2Definition Dr. Doaa Abdel Wahab Degree of burn MEDICOLEGAL ASPECTS M.L. aspects of thermal injuriesDegree of burnDefinitionTypes of thermal injuriesMEDICOLEGAL ASPECTSOF THERMAL INJURIESOld classificationRecent classificationA thermal injury is a tissue injury resultingfrom the application of heat in any form tothe external or internal surface of the body.First degree burnEpidermal degree1st & 2nd degreeDry or simple burn.Scald or moist burn.Chemical or corrosive burn.Electric burn.Radiation burn.Second degree burnByThird degree burnDermo - epidermal burn3rd & 4th degreeFourth degree burnDr. Doaa Abdel WahabLecturer of Forensic Medicine & Clinical ToxicologyFifth degree burnDeep burn5th & 6th degreeSixth degree burn
3Eaten Singed Wet Wet With mineral acid Present Absent M.L. aspects of thermal injuriesDry burnScaldCorrosiveDegreeAny degree1st, 3rd, 4th1st, 2nd & 3rdAir passageContains sootNo sootNo sootEatenHairSingedWetBloodThick, viscid & contains COHbSkinDry & charredSodden & bleachedStained & corrodedFlame or heated bodyCauseSteam or hot liquidCorrosive acid or alkaliMuch disfigurementThick with disfigurementLess disfigurementScarEatenClothesBurntWetFrom below upwardFrom above downwardAt & below site of contactSite & spreadWith mineral acidCharringPresentAbsentAt circumference of burnt areaOver burnt areaVesiclesRarely found
4M.L. aspects of thermal injuries Factors affecting degree of burn A) Extent of burnt area:is determined by rule of nine of Wallace.B) Depth of burn:The 3rd degree burn is the most serious one.C) Site of burn.Neck, abdominal wall or genitalia are moredangerous than those of the extremities.D) AgeE) SexF) General health.
5II) Rapid death "within 6-48 hours”: M.L. aspects of thermal injuriesCauses of death from burnIV) Death after one week:II) Rapid death "within 6-48 hours”:III) Death within 2-7 days:Immediate causes "within 6 hours“Neurogenic shock.Associated accidental serious injuries to vital organs.Asphyxia (suffocation).Traumatic asphyxia.Secondary oligaemic shock.Secondary toxaemic shock.Acute oedema of glottis (in the neck).Pulmonary fat embolism (burn in a fatty area.(Supra-renal haemorrhage.Bronchopneumonia.Inflammation of serous membranes.Septicemia.- Tetanus, gangrene and erysipelas.:- Rupture of an acute duodenal ulcer (at 12th day) (curling's ulcer) (stress ulcer): may be due to hypovolaemia causing devitalization of mucous membrane in addition to the absorbed burn toxins which are excreted by the liver into the duodenum.-Liver, kidney or heart damage: cell degeneration and necrosis of these organs due to the effect of burn toxins metabolism.
6M.L. aspects of thermal injuries Burn vitalityAge of BurnAntemortem burnPostmortem burnAppearsimmediatelyErythema36 hs48 hsLine of hyperemiaPresentAbsentAppears2-3hsVesicles1 w2 wsPresence of COHbVesiclesAlbuminous fluidrich in chloridePresentAbsentabsent poor inalbumin and chlorideSepsis2 – 3days36 hsVital reactionInfl., pushealingNilSuperficial slough1 wNothingBut burnOther causesCause of deathDeep slough3 wsSoot in URTPresentAbsentRedCopperyScar6 m2 m
7M.L. aspects of thermal injuries Postmortem Picture of Burn Complications of Burn- Particles of soot are present in the airpassage.Subcutaneous or subserous peticheal hgemay be present .Haemoconcentration of blood due to lossof plasma and cherry red colour of the skin.- Skull may show thermal fracture "fissurefracture“.- The body shows evidence of antemortemburns of various degrees.The body presents a peculiar attitude;attitude of defence, boxing or "Pugilisticattitude".Crimson red colour of hypostasis.Generalized visceral congestion and Hgein the internal organs.SepsisDeformitiesKeloid formation
8Postmortem signs of burn Other postmortem signs of death M.L. aspects of thermal injuriesPoints of differentiation () thermal & traumatic fractureTraumatic FractureThermal FractureThe fracture is displacedPostmortem signs of burnThe fracture is not displacedThe brain is edematousOther postmortem signs of death& associated with contused wound in scalpThe brain is shrunkenExtradural haematomafill the spaceExtradural haematomadoesn’t fill the space
9Electric burn Physical Physiological Resistance of body tissue Voltage M.L. aspects of thermal injuriesElectric burnFactors influencing the effect of electric currentPhysicalPhysiologicalResistance of body tissueVoltageHumidityNature of currentPathway of currentAnticipation of shockDuration of contactGeneral health
10M.L. aspects of thermal injuries Ventricular fibrillation Causes of DeathVentricular fibrillationCentralRespiratory failurePeripheralCardiac arrestCerebral anoxiaElectric burnHyperthermic effect
11Rapid onset of rigor mortis Compression of the stratum corni which M.L. aspects of thermal injuriesCurrent MarksP.M. Picture of Electric BurnN / E appearanceMicroscopic appearanceRapid onset of rigor mortisCompression of the stratum corni whichstains deeply with superficial carbonization.Separation of the cells in the form of slits(electric channels).- Elongation of both cells and nuclei.It is of the same size and shape as theconductor.Grayish-white painless areas of asepticnecrosis.- They vary from superficial circumscribedlesions to severe burns with full thicknesstissue necrosis.Marked hypostasisPresence of current markInternal signs of asphyxia
12M.L. aspects of thermal injuries LightiningLightning syndromeDefinitionThe electric current is DC not AC.About amperes.About million volts.- A single flash lasts 1/1000th of a second.Characterized by:Loss of consciousness.Skin burn (similar to 1st degree burn.Conductive deafness.It is the discharge of the atmospherepotential () clouds, or () clouds andEarth.