Electrical Injuries

Objectives

To outline the treatment of electrical injuries in the pre-hospital environment, including lightning.

Scope

• Background
• Initial assessment
• Advanced assessment and management
• Criteria for discharge
• Lightning strikes
• Prolonged casualty care

This guideline will focus on the investigation and management of electrical injuries, including those secondary to lightning.

Audience

• Doctors
• Nurses
• Paramedics

Initial Assessment & Management

Background

In the deployed space there is a risk of SP becoming electrically injured, while exposed to damaged infrastructure or through improper use of equipment for example. The severity and pattern of injury can vary and is influenced by the nature of electrical insult (e.g. voltage, current). The risk is generally increased with higher voltages. Be aware of underestimating burn severity from internal passage of current resulting in injuries not visible externally.

Causes for cardiorespiratory arrest include current-induced dysrhythmia (asystole, VF, VT), hypoxia (respiratory tetany and apnoea) and hypovolaemia.

This CGO will also cover electrical injuries secondary to lightning.

Wet skin has a very low level of resistance. This is an important factor during lightning storms, where a wet patient is likely to receive a greater injury than a dry patient, assuming they both receive the same ‘source’ of electricity.

It is also important to be aware of secondary injuries sustained after the initial electrical insult, e.g. fall from height.

Initial Assessment

Patient presenting forward of deployed hospital care.

SAFE approach to scene – DO NOT approach the patient until the electricity supply is isolated/no longer live.

Assess MARCH

If patients believed to have been exposed to a large current/high voltage electrical injury attach defibrillator pad/AED at the earliest opportunity and keep defibrillator with the patient until handover to the next level of care.

For patients in cardiorespiratory arrest follow BLS/ILS algorithms.

M - The patient is unlikely to have any major haemorrhage from an electrical injury. However, be aware of secondary injuries as a result.

A – Assess for airway/facial burns. Check airway patency and asses need for early intervention (eg airway adjuncts)

Consider risk of secondary traumatic C-spine injury. Immobilise accordingly and manage as per Trauma.

R – Assess for rate, depth and effort. Assess for chest wall injuries. Assess SpO2, administer Oxygen if indicated and available (target sats 94-98%). Lung damage my result in apnoea, dyspnoea, haemoptysis or hypoxaemia.

C – Assess haemodynamic status, measuring HR, BP, CRT. Undertake a 12-lead ECG and consider continuous 3-lead monitoring as arrhythmias may develop. Extensive burns will require fluid resuscitation via an unaffected limb. IV access may be challenging, and IO access may be required. Look for myoglobinuria (dark, tea-coloured or coke coloured urine and urine dipstick positive for blood). There are often extensive muscle injuries causing myoglobinaemia. Be aware that this can also result in hyperkalaemia.

H – Assess AVPU, pupils, and look for signs of head injury, upper and lower limb function. Seizures may occur. Consider pain relief.

Cool burns with cool running water if able for 10-20 minutes. Be aware of causing hypothermia (heat loss may be exacerbated due to skin loss). Cover burns with burns dressing or sterile non-adherent dressing or cling film (taking care not to circumferentially wrap limbs). Wrap patient in thermal blanket.

See burns CGO for further details.

Patients who have been exposed to a small current/low voltage injury, who are asymptomatic, with no injuries and have normal initial 12-lead ECG and was dry at the time of electrocution may not require higher level of care and can be returned to front line duties.

The risk of malignant dysrhythmia is thought to be low in cases of low voltage, no loss of consciousness, no transthoracic pathway.

Criteria for escalation – if any patient who has abnormal observations, has had loss of consciousness or life-threatening injuries escalate care through the care pathway.

Advanced Assessment & Management

Measures available at R2/3 (or on MERT)

A location with a more established medical layout permits more advanced assessment and interventions.

Assess MARCH

If patients believed to have been exposed to a large current/high voltage electrical injury attach defibrillator pad/AED at the earliest opportunity and keep defibrillator with the patient until handover to the next level of care

For patients in cardiorespiratory arrest follow ALS algorithms.

M - The patient is unlikely to have any major haemorrhage from an electrical injury. However, be aware of any secondary injuries.

A – Assess for impending/current airway compromise. Respiratory muscle paralysis can be seen and have a low threshold for intubation and ventilation indicated. For patients requiring a definitive airway consider RSI.

Consider risk of secondary traumatic C-spine injury. Immobilise accordingly and manage as per Trauma.

R – Monitor RR and SpO2, administer Oxygen if indicated and available (target sats 94-98%). Patients with breathing difficulties consider an XRAY/CT. Escharotomies may be required in extreme chest wall burns impeding ventilation.  

C – Assess HR, BP. Obtain access (if not already done so). Administration of large volumes of fluid (often much larger than initially appreciated) may be required to compensate for large fluid losses into damaged tissues. Adherence to traditional resuscitation formulae for thermal burns can result in insufficient fluid administration but be mindful of haemodilution in aggressive fluid resuscitation. Risk of rhabdomyolysis from muscular damage, urine dip and record urine output. Check bloods: electrolytes, CK

H – Assess GCS and evidence of head injury. Treat seizures. Asses neurological status. Consider analgesia. Be aware of acoustic trauma.

Distal pulses, function, limb temperature and pain should be assessed regularly to assess for compartment syndrome. Fasciotomy may be required.

Simply considering surface burns may result in gross underestimation of the extent of internal thermal injury. Assessment of possible current pathway by examining entrance and exit burns allows appreciation of which internal structures may have been involved.

Early establishment of invasive monitoring is useful to assess and guide fluid resuscitation.

Plastic surgical consultation may be required in the R3/R4 space. Obtain early ophthalmology review for eye symptoms.

Consider need for antibiotics and tetanus prophylaxis.

Compartment syndrome should be actively sought but can be difficult to distinguish from muscle ischaemia secondary to vascular injury. Vasospasm of limb arteries may be transient but arterial thrombosis may present with distal ischaemia and infarction. Distal pulses, limb temperature and pain should be assessed regularly. Vessel injury requires vascular surgery consultation.

Skeletal muscle damage results in electrolyte derangement and myoglobin release. Serum potassium, phosphate, calcium and CK measurements are necessary and should be repeated if rhabdomyolysis is a possibility. Hyperkalaemia poses the main threat to myocardial stability.

Myoglobin release produces a brown discolouration of the urine and impairs renal tubular function. Dipstick analysis of urine will demonstrate a false positive finding for haematuria in the presence of myoglobin. Maintenance of adequate renal perfusion by restoring circulating volume and blood pressure helps to prevent renal failure. Alkalisation of the urine may also have a role. Ultimately if renal failure ensues, haemofiltration may be required.

Severely burned patients demonstrate evidence of the systemic inflammatory response syndrome (SIRS). SIRS may develop with resulting multi organ dysfunction. Early effective resuscitation of the patient with severe electrical injury may reduce the severity of multi organ dysfunction and failure.

Criteria for discharge

Patients meeting ALL the following criteria can be considered for return to frontline duties:

• Small current/low voltage
• Asymptomatic and normal physical examination
• No loss of consciousness
• Normal 12-lead ECG
• No transthoracic pathway of current
• Dry at time of electrocution

The risk of malignant dysrhythmia is thought to be low in these cases.

Current (and therefore injury) is greatest when voltage is high, and resistance is low. Resistance can be impacted by many factors (different body tissues have different levels of resistance), but the patient being wet or dry at time of electrocution is the main factor in affecting resistance. Wet skin has a very low level of resistance, resulting in worse injuries.

Class injuries as high voltage (>1000V) or low voltage (<1000V). Most mains AC electrical supply operates at <240V worldwide.

Prolonged Casualty Care

ALL patients believed to have been exposed to a large current/high voltage electrical injury should be evacuated to higher level of care, where this is not reasonable or practical the patient will require prolonged observations and serial ECGs. For patients with open wounds/burns, refer to wound management. Beware of hypothermia.

Patients who have been exposed to a small current/low voltage injury, who are asymptomatic, with no injuries and have normal initial 12-lead ECG may not require higher level of care. Following a comprehensive assessment patients may be returned to front line duties.

Paediatric Considerations

As above.

For paediatric patients in cardiorespiratory arrest follow EPALS algorithms.

IV/IO access and fluid resuscitation as per EPALS.