Electrical & Lightning Injury Richard Dionne MD Emergency Medicine –University of Ottawa March 2013

Electrical & Lightning Injury Goals & Objectives Comprehensive understanding of Ohm’s law Discuss the differences of AC vs DC and it’s potential clinical impact Discuss the early and late systems complications seen in both and their management Comprehensive ER management of a victim of low vs High voltage electrical injuries

Case Patient came into contact with electrical source, touching Left hand accidentally. Source Industrial motor? What is your approach ? What do you need to know?

« Electrical Injury » Damage proportionnal to current flow intensity Y Ohm’s Law : Current : I = V/R Intensity (amp) = Voltage / Resistance

Description Telephone lines: 65 V Household circuits: 110 V Range / Dryer : 220 V Power lines: 220 V Subway rails: 600 V Residential Trunk lines: 7000 V

Current types Alternating (AC) – Periodic cycles (reversal of flow) – Residential power – Produces muscle tetany & prolongs contact – Higher risk of Ventricular Fibrillation Direct (DC) – Continuous flow one direction – Defibrillators / industrial sources – Single forcefull contraction – throws patient – Higher risk of asystole

Resistance Y Mucous membranes100 Ohm / cm2 Y Wet skin “” Y Sweat “” Y Skin “” Y Plantar Skin “” Y Callouses “” Bone > Tendon > Skin > Muscle > Vessels > Nerve

Intensity Y mA… Tingling / paresthesia Y 4 mA… « Let-go » child Y mA… « Let-go » adult Y mA… Tetany Y mA… Resp. arrest (medulla) Y mA… Ventricular Fibrillation Y A… Burns Y A… Asystole

Case … What is the significance of this?

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Factors associated with Severity Y Voltage … ( high > 1000 V… low < 1000 V ) Y Amperage … ( intensity of current ) Y Type of current … ( AC > DC ) Y Tissue resistance & Contact surface Y Contact duration … Y Current Trajectory … Y hand-hand / hand-foot / head - foot / foot - foot Y Environnemental … (water / metal / etc.)

Trimodal Distribution Toddlers Household cords & outlets Teenagers Risk-taking behavior Adults Work related injuries

Types of Injury Primary Electrical Phenomena – Cardiac arrythmias / muscle tetany Tissue Destruction – Superfical & deep burns – Deep tissue injury / necrosis … misleading Secondary Injury from Trauma – Being thrown

Target Organ Injury Neurology Respiratory arrest Delayed neurologic injury ; RSD Vascular: Thrombosis / Compartment syndromes Nephrology: ARF & ATN / myoglobinuria Orthopedic Posterior shoulder dislocation / trauma Ophtalmological Corneal burns / delayed cataracts

Work-up ECG Urinalysis for myoglobin Cardiac monitoring Prolonged monitoring not necessary in asymptomatic patients with normal ECG, no dysrythmias & exposure < 240 V… Cardiac Markers Abnormal ECG or dysrythmias High-voltage exposure

Treatment A-B-C’s Burns & Trauma Fluid resuscitation as needed Rhabdomyolysis – NaHCO3 / Lasix / Mannitol ? Pain control +++

Different Types Flash Burns Arc Burns Contact Burns

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Case 25 yrs old was talking over an outdoor phone when lightning hit a metal post about 1 Km away. She felt a jolt on the phone and feels tinnitus, headache and tired ever since. No specific limb pain or burns felt.

Lightning Injury Lightning is a stream of negative current downward from cloud to ground Brief duration msec Tends to pass over the skin rather than through (flashover)

« Lightning Injury » Y High energy level at a short duration … Y Clinical : Asystole >>> V. Fibrillation YCardiac automaticity restarts, but Respiratory arrest persists … « Medullary concussion » Y Important : Rapid Ventilatory Support … Y Inverse Triage Notion if Disaster !!!

Lightning Mechanism of injury: – Direct strike – Side splash injury – Contact strike – Ground strike – Blunt injury / fall – Thermal burning – Usually outdoor activity / handling of electrical equipment or telephones

Lightning Cardio-Respiratory Arrest Medullary center “concussion” = triage reversed Asystole (DC) Neurologic long term deficit Paresthesias / Tinnitus / depression / etc. ENT Ruptured tympanic membranes & ossicular disruption Ophtalmo Cataract / retinal hemorrhages & detachment Dermatology Ferning pattern that resolves

Ferning Flash Burn

Comparison Lightning vs High Voltage LightningHigh Voltage Duration instantprolonged Energy Level - Voltage 3000 – V> 1000 V - Amperage A A Character Direct (DC)Alternative (AC) Pathway FlashoverHorizon. / Vert. Burns SuperficialDeep Rythm AsystoleV. Fibrillation Myoglobinuria rarecommon Fasciotomy rarecommon Blunt injury explosiveprojection

Complications 1- Cardiovascular 2- Respiratory 3- Neurologic ( acute & long term ) 4- Renal 5- Musculoskeletal (Trauma & Burns) 6- Ophtalmology 7- ENT 8- GI

Complications : Neurologic Short & Long term … YChronic pain syndrome YSevere headache : post-concussive like syndrome YVertigo & Ataxia YSeizures YNeurocognitive : Y short-term memory loss / personnality change / difficulty in multitasking or learning new abilities YSleep distubances YPeripherical nerves (médian & ulnar) YReflex Sympatic Dystrophy

When to discharge or admit?

Indication for Admission Y High tension « > 1000 Volts » … or Y Low tension & associated : ý Current via : thorax / head … ýLoss of consciousness … ýECG anomalies or arythmia … ý Electrothermic (deep) burns … ýNeurovascular compromise of extremity …

Criteria for Discharge ( Cunningham et al. ) 1- Patient asymptomatic & low risk … 2- Tension < 220 Volts … 3- Exam & ECG initially normal 4- Observation 4 - 8h normal in ER...

Case A 14 month old bambino decides to snack with an electrical cord. It is an extension cord from an household appliance on 110V. He presents to the ER with burns to the mouth, no active bleeding, no airway compromise.

Oral Burns

Contact Burn Mucosa & Eschar Plastic Surgery Consultation … Y Need for splinting to prevent retraction scarring Admission & Monitoring ? … Y eschar can fall & labial artery hemorrhage … ( up to 10 % in days )

Case A 22 yr old, 6 months pregnant, accidently felt a jolt when touching a lampshade. She felt the energy from her Right hand to her Right foot. It was regular household current of 110 V. She is worried about her pregnancy...

Electrical Injury & Pregnancy ý High risk for: ýMiscarriage ýFetal demise ýStillbirth ýAbruptio placentae (trauma) ý Risk of Stillbirth … Low voltage... Y Fatovich et al. 73 % ( 15 pts ) ??? Y Einarson et al. 15 % ( 62 pts )

Electrical Injury & Pregnancy ý High risk of fetal demise : Y current crosses uterus YFetus must less resistant to shock Y > 220 V Y First Trimester … ý Observation of fetal movements … ýhigher risk of fetal demise if dimished fetal movements noted closely after incident...

Electrical & Lightning Injury Key Concepts High-voltage injury can cause significant tissue & organ damage along the entry & exit pathway Patients with low voltage electrical injury who have only minor cutaneous burns may be discharged safely if ECG, urine & 4 hour monitoring is normal. Lightning injury may cause significant injury, mainstay is to observe these patients.

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TASER Richard Dionne MD Emergency Medicine – University of Ottawa March 2013

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TASER Thomas A. Swift Electric Rifle (TASER) Mechanics: – Air rifle shot 10 meters away with 1200 V in 19 pulses per sec. over 5 sec. – Short duration total charge of V, but very low amperage < 3 mA… (0.03 A) – Comparison… Wall outlet 110 V at 15 A 60 W light bulb 0,5 A Christmas Tree bulb 1 A

TASER Conducted Energy Weapons

Traditional “Blunt” Pulse High Energy, “Brute Force” Approach 90% Energy Loss Traditional “Blunt” Pulse New Shaped Pulse ™ Arc Phase Stim Phase New Shaped Pulse ™ Full Energy Penetration

TASER Between 2001 – Americans died after shock – (Amnesty International) … 50 directly related??? June 2008, $5 million damages, death Robert Henson, 40, San Jose California 15% related to stun gun & 85 % related to amphetamines …

TASER Canadian data Quebec Provincial Police 2006, used 51 times, no adverse outcomes RCMP in 2009, used 1106 times, no adverse outcome reported

TASER Oct 2007, Robert Dziekanski, 40, Vancouver Airport… Shocked 5 times Excited Delirium … vs … TASER ???

60% SMALLER

TASER Conducted Energy Weapons Concerns have been raised about CEW role in deaths 5/18 patients in Stratton study tasered prior to death Several studies have examined effect of taser on healthy volunteers – 25 exercised to exhaustion then tasered for 15 seconds and EKG performed- no changes observed (Ho et al, JEM, 2011) – 25 exercised to exhaustion then tasered for 5 seconds and performed EKG, vital signs, ABG, lactate- no difference between shocked and non-shocked (Vilke et al, Acad Emerg Med, 2009) But not acidotic, hyperthermic, hyperadrenergic people

TASER Conducted Energy Weapons Most common theory is that taser causes dysrhythmia Swerdlow et al, Acad Emerg Med, 2009 – 56 people died within 15 minutes of being tasered – 7% had shockable rhythm, 93% PEA or asystole – Time from collapse to first recorded rhythm less than 5 minutes in 77% of patients – Only 2% collapsed immediately, 7% within one minute, and 91% more than 1 minute later – “…electrically-induced VF is not a common mechanism of death after tasering.”

Cause of Death in Exited Delirium Putting it all together – Hypertrophied, fibrotic heart – Hyperadrenergic state – Oxygen demand exceeds supply in setting of tachycardia, hypertension, CAD, vasoconstriction, myocardial hypertrophy, and physical restraint of chest – Severe acidosis requiring huge respiratory compensation, with physical restraint of the chest – Cardiovascular collapse

Questions ?