Describe burns and scalds with their classification, causes of death and medicolegal aspects.

Definitions and Classification

• The historical classifications remain examinable — dupuytren'S six degrees and WILSON'S three-fold division into epidermal, dermo-epidermal and deep
• Extent is estimated by the rule OF nine (wallace) in adults — head and neck 9%, each upper limb 9%, each lower limb 18%, front of trunk 18%, back of trunk 18%, and perineum 1%. The palm of the patient's own hand is about 1%, which is a practical way of measuring scattered burns
• The rule of nine is inaccurate IN children, whose head is proportionately much larger and limbs smaller; the LUND and browder chart is used instead and corrects for age
• Prognosis — broadly, burns over one-third of the body surface are dangerous to life and over 50 to 60% usually fatal, though modern burn care has improved this; extremes of age, inhalational injury, full-thickness burns and delay in treatment all worsen it

Causes of Death and Antemortem Burns

• Immediate (within hours) — primary neurogenic shock from pain and fright; asphyxia from laryngeal oedema and inhalation of hot gases; and carbon monoxide poisoning, which is the commonest cause of death in a house or vehicle fire and often kills before any significant burning
• Early (first few days) — secondary (hypovolaemic) shock from massive plasma loss through the burned surface; and acute renal failure
• Delayed (after the first week) — infection and septicaemia, which is the commonest cause of death overall in those who survive the first days, with Pseudomonas, Staphylococcus and Klebsiella; curling'S ulcer of the duodenum with haemorrhage or perforation; acute respiratory distress syndrome; pulmonary embolism; and multi-organ failure
• Late — contractures and disfigurement, and rarely malignant change (Marjolin's ulcer) in a chronic scar

• Soot below the larynx and a raised carboxyhaemoglobin are the two findings that settle the question, and both should be sought in every fire death; a body burnt after death shows neither, which indicates that death preceded the fire and the true cause lies elsewhere
• Heat artefacts must not be mistaken for injuries — the pugilistic attitude, a flexed "boxer" posture from heat coagulation of muscle, occurring whether the person was alive or dead; heat ruptures and skin splits resembling lacerations or incised wounds, which have no vital reaction and occur along lines of tension; heat fractures of the skull; and the heat haematoma, a chocolate-brown, honeycombed extradural collection on the side exposed to heat, with NO skull fracture and no scalp injury, which mimics a traumatic extradural haematoma

Examination of a Burnt Body

Preserve the clothing and any residue for identification of an accelerant; note the smell of kerosene or petrol before the body is washed → Estimate the surface area and depth of burning, and record the distribution — front or back, upper or lower body — which bears directly on the manner → Look for the red line of demarcation at the margins and examine the blister contents — the vital reactions → Open the airway and look for soot below the larynx, recording how far down it extends; and take blood for carboxyhaemoglobin and cyanide before anything else → Search beneath the burns for injuries the fire cannot explain — the neck structures and hyoid, the scalp, and any fracture or stab wound → Distinguish the heat artefacts — pugilistic attitude, heat ruptures, heat fractures and heat haematoma — and state that they are artefacts → Preserve viscera for toxicology, since a sedative or poison may have been given first → Establish identity — teeth, radiographs and DNA, since the features are usually destroyed

Manner and Applied Aspects

• Accidental burns are much the commonest in India — kitchen accidents with kerosene stoves and open fires, loose synthetic clothing and the dupatta or sari catching fire, and children scalded by hot liquids
• Suicidal — self-immolation, usually with kerosene poured over the head and shoulders so the burns are extensive and involve the front and the head; a container may be present; and the person is usually alone with the doors closed
• Homicidal — dowry-related bride burning, and the burning of a body to conceal a homicide; suggested by injuries not explained by the fire, absence of soot and carboxyhaemoglobin, and evidence of restraint
• Always perform a complete autopsy and take blood for carboxyhaemoglobin, cyanide and alcohol, and preserve viscera; the question of whether the person was alive when the fire began is the central issue in every such case
• Examine the airway for soot down to the bronchi, and record the level reached; and examine the burnt body fully, since the trunk cavities are often well preserved beneath charred skin
• Record a dying declaration where the person is conscious, with certification of mental fitness before and after; in burns cases this is frequently the only direct evidence, and extensive burns do not by themselves make a person unfit
• Do not report the pugilistic attitude as a defensive posture or a heat rupture as a laceration; these artefacts have led to entirely wrong reconstructions
• Scalds never char and burns singe hair; these two features separate moist from dry heat more reliably than anything else
• The rule of nine is wrong in children, whose head is proportionately far larger; use the Lund and Browder chart, or the palm-equals-one-percent rule for scattered burns
• Septicaemia is the commonest cause of death overall in those who survive the first days, which makes burn units an infection-control problem before anything else
• A heat haematoma has no fracture and no scalp injury, is chocolate-brown and honeycombed, and lies on the side exposed to the fire — which separates it from a traumatic extradural
• Estimate the surface area before the burns are dressed; once covered, the assessment cannot be repeated and the figure drives both the treatment and the medicolegal opinion
• Take carboxyhaemoglobin and cyanide in every fire death; both are produced by burning household materials, and both prove the person was breathing
• Blister fluid rich in albumin and chloride means antemortem; air with a dry yellow base means the blister formed after death
• Full-thickness burns are painless, so testing sensation is a bedside way of assessing depth and a painless white area is the worse injury
• Curling ulcer causes late haemorrhage in a burns patient and should be considered in any gastrointestinal bleed after burns
• Kerosene stove accidents remain the commonest cause in India, and the distinction from bride burning rests on the distribution, the injuries beneath and the circumstances
• Look for injuries beneath the burns — the neck structures, hyoid and scalp — since strangulation followed by burning is the characteristic homicidal pattern