Electrical injuries

Disclaimer These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline.  Read the full CAHS clinical disclaimer

Aim

To guide Emergency Department (ED) staff with the assessment and management of electrical injuries.

Background^1,2,3

• 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
• It is imperative to look for and treat not only electrical injuries, but also those caused indirectly, e.g., by falls or being thrown.

The extent of the damage done is determined by:^1,2

Voltage

• High voltage (>1000V) vs low (<1000V). High voltage may cause deep injuries that may not be readily obvious and need to be sought.

Type of current (AC v DC)

• Alternating current (AC): Most common in Australian homes, is more dangerous, may causes tetanic muscle contraction (‘lock-on’ effect) and cardiac arrest
• Direct current (DC): 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%
• Regardless of the current path, damage to underlying structures (e.g. myolysis) is always a possibility and should be investigated.

Which tissues did it flow through?

• Moist tissue (mouth) or wet skin increases conduction and therefore results in a more severe injury.

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 syndrome, 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 (depolarises entire myocardium) or respiratory arrest (thoracic muscle spasm/central respiratory depression).

Assessment

History

• Electrical source, voltage, duration of contact, environmental factors at scene, resuscitative measures already provided
• 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 – ventricular fibrillation (VF) is the most common arrhythmia in arrested patients. Asystole is common with high voltage and lightning strikes. Other arrhythmias are also possible.
  

Specific

Skin

• Size and location of burns
• Entry and exit wounds: may be deceptively small, with extensive underlying soft tissue damage
• Wounds location give information about the pathway of the current through the body. If they are far apart, there is more potential for tissue damage along the path
• Low voltage - present as small, well-demarcated contact burns at entry and exit sites
• High voltage - present as serious burns which are often painless, yellow-grey charred craters and central necrosis, or skin sparing with damage to the underlying soft tissue and bone
• Kissing burn: occurs at flexor crease when current arcs across both flexor surfaces. This can be associated with extensive underlying tissue damage.

Neurological exam

• The most common CNS symptom is loss of consciousness
• Other CNS symptoms may include acute peripheral neuropathy and transient paralysis/paraesthesia
• The incidence of spinal cord damage is 2-27% following high voltage injury when the current travels arm to arm or arm to leg

Eyes

• Assess visual acuity and perform fundoscopy due to risk of direct trauma and cataract.

Ears

• Assess hearing and tympanic membrane due to risk of tympanic membrane rupture.

Limbs

• Check range of movement and for bony tenderness
• Perform neurovascular observations to extremities to assess for vascular damage/delayed onset compartment syndrome.

Initial electrocardiogram (ECG): 

• ECG is not indicated for low voltage exposure without cardiac arrest, loss of consciousness or burns.
• Look for arrhythmia or cardiac ischaemia.
• Delayed arrhythmias are rare and occur mostly following cardiac arrest or after exposure to high voltage (>1000V). In these cases, cardiac monitoring is imperative.

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

Urinalysis

• Is performed to detect 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), creatine kinase, full blood count, urea, electrolytes and creatinine, liver function tests & 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^3,4

Initial management

• Resuscitate as required according to Advanced Paediatric Life Support (APLS) trauma, burns and cardiac life support guidelines
• Seek and treat associated trauma from falling or being thrown.
• Consider whether airway involvement will cause airway issues.
• Cardiac monitoring for the duration of the admission 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
• Analgesia.

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 is 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 (if indicated)
• No history of loss of consciousness
• No burn/trauma injury requiring admission.

References

1. Czuczman AD, & Zane RD, Electrical injuries: a review for the emergency clinician. Emergency Medicine Practice. Evidence Based Medicine. 2009, Vol 11 (no. 10).
2. 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.
3. Pinto DS, Clardy PF. Environmental and weapon-related electrical injuries UpToDate. Last updated January 2020. Cited: June 2022. Available from: Environmental and weapon-related electrical injuries - UpToDate (health.wa.gov.au)
4. Advanced Paediatric Life Support Manual, 6th edition 2017

Endorsed by:	Nurse Co-Director, Surgical Services	Date:	Jun 2022
		Review date:	Jun 2025

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