Transcript Presentation Title

Electrical Burns
April 2012
Singh M
www.setpras.org
Learning Objectives
• Understand the classification of electrical injuries
• Understand the pathophysiology of an electrical injury
• Know how to initially assess and manage patients with
electrical burns
• Know how to manage wounds and complications that
may result from an electrical injury
Introduction
• Electrical burns have an incidence of around 3% of all
burns1
• They can be classified into 3 groups:
– 1) Low voltage
• <1000V
• Examples: Home electrical supply, car batteries, surgical diathermy2
– 2) High voltage
• >1000V
• Examples: Industrial supplies, power lines
– 3) Lightning
• High voltage and current, short duration
Pathophysiology
• Joule’s First Law:
– Q=I2RT
• Q = heat produced, I = current, R = resistance, T = time
• Therefore most heat generated when high current, high
resistance and prolonged time
• Different tissues have different resistances:
• Blood<Muscle<Nerves<Skin<Bone
• Lowest resistance to Highest
• Therefore different patterns of injury between different
body tissues
Low Voltage
• Low Voltage Burns:
–
–
–
–
Causes local tissue necrosis
Mimic thermal burn injuries
No deep tissue injury
Household 50Hz AC supply can cause muscle spasm/tetany
• This is sometimes why patients cannot release their grasp of an electrical
source
– May cause cardiac arrest
High Voltage
• High Voltage Burns:
– Causes both local tissue and deep tissue injury
– Generally has an entrance and exit point (must be looked for on
patients). These and other contact areas are likely to be full
thickness defects
– Deep muscle injury may be severe with little overlying skin injury
– This can lead to excessive muscle necrosis, rhabdomyolysis and
compartment syndrome, secondary to muscle swelling
– Must be observant for signs of this as patients may need urgent
fasciotomies
– May also suffer bowel perforation or spinal cord transection3
Lightning
• Lightning Burns:
– Can cause injury by:
• Direct strike
• Ground splash
• Side splash
– Typically, current flows superficially, causing partial thickness
burns2
– May have exit wounds on feet
– Cardiorespiratory arrest is common. Usually reversible, therefore
prolonged resuscitation worthwhile
– Lichtenberg flowers are pathognomonic
– May cause cardiac dysrhythmias, tympanic membrane
perforations and corneal damage
Management
• Initial management must be: ABCDE approach
• Include protection of C-spine, many patient have
suffered concurrent trauma
• Full primary and secondary survey with resuscitation
• Catheterise – to monitor for urine discolouration
(haemochromogenuria) and urine output
• Aim for urine output in an adult of 50-75ml/hr, if pigments
in urine, increase to 75-100ml/hr
Management
• May require aggressive fluid resuscitation due to
underlying muscle injury
• Mannitol may be used where difficulty maintaining urine
output
• ECG monitoring for cardiac damage/dysrhythmias
• Must assess limbs for signs of compartment syndrome
or vascular compromise – May need fasciotomy
• Cutaneous injuries should be managed as for thermal
burns
Conclusions
• 3 types of electrical injuries
• Electrical burns may produce cutaneous wounds similar
to thermal burns or deep compartment damage, that
may be difficult to detect
• Patients should be assessed and managed as for
trauma
• Cardiac and urine output monitoring are both useful
adjuncts
• Mortality ranges from 8-14%1
References
• 1. Giele H, Cassell O. Oxford Handbook of Plastic and
Reconstructive Surgery. Oxford: Oxford University
Press; 2008
• 2. Emergency Management of Severe Burns Course
Manual. Australia and New Zealand Burn
Asociation;2006
• 3. Stone, C. Plastic Surgery Facts. New York: Cambridge
University Press; 2006