Ann. Medit. Burns Club - vol. VII - n. 2 - June 1994
ELECTRICAL INJURIES CAUSED BY RAILWAY OVERHEAD CABLES - A REVIEW OF 24 CASES
Koller J, OrsAg M, GrOinger L,
KvaMni K, Ondrias'ovA E.
Burns Department, NsP Ru-zinov,
Bratislava, Slovakia
SUMMARY. Twenty-one patients
with electrical burns due to railway overhead cables were treated at the Bratislava Bums
Department over a period of three years. All the injuries occurred with the same mechanism
- climbing on top of railway carriages and approaching the 25,000 V a.c. overhead cables.
The cutaneous bums, ranging from 18 to 79% BSA, were mostly deep partial- to
full-thickness injuries. Exceptionally, deep structures were involved in small areas of
electrocution. The age range of the patients was from 9 to 41 years. Six of' the patients
were adults and the remaining 18 were under 18 years of age. Two patients, a 14-year-old
boy and an 18-year-old man, died respectively on days 5 and 9 post-burn. No amputations
were necessary. ne pathophysiology and possible preventive measures are discussed. It must
be stressed that arcing can be induced by an earthed moving object simply by approaching,
and not necessarily touching, a cable carrying high voltage.
Electrical injury occurs infrequently and
presents many unique and complex problems to the physician. It constitutes about 5% of all
burn admission to our Burns Department.
Electrical injuries can be categorized into flash burns, are burns, and true or direct
electrical burns. Flash burns result from the effect of heat from electrical flash on
uncovered parts of the body, and may also ignite the victim's clothes. Arc burns are
produced by short circuiting of high currents which pass externally to the body. True or
direct electrical injuries occur when the body becomes part of the electrical circuit.
Characteristic features of these injuries are the entrance and exit wounds. The degree of
tissue damage is proportional to the intensity of current, as stated in Ohm's Law.
Materials and methods
During the last three years 24
patients who suffered injuries from railway overhead cables were treated at the Bratislava
Burns Department.
Throughout the Bratislava region the railway is supplied by overhead cables carrying
25,000 V a.c. All 24 victims tried to climb on top of railway carriages (Fig. 1). Close
approach to the live overhead cables caused arcing to occur, thereby causing severe burn
injuries. All the victims but two fell to the ground from heights ranging from 2.5 to 4
in. Two victims remained lying on the roofs of carriages. In eight cases the victims'
clothing caught fire and burned off.
All the victims but one were males (Tab. 1). The sole female in the series was a
15-year-old high-school student. Fourteen of the 24 patients were boys between 9 and 15
years old (Tab. 2).
Only two of the accidents were work-related. Sixteen accidents occurred during play within
the station area and five in connection with alcohol abuse.
Sixteen patients were treated primarily at our department, while the remaining eight were
initially treated at local hospitals and transferred on days I to 4 post-burn to our
department. All the patients received the standard resuscitation treatment regimen
according to the Parkland formula. Early excision of deep anaesthefic bums was carried out
on days 2 or 3 post-bum, and the excised areas were covered with auto
grafts, when available, and allografts, which were later replaced by autografts. In
extensive burns several excision and transplantation procedures were performed 3 to 5 days
apart until complete coverage of the wounds was achieved. The extent of cutaneous burns
varied between 24 and 79% BSA, while the extent of full-thickness burns was between 2 and
70% BSA. The mean BSA burned was 53.08%, the mean full-thickness loss representing 27.28%.
Pt. |
Sex |
Age |
% BSA
total |
% BSA
III |
Adm.
pbd. |
Other
ini. |
Oper. |
Complic. |
Heal.
days |
Outcome |
1. P.R. |
M |
14 |
79 |
70 |
0 |
0 |
1 |
RDS |
(+5) |
died |
2. H.M. |
M |
16 |
61 |
40 |
0 |
0 |
6 |
sepsis |
104 |
surv. |
3. K.I. |
M |
11 |
51 |
15 |
0 |
0 |
3 |
|
60 |
surv. |
4. T.R. |
M |
12 |
47.5 |
25 |
0 |
0 |
3 |
|
54 |
surv. |
5. F.M. |
M |
11 |
38.5 |
21 |
0 |
0 |
3 |
|
48 |
surv. |
6. m.i. |
M |
17 |
24 |
8 |
|
0 |
1 |
delayed |
57 |
surv. |
|
|
|
|
|
|
|
|
parapar. |
|
|
7. B.J. |
M |
21 |
24 |
2 |
|
0 |
1 |
|
13 |
surv. |
8. P.N. |
F |
15 |
58 |
15 |
0 |
0 |
3 |
|
27 |
surv. |
9. M.M. |
M |
41 |
56 |
42 |
|
0 |
6 |
GI bleed., |
102 |
surv. |
|
|
|
|
|
|
|
|
decubitus |
|
|
10. T.V. |
M |
13 |
78.5 |
40 |
0 |
Transferred |
|
|
|
surv. |
|
|
|
|
|
|
to Sweden |
|
|
|
|
11. V.I. |
M |
25 |
64 |
25 |
|
|
2 |
|
60 |
surv. |
12. B.S. |
M |
9 |
40.5 |
29 |
0 |
0 |
4 |
delayed |
96 |
surv. |
|
|
|
|
|
|
|
|
healing (eel. im. d.) |
|
|
13. B.A. |
M |
12 |
44.5 |
13.5 |
0 |
0 |
2 |
11 |
70 |
surv. |
14. B.L. |
M |
31 |
51 |
23 |
5 |
0 |
3 |
0 |
42 |
surv. |
15. F.R. |
M |
20 |
54.5 |
47.5 |
1 |
Cont. cer. |
I |
sepsis |
(+7) |
died |
|
|
|
|
|
|
SAB |
|
ARDS |
|
|
|
|
|
|
|
|
Frontal lac. |
|
|
|
|
16. B.D. |
M |
42 |
65 |
25 |
2 |
0 |
4 |
local inf. |
53 |
surv. |
17. K.M. |
M |
21 |
62 |
10 |
0 |
Fx pr.tr.l'h |
4 |
local inf. |
62 |
surv. |
|
|
|
|
|
|
Frontal Jac. |
|
|
|
|
18. M.R. |
M |
11 |
70 |
50 |
0 |
0 |
7 |
RDS |
95 |
surv. |
|
|
|
|
|
|
|
|
sepsis |
|
|
19. M.M. |
M |
16 |
48 |
23 |
1 |
0 |
4 |
fistula |
53 |
surv. |
|
|
|
|
|
|
|
|
urethrae |
|
|
20. C.G. |
M |
12 |
71 |
60 |
0 |
0 |
7 |
sepsis |
175 |
surv. |
|
|
|
|
|
|
|
|
delayed healing |
|
|
21. M1 |
M |
9 |
45.5 |
32.5 |
2 |
0 |
2 |
0 |
28 |
surv. |
22. K.R. |
M |
12 |
49.9 |
6 |
0 |
0 |
1 |
0 |
26 |
surv. |
23. M.M. |
M |
14 |
38 |
5 |
0 |
0 |
1 |
0 |
35 |
surv. |
24. M.M. |
M |
15 |
31 |
4 |
0 |
0 |
1 |
0 |
24 |
surv. |
|
Table I - The patients treated |
|
Abbreviations:
Pt. = patient; BSA = body surface
area; Adm. = admission; pbd. = post-burn day; inj. = injury; Oper. = operations; Complic.
= complications; Heal. = healing; RD,' = respiratory distress syndrome; GI =
gastrointestinal; cel.im.d. = cellular immunity deficiency; inf. = infection; Cont.cer. =
cerebral contusion; SAB = subarachnoi dal bleeding; lac. = laceration; Fx = fracture; pr.
= processus; tr. = transversus; surv. = survived.
Results
Two patients died as a cQnsequence of
their injuries. One of these was a 14-year-old boy with 79% BSA burns and 70%
full-thickness loss, with inhalation injury, who died 5 days after the accident owing to
respiratory failure. The other fatal case was a 20-year-old male with 54.5% BSA burns and
47.5% full-thickness loss, with associated cerebral contusion, subarachnoidal haematoma
and frontal laceration, who died on day 7 post-burn from ARDS and resulting
respiratory failure.
The depth of the burns varied from deep
partial-thickness to full-thickness injuries, reaching down to the deep fascia in some
patients.
INJURY |
NUMBER |
Cerebral contusion
Subarachnoidal haematoma
Frntal laceration
Th 4 transverse process FX. |
1
1
2
1 |
|
Table IV - Other injuries |
|
In five patients other concomitant
injuries were observed (Tab. 4). The most severe injury was a subarachnoidal
haematoma.
The complication rate was appropriate to the type of the injury (Tab. 5). The most
frequent complication was delayed healing (7 cases) and local infection and sepsis (4
cases). In one patient complete unilateral blindness with atrophy of the optical nerve
occurred, without any apparent direct damage to the globe or face. Delayed spinal cord
damage developed in a 17-year-old boy with a 24% BSA burn. This condition presented itself
as a T4-6 level motor paraparesis with no sensory loss beginning 3 weeks post-bum.
Recovery from the paresis was very slow, taking several months.
COMPLICATION |
NUMBER |
Sepsis |
4 |
Respiratory
distress syndrome |
3 |
Delayed healing |
7 |
Local infection |
4 |
Severe GI
bleeding |
1 |
Decubitus |
1 |
Urethral fisula |
1 |
Immune
defficiency |
1 |
Delayed
paraparesis |
1 |
Unilateral
blindness |
1 |
|
Table V - Complications |
|
PARAMETER |
REICHL
& KAY 1985 |
KOLLER
1993 |
Time period |
6 yr |
3 yr |
Population area |
? |
2.500,000 |
Cases (no.) |
9 |
24 |
Age range (yr) |
7-17.6 |
9-42 |
No. under 18 |
9 |
17 |
Injuries at play |
5 |
17 |
BSA burned range (%) |
12-65 |
23-79 |
Clothes on fire (no.) |
3 |
9 |
Mean BSA burned (%) |
34.8 |
35.08 |
BSA grafted (%) |
26.5 |
27.28 |
Other injuries |
None |
5 |
Died (no.) |
2 |
|
|
Table VI - Comparison
of two patient groups |
|
All the patients but
one underwent surgery - excision of deep burns and grafting procedures. The mean number of
operating procedures was 2.9 per patient. The patients' hospital stay ranged from 13 to
175 days, with a mean stay of 62 days.
Discussion
Electric-arc induced thermal burns on
railway lines continue to be a serious problem. Artursson (1984) reported 19 patients
admitted to the Uppsala Burn Center in a period of 13 years. Reichl (1985) reported a
series of nine cases occurring in the southern part of the north-west region of the UK
over a period of 6 years. Our first report (Koller, 1991) included I I patients. The
observations of Artursson and Reichl were very similar to ours (Tab. 6).
IN GENERAL |
IN OUR PATIENTS |
Type of injury
Voltage
Type of current
Current intensity
Current pathway
Area of contact
Duration of arcing
Tissue resistance
Secondary damage
|
Arc
High 25,000 V
A.C.
High
External to the body
Dispersed
Very short
High (skin)
Clothing ignition
Closed injuries |
|
Table V11 - Aetiological factors |
|
In the analysis of the pattern of the
injuries, several factors had to be taken into account (Tab. 7). It was obvious that all
the injuries were caused by high-tension electrical arc exposure to high temperatures and
in some cases by ignition of clothing.
An electric are is formed between two bodies of sufficiently different potential (Nichter,
1984). In our cases the power source was the overhead cable carrying 25,000 V a.c. towards
the metal parts of the carriages grounded by the rails. The temperature generated by an
electrical arc can be in the range of 3,000-20,000 'C (Bingham, 1986). An important fact
is that arcing will cross 2-3 cm for every 10,000 V (Skoog, 1970) so that no direct
contact is necessary to trigger arcing at 25,000 V. In addition, once an electrical arc is
established, it may extend over several metres (Skoog, 1970). The so-called critical
distance is the distance between the power source and another grounded subject which may
trigger arcing. In moving subjects, such as in our victims, the arcing can be triggered
over a longer distance than in static ones.
The appearance of the cutaneous burns was variable. The burns were mostly found to be more
superficial than expected in high-voltage accidents. Only in patients whose clothing was
ignited were the lesions similar to other flame-type deep burns. This finding could be
partially explained by the fact that in burns caused by high-tension electric arc the
current travels externally to the body from the point nearest the power source to the
ground by the shortest way (Lee, 1987). Circumscribed burns occur where portions of the
arc contact the patient's body surface. These contact points may be multiple, single, or
diffuse, and they vary in depth. The picture is somewhat different when clothing is set on
fire by the intense heat of the arc. We believe that the current did not pass through the
body to any significant extent because:
- there appeared to be no direct contact between the patient
and the live cable; and
- the duration of an arc is extremely short.
At very high temperatures, extremely short
thermal exposures do not transmit all their energy into the skin because of the skin's
reflectance and thermal resistance (Ripple, 1990). in this context it also seems important
that the victims were rapidly thrown away from the power source, thus interrupting the
flow of the current before the resistance of the skin to the current could be broken down.
The explanation for the delayed spinal cord damage observed in one patient is not apparent
(Koller, 1989). This may have been associated with deep burns involving a few per cent of
the lower angle of the left scapula. Initially it was believed that this injury was caused
solely by areinduced ignition of the clothes covering this area. The later development of
paraparesis suggested the possibility of the passage of some current through the tissues
adjacent to the spine. However, no current exit point could be found anywhere else on the
body and surgical excision of the necrotic eschar over the lower angle of the scapula did
not reveal any macroscopic damage in the deeper subcutaneous layers of tissue.
In conclusion, electrical-arc induced thermal burns from railway overhead cables continue
to be a problem of considerable importance. All the injuries reported in this review were
preventable.
RESUME. Pendant une période
de trois ans nous avons traité chez le Centre des Brûlés de Bratislava 21 patients
atteints de brûlures électriques causées par les câbles aériens ferroviaires. Toutes
les lésions ont été produites par le même mécanisme - la victime est montée sur le
haut d'une voiture ferroviaire et s'est approchée des câbles aériens à 25000 volts
courant alternatif. Les brûlures cutanées (18 - 79% de la superficie corporelle)
étaient pour la plupart des lésions profondes à épaisseur partielle ou totale.
Exceptionellement, les structures profondes étaient atteintes dans des zones limitées
d'électrocution. L'âge des patients variait de 9 à 41 ans. Six patients étaient
des adultes et les autres 18 étaient âgés de moins de 18 ans. Deux
patients, un garçon de 14 ans et un jeune homme de 18 ans, sont morts
respectivement le jour 5 et le jour 8 après l'accident. Nous discutons la
pathophysiologie et les mesures de prévention possibles. Nous soulignons que le
phénomène de l'arc électrique peut être causé par un objet mis à la masse en
mouvement qui simplement s'approche d'un câble à haute tension, même sans le toucher.
BIBLIOGRAPHY
- Artursson G., Hedlund A.: Primary treatment of 50
patients with high-tension electrical injuries. Scand. J. Plast. Surg., 18: 111, 1984.
- Bingham H.: Electrical burns. Clin. Plast. Surg.,
13: 75, 1986.
- Koller J., Orsdg J.: Delayed neurological sequelae
of high-tension electrical bums. Burns, 15: 175-7, 1989.
- Koller J.: High-tension electrical-arc-induced
thermal burns caused by railway overhead cables. Bums, 17: 411-4, 1991.
- Lee R.C., Kolodney M.S.: Electrical injury
mechanism. Dynamics of the thermal response. Plast. Reconstr. Surg., 80: 663-71, 1987.
- Lee R.C., Kolodney M.S.: Electrical injury
mechanism. Electrical breakdown of cell membranes. Plast. Reconstr. Surg., 80: 672, 1987.
- Nichter L.S., Bryant C.A., Kenney J.G. et a].:
Injuries due to commercial electric current. J. Bum Care Rehabil., S: 124, 1984.
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railway overhead cables. Burns, 11: 423-5, 1985.
- Ripple G.R., Torrington K.G., Phillips Y.Y.:
Predictive criteria for bums from thermal exposures. J. Occup. Med., 32: 215, 1990.
- Skoog T.: Electrical injuries. J. Trauma, 10: 487,
1970
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