Level 2 of 6Must-remember

Electrical injury and lightning strike

Assess, manage and stay safe — enough on its own

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The card — assess, manage, caution

Assessment— look, ask, measure

Establish the source before anything else: low-voltage alternating current (below 1000 V) from domestic wiring, faulty appliances, immersion heaters, fans, irrigation pumps or exposed sockets; high-voltage alternating current (above 1000 V) from transmission lines, transformers, substations, railways or industrial plant; direct current from batteries, welding equipment or traction systems; or lightning.
Skin findings are not indicative of the depth of tissue injury and may appear misleadingly minor — the visible electrical burn is commonly restricted to the skin even where muscle necrosis and spinal cord damage have occurred beneath it.
Reconstruct the current pathway between contact points: a hand-to-hand or hand-to-opposite-foot (transthoracic or vertical) pathway has crossed heart, mediastinum, cord and abdominal viscera and carries the highest risk; foot-to-foot carries the lowest risk but does not exclude injury; head or neck contact raises the possibility of intracranial injury, tympanic rupture and delayed cataract.
The presence of entrance and exit burns signifies an increased risk of deep tissue damage and compartment syndrome — a dramatic flash burn of the face is a distraction if it draws attention from a five-millimetre entry wound on the palm.
Distinguish the three burn types, since one patient often has all three: flash (arcing) burns where the arc passed over rather than through the body; flame (clothing) burns, which may constitute the largest part of the injury and should prompt consideration of smoke inhalation; and the direct heating effect of tissues by the current, invisible from the surface, producing small dry charred punched-out often painless lesions at contact and departure points.
Ask about lightning mechanism from witnesses, because it predicts severity: direct strike; side flash from an adjacent struck object such as a tree; contact with a struck object; ground current spreading through the earth (the commonest mechanism where several people are injured at once); and blast injury from explosive expansion of superheated air.
The lightning casualty is characteristically pulseless, not breathing and in coma, with fern-shaped Lichtenberg figures which are pathognomonic, are not true burns, fade within about twenty-four hours and mark the mechanism not the severity, and with clothing exploded off the body by flash-vaporisation of surface moisture; tympanic rupture is common and the casualty carries no residual charge.
Take a full trauma survey — every electrical casualty is a trauma patient: tetanic contraction is severe enough to fracture bone or dislocate joints, and posterior shoulder dislocation and thoracic compression fractures are classically produced by tetany and classically missed.
Cardiac and respiratory features: arrest may be the presenting feature; in survivors expect palpitations, chest pain, syncope and dysrhythmias, with sinus tachycardia and non-specific ST–T changes common and usually transient.
Airway red flags: hoarseness, stridor, soot in the nares, singed nasal hair or facial burn predict swelling and impending obstruction — and where clothing burned or the event occurred in an enclosed space, smoke inhalation may dominate with immediate breathlessness, tachypnoea, choking and fatal pulmonary oedema.
Neurological features: loss of consciousness, confusion, agitation, amnesia, headache, seizures and focal deficits, with peripheral neuropathy immediate or delayed by days to weeks; after lightning, keraunoparalysis is a transient paralysis of predominantly the lower limbs with cold, mottled, blue, pulseless extremities from autonomic vasospasm, typically resolving over minutes to hours — but genuine spinal cord damage does occur after major shock.
Dark, tea- or cola-coloured urine indicates myoglobinuria and is the bedside marker of significant rhabdomyolysis; on dipstick, positive for blood with no red cells on microscopy confirms it.
Compartment syndrome signs appear in order: pain out of all proportion to the visible injury (earliest and most reliable), pain on passive stretch, a tense woody compartment, then paraesthesia and sensory loss — pallor, paralysis and pulselessness are late, and a palpable distal pulse does not exclude it.
Check glucose in anyone with reduced consciousness — hypoglycaemia is a treatable cause of the coma attributed to the current — and measure carboxyhaemoglobin after fire, smoke or enclosed-space exposure, because pulse oximetry reads falsely normal in carbon monoxide poisoning.
Never attribute hypotension to 'the shock': consider haemorrhage, tension pneumothorax, neurogenic shock and arrhythmia.
Special situations to elicit: an oral commissure burn in a toddler from chewing a live flex; pregnancy, where uterus and amniotic fluid conduct current well and the foetus may be harmed even where the mother appears barely injured; a changing or developmentally implausible history raising inflicted injury; deliberate self-harm or assault; and occupational injury where other workers may be exposed to the same fault.

Management— do this, in order

Separate the patient from the current before resuscitation begins: for low-voltage sources switch off at the mains or unplug the appliance, attempting separation beforehand only from a dry insulating surface with a dry non-conducting object; for high-voltage sources nobody approaches until the line is confirmed de-energised and earthed, since high-tension current arcs across air and spreads through the ground around a fallen conductor — lightning is the exception, as the casualty carries no residual charge.
Begin resuscitation on every victim, because clinical findings of death are deceptive and unreliable, and continue longer than instinct suggests — these are typically young patients with structurally normal hearts whose arrest is electrical rather than ischaemic.
Low-voltage AC arrest means ventricular fibrillation: defibrillate immediately, adult 150–200 J biphasic, paediatric 4 J/kg; adrenaline 1 mg IV/IO after the third shock and every 3–5 minutes thereafter; amiodarone 300 mg IV after the third shock and 150 mg after the fifth; paediatric adrenaline 10 microgram/kg (0.1 mL/kg of 1:10 000) every 3–5 minutes and amiodarone 5 mg/kg.Doctor / NurseNot available at your setup — Defibrillator.
DC and lightning arrest means asystole: compressions and adrenaline 1 mg IV/IO every 3–5 minutes (paediatric 10 microgram/kg) with relentless attention to ventilation — respiratory arrest outlasts cardiac arrest, so a patient whose rhythm returns must continue to be ventilated, and prolonged assisted ventilation is expected rather than a ground for pessimism.Doctor / Nurse
With several lightning casualties triage is reversed: treat the apparently dead first, because those breathing and conscious have already survived whereas those in arrest will die within minutes and are the group who can be saved.
Assess by the full trauma protocol — airway with cervical spine control, breathing, circulation, disability, exposure — and remove rings, bangles, watches and tight footwear at once, before the limb swells.
Airway and breathing: assume cervical spine injury until cleared, give high-concentration oxygen, and secure the airway early where soot, singed nasal hair, hoarseness, stridor or facial burn predict swelling, before oedema makes intubation impossible; avoid suxamethonium where there is established muscle necrosis or hyperkalaemia and use rocuronium 1 mg/kg IV (paediatric 1 mg/kg) or vecuronium 0.1 mg/kg IV.Doctor / NurseNot available at your setup — Endotracheal intubation kit.
Fluid: burns exceeding 15% of total body surface area require large volumes of intravenous crystalloid guided by the Parkland formula — 4 mL/kg body weight multiplied by %TBSA burned in the first 24 hours, half in the first 8 hours from the time of injury and the remainder over the following 16 hours — using compound sodium lactate (Hartmann's or Ringer's lactate) or 0.9% sodium chloride.
In electrical injury Parkland systematically under-estimates requirement because the destroyed tissue lies beneath the skin and never enters the calculation — the formula is the opening bid, urine output is the prescription.
Shock bolus: adult 500 mL isotonic crystalloid over 15 minutes reassessing before repeating; paediatric 20 mL/kg reassessing after each; children also receive normal maintenance fluid in addition to Parkland, which must not be omitted.
Urine output targets: adult 1–2 mL/kg/h, about 2 mL/kg/h while urine is pigmented; child at least 1 mL/kg/h, infants at least 2 mL/kg/h — catheterise with an hourly chart recording urine colour, while monitoring for volume overload which may cause pulmonary complications or compartment syndromes.
Treat hyperkalaemic ECG changes at once — peaked T waves, flattened P waves, a broadening QRS or a sine-wave pattern signal imminent arrest: calcium gluconate 10%, adult 10–30 mL IV over 5–10 minutes repeated if the ECG does not improve, paediatric 0.5 mL/kg IV over 5–10 minutes to a maximum 20 mL; then soluble insulin 10 units in 25 g glucose (50 mL of 50% or 125 mL of 20%) IV over 15–30 minutes with glucose monitored for 6 hours, paediatric 0.1 unit/kg with 2 mL/kg of 10% glucose IV over 30 minutes; plus nebulised salbutamol adult 10–20 mg, paediatric 2.5 mg under 25 kg or 5 mg.Doctor / Nurse
Examine every limb in the current pathway, plus both forearms and both lower legs, at least hourly: fasciotomy is indicated for any compartment syndrome, and escharotomy incisions can be limb- and life-saving where a constricting eschar of extremity, neck or chest, or a circumferential full-thickness trunk burn, produces ischaemia or ventilatory restriction.
Pending operation release all constricting items and circumferential dressings down to skin, keep the limb at heart level rather than elevated (elevation lowers perfusion pressure to an already ischaemic compartment), and maintain analgesia and normovolaemia.
Analgesia, which is routinely under-given because the skin looks unimpressive: morphine 2–5 mg IV slowly repeated every 5–10 minutes to effect with respiratory rate and saturation monitored (paediatric 0.1 mg/kg IV slowly, titrated); fentanyl 1 microgram/kg IV titrated as an alternative (paediatric the same); ketamine 0.25–0.5 mg/kg IV for procedures (paediatric 0.5–1 mg/kg IV); paracetamol 1 g IV or orally 6-hourly to a maximum 4 g/24 h (paediatric 15 mg/kg 6-hourly orally, rectally or IV); ondansetron 4 mg IV (paediatric 0.1 mg/kg IV, maximum 4 mg).Doctor / Nurse
Wound care: cool fresh thermal and flash burns under running water for about 20 minutes, then stop cooling and start warming — keep environmental temperature at or above 30°C where burns exceed 20% of TBSA — cleanse and debride loose devitalised tissue, leave blisters over ordinary partial-thickness burns intact unless infected, cover all non-superficial wounds with topical antibiotics and a loosely applied non-adherent sterile dressing, and verify and update tetanus prophylaxis in all patients with burns.
Surveillance for at least the first 24 hours: hourly urine output with its colour, hourly limb-by-limb compartment examination, conscious level and vital signs, with the 12-lead ECG repeated at 6 and 24 hours and potassium, creatinine, CK, blood gas and full blood count in parallel.Not available at your setup — Serum electrolytes, Renal function (creatinine/urea), Arterial blood gas.

Caution— what harms

Never approach a high-voltage casualty until the line is confirmed de-energised and earthed — high-tension current arcs across air and spreads radially through the ground around a fallen conductor, so the victim need never have touched the cable and the rescuer need not either.
Never let the appearance of death stop you: clinical findings suggestive of death are unreliable after electrical injury, and the patient who looks dead after lightning may recover completely.
Never assume the skin tells you the depth: nerve is the most vulnerable tissue and bone the most resistant, so bone heats and cooks the muscle lying against it and a limb may be destroyed beneath intact-looking skin.
Never treat electrical injury as a burn with a wire attached — treatment differs from that of other types of burns, and general burn scores such as the Abbreviated Burn Severity Index systematically underestimate it because the destroyed tissue never enters the calculation.
Never rely on Parkland alone — it under-estimates requirement in electrical injury; titrate to urine output, while watching for volume overload which may itself cause pulmonary complications or compartment syndromes.
Never give suxamethonium where there is established muscle necrosis or hyperkalaemia — use rocuronium 1 mg/kg IV or vecuronium 0.1 mg/kg IV.Doctor / Nurse
Never wait for an absent pulse to diagnose compartment syndrome — pallor, paralysis and pulselessness are late, a palpable distal pulse does not exclude it, and waiting for an absent pulse is waiting for an amputation; compartment pressure above 30 mmHg, or a diastolic-minus-compartment difference below 30 mmHg, supports the diagnosis but never overrides convincing clinical findings.
Never elevate the limb with a threatened compartment — keep it at heart level, because elevation lowers perfusion pressure to already ischaemic tissue.
Never assume escharotomy is enough — escharotomy releases skin only, and progressive swelling despite it requires fasciotomy of all involved compartments.
Never interpret a raised troponin as coronary occlusion by default: it is frequently raised by direct myocardial current injury, by arrest or by hypotension, and only a convincing ST-elevation pattern or a history suggesting an ischaemic event caused the accident should redirect management.Not available at your setup — Cardiac troponin.
Never miss the classic skeletal injuries: posterior shoulder dislocation and thoracic compression fractures from tetany may look near-normal on a single anteroposterior film — obtain two views.
Never rely on pulse oximetry after fire, smoke or enclosed-space exposure — it reads falsely normal in carbon monoxide poisoning; measure carboxyhaemoglobin.
Never give NSAIDs where there is rhabdomyolysis, hypovolaemia or any rise in creatinine, and never give prophylactic systemic antibiotics — antibiotics are for established infection, guided by culture; silver sulfadiazine is no longer recommended.
Never let a large-burn patient become hypothermic — cooling stops after about 20 minutes and warming begins, because a cold large-burn patient becomes coagulopathic.
Never discharge a toddler with an oral commissure burn without warning the carers explicitly that when the eschar separates, typically five to fourteen days after injury, the labial artery may bleed torrentially — show them how to pinch the lip firmly between finger and thumb and tell them to return immediately.
Never assume the wound you see today is the wound tomorrow: electrical wounds declare themselves late and extend, a coin-sized eschar on day one often becoming a hand-sized area of necrosis by day three, so re-evaluate within 24–72 hours and repeatedly thereafter.

Refer / escalate

Admit or transfer for high-voltage exposure, abnormal cardiac rhythm or ECG changes, large burn size, neurological, pulmonary or cardiac symptoms, suspicion of significant deep tissue or organ damage, a transthoracic current pathway, a history of cardiac disease or other significant comorbidity or injury, loss of consciousness at any point, dark urine, suspected compartment syndrome, or any need for surgery — and refer any pregnant patient for obstetric assessment and foetal monitoring after any electrical exposure, however trivial.

The card — assess, manage, caution

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