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Burns caused by electricity
BURNS CAUSED BY ELECTRICITY
A Review of Seventy Cases By MARY R. DAVIES,M.B., Ch.B. Research Registrar, Medical Research Council Industrial Injuries and Burns Research Unit, Birmingham Accident Hospital ELECTRICAL injuries form a comparatively small proportion of all burns, but they present special problems. The severity of the injury is easily underestimated initially ; the necrotic tissue is slow to separate and damage to blood-vessels may result in secondary h~emorrhage. The hand is commonly involved, and the depth of injury and added infection combine to make these injuries crippling. Although immediate excision sometimes fails to remove all dead tissue, early healing to reduce the risk of infection and joint stiffness is most desirable. This review was undertaken in an attempt to clarify the treatment used and to find out which methods gave the best final result. It covers the five-year period I951-55 at the Birmingham Accident Hospital, during which time seventy out of 1,893 admissions to the Burns Unit were the result of accidents caused by electricity. MATERIAL Of the seventy patients with burns caused by electricity, the cause of the injury was electric contact alone in thirty-five, contact and heat in seventeen, contact and flash in five, and flash alone in thirteen. Their ages ranged from I4 months to 75 years (average 27 years). Thirty-eight of these patients were involved in domestic accidents with the household electricity supply of 230 to 24o volts. Of the industrial accidents, the voltage was not known in twenty ; it was 230 to 240 volts in two ; 400 to 440 volts in five ; 6,000 to 6,600 volts in two ; 33,ooo volts in one ; and 68,ooo volts in two. In most cases the size of the burn was small. In forty-six patients the area involved was less than I per cent. of the body surface, and in twenty it was more than I per cent. but less than Io per cent. In the remaining four patients flash was responsible for part or all of the burn (area of burn Io½, I4, I7, and 4o per cent.). The hands were involved in all but five cases. In thirty-three cases one hand only was burned (right in fifteen, left in eighteen) ; both hands were burned in thirty-two cases. In twenty-seven patients there was a burn of another part o f the body. The face was involved in seventeen of these, all but one being the result of a flash burn. Fifty-six patients (8o per cent.) reached this hospital within six hours of injury. Of the eleven patients arriving here more than twenty-four hours after the accident, six were transferred from other hospitals (one to twenty-nine days after injury) and five had been at home (seen two to thirty-five days after injury). Three patients were reported to have been unconscious following the accident, 288
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but all were fully conscious on admission. Initial resuscitation was required only for the extensively burned and not for electrocution. After discharge from the ward patients were followed up as out-patients until full function was restored or it was considered that no further improvement would be obtained. Five patients were referred to other hospitals for follow-up and four patients failed to attend the clinic. In the others, supervision was maintained for two weeks to five years (average fourteen and a half months), with two patients still attending. Time of healing has been taken as the day on which the patient was seen with no crust or raw area present. In out-patients this has frequently resulted in an overstatement of the true healing time by up to seven days, but for purposes of comparison a similar error is probably present in all groups. RESULTS In assessment of the results, the injuries caused by electric contact alone, by contact and heat, contact and flash, and flash only, are dealt with separately. In each group the results obtained by primary excision and grafting are compared with the results of later operation; and the type of graft used for different severities of injury is considered. ELECTRIC CONTACT BURNS Thirty-five patients were injured by electric contact alone, the usual history being accidental contact with a live wire, holding a cable when the current was switched on, or touching something which short-circuited. Fourteen of the accidents were industrial and twenty-one domestic. The patients' ages varied from 14 months to 75 years (average 28 years).
Primary or Delayed Operation--Patients were treated by primary excision and grafting within forty-eight hours of injury unless contraindicated. This method was chosen since it seemed likely to give the shortest duration of treatment and earliest return of function. Nineteen patients had this treatment ; fifteen were grafted at a later period, and one healed by scarring. Operation was delayed in four cases because of late transfer to this hospital, in one case because of intercurrent illness, and in two cases because no bed was available. The primary and delayed grafting groups were similar as regards severity of injury, and can be compared in the following ways : The mean healing time of the cases treated by primary excision was shorter (44"5 days) than in those grafted late (57"3 days) (Table I). Some of these cases were treated with flaps. If the cases receiving split-skin grafts only are considered, then the primary excision and later grafting groups were more strictly comparable. The former group healed on average fourteen days earlier than the latter (Fig. I). In spite of this, however, the mean duration of stay in hospital was only four days less in the primary excision group, since the others were usually treated as out-patients until the time of grafting (see Table IV). Repeat operations were more frequently required in those grafted early (twelve out of nineteen) than in those grafted later (five out of fifteen). The need for further excision of dead tissue was the cause of half the second operations
(Table II). 4e
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TABLE I Contact Burns--Relationship of Time of Grafting to Healing Time Number of Cases. i Time of Grafting. Days. oto 2 3 tO 7 8 tO 14
18 2 I 2 I
1 5 tO 2 I 22 to 28
29 to 35 36 to 42 71
4 2 I
Average Time of Healing. Days. 44'5 37"o 48.0 I 72. 5 I 68"o I Average 49"3 157"3 days 64"0 [ 85-o J
(Three cases healing time not known ; grafted on day o, 22, and 30.)
TABLE II Contact Burns--Reasons for Repeat Operations Primary Excision.
Later Grafting.
Further excision required Separation of flaps . . . Whole area not grafted at first operation . Dressing pulled off after first operation Total
I2
TABLE III Contact Burns--Final Results Primary Excision. Full movements, good texture graft. Full movements, graft wrinkled or unsightly Slight disability (not interfering with work) Moderate disability (i due to arthritis and I due to amputation) Total
Later Grafting. 3 3 4
18
IO
(One primary excision and five later grafting cases, final result not known.)
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Final function, as judged from the clinical records, was similar with both methods of treatment (Table III). In the pure contact injury, therefore, primary excision is associated with earlier healing but a greater likelihood of repeat operations. gO
T y p e of Graft--Patients were treated with free grafts unless deep tissues, such 7o as tendon, bone, or joint, were exposed. X In these more severe burns, attempts to 6o X save severely damaged digits with a flap 50 lengthened treatment (Table IV). The Xx knowledge that a second operation was ~4c essential if a flap was raised, tended to deter the surgeon from using this method when he thought a free graft would take. ~ In seventeen of the thirty-five contact burns (49 per cent.) no deep tissues were exposed at any time. One of these healed without grafting. All the others were o lo 2o 30 4O 50 60 70 8O TIME. OF GRAFTING -- OAY5 AFTER BURN treated with a free graft and healed FIG. I uneventfully, apart from two patients who pulled off their dressings and the Electric contact burns treated with free grafts. graft with it. These healed when a Relationship of healing time to time of grafting. second split-skin graft was applied. In three other patients (8 per cent.) deep tissues were exposed later. At the first operation (on the day of injury in two cases and on the third day in one), a split-skin graft was applied, but there was further loss of subcutaneous tissue and tendon was then exposed. In one an abdominal flap was then used successfully.
TABLE IV Contact Burns--Type of Graft at First Operation in Relation to Healing Times and Stay in Hospital Primary Excisions.
Later Grafting.
I
Average Number. I Days in I Hospital.
Average Healing Time.
Number.
Average Days in Hospital.
Average Healing Time.
12
25 "7
Days. 55.2 (io patients)
o 2
25J0
i
Split-skin graft Wolfe graft plus S.S.G. Flap . Flap plus Wolfe graft . Amputation plus S.S.G. Amputation plus flap plus S.S.G.
Days. I 40'9 (xo patients) 32"7
21 "3
II
I I I
I6'3 28 '5 2o'o 38 "0
50"5
IO5"o 32 'O
56"0
56"0
!
0
I
6920
0
...
6"5";0 6"3";0
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Another, a baby, was treated with repeated split-skin grafts, and although healing was achieved the digit was amputated later because of tendon loss and skin shortage. In the third patient a local flap was unsuccessful, and the digit was amputated. In the remaining fifteen patients (43 per cent.) deep tissues were exposed at the first operation (eight primary excisions, seven later operations). Three had primary amputations--one requiring later split-skin grafts for other areas, another having further amputations for necrotic bone, and the third had flaps applied to other areas at the same time with uneventful healing. Five patients had primary flaps for exposure of bone (three pectoral, one cross-arm, one cross-finger) ; one of these required ,o I' x a third operation for removal of necrotic bone, the other two healed uneventfully. The remaining seven patients were treated ,o initially with a split-skin graft. In three this was ' successful in spite of exposure of tendon (two) or 7o fascia (one); and in another a second split-skin 60 graft resulted in healing. In two patients the digit was amputated at the second operation, and in the last patient (a baby) a flap was raised at the ~° second operation, and after some difficulty with immobilisation this was successful. ~40 X x Where no deep tissues were exposed, therefore, o 3o x a free graft was almost always satisfactory ; but a ~ flap was usually required to cover tendon or bone. 2o Amputation was necessary for very destructive x injuries. 195
IO
ELECTRIC CONTACT AND HEAT BURNS =
i
t
=
J
o TIME OF ,o C.~RAFT|NG ,~ ~ 3o 4o ~o DAYS AFTER BURN
Burns caused by a combination of contact and heat occurred in seventeen patients, ranging Fro. 2 in age from 15 months to 69 years (average I I Contact and heat burns treated years)" thirteen patients were under II years of with free grafts. Relationship of healing time to time of grafting, age. All burns were caused by contact with an electric fire, fourteen of them from grasping the element. In these cases only a small proportion of the supply volts pass through the injured part, and damage is mainly due to heat. Nevertheless there can be enough current to make it difficult for the patient to remove his hand. P r i m a r y or D e l a y e d O p e r a t i o n . - - N i n e patients were treated by primary excision and grafting, seven by later grafting, and one healed without operation. T h e reasons for delayed grafting were that the patient was referred late to this hospital (four cases), that no bed was available (one case), and that the burn was initially thought to be partial skin loss (two cases). Healing times were shorter in the majority of those treated by primary excision than in those operated upon later (Fig. 2). T h e difference is less than in the group of pure contact burns, since earlier separation of the slough allowed " l a t e " grafting to be carried out at sixteen to nineteen days after injury instead of more than thirty days. In this respect these b u m s are like ordinary heat burns.
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Repeat operations were again more frequently required in the primary excision group because of inadequate excision at the first operation (Table V). Infection caused graft failure in two of those grafted late, and both required repeated plastic repairs to improve function after healing was achieved. These two patients were left with moderate disability of the hands (Fig. 4), and because of them final function was better in the primary excision group (Table VI). T y p e of Graft.mFourteen out of the seventeen patients with contact and heat burns (82 per cent.) had no deep tissues exposed at any time. One healed without TABLE V
Contact and Heat Burns--Reasons for Repeat Operations Primary Excisions.
Later Grafting.
Further excision required Separation of flap Slipping of graft Infections. Total
TABLE VI Contact and Heat Burns--Final Results Primary Excisions.
Later Grafting.
Full movement, good texture graft Full movement, poor texture graft Slight disability. Moderate disability Total (One primary excision case, final result not known.)
grafting. The others were successfully treated with free grafts (two Wolfe grafts, five thick split-skin grafts, six thin split-skin grafts) (Fig. 3). Three of these cases required a second split-skin graft to complete healing. One patient had deep tissues exposed later. At primary excision a split-skin graft was applied, but there was sloughing, and tendon and bone were exposed. Repeated split-skin grafts were applied after removal of the necrotic parts of the lateral maUeolus. Although final healing was not recorded until seven months (I95 days) after injury, he was discharged from the ward at two months and the final result was satisfactory with full function. Two patients had deep tissues exposed at primary excision. One (an epileptic) had a burn of elbow involving muscle and bone. A flap was raised after primary
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A
C FIG. 3 Patient R. B. grasped the element of an electric fire. He was treated by primary excision and application of thick split-skin grafts. The hands are shown on the day of injury and four years later
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excision, but repeated operations were required for improving the appearance of the flap and removing devitalised bone. Full function was restored. The other patient (an attempted suicide) had multiple burns of both hands treated
A
B Fro. 4 Patient C. P. sustained a similar injury to that shown in Fig. 3. Transferred here late, he had split-skin grafts applied twentysix days after injury. These failed because of infection, but repeat grafting twelve days later was successful. The disability of the hands is shown three years after injury.
initially with split-skin grafts. After the second operation an abdominal flap was raised, but it became infected. The areas were eventually healed with split-skin grafts. In this group fewer burns involved deep structures than in the pure contact burns, and a larger proportion were therefore treated successfully with free grafts. The indications for raising a flap were the same, whether the cause of injury was electric contact or heat.
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Five patients received burns by contact and flash. All were industrial injuries. The severity of the injury varied considerably with the degree of contact and voltage of the current. One patient died. He was line=laying when the thick copper wire he was holding became live from a pylon carrying 68#oo volt supply. He sustained a 4 ° per cent. burn of his right hand, trunk, right lower limb, and feet. He was resuscitated with plasma and blood, but severe oliguria and myoglobinuria were present. He became anuric and died six days after injury. Two patients required amputation. One was working in a transformer station when the electricity supply of 33,ooo volts was switched on. He sustained a 17 per cent. burn of the left arm and hand, back, and feet. Two toes were amputated on the sixteenth day and split-skin grafts applied to other areas at two subsequent operations. Healing was not achieved till four months after injury (IO8 days) and he was left with moderate disability. The other patient had an above-elbow amputation on the day of injury, after contact with a 6,000 volt supply which charred his whole forearm and hand. Healing was complete by the eighteenth day and he returned to a slightly lighter job on work similar to his pre-accident employment. The other two patients had less severe injuries (voltage not known). The one had a flash burn of the face and a contact burn on the hand. The latter was grafted with a split-skin graft on the seventeenth day and healed by the thirty-fifth day. He had slight residual disability from weakness of grip. The other patient had multiple superficial burns which healed without grafting by the forty-first day, leaving no disability. ELECTRIC FLASH BURNS
Thirteen patients received burns from electric flash without contact with the current. All were industrial injuries and involved the face and one or both hands. A typical case was patient W. H. who was replacing a fuse with his left hand when something shorted, giving a flash. He sustained partial-skin loss burns of the right side of his face and neck, and whole-skin loss burns of the dorsum of his left hand and fingers of his right hand. Treated by primary excision and grafting of his hands, he was completely healed in twenty-five days. In six patients the burn healed without grafting in twenty-five to fifty days (average 34"4 days). All those requiring grafting were treated with split-skin grafts. In five patients this followed a primary excision and gave a mean healing time of thirtysix days. In two patients grafting was performed later (eighteen and twenty-eight days) with a mean healing time of 53"5 days. Operation in these cases was delayed because of uncertainty as to the extent of whole-skin loss (total area of burn, 14 and IO½ per cent.). All these patients had full functional recovery. HIGH VOLTAGE BURNS
Ten patients were involved in accidents known to be caused by a current of higher voltage than the domestic supply. They have been included in the previous sections, but the severity of these injuries may now be noted.
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Two patients had flash burns only and did not differ from the other cases. Of the other eight patients one died and six required amputation of digits or limb. The only patient who did not require amputation was in contact with a 6,6oo volt supply. Transferred here twenty-three days after injury, he had sloughing areas on arm and thigh which healed with split-skin grafts. By contrast, three patients out of the forty known to be injured by 23o to 240 volt supply had amputation of a digit. One of these was an attempted suicide, in whom it can be presumed that good contact would be made with the power supply. It would therefore appear that accidental contact with the domestic electricity supply rarely causes sufficient damage to necessitate amputation, but that with higher voltage supply, damage is more extensive and amputation frequently required. DISCUSSION Perusal of the literature shows considerable variation of opinion as to the way in which an electric current causes damage and the best method of treating it. There is agreement that the amperage of current passing through the body is of the utmost importance (Gaby, I927; Pearl, I933 ; Urquhart, I95I; Dale, I954 ; McLaughlin and Coe, I954 ; Clarke, I957; Muir, x957). This is not known since the resistance at the point of contact varies ( A = ~ ) .
Skin
resistance is normally around 5,000 ohms but is altered by the degree of moisture and cleanliness (Gaby, I927; Pearl, I933; McLaughlin and Coe, I954; Clarke, I957). With 24o volts and skin resistance of 5,ooo ohms, the flow through the body would be 48 ma. It has been stated that an alternating current of IO ma. at frequency 2o to 50 cycles per second for one second is the maximum safe current across the chest, and that anything over Ioo ma is fatal (Clarke, 1957). I f this is accepted as the lethal current, then the total resistance between the cable and earth in the two patients who survived contact with 68,0o0 volts must have been at least 68o,0o0 ohms. The resistance is obviously exceedingly variable but the voltage can usually be ascertained and will give a guide to the extent of damage one can expect. It is also agreed that the extent of injury is frequently underestimated initially (Gaby, I927 ; Lewis, I95O; Dale, I954). This has probably led to the theory that there is progressive necrosis following an electric burn (Lewis, 1958). However, as Muir (I957) has pointed out, deep tissues may be damaged under normal skin. In the experience of this unit, there has been no evidence of progressive necrosis. Damage may be increased by infection, or apparently increased when gangrene due to a damaged vessel is not immediately visible. There is considerable variety of opinion as to the best treatment. Wells (I929) first suggested primary excision and grafting. Brown and Fryer (I956, I957) suggest it may be done in some areas " if the exact extent of burn is recognisable," and recommend a free graft initially and " complicated flaps " later. Muir (I957) advocates primary excision and repair by flap at the first operation. McLaughlin and Coe (I954) suggest " early " d~bridement of the burned area " as soon as reasonably demarcated." Lewis (I95o) and Dale (I954) consider conservative treatment imperative and graft only after the slough has separated. Jellinek (I936) states that, after an initial latent period, these injuries show an " extraordinarily great tendency to h e a l " and that complications arise
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only when surgical, instead of conservative, treatment is carried out. Elsewhere, however (Jellinek, I938), he reports a case where the skin was still unhealed five years after injury. The aims in treatment should be borne in mind when a decision is being made on the method to be used in any particular case. These may be summarised as (I) good final function, (2) good cosmetic appearance, (3) early return to normal life. While the surgeon seeks perfection in the first two, some patients are prepared to sacrifice a little in function or appearance for the sake of a shorter stay in hospital or early return to work. The methods which may be used to attain these ends are :-I. Conservative Treatment.--This method is suitable for the small burn which does not go down to deep tissues and does not prevent the patient continuing work while healing proceeds. If used for the larger burn, then scarring gives a poor cosmetic result; or in the deeper burn infection may result in extension of the injury and considerable loss of function. The slough is slow to separate (usually more than four weeks) and if the patient is in hospital or away from work, return to normal life is considerably delayed. 2. Early Excision and Free Grafting.--Early excision in this series has been shown to give as good function (see Table III) and sometimes better function (see Table VI ; Figs. 3 and 4) than late operation ; it also gives as good a cosmetic result and shorter healing time. The difficulty of determining the extent of necrosis within twenty-four hours of injury seems sufficiently great to make another operation necessary in a proportion of cases. In the experience of this unit it has been found that bleeding is not a good index of viability on the day of injury. Under a tourniquet, however, dead fat is coagulated or pink compared with the normal yellow, and dead tendon loses its glistening appearance (Jackson, 1953). Careful attention to this may reduce the number of inadequate excisions. (In the last two years of the review only one patient required further removal of dead tissue after primary excision compared with eight in the three earlier years.) The type of graft used must depend on the depth of the burn. We have had few failures from free grafts when no deep tissues were exposed at the first operation (three out of nineteen, contact alone ; one out of thirteen, contact and heat). Full thickness or thick split-skin grafts contract less and give the best cosmetic result for the palmar aspect of the hand. Ordinary split-skin grafts are adequate for other sites and do not involve scarring of the donor area. The failure rate increases considerably if a free graft is applied to a base of tendon or fascia (three out of seven, contact alone ; one out of one, contact and heat). Where deep tissues are exposed a free graft should therefore be used only under special circumstances, for example when multiple areas are involved, making it impossible to use flaps for all sites. 3 - E a r l y Excision and Primary Flap.--This is the method of choice when deep tissues such as tendon, bone, or joint are exposed. The surgeon undertaking a primary excision should have planned where to raise a flap if required at the same operation, and the patient should be warned of the possibility. The disadvantages are the necessity for two operations, the scarring of another area, and longer healing time.
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4" Late Excision and G r a f t i n g . - - I f primary excision has not been carried out then late excision is possible to remove the slough. There is no certainty that excision will be more adequate than on the day of injury, and the helpful sign of red fat is absent after about the fourth day. The only indication for such treatment should be intercurrent illness precluding primary excision. 5. Grafting after Separation of Slough.--In the contact burn the slough usually takes more than four weeks to separate. Healing time, on average, is fourteen days longer than after primary excision, even though a proportion of the latter require further excision. The smaller proportion of cases requiring a second operation is the only advantage of late grafting, and its use should therefore be limited to the poor anaesthetic risk or to the case where there is doubt as to whether the burn is whole-skin loss. The risk of infection, however, is greater and must be balanced against any advantage gained. 6. A m p u t a t i o n . - - T h i s is required in a large proportion of the injuries caused by current of higher voltage than the domestic supply, and the possibility must be borne in mind in making a diagnosis and assessing prognosis. While such a procedure will be limited to the worst injuries, early amputation of a severely damaged digit allows early return of function of the rest of the hand and is usually preferable to lengthy procedures to save a useless digit. From the results of this series, amputation is rarely required after contact with a 230 t o 240 volt current, and then only when unusually good contact has been made. SUMMARY Seventy burns caused by electricity during the years 1951-55 are reviewed. Thirty-five of these were the result of contact alone, and twenty-two of contact combined with heat or flash. From this review the best treatment seems to be: Primary excision--in fit patients, combined with (I) free graft--if no deep tissues are exposed, using a thick split-skin graft or Wolfe graft for the flexor aspect of the hand ; (2) flap--if tendon, joint, or bone are exposed ; (3) amputation--when there is no reasonable chance of functional recovery (this is not likely except in high voltage injuries). The exceptions to this line of treatment are: (I) conservative treatment for the small burn which will heal within four weeks or which does not interfere with continuation of work ; (2) late excision and grafting where intercurrent illness or late attendance precludes primary excision ; (3) late grafting after separation of slough may be indicated in the poor ana-sthetic risk. I am grateful to Mr D. M. Jackson for guidance in carrying out this review and for permission to use the records of patients admitted under his care. I am also indebted to Dr J. P. Bull, Director of the Research Unit, for helpful criticism in preparation of this paper.
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REFERENCES BROWN, J. B., and FRYER, M. P. (1956). Plast. reconstr. Surg., x8, 177(1957). Ann. Surg., x46, 342. CLARKE, T. (1957)- Brit. J. industr. Safety, 4, 22. DALE, R. H. (1954). Brit. J. plast. Surg., 7, 44. GABY, R. E. (1927). Canad. reed. Ass. J., 17, 1343. JACKSON, D. M. (1953). Personal communication. JELLINEK, S. (1936). Edinb. reed. J., 43, 587. -(1938). Virchows Arch., 3ox, 28. LEWIS, G. K. (195o). Ann. Surg., x3x, 80. (1958). J. Bone Jr. Surg., 4oA, 27. McLAuGHLIN, C. W., and COE, J. D. (1954). Arch. Surg.,rChicago,r68,r53I. MUIR, I. F. K. (1957). Brit. J. plast. Surg., Io, 292. PEARL, F. L. (1933). Arch. Surg., 27, 227. URQUHART,R. W. X. (1951). Ont. med. Rev., iS, I. WELLS, D. B. (I929). Ann. Surg., 9 o, lO69. -
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A Review of Seventy Cases By MARY R. DAVIES,M.B., Ch.B. Research Registrar, Medical Research Council Industrial Injuries and Burns Research Unit, Birmingham Accident Hospital ELECTRICAL injuries form a comparatively small proportion of all burns, but they present special problems. The severity of the injury is easily underestimated initially ; the necrotic tissue is slow to separate and damage to blood-vessels may result in secondary h~emorrhage. The hand is commonly involved, and the depth of injury and added infection combine to make these injuries crippling. Although immediate excision sometimes fails to remove all dead tissue, early healing to reduce the risk of infection and joint stiffness is most desirable. This review was undertaken in an attempt to clarify the treatment used and to find out which methods gave the best final result. It covers the five-year period I951-55 at the Birmingham Accident Hospital, during which time seventy out of 1,893 admissions to the Burns Unit were the result of accidents caused by electricity. MATERIAL Of the seventy patients with burns caused by electricity, the cause of the injury was electric contact alone in thirty-five, contact and heat in seventeen, contact and flash in five, and flash alone in thirteen. Their ages ranged from I4 months to 75 years (average 27 years). Thirty-eight of these patients were involved in domestic accidents with the household electricity supply of 230 to 24o volts. Of the industrial accidents, the voltage was not known in twenty ; it was 230 to 240 volts in two ; 400 to 440 volts in five ; 6,000 to 6,600 volts in two ; 33,ooo volts in one ; and 68,ooo volts in two. In most cases the size of the burn was small. In forty-six patients the area involved was less than I per cent. of the body surface, and in twenty it was more than I per cent. but less than Io per cent. In the remaining four patients flash was responsible for part or all of the burn (area of burn Io½, I4, I7, and 4o per cent.). The hands were involved in all but five cases. In thirty-three cases one hand only was burned (right in fifteen, left in eighteen) ; both hands were burned in thirty-two cases. In twenty-seven patients there was a burn of another part o f the body. The face was involved in seventeen of these, all but one being the result of a flash burn. Fifty-six patients (8o per cent.) reached this hospital within six hours of injury. Of the eleven patients arriving here more than twenty-four hours after the accident, six were transferred from other hospitals (one to twenty-nine days after injury) and five had been at home (seen two to thirty-five days after injury). Three patients were reported to have been unconscious following the accident, 288
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but all were fully conscious on admission. Initial resuscitation was required only for the extensively burned and not for electrocution. After discharge from the ward patients were followed up as out-patients until full function was restored or it was considered that no further improvement would be obtained. Five patients were referred to other hospitals for follow-up and four patients failed to attend the clinic. In the others, supervision was maintained for two weeks to five years (average fourteen and a half months), with two patients still attending. Time of healing has been taken as the day on which the patient was seen with no crust or raw area present. In out-patients this has frequently resulted in an overstatement of the true healing time by up to seven days, but for purposes of comparison a similar error is probably present in all groups. RESULTS In assessment of the results, the injuries caused by electric contact alone, by contact and heat, contact and flash, and flash only, are dealt with separately. In each group the results obtained by primary excision and grafting are compared with the results of later operation; and the type of graft used for different severities of injury is considered. ELECTRIC CONTACT BURNS Thirty-five patients were injured by electric contact alone, the usual history being accidental contact with a live wire, holding a cable when the current was switched on, or touching something which short-circuited. Fourteen of the accidents were industrial and twenty-one domestic. The patients' ages varied from 14 months to 75 years (average 28 years).
Primary or Delayed Operation--Patients were treated by primary excision and grafting within forty-eight hours of injury unless contraindicated. This method was chosen since it seemed likely to give the shortest duration of treatment and earliest return of function. Nineteen patients had this treatment ; fifteen were grafted at a later period, and one healed by scarring. Operation was delayed in four cases because of late transfer to this hospital, in one case because of intercurrent illness, and in two cases because no bed was available. The primary and delayed grafting groups were similar as regards severity of injury, and can be compared in the following ways : The mean healing time of the cases treated by primary excision was shorter (44"5 days) than in those grafted late (57"3 days) (Table I). Some of these cases were treated with flaps. If the cases receiving split-skin grafts only are considered, then the primary excision and later grafting groups were more strictly comparable. The former group healed on average fourteen days earlier than the latter (Fig. I). In spite of this, however, the mean duration of stay in hospital was only four days less in the primary excision group, since the others were usually treated as out-patients until the time of grafting (see Table IV). Repeat operations were more frequently required in those grafted early (twelve out of nineteen) than in those grafted later (five out of fifteen). The need for further excision of dead tissue was the cause of half the second operations
(Table II). 4e
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TABLE I Contact Burns--Relationship of Time of Grafting to Healing Time Number of Cases. i Time of Grafting. Days. oto 2 3 tO 7 8 tO 14
18 2 I 2 I
1 5 tO 2 I 22 to 28
29 to 35 36 to 42 71
4 2 I
Average Time of Healing. Days. 44'5 37"o 48.0 I 72. 5 I 68"o I Average 49"3 157"3 days 64"0 [ 85-o J
(Three cases healing time not known ; grafted on day o, 22, and 30.)
TABLE II Contact Burns--Reasons for Repeat Operations Primary Excision.
Later Grafting.
Further excision required Separation of flaps . . . Whole area not grafted at first operation . Dressing pulled off after first operation Total
I2
TABLE III Contact Burns--Final Results Primary Excision. Full movements, good texture graft. Full movements, graft wrinkled or unsightly Slight disability (not interfering with work) Moderate disability (i due to arthritis and I due to amputation) Total
Later Grafting. 3 3 4
18
IO
(One primary excision and five later grafting cases, final result not known.)
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Final function, as judged from the clinical records, was similar with both methods of treatment (Table III). In the pure contact injury, therefore, primary excision is associated with earlier healing but a greater likelihood of repeat operations. gO
T y p e of Graft--Patients were treated with free grafts unless deep tissues, such 7o as tendon, bone, or joint, were exposed. X In these more severe burns, attempts to 6o X save severely damaged digits with a flap 50 lengthened treatment (Table IV). The Xx knowledge that a second operation was ~4c essential if a flap was raised, tended to deter the surgeon from using this method when he thought a free graft would take. ~ In seventeen of the thirty-five contact burns (49 per cent.) no deep tissues were exposed at any time. One of these healed without grafting. All the others were o lo 2o 30 4O 50 60 70 8O TIME. OF GRAFTING -- OAY5 AFTER BURN treated with a free graft and healed FIG. I uneventfully, apart from two patients who pulled off their dressings and the Electric contact burns treated with free grafts. graft with it. These healed when a Relationship of healing time to time of grafting. second split-skin graft was applied. In three other patients (8 per cent.) deep tissues were exposed later. At the first operation (on the day of injury in two cases and on the third day in one), a split-skin graft was applied, but there was further loss of subcutaneous tissue and tendon was then exposed. In one an abdominal flap was then used successfully.
TABLE IV Contact Burns--Type of Graft at First Operation in Relation to Healing Times and Stay in Hospital Primary Excisions.
Later Grafting.
I
Average Number. I Days in I Hospital.
Average Healing Time.
Number.
Average Days in Hospital.
Average Healing Time.
12
25 "7
Days. 55.2 (io patients)
o 2
25J0
i
Split-skin graft Wolfe graft plus S.S.G. Flap . Flap plus Wolfe graft . Amputation plus S.S.G. Amputation plus flap plus S.S.G.
Days. I 40'9 (xo patients) 32"7
21 "3
II
I I I
I6'3 28 '5 2o'o 38 "0
50"5
IO5"o 32 'O
56"0
56"0
!
0
I
6920
0
...
6"5";0 6"3";0
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Another, a baby, was treated with repeated split-skin grafts, and although healing was achieved the digit was amputated later because of tendon loss and skin shortage. In the third patient a local flap was unsuccessful, and the digit was amputated. In the remaining fifteen patients (43 per cent.) deep tissues were exposed at the first operation (eight primary excisions, seven later operations). Three had primary amputations--one requiring later split-skin grafts for other areas, another having further amputations for necrotic bone, and the third had flaps applied to other areas at the same time with uneventful healing. Five patients had primary flaps for exposure of bone (three pectoral, one cross-arm, one cross-finger) ; one of these required ,o I' x a third operation for removal of necrotic bone, the other two healed uneventfully. The remaining seven patients were treated ,o initially with a split-skin graft. In three this was ' successful in spite of exposure of tendon (two) or 7o fascia (one); and in another a second split-skin 60 graft resulted in healing. In two patients the digit was amputated at the second operation, and in the last patient (a baby) a flap was raised at the ~° second operation, and after some difficulty with immobilisation this was successful. ~40 X x Where no deep tissues were exposed, therefore, o 3o x a free graft was almost always satisfactory ; but a ~ flap was usually required to cover tendon or bone. 2o Amputation was necessary for very destructive x injuries. 195
IO
ELECTRIC CONTACT AND HEAT BURNS =
i
t
=
J
o TIME OF ,o C.~RAFT|NG ,~ ~ 3o 4o ~o DAYS AFTER BURN
Burns caused by a combination of contact and heat occurred in seventeen patients, ranging Fro. 2 in age from 15 months to 69 years (average I I Contact and heat burns treated years)" thirteen patients were under II years of with free grafts. Relationship of healing time to time of grafting, age. All burns were caused by contact with an electric fire, fourteen of them from grasping the element. In these cases only a small proportion of the supply volts pass through the injured part, and damage is mainly due to heat. Nevertheless there can be enough current to make it difficult for the patient to remove his hand. P r i m a r y or D e l a y e d O p e r a t i o n . - - N i n e patients were treated by primary excision and grafting, seven by later grafting, and one healed without operation. T h e reasons for delayed grafting were that the patient was referred late to this hospital (four cases), that no bed was available (one case), and that the burn was initially thought to be partial skin loss (two cases). Healing times were shorter in the majority of those treated by primary excision than in those operated upon later (Fig. 2). T h e difference is less than in the group of pure contact burns, since earlier separation of the slough allowed " l a t e " grafting to be carried out at sixteen to nineteen days after injury instead of more than thirty days. In this respect these b u m s are like ordinary heat burns.
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Repeat operations were again more frequently required in the primary excision group because of inadequate excision at the first operation (Table V). Infection caused graft failure in two of those grafted late, and both required repeated plastic repairs to improve function after healing was achieved. These two patients were left with moderate disability of the hands (Fig. 4), and because of them final function was better in the primary excision group (Table VI). T y p e of Graft.mFourteen out of the seventeen patients with contact and heat burns (82 per cent.) had no deep tissues exposed at any time. One healed without TABLE V
Contact and Heat Burns--Reasons for Repeat Operations Primary Excisions.
Later Grafting.
Further excision required Separation of flap Slipping of graft Infections. Total
TABLE VI Contact and Heat Burns--Final Results Primary Excisions.
Later Grafting.
Full movement, good texture graft Full movement, poor texture graft Slight disability. Moderate disability Total (One primary excision case, final result not known.)
grafting. The others were successfully treated with free grafts (two Wolfe grafts, five thick split-skin grafts, six thin split-skin grafts) (Fig. 3). Three of these cases required a second split-skin graft to complete healing. One patient had deep tissues exposed later. At primary excision a split-skin graft was applied, but there was sloughing, and tendon and bone were exposed. Repeated split-skin grafts were applied after removal of the necrotic parts of the lateral maUeolus. Although final healing was not recorded until seven months (I95 days) after injury, he was discharged from the ward at two months and the final result was satisfactory with full function. Two patients had deep tissues exposed at primary excision. One (an epileptic) had a burn of elbow involving muscle and bone. A flap was raised after primary
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A
C FIG. 3 Patient R. B. grasped the element of an electric fire. He was treated by primary excision and application of thick split-skin grafts. The hands are shown on the day of injury and four years later
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excision, but repeated operations were required for improving the appearance of the flap and removing devitalised bone. Full function was restored. The other patient (an attempted suicide) had multiple burns of both hands treated
A
B Fro. 4 Patient C. P. sustained a similar injury to that shown in Fig. 3. Transferred here late, he had split-skin grafts applied twentysix days after injury. These failed because of infection, but repeat grafting twelve days later was successful. The disability of the hands is shown three years after injury.
initially with split-skin grafts. After the second operation an abdominal flap was raised, but it became infected. The areas were eventually healed with split-skin grafts. In this group fewer burns involved deep structures than in the pure contact burns, and a larger proportion were therefore treated successfully with free grafts. The indications for raising a flap were the same, whether the cause of injury was electric contact or heat.
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Five patients received burns by contact and flash. All were industrial injuries. The severity of the injury varied considerably with the degree of contact and voltage of the current. One patient died. He was line=laying when the thick copper wire he was holding became live from a pylon carrying 68#oo volt supply. He sustained a 4 ° per cent. burn of his right hand, trunk, right lower limb, and feet. He was resuscitated with plasma and blood, but severe oliguria and myoglobinuria were present. He became anuric and died six days after injury. Two patients required amputation. One was working in a transformer station when the electricity supply of 33,ooo volts was switched on. He sustained a 17 per cent. burn of the left arm and hand, back, and feet. Two toes were amputated on the sixteenth day and split-skin grafts applied to other areas at two subsequent operations. Healing was not achieved till four months after injury (IO8 days) and he was left with moderate disability. The other patient had an above-elbow amputation on the day of injury, after contact with a 6,000 volt supply which charred his whole forearm and hand. Healing was complete by the eighteenth day and he returned to a slightly lighter job on work similar to his pre-accident employment. The other two patients had less severe injuries (voltage not known). The one had a flash burn of the face and a contact burn on the hand. The latter was grafted with a split-skin graft on the seventeenth day and healed by the thirty-fifth day. He had slight residual disability from weakness of grip. The other patient had multiple superficial burns which healed without grafting by the forty-first day, leaving no disability. ELECTRIC FLASH BURNS
Thirteen patients received burns from electric flash without contact with the current. All were industrial injuries and involved the face and one or both hands. A typical case was patient W. H. who was replacing a fuse with his left hand when something shorted, giving a flash. He sustained partial-skin loss burns of the right side of his face and neck, and whole-skin loss burns of the dorsum of his left hand and fingers of his right hand. Treated by primary excision and grafting of his hands, he was completely healed in twenty-five days. In six patients the burn healed without grafting in twenty-five to fifty days (average 34"4 days). All those requiring grafting were treated with split-skin grafts. In five patients this followed a primary excision and gave a mean healing time of thirtysix days. In two patients grafting was performed later (eighteen and twenty-eight days) with a mean healing time of 53"5 days. Operation in these cases was delayed because of uncertainty as to the extent of whole-skin loss (total area of burn, 14 and IO½ per cent.). All these patients had full functional recovery. HIGH VOLTAGE BURNS
Ten patients were involved in accidents known to be caused by a current of higher voltage than the domestic supply. They have been included in the previous sections, but the severity of these injuries may now be noted.
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ELECTRICITY
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Two patients had flash burns only and did not differ from the other cases. Of the other eight patients one died and six required amputation of digits or limb. The only patient who did not require amputation was in contact with a 6,6oo volt supply. Transferred here twenty-three days after injury, he had sloughing areas on arm and thigh which healed with split-skin grafts. By contrast, three patients out of the forty known to be injured by 23o to 240 volt supply had amputation of a digit. One of these was an attempted suicide, in whom it can be presumed that good contact would be made with the power supply. It would therefore appear that accidental contact with the domestic electricity supply rarely causes sufficient damage to necessitate amputation, but that with higher voltage supply, damage is more extensive and amputation frequently required. DISCUSSION Perusal of the literature shows considerable variation of opinion as to the way in which an electric current causes damage and the best method of treating it. There is agreement that the amperage of current passing through the body is of the utmost importance (Gaby, I927; Pearl, I933 ; Urquhart, I95I; Dale, I954 ; McLaughlin and Coe, I954 ; Clarke, I957; Muir, x957). This is not known since the resistance at the point of contact varies ( A = ~ ) .
Skin
resistance is normally around 5,000 ohms but is altered by the degree of moisture and cleanliness (Gaby, I927; Pearl, I933; McLaughlin and Coe, I954; Clarke, I957). With 24o volts and skin resistance of 5,ooo ohms, the flow through the body would be 48 ma. It has been stated that an alternating current of IO ma. at frequency 2o to 50 cycles per second for one second is the maximum safe current across the chest, and that anything over Ioo ma is fatal (Clarke, 1957). I f this is accepted as the lethal current, then the total resistance between the cable and earth in the two patients who survived contact with 68,0o0 volts must have been at least 68o,0o0 ohms. The resistance is obviously exceedingly variable but the voltage can usually be ascertained and will give a guide to the extent of damage one can expect. It is also agreed that the extent of injury is frequently underestimated initially (Gaby, I927 ; Lewis, I95O; Dale, I954). This has probably led to the theory that there is progressive necrosis following an electric burn (Lewis, 1958). However, as Muir (I957) has pointed out, deep tissues may be damaged under normal skin. In the experience of this unit, there has been no evidence of progressive necrosis. Damage may be increased by infection, or apparently increased when gangrene due to a damaged vessel is not immediately visible. There is considerable variety of opinion as to the best treatment. Wells (I929) first suggested primary excision and grafting. Brown and Fryer (I956, I957) suggest it may be done in some areas " if the exact extent of burn is recognisable," and recommend a free graft initially and " complicated flaps " later. Muir (I957) advocates primary excision and repair by flap at the first operation. McLaughlin and Coe (I954) suggest " early " d~bridement of the burned area " as soon as reasonably demarcated." Lewis (I95o) and Dale (I954) consider conservative treatment imperative and graft only after the slough has separated. Jellinek (I936) states that, after an initial latent period, these injuries show an " extraordinarily great tendency to h e a l " and that complications arise
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only when surgical, instead of conservative, treatment is carried out. Elsewhere, however (Jellinek, I938), he reports a case where the skin was still unhealed five years after injury. The aims in treatment should be borne in mind when a decision is being made on the method to be used in any particular case. These may be summarised as (I) good final function, (2) good cosmetic appearance, (3) early return to normal life. While the surgeon seeks perfection in the first two, some patients are prepared to sacrifice a little in function or appearance for the sake of a shorter stay in hospital or early return to work. The methods which may be used to attain these ends are :-I. Conservative Treatment.--This method is suitable for the small burn which does not go down to deep tissues and does not prevent the patient continuing work while healing proceeds. If used for the larger burn, then scarring gives a poor cosmetic result; or in the deeper burn infection may result in extension of the injury and considerable loss of function. The slough is slow to separate (usually more than four weeks) and if the patient is in hospital or away from work, return to normal life is considerably delayed. 2. Early Excision and Free Grafting.--Early excision in this series has been shown to give as good function (see Table III) and sometimes better function (see Table VI ; Figs. 3 and 4) than late operation ; it also gives as good a cosmetic result and shorter healing time. The difficulty of determining the extent of necrosis within twenty-four hours of injury seems sufficiently great to make another operation necessary in a proportion of cases. In the experience of this unit it has been found that bleeding is not a good index of viability on the day of injury. Under a tourniquet, however, dead fat is coagulated or pink compared with the normal yellow, and dead tendon loses its glistening appearance (Jackson, 1953). Careful attention to this may reduce the number of inadequate excisions. (In the last two years of the review only one patient required further removal of dead tissue after primary excision compared with eight in the three earlier years.) The type of graft used must depend on the depth of the burn. We have had few failures from free grafts when no deep tissues were exposed at the first operation (three out of nineteen, contact alone ; one out of thirteen, contact and heat). Full thickness or thick split-skin grafts contract less and give the best cosmetic result for the palmar aspect of the hand. Ordinary split-skin grafts are adequate for other sites and do not involve scarring of the donor area. The failure rate increases considerably if a free graft is applied to a base of tendon or fascia (three out of seven, contact alone ; one out of one, contact and heat). Where deep tissues are exposed a free graft should therefore be used only under special circumstances, for example when multiple areas are involved, making it impossible to use flaps for all sites. 3 - E a r l y Excision and Primary Flap.--This is the method of choice when deep tissues such as tendon, bone, or joint are exposed. The surgeon undertaking a primary excision should have planned where to raise a flap if required at the same operation, and the patient should be warned of the possibility. The disadvantages are the necessity for two operations, the scarring of another area, and longer healing time.
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ELECTRICITY
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4" Late Excision and G r a f t i n g . - - I f primary excision has not been carried out then late excision is possible to remove the slough. There is no certainty that excision will be more adequate than on the day of injury, and the helpful sign of red fat is absent after about the fourth day. The only indication for such treatment should be intercurrent illness precluding primary excision. 5. Grafting after Separation of Slough.--In the contact burn the slough usually takes more than four weeks to separate. Healing time, on average, is fourteen days longer than after primary excision, even though a proportion of the latter require further excision. The smaller proportion of cases requiring a second operation is the only advantage of late grafting, and its use should therefore be limited to the poor anaesthetic risk or to the case where there is doubt as to whether the burn is whole-skin loss. The risk of infection, however, is greater and must be balanced against any advantage gained. 6. A m p u t a t i o n . - - T h i s is required in a large proportion of the injuries caused by current of higher voltage than the domestic supply, and the possibility must be borne in mind in making a diagnosis and assessing prognosis. While such a procedure will be limited to the worst injuries, early amputation of a severely damaged digit allows early return of function of the rest of the hand and is usually preferable to lengthy procedures to save a useless digit. From the results of this series, amputation is rarely required after contact with a 230 t o 240 volt current, and then only when unusually good contact has been made. SUMMARY Seventy burns caused by electricity during the years 1951-55 are reviewed. Thirty-five of these were the result of contact alone, and twenty-two of contact combined with heat or flash. From this review the best treatment seems to be: Primary excision--in fit patients, combined with (I) free graft--if no deep tissues are exposed, using a thick split-skin graft or Wolfe graft for the flexor aspect of the hand ; (2) flap--if tendon, joint, or bone are exposed ; (3) amputation--when there is no reasonable chance of functional recovery (this is not likely except in high voltage injuries). The exceptions to this line of treatment are: (I) conservative treatment for the small burn which will heal within four weeks or which does not interfere with continuation of work ; (2) late excision and grafting where intercurrent illness or late attendance precludes primary excision ; (3) late grafting after separation of slough may be indicated in the poor ana-sthetic risk. I am grateful to Mr D. M. Jackson for guidance in carrying out this review and for permission to use the records of patients admitted under his care. I am also indebted to Dr J. P. Bull, Director of the Research Unit, for helpful criticism in preparation of this paper.
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REFERENCES BROWN, J. B., and FRYER, M. P. (1956). Plast. reconstr. Surg., x8, 177(1957). Ann. Surg., x46, 342. CLARKE, T. (1957)- Brit. J. industr. Safety, 4, 22. DALE, R. H. (1954). Brit. J. plast. Surg., 7, 44. GABY, R. E. (1927). Canad. reed. Ass. J., 17, 1343. JACKSON, D. M. (1953). Personal communication. JELLINEK, S. (1936). Edinb. reed. J., 43, 587. -(1938). Virchows Arch., 3ox, 28. LEWIS, G. K. (195o). Ann. Surg., x3x, 80. (1958). J. Bone Jr. Surg., 4oA, 27. McLAuGHLIN, C. W., and COE, J. D. (1954). Arch. Surg.,rChicago,r68,r53I. MUIR, I. F. K. (1957). Brit. J. plast. Surg., Io, 292. PEARL, F. L. (1933). Arch. Surg., 27, 227. URQUHART,R. W. X. (1951). Ont. med. Rev., iS, I. WELLS, D. B. (I929). Ann. Surg., 9 o, lO69. -
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