23.7 — Burns and Electrical Injury

Twenty minutes of cool running water.

That is the treatment for a burn, and it is effective for up to three hours after the injury — not just in the first minute.

Studies of burn outcomes consistently find that adequate cooling reduces the depth of the burn, reduces the need for skin grafting, reduces scarring and reduces the time in hospital.

And most people cool for a minute or two, or not at all, or reach for ice, butter, toothpaste or cream — every one of which makes it worse.

Twenty minutes. Cool running water. Set a timer.

What a burn is

Heat destroys proteins in the skin.

And the injury does not stop when the heat source is removed — retained heat in the tissue continues to damage cells for some time afterwards, which is exactly why cooling changes the outcome.

A burn has three zones: a central zone of coagulation, where cells are already dead; a surrounding zone of stasis, where blood flow is compromised and cells may survive or die; and an outer zone of inflammation.

Cooling saves the zone of stasis. That is the mechanism, and it is why 20 minutes of water can be the difference between a burn that heals on its own and one that needs surgery.

Depth

Superficial — first degree. Epidermis only. Red, painful, dry, no blisters, and it blanches when pressed. Like sunburn. Heals in 3 to 7 days with no scarring.

Superficial partial thickness — second degree. Into the upper dermis. Blisters, very painful, moist, red, blanches. Heals in 1 to 3 weeks, usually without significant scarring.

Deep partial thickness. Into the deeper dermis. Blotchy red or white, less painful because nerve endings are damaged, and sluggish or absent blanching. Takes over 3 weeks and usually scars, and frequently needs grafting.

Full thickness — third degree. Through the whole dermis. White, brown, black or waxy; dry and leathery; and painless, because the nerves are destroyed. Needs grafting.

And the counter-intuitive point worth remembering: a painless burn is worse than a painful one. Absent sensation means the nerves have been destroyed. Do not take lack of pain as reassurance.

Fourth degree — into fat, muscle or bone.

Burns are frequently mixed depth, and the true depth may not be apparent for 48 to 72 hours, which is why an initially reassuring burn can be reassessed as deeper.

Size

Assessing the area matters because it drives fluid replacement and the decision to transfer to a burns unit.

The palm rule: the person's own palm including the fingers is roughly 1 percent of their body surface area. Simple and good enough for a bystander.

The rule of nines in adults: head 9 percent; each arm 9; each leg 18; front of trunk 18; back of trunk 18; genitals 1.

And the proportions differ substantially in children — a small child's head is around 18 percent and each leg around 14 — which is why the adult rule underestimates head burns and overestimates leg burns in children.

Superficial burns are not counted in the total.

Treating a burn — exactly

1. Stop the burning process.

Remove them from the source.

Flames: stop, drop, cover and roll.

Remove clothing and jewellery, quickly, before swelling starts. Rings in particular must come off fast, because a swollen finger with a ring on can lose its blood supply.

But do not remove anything stuck to the skin. Cut around it.

Chemical burns: brush off dry powder first, then irrigate.

2. Cool with running water for 20 minutes.

Cool, not cold — around 15 degrees, ordinary tap water.

Effective up to 3 hours after the injury, so it is never too late to start.

Never use ice or iced water. It causes vasoconstriction, reduces blood flow to the injured tissue, and deepens the burn. Ice can also cause a cold injury on top of the burn.

Watch for hypothermia, particularly in children, in large burns, and in cold environments. Cool the burn, warm the person — keep the rest of them covered while the burn is under water.

For large burns in a cold environment, cool for a shorter period and prioritise keeping the person warm, because hypothermia in major burns worsens survival.

3. Cover it.

Cling film is the recommended dressing. Laid on in strips, not wrapped around a limb — wrapping constricts as the limb swells.

Discard the first few centimetres from the roll, and do not use it on the face.

Alternatives: a clean non-fluffy cloth, a clean plastic bag for a hand or foot, or a specific burn dressing.

Do not use cotton wool or anything fluffy, which sticks into the wound.

4. Nothing else on it.

No butter, oil, toothpaste, egg white, flour, ash, soy sauce, ice or antiseptic cream.

These trap heat, introduce infection, and make it impossible for the hospital to assess the burn without painful cleaning.

Honey and aloe vera have some evidence for minor burns and are used after proper cooling and assessment, not as the first response.

5. Do not burst blisters.

The blister roof is a sterile biological dressing. Large or awkwardly placed blisters may be dealt with medically.

6. Pain relief and fluids.

Paracetamol and ibuprofen.

For large burns, sips of fluid if fully alert and not requiring immediate surgery — though in a significant burn, fluids are given intravenously.

7. Elevate, to reduce swelling.

When a burn needs hospital

Any burn that is:

Larger than the person's palm, or over 1 percent.

On the face, hands, feet, genitals or over a major joint.

Circumferential — going all the way round a limb, chest or neck. A tight, inflexible circle of burned tissue can act as a tourniquet as swelling develops, cutting off the blood supply or restricting breathing. This may require surgical release.

Deep partial or full thickness — any white, leathery or painless area.

Chemical or electrical.

In a child under 5 or an adult over 60.

In anyone with diabetes, immunosuppression or significant illness.

And any burn with suspected inhalation injury.

Inhalation injury

And this is the one that kills after the fire is out.

Suspect it with: a fire in an enclosed space; burns to the face or neck; singed nasal hairs, eyebrows or facial hair; soot around the mouth, nose or in the sputum; hoarseness or a change in voice; stridor; cough; and breathing difficulty.

The danger is progressive swelling of the airway. Someone talking normally at the scene can be unable to breathe an hour later, as heat-injured tissue swells.

Which is why anyone with suspected inhalation injury goes to hospital urgently even when they seem well, and why intubation is done early rather than waiting — because once the airway swells shut, it may be impossible to secure.

Also consider carbon monoxide poisoning (Chapter 23.6) and cyanide poisoning from burning plastics and furnishings, both of which cause confusion and collapse with no visible burn at all.

Give high-flow oxygen if available.

Specific burns

Chemical burns.

Brush off dry chemicals before adding water, because water can activate some powders.

Irrigate for at least 20 minutes, and longer for alkalis — up to an hour or more (Chapter 23.6).

Alkalis penetrate deeper and keep burning, so they need more irrigation than acids.

Do not attempt to neutralise.

Take the chemical container or its name to hospital.

Hydrofluoric acid deserves specific mention — used in glass etching, rust removers and industry. It penetrates skin and binds calcium in the body, causing severe pain that can be delayed for hours, and it can cause fatal low calcium and cardiac arrest from a relatively small skin exposure. The specific treatment is calcium gluconate gel, and it is an emergency.

Eye burns: irrigate immediately with copious water for at least 20 to 30 minutes, holding the lids open, and continue on the way to hospital. Do not delay to find anything better than tap water.

Sunburn: cool, moisturise, fluids, and pain relief. Blistering sunburn over a large area, particularly in a child, needs medical assessment.

Bitumen and tar: cool with water and do not attempt to peel it off. It is removed with an appropriate solvent by professionals.

Friction burns: clean thoroughly, because road rash carries embedded grit that causes tattooing and infection.

Electrical injury

And electricity is different from every other burn, because the damage you can see bears almost no relationship to the damage inside.

Making the scene safe — first, always

Do not touch the person if they are still in contact with the source.

Low voltage — domestic supply: switch off at the socket or the main breaker. If you cannot, stand on something dry and insulating and push them clear with a dry wooden or plastic object.

High voltage — overhead lines, railway lines, substations: stay at least 25 metres away.

Electricity can arc across a gap, and current spreading through the ground creates a voltage gradient — so the ground near a downed cable can kill you through your feet. If you must move away from a downed line, shuffle with your feet together rather than taking steps.

Wait for the supply to be confirmed dead by the utility company. Not switched off — confirmed.

What it does

Current travels through the body along the path of least resistance — nerves, blood vessels and muscle.

Which produces the central problem: entry and exit wounds may be small, and the tissue between them can be destroyed.

Deep muscle damage releases myoglobin, which damages the kidneys — rhabdomyolysis (Chapter 21.6). Dark cola-coloured urine is the sign, and it needs aggressive fluids.

Cardiac arrhythmias, including ventricular fibrillation and cardiac arrest.

AC current — mains electricity — causes tetanic muscle contraction, so the person grips the source and cannot let go, which prolongs contact and makes the injury worse. DC tends to throw the person clear.

Respiratory arrest if the current crosses the chest and paralyses the breathing muscles.

Fractures and dislocations from violent muscle contraction — including posterior shoulder dislocation and spinal fractures, which occur without any fall.

Falls from height after a shock.

Neurological effects — confusion, seizures, weakness, and delayed peripheral nerve damage that may appear days later.

Cataracts, appearing months later after high-voltage injury to the head.

What to do

1. Make the area safe.

2. Check response, airway and breathing. Start CPR if needed (Chapter 23.2) — and electrical cardiac arrest has a relatively good outcome with prompt CPR and defibrillation, because the heart and the person are frequently otherwise healthy.

3. Look for two burns — entry and exit. The exit is often on a foot.

4. Treat burns as above, and immobilise if there is any suspicion of a fall or spinal injury.

5. Everyone with a significant electrical injury goes to hospital, even if they feel fine.

Because arrhythmias can occur hours later, and internal damage is not visible.

Anyone with high-voltage exposure, loss of consciousness, chest pain, palpitations, an abnormal ECG, current crossing the chest, or pregnancy needs cardiac monitoring.

A brief low-voltage shock from a household appliance in someone who feels completely well, with no loss of consciousness and no symptoms, may not need admission — and it should still be assessed.

Lightning

Different again.

Extremely high voltage, extremely short duration, which means deep burns are actually less common than in industrial electrical injury.

Characteristic features: Lichtenberg figures — fern-like patterns on the skin, which are not burns and fade within days; ruptured eardrums; cataracts; and keraunoparalysis — temporary paralysis and blue, pulseless limbs, which usually resolves within hours.

Death is from cardiac and respiratory arrest.

And the crucial point about lightning casualties: reverse triage.

Normally you treat the living first and leave those in cardiac arrest. With lightning, you treat those who appear dead first, because the heart frequently restarts spontaneously while the respiratory drive stays paralysed for longer — so a person in respiratory arrest will progress to cardiac arrest unless ventilated, while those who are moving and breathing will usually survive.

Lightning victims do not carry a charge. It is completely safe to touch them.

Prevention: when thunder follows lightning by 30 seconds or less, go indoors or into a hard-topped vehicle, and stay there for 30 minutes after the last thunder. Avoid open ground, tall isolated trees, water, and metal structures.

Preventing burns at home

Smoke alarms on every level, tested monthly.

Hot water thermostat at or below 50 degrees — water at 60 degrees causes a full-thickness burn on a child's skin in about 1 second; at 50 degrees it takes around 5 minutes.

Hot drinks out of reach. A hot drink can scald a small child up to 15 minutes after it was made, and hot drink scalds are the commonest burn in toddlers.

Pan handles turned inward, and a guard on the hob.

Never leave cooking unattended, and never put water on an oil fire — cover it or use a fire blanket.

Fire blanket in the kitchen, and a known escape plan.

Bath water run cold first, hot second, and always tested.

What the next page fixes

Chapter 23.8 covers fractures, dislocations and head injury — what to immobilise, what not to move, and the specific signs after a head injury that mean going to hospital immediately.