardiac ischaemia
  • Incidence of arrhythmias is 4-17%
  • Low volt AC is more likely to cause cardiac consequences
  • Delayed arrhythmias are rare, only in those with arrhythmia on presentation (hence screening ECG on arrival)

   Further investigation is only required for significant electrical injuries such as:

Urinalysis

  • For myoglobinuria to exclude rhabdomyolysis

Bloods

  • In those at risk for conductive electrical injury (patients with entry/exit wounds or cardiac arrhythmia and patients with high voltage injury), CK, FBC, U & E’s, LFTs & Lipase (if intra-abdominal injury is suspected
  • Patients may have a high potassium, low calcium, high phosphate or metabolic acidosis

Radiology

  • Consider as clinically indicated

 

Management

Initial management

  • Resuscitate as required according to advanced life support, specifically consider whether airway involvement will cause airway issues
  • Cardiac monitoring if evidence of ischaemia or arrhythmia on ECG, loss of consciousness or high voltage injury
  • Remove jewellery/constricting objects early to reduce risk of oedema
  • Cool burns
  • If patient appears well following a low voltage injury, they are likely well

 

Further management

  • Supportive care:
    • Consider IV fluid to maintain urine output  of 1-1.5ml/kg/hour (Burns Parkland formula not applicable for fluid calculation)
    • Discuss with Paediatric Burns Team early

Medications

  • Ensure tetanus immunisation up to date

Admission criteria

  • History of loss of consciousness, documented dysrhythmia or evidence of cardiac ischaemia- admit for cardiac monitoring
  • Evidence of significant burns- admit under Paediatric Burns Team
  • Evidence of significant trauma- admit  under Paediatric Surgical, Orthopaedic, or Burns Team dependent on injury
  • Evidence of rhabdomyolosis- admit under Paediatric Burns Team or other Team depending on other injuries

Discharge criteria

  • Normal ECG
  • No history of loss of consciousness
  • No burn/trauma injury requiring admission 

Nursing

References

PMH ED Guidelines:  Electrical Injuries – Last Updated 25/08/14
http://lifeinthefastlane.com/education/ccc/electrical-injury
Czuczman AD, & Zane RD, Electrical injuries: a review for the emergency clinician. Emergency Medicine Practice. Evidence Based Medicine. 2009, Vol 11 (no. 10)
Arnoldo B, Klein M & Gibran NS, Practice Guidelines for the Management of Electrical Injuries. Journal of Burn Care and Research. 2006, (Jul/Aug) pp439-447

Tags

We want your feedback!

Help us provide guidelines that are useful to you, the clinician.

Give feedback here