electrical injury

Epidemiology: 1) 1000 death/year in USA 2) 1% of deaths due to trauma 3) 60% of fatalities are in males, most commonly age 20-34 4) 1/2 of low voltage injuries occur in young children Pathology: 1) electrical burns occur due to conversion of energy to heat 2) at low voltages alternating current is 3 times more dangerous than direct current 3) death many occur due to: a) ventricular fibrillation b) central respiratory arrest c) asphyxia due to tetanic respiratory muscle contractions 4) death may occur from as little as 50 volts; conversely individuals may survive shocks of > 100,000 volts 5) high voltage shock is associated with more extensive tissue necrosis 6) all tissues & organs may be affected by electrical injury a) skin burns are typically full-thickness -> flexor surfaces of wrist, elbow & axilla are most commonly involved because the hand is the most commonly involved part of the body b) nervous tissue is highly susceptible to injury 1] neurologic deficits may be seen initially or up to 3 years later 2] spontaneous resolution of early deficits is common 3] permanent deficits a) may be delayed days to months b) gradual onset with slow progression c) spinal cord damage is the most common permanent sequella of electrical injury (seldom complete) 4] peripheral neuropathies can develop in unburned limbs 5] reflex sympathetic dystrophy (RSD) 6] causalgia c) cataracts may occur following high-voltage injury 1] generally head injury 2] usually bilateral 3] onset of blurred vision ranges from a few weeks to 3 years d) vascular injury a) smaller vessels unable to dissipate heat are susceptible to thrombosis b) larger vessels are susceptible to mural necrosis & delayed hemorrhage c) vascular injury contributes to high amputation rate from electrical injury Management: 1) cardiopulmonary support during acute phase as necessary 2) treat as burn injury a) fluid replacement b) burn center referral may be indicated c) silver sulfadiazine has antimicrobial activity d) sulfamylon (a burn cream) may have better tissue penetration 3) low voltage injuries a) evolution of tissue injury & vascular necrosis is complete within 7-10 days b) wounds are allow to slough & heal by contracture 4) high-voltage injuries a) surgical debridement as needed b) formal amputation & surgical debridement delayed for 2-4 days following injury

Related

burn electrical resistance

References

Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 2557-58