E&L Inj


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Dr Saud Al Sulimani

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E&L Inj

  1. 1. Electrical & Lightening Injuries Dr.Suad Al-Sulimani( R2)
  2. 2. Outline <ul><li>Physics of injury </li></ul><ul><li>Clinical featurs & effect on different body systems </li></ul><ul><li>Management </li></ul><ul><li>disposition </li></ul>
  3. 3. Physics <ul><li>P = I2Rt ( I=V/R) </li></ul><ul><li>P thermal power I , in joules </li></ul><ul><li>I current , ampers </li></ul><ul><li>R resistance in ohms </li></ul><ul><li>T time in seconds </li></ul><ul><li>V Potential , in volts </li></ul>
  4. 4. Q: All of the following are factors determining the electrical injury except ? <ul><li>Type of circuit </li></ul><ul><li>Duration of contact </li></ul><ul><li>resistance of tissue </li></ul><ul><li>Pathway of current </li></ul><ul><li>Surface area of victim </li></ul>
  5. 5. Q: All of the followings are true facts about type of circuit except ? <ul><li>DC ( direct current ) cause single muscle injury , shorter duration of contact & less traumatic blunt injury </li></ul><ul><li>AC ( alternative current) tend to be three times more dangerous than DC due to continious muscle contraction </li></ul><ul><li>flexor muscle contraction with exposure to AC prevent the victum from releasing his hand leading to prolong exposure </li></ul><ul><li>Breief contact with DC can result in cardiac arrythmias </li></ul>( tendes to through the victim from the source)
  6. 6. Resistance <ul><li>Q:Which of the following tissues are the most resistant ? </li></ul><ul><li>bone </li></ul><ul><li>nerve </li></ul><ul><li>muscle </li></ul><ul><li>blood vessel </li></ul>
  7. 7. <ul><li>The higher is the resistance of tissue the greater transformation of electrical to thermal injuries </li></ul><ul><li>Muscles & blood vessels has low resistance & good conductor </li></ul><ul><li>Bone tendon & fat have high resistance & tend to heat & coagulate rather than transmit the current </li></ul><ul><li>Callosed skin has more resistance than normal skin </li></ul><ul><li>Moister & sweaty skin decrease the resistance </li></ul>
  8. 8. Resistance of body tissues Most tendon Fat Bone intermediate dry skin Least Nerve Blood Muscle Membrane Muscle
  9. 9. Current ( Ampreage ) ( the measure of the amount of energy flows through an object ) <ul><li>Remember I=V/R </li></ul><ul><li>The voltage of the sourse is known but the resistance varies </li></ul><ul><li>The physical effect vary with different </li></ul><ul><li>amprage </li></ul>
  10. 10. <ul><li>&quot;let go&quot; current </li></ul><ul><li>the maximum current at which a person can grasp the current and then release it before muscle tetany makes letting go impossible. </li></ul><ul><li>child is 3-5 mA; this is well below the 15-30 A of common household circuit breakers. </li></ul><ul><li>adults, the &quot;let go&quot; current is 6-9 mA, slightly higher for men than for women </li></ul>
  11. 11. <ul><li>The thoracic tetany occur just above the let go </li></ul><ul><li>current & result in respirator arrest </li></ul><ul><li>VF occur at an amperage of 60 to 120 </li></ul><ul><li>VF occur more with alternative current while asystole with DC </li></ul>
  12. 13. Duration of contact <ul><li>The longer the duration they greater the electro thermal energy & tissue distraction in electrical injury </li></ul><ul><li>With lightening injury </li></ul><ul><li>Short duration less skin damage flash over the current around the body </li></ul>
  13. 14. Voltage (the measure of diffrence in electrical potential between two points) -depend on the source -the higher the voltage the more is tissue distraction - no fatalities with low voltage 500V or 1000V used as a cutpoint
  14. 15. Pathway , which of the following is false: <ul><li>Current through heart & thorax can cause arrythmia & myocardial damage </li></ul><ul><li>Cerebral current cause respiratory arrest & seizure </li></ul><ul><li>Truncal current cause more damage than single digit current . </li></ul><ul><li>Current passing through head & neack are more likely inducing cataract </li></ul>
  15. 16. <ul><li>As the current density increase the tendency to flow to less resistance tissue is overcome </li></ul><ul><li>With high voltage current the damage occur at a site distant from apparent contact area </li></ul><ul><li>Electrical field strength = voltage /length </li></ul>
  16. 17. Histological changes <ul><li>Coagulation necrosis of muscles (periosteal , shortening of sarcomers) </li></ul><ul><li>Vascular damage </li></ul><ul><li>( hemorrhage , thrombosis , progressive tissue necrosis) </li></ul><ul><li>Neural tissue damage </li></ul><ul><li>( Coagulation necrosis , compartment </li></ul><ul><li>syndrome) </li></ul>
  17. 18. Mecechanism of injury ( Electrical injury ) <ul><li>1-Direct contact : Electrothermal heating </li></ul><ul><li>Low voltage :limited to the affected area </li></ul><ul><li>High voltage : burn any where along the current path </li></ul>
  18. 19. <ul><li>2-Indirect contact: Electrical Arc </li></ul><ul><li>formed between two objects differing in potential , not in contact </li></ul><ul><li>Result in deep thermal injury because of high temp of the electrical arc or sometimes flame burn or splashing across the entire body </li></ul>
  19. 20. <ul><li>Flame: Ignition of clothing causes direct burns from flames. </li></ul><ul><li>Flash : When heat from a nearby electrical arc causes thermal burns but current does not actually enter the body </li></ul>
  20. 21. Lightning Injury <ul><li>Direct strike </li></ul><ul><li>( orifice entry ) </li></ul><ul><li>Contact </li></ul><ul><li>( when a person touch an object in the path way of lightning ) </li></ul>
  21. 22. <ul><li>Side flash </li></ul><ul><li>( lightning jump from primary strike object to near by person) </li></ul><ul><li>Ground current </li></ul><ul><li>( Difference in electrical potential between person feet) </li></ul><ul><li>Blunt trauma </li></ul><ul><li>(expulsive or impulsive force) </li></ul>
  22. 24. Clinical features : Head & neck <ul><li>Which of the following is false? </li></ul><ul><li>Head & neck are common Points of high voltage injury </li></ul><ul><li>Cataracts develop in 6% more typically short after the injury </li></ul><ul><li>Tympanic membrane rupture occur in lightening injury </li></ul><ul><li>Ocular injuries occur ( uveitis , iridocyclitis , vitrous hemorrhage & retenal detachment ) & the common is cataract </li></ul>
  23. 25. <ul><li>Cardiac arrest from Asystole(lightening) or VF(electrical ) in electrical injuries </li></ul><ul><li>Cardiac arrest from shock or induced vascular spasm in lightening injury </li></ul><ul><li>Hypertension is commonly present after lightening injury. </li></ul>Clinical features : cardiovascular
  24. 26. <ul><li>All of the following are ecg changes in electrical injuries except : </li></ul><ul><li>Transient ST elevation </li></ul><ul><li>Prolonged QT </li></ul><ul><li>Premature ventricular contaction </li></ul><ul><li>AF </li></ul><ul><li>Bundle brach block </li></ul><ul><li>VT </li></ul><ul><li>AMI is rare ,, can be misdiagnosed due top high CK </li></ul>
  25. 27. <ul><li>Clinical features : skin </li></ul><ul><li>all of the following are true except ? </li></ul><ul><li>deep burn occur in electrical injuries especially in hand </li></ul><ul><li>& skull </li></ul><ul><li>heels are most common site of ground contact point </li></ul><ul><li>kissing burn commonly occur in extensor creases </li></ul><ul><li>electrical flash burn are superficial partial thickness </li></ul><ul><li>electrical injury burn is 10 % -25 % surface area </li></ul><ul><li>most common burn in children is mouth burn </li></ul><ul><li>complicated by orbicularis oris muscular injury , </li></ul><ul><li>labial artery damage , damage to developing </li></ul><ul><li>dentition </li></ul>
  26. 28. <ul><li>deep burns occur in only 5% of lightening injury </li></ul><ul><li>superficial burns ( linear , punctate , feathering , thermal burns ) </li></ul>feathering Clinical features : skin (flash/ferning).
  27. 29. <ul><li>17 years old boy, suffered injuries to both upper limbs caused by accidental contact with high-voltage electric current. Under medical care, he was transferred to our service on the day of the accident and continued treatment in our intensive care unit. </li></ul><ul><li>On the second day of treatment he was taken to the operating theatre and debridement of the wounds in the radiocarpal areas </li></ul><ul><li>day 3 there was clear evidence of full necrotic tissues also on all the fingers, which until then had been ischaemic ? </li></ul><ul><li>What is the mechanism explaining this finding </li></ul><ul><li>compartment syndrome </li></ul><ul><li>thrombus in brachial artery </li></ul><ul><li>nerve injury </li></ul><ul><li>vascular delayed hemorrhage </li></ul>
  28. 30. Clinical features : Extremities <ul><li>Electrical injury </li></ul><ul><li>Muscle necrosis might occur at area distant from the skin injury point </li></ul><ul><li>Compartment syndrome is common </li></ul><ul><li>Renal failure is secondry to myoglobulinuria </li></ul><ul><li>Joints exhibit more severe injury than muscles,, why ? </li></ul><ul><li>Vascular injury should be assesed continiously </li></ul><ul><li>( thrombosis or hemorrhage ) </li></ul>
  29. 31. Clinical features : Extremities <ul><li>Lightening injury </li></ul><ul><li>Cause transient vasospasm ,, extremity cold , </li></ul><ul><li>blue, pulseless </li></ul><ul><li>Resolve spontiniously within hours </li></ul><ul><li>Long bones fracture , shoulder dislocation migt occur .( rotator cuff muscle spasm ) </li></ul>
  30. 32. Clinical features : Nervous system <ul><li>Electrical injury: </li></ul><ul><li>( high voltage injury ) </li></ul><ul><li>= transient LOC , confusion , flat effect </li></ul><ul><li>Short memory loss </li></ul><ul><li>Seizure direct effect </li></ul><ul><li>traumatic injury </li></ul><ul><li>hypoxia </li></ul>
  31. 33. neurologicasl damage immediate Delayed Within hours Weakness paraesthesia Days to years Lateral sclerosis Transverse mylities Ascending paralysis
  32. 34. Q:which of the following statements regarding lightening strike is correct ? <ul><li>Absence of pupil reactivity is reliable examination confirming brain death </li></ul><ul><li>In mass causality incidents involving lightening cardiopulmonary arrest victums mandate high priority </li></ul><ul><li>Lower extremity paralysis is typically permanent </li></ul><ul><li>Vitrous hemorrhage is the most frequently observed ocular sequale </li></ul>
  33. 35. <ul><li>25 years old man , after exposure of lightening injury was found to have lower limb paralysis that apper to be blue , mottled , cold & pulseless </li></ul><ul><li>What immediate intervention is required: </li></ul><ul><li>- admit for serial perephral vascular examination </li></ul><ul><li>- immideiate surgical intervention - discharge home - observe in the emergency for 6 hrs i - perform radiological study to confirm diagnosis in ED </li></ul>
  34. 36. Neurological symptoms ( lightening ) <ul><li>Keraunoparalysis </li></ul><ul><li>( clear within hours) </li></ul><ul><li>Intracranial hemorrhage, seizure , loc </li></ul><ul><li>Might occur </li></ul>
  35. 37. Management , prehospital : <ul><li>Securing the scene </li></ul><ul><li>Power source should be turned off </li></ul><ul><li>Use of electrical gloves by medical personnale is </li></ul><ul><li>dangerous </li></ul><ul><li>DEnergizing the lines </li></ul><ul><li>Triage should be concentrated on the presence of </li></ul><ul><li>cardiac or respiratory arrest </li></ul><ul><li>Patients require cardiac & trauma care </li></ul>
  36. 38. Remember <ul><li>ABCs </li></ul><ul><li>IV-O2 monitoring </li></ul><ul><li>Folyes catheter </li></ul><ul><li>NGT in severe injuryies </li></ul>
  37. 39. Fluid resusitation <ul><li>Al least 1 large bore cannula should be there </li></ul><ul><li>Initial resuscitation by 20 ml /kg isotonic fluid </li></ul><ul><li>Body surface area formulas for calculating fluid requirement is not applicable </li></ul><ul><li>Lightening injury does not require fluid overload </li></ul>
  38. 40. Q: 2-years old girl a brought to ED found crying holding her right index finger, unprotecteted electrical wall socket was nearby visual inspection reveals localized areythema , good capillary refill , good pulses , full range of movement Chest auscultation reveals normal heart sounds , no other signs of trauma . What diagnostic test should be performed to complete the evaluation of this child ? <ul><li>Urinalysis </li></ul><ul><li>Basic metabolic panel </li></ul><ul><li>chest x-ray </li></ul><ul><li>ECG </li></ul><ul><li>Arterial doppler </li></ul>
  39. 41. Monitoring : <ul><li>Cardiac monitoring is indicated in: </li></ul><ul><li>Cardiac arrest </li></ul><ul><li>Documented Loc </li></ul><ul><li>H/O cardiac disease </li></ul><ul><li>Suspicious of conductive injury </li></ul><ul><li>Hypoxia </li></ul><ul><li>Chest pain </li></ul><ul><li>A bnorml ECG </li></ul>
  40. 42. <ul><li>All patients require : </li></ul><ul><li>ECG </li></ul><ul><li>Cardiac enzymes </li></ul><ul><li>CT scan for victims with altered mentation </li></ul><ul><li>or detororation of neurological status </li></ul><ul><li>Laboratory : </li></ul><ul><li>Cbc , ue 1 , urinalysis </li></ul><ul><li>Liver & pancreatic enzymes , coagulation if there is </li></ul><ul><li>abd trauma </li></ul><ul><li>Check for myoglobulinuria </li></ul><ul><li>CK level ( predict muscle injury) </li></ul><ul><li>Radiological study according to the injured area </li></ul>
  41. 43. Specific therapy <ul><li>Rhabdomyalisis </li></ul><ul><li>Urinary alkalinization </li></ul><ul><li>Mannitol & frusamide </li></ul><ul><li>Urine output maintained at 1-1.5 ml/kg/hr </li></ul><ul><li>Ph of blood maintained at 7.4 by sodium carbonate </li></ul><ul><li>Burn wound care : </li></ul><ul><li>Dressing with silver sulfadiazine </li></ul><ul><li>TT </li></ul><ul><li>High dose of penicillin ( clostriridial myositis </li></ul>
  42. 44. <ul><li>Extremities injury </li></ul><ul><li>Spilint </li></ul><ul><li>Durgical amputaion </li></ul><ul><li>Surgical wound care </li></ul><ul><li>Debridement </li></ul><ul><li>Skin grafts and flaps </li></ul><ul><li>Escharotomy </li></ul><ul><li>Fasciotomy: </li></ul><ul><li>Nerve release </li></ul><ul><li>ArthroplastyAmputation </li></ul>
  43. 45. <ul><li>Disposition </li></ul>
  44. 46. Q: 4-years old boy represent after sticking a fork in to a home Electrical outlet with his right hand and get shocked . His right elbow was on the ground he remained asymptomatic physical examination reveals two extremely small first-degree burns on his right hand and elbow; a 12-lead ECG is normal . The most appropriate disposition is ? -admit to monitored bed for 24 hours - admit to non monitored bed for serial perephral vascular examination - discharge home - observe in the emergency for 6 hrs if no dysarrythmiias occur discharge home - perform echocardiography in ED
  45. 47. Disposition:which patient can be dischrged home ? <ul><li>52 years old with high voltage current & chest pain </li></ul><ul><li>30 years old with low voltage injury, coetaneous burn & mild persistent symptoms </li></ul><ul><li>22years old man with lightening injury & altered mentation </li></ul><ul><li>60 years old man with low voltage exposure known to have cardiac illness but asymptomatic & normal ECG </li></ul><ul><li>3years old boy with electrical lip burn & non caring parents </li></ul>
  46. 48. Thank you