Postgrad Med J: first published as 10.1136/pgmj.33.379.219 on 1 May 1957. Downloaded from 219 THE MANAGEMENT OF ELECTRICAL BURNS By I. F. K. MUIR, M.B.E., M.B., F.R.C.S. Mount Vernon Centre for Plastic Surgery due Injuries to electrical currents-so called .. electrical burns--form a small but important .i.:..9- section of all burning accidents. They have certain features which distinguish them from :i. thermal burns, and which have an important bearing on prognosis and treatment. The of electrical burns seen in this i}:: majority :.: country are caused by accidents involving the ..:. domestic electrical supply (usually 220-250 volts A.C.), but burns caused by the high voltage grid system (e.g. 66,ooo volts, or 33,000 volts) are occasionally seen. These high tension injuries *...:... are usually much more severe than those caused *:-3,X9 by the domestic supply, and are more often fatal. Physics by copyright. The damage is due to the passage of electricity through the tissues, and the extent and severity of the damage depends on the strength of the current (in amperes) and the time for which contact is maintained. The voltage is dependent on the nature of the supply, and as has been stated is usually 220-250 volts. The amperage depends upon the resis- stance offered to the current by the body in ac- http://pmj.bmj.com/ cordance with Ohm's Law. V A- R FIG. I.-An electrical burn of the hand. Shows the entry and exit wounds on the same hand. Loose The large fluid content of tissues, particularly horny skin has been removed. A patient of of the blood plasma and interstitual fluids, makes Mr. Rainsford Mowlem, F.R.C.S. the interior of the body an excellent conductor (i.e. of low resistance), and the main variability of on September 27, 2021 by guest. Protected resistance lies in the skin and in the nature of its with a water-pipe or drainpipe. Under ordinary contact with the source of electricity. Thus wet conditions the floor of a house is insulated from skin in firm contact with the source will allow the ground and a burn will not occur even when more current to pass than dry skin in light contact. the live wire is firmly held unless this second It should also be remembered that if current is to contact is made. pass in the body two contacts must be made. The It will therefore be clear that there will always ordinary two-point domestic supply consists be an entry and an exit wound although, because of a live or active wire and a neutral wire. The of differences in contacts and local resistance, extra point in a three-point supply is used to earth these may differ very much in severity. Often the frame of the apparatus. Current will pass both wounds are on the same hand. Sometimes when one contact is made with the live wire and a there is one on each hand, less frequently other second contact with either the neutral wire or the parts of the body are involved (Fig. 2). 'earth.' 'The' earth' connection may be by actual The hands are involved in the vast majority of direct contact with the ground or by indirect contact accidents. The last 27 patients with domestic Postgrad Med J: first published as 10.1136/pgmj.33.379.219 on 1 May 1957. Downloaded from 220 POSTGRADUATE MEDICAL JOURNAL May 1957 supply electrical burns admitted to the Mount grasp the unguarded hot element of an electric fire Vernon Plastic Centre, had burns of the hands, no are in fact heat burns and not electrical burns, as no other part of the body being involved, and of current passes through the child. This has an seven patients with high tension injuries, four had important bearing on treatment and prognosis for severe injuries of one or both hands, two had these hot element burns are usually less deep than severe injuries of one arm and only one had no electrical burns (the damage is seldom deeper than burn on the upper limbs. In all these high tension the skin itself) and they are much more easily cases there were severe burns on other parts of the treated. body. Superficial burns may also be caused by an Fortunately the body resistance usuallykeeps the electric flash, as when a fuse blows or an electric amount of current below that necessary to produce arc is struck as a result of a short circuit. These severe systemic disturbances. Temporary un- flash burns are again heat burns caused by a consciousness is not uncommon in -domestic high temperature for a very short time and may accidents, but death is rare and only occurs when present an alarming appearance as the face and' contacts are exceptionally good, the classic hands may be blackened by a film of carbon. example being the man excellently earthed by This is easily cleaned off and the underlying skin standing in a bath filled with water who then is found to be minimally damaged. makes contact with the mains, by reason of a faulty light or heater switch. Pathology Many different types of electrical apparatus are There is still some disagreement as to the responsible for accidents: sometimes this is due immediate cause of the damage, it being held on to the development of a defect in the insulation so the one hand that it is due to heat generated by the that a frayed wire causes a short circuit but some- passage of the current, and on the other to a times it is due to faulty construction or assembly. specific action of the current on the tissues. It is Thus in some instances it is found that the on-off true that high temperatures may be produced by switch has been incorrectly placed in the neutral the passage of electrical currents through tissues, instead of the live wire so that the element remains but the natural history of electrical burns differs by copyright. live even when the switch is in the off position. so clearly from that of thermal burns that it is Under these conditions the unfortunate victim impossible to avoid the conclusion that some may touch the element and accidentally complete specific effect is at least partially responsible for the the circuit with his own body. damage. Almost all domestic supply is now by means of The skin wound of an electrical burn is clearly alternating current (A.C.) and in many instances circumscribed to the area of contact and this skin the period of contact is prolonged by the muscles is dead. Deep to the skin the area of injury being thrown into tetanic spasm by the current extends towards the other point of contact with so that the victim is unable to let go until destruction of deeper tissues. Because of their http://pmj.bmj.com/ the current is switched off, although some de- fluid content main vessels form good conductors termined patients retain sufficient presence of and thrombosis of digital or other main vessels mind to prise off the offending apparatus with may occur with important consequences. their feet or wrench it away bodily until the plug In a thermal burn (e.g. the pure heat burn from comes out of its socket. a hot element) the dividing line between destroyed Direct current (D.C.) injuries may rarely be and surviving tissue is clear cut and a healthy seen and in these there is a single sharp shock zone of reaction soon forms. The soon slough on September 27, 2021 by guest. Protected which causes a typical electrical burn and has the separates in io to 14 days, exposing red healthy effect of blowing the victim off the source ofsupply. granulations on which skin grafts take readily, These injuries are sometimes sustained (usually by and it is exceptional for nerves, tendons or joints errant children) on the electric railway line (66o to be damaged or exposed during the course of volts D.C.). Only the Southern Region of healing. British Railways is extensively electrified, and In an electrical burn, however, the local defence although Dale of East Grinstead reported several reaction in the marginal zone of surviving tissue is of these injuries they are rarely seen in other parts imperfect and slow to develop; sloughs are slow td of the country (Dale, I954). separate and the granulations, when they are The types of accidents described are all re- exposed, are pale and oedematous, and free skin sponsible for causing true electrical burns with all grafts take poorly. Furthermore, this surviving their typical features but it must be remembered but damaged tissue, by reason of its depressed that not all burns sustained on electrical apparatus cellular activity, offers poor resistance to bacterial are in fact of this nature; indeed, the majority of invasion and infection may lead to further burns sustained by children when they fall and necrosis of tissue with exposure of tendons or Postgrad Med J: first published as 10.1136/pgmj.33.379.219 on 1 May 1957. Downloaded from May 1957 MUIR: The Management of Electrical Burns 221 - a' a:::: :::.: 1i:i . - i :;'c;i· |" .1lEa~:1- |r+ by copyright. idei.:'teil-jiiljli:ii ~ ·lii~~1 ·"JE~:t"i'~:i :~i~~~f':::" "· http://pmj.bmj.com/ on September 27, 2021 by guest. Protected FIG. 2.-An electrical burn of the thumb treated by excision and the application of a cross finger flap from the dorsum of the index finger.