Electrocution-related mortality: a retrospective review of 118 deaths in Coimbatore,India,between January 2002 and December 2006

Abstract

Electrical injuries currently remain a worldwide problem. These injuries are responsible for considerable morbidity and mortality, but are usually preventable with simple safety measures. A retrospective study was undertaken of deaths due to electrocution that occurred over a five-year period from January 2002 to December 2006. The bodies were autopsied at the Department of Forensic Medicine, Coimbatore Medical College and Hospital, Coimbatore, Tamil Nadu, India. A total of 118 cases were identified and all were accidental: 107 males (91%) and 11 females (9%) (male:female ratio = 9.72). The majority of deaths occurred in the 21–30 year age group (n = 57, 48%). Most deaths (n = 98; 83%) were due to low-voltage circuits (<1000 V); a minority were due to high voltages (n = 20, 17%). Domestic accidents were responsible in 73 cases (61.86%). Deaths were caused most frequently by touching an electric wire (n = 62; 52.54%). Most deaths occurred in the summer (n = 50; 42%) with the lowest number of deaths occurring in winter. There was no electrical contact mark present in eight cases (6.7%). One hundred and four cases (88%) were dead on arrival at hospital. The most common cause of death was cardiac arrest, followed by septicaemia and renal failure. Congestion of the brain and oedematous lungs were frequent non-specific postmortem findings.

Introduction

Electricity is an integral part of modern society. Millions of people have access to electricity as an invaluable source of light and power. Carelessness, misuse or improper maintenance of equipment and wiring are the most common causes of electrocution. Most of the fatalities due to electricity are accidental and result from passage of an electrical current (both low voltage and high voltage) through the body. Suicides and homicides from electrocution are very rare. They virtually always involve alternate current and the use of direct current is rare. The following study was undertaken to investigate the epidemiology of electrical fatalities occurring in Coimbatore.

Materials and methods

The current study was a retrospective investigation of deaths from electrocution in Coimbatore. Data were obtained from the Department of Forensic Medicine, Coimbatore Medical College for the period between January 2002 and December 2006. Records of medicolegal deaths were available for our study.

The cases were evaluated in terms of age, sex, voltage, contact details, body region distribution, place and season of occurrence. Pathological findings such as typical electrical burns, non-specific burns and the presence and distribution of petechial haemorrhages were noted.

Results

A total of 118 cases of death by electrocution were identified during the five-year study period from January 2002 to December 2006. All deaths were accidental. The majority of the victims were male (107; 91%) as compared with female (11; 9%) and the male:female ratio was 9.72.

The most common age group involved was 21–30 years (48%), followed by 31–40 years (19%) and 11–20 years (14%) (Figure 1). The upper extremity was by far the most common site involved (105 deaths; 52.3%) followed by the lower extremity (Table 1).

Figure 1

Age distribution of the victims of electrocution

Table 1

Location of lesions

	n	%
Head and neck	20	10.2
Thorax	26	13.2
Abdomen	13	6.7
Upper extremity	105	52.3
Lower extremity	35	17.6
Genital	2	1.0

Among the victims, only contact electric mark entry was present in 97 cases (82.12%), both entry and exit (grounding) electric mark in 13 (11.18%) and no electrical burn marks in eight (6.7%) cases.

Most deaths (n = 98, 83%) were due to low-voltage circuits (<1000 V), with fewer deaths due to high voltage (n = 20, 17%). Domestic accidents were responsible for 73 deaths (61.86%) and non-domestic occurred in 45 cases (38.14%) (Table 2). Considering the contact details, deaths were caused most frequently by touching an electric wire (52.54%) followed by touching an electric water heater in the bathroom (24.57%) (Table 3).

Table 2

Place where electrocution occurred

	n	%
Domestic	73	61.86
Street	29	24.58
Farmland	7	5.93
Shop	9	7.63
Total	118	100.00

Table 3

Type of material causing electrocution

	n	%
Electric wire	62	52.54
Electric water heater	29	24.57
Electric cable	23	19.49
Electric stove	2	1.70
Refrigerator	1	0.85
Washing machine	1	0.85
Total	118	100.00

Out of 118 cases, 110 (93.23%) had characteristic electrical burns consisting of small circular indurate lesions with grey or black centres surrounded by a zone of pallor caused by arteriolar spasm. Fourteen were associated with other non-specific burns, and 96 had no other burns. In eight cases (6.77%) no characteristic electrical burn could be identified; five had other non-specific burns and three had no burns at all (Table 4). Twenty-seven cases exhibited epicardial and/or pleural petechiae; 21 cases had petechiae of the face, chest or conjunctivae and nine cases had petechial haemorrhages of the skin and viscera. Small superficial injuries like abrasions and bruises were commonly described, but other more severe injuries were rare.

Table 4

Pathological findings in deaths due to electrocution

Presence of typical electrical burn/s	110 (93.23%)	Other non-specific burns	14 (11.87%)
		No other burns	96 (81.36%)
Absence of typical electrical burn	8 (6.77%)	Other non-specific burns	5 (4.23%)
		No other burns	3 (2.54%)
Petechiae	57 (48.30%)	Viscera alone	27 (22.88%)
		Conjunctivae and/or skin alone	21 (17.80%)
		Viscera and skin	9 (7.62%)

There was an increase in electrocution fatalities in the summer (50, 42%) followed by autumn (31, 26%) (Table 5). The peak time period in 50 deaths (42.3%) was between 6:00 and 12:00 (Table 6). Of all cases, 104 (88%) were dead on arrival at hospital, eight (7%) died during treatment within 24 hours and six (5%) died after 24 hours of treatment due to septicaemia.

Table 5

Seasonal distribution

	n	%
Summer (June–July–August)	50	42.37
Autumn (September–October–November)	31	26.27
Winter (December–January–February)	12	10.16
Spring (March–April–May)	25	21.18
Total	118	100.0

Table 6

Time of day

	n	%
6:00–12:00	50	42.37
12:00–18:00	27	22.88
18:00–24:00	31	26.27
24:00–6:00	10	8.47
Total	118	100.0

Discussion

Deaths from electrocution are uncommon and are usually due to ventricular fibrillation from a direct effect on the heart, or respiratory paralysis from a direct effect on respiratory muscles or from cardiorespiratory arrest following damage to autonomic centres within the brainstem. Death may also be caused by burns or subsequent multiorgan failure. The effect of electricity depends on the voltage, type of current (direct/alternating), the area and duration of contact, skin resistance and path of current flow through tissues and organs.¹ Skin resistance is an important factor in determining current flow and is influenced by the wetness or dryness of the skin and the region of the body in contact with an electrical conductor.^1,2

Electrocution is an uncommon cause of death and is usually due to an accident.³ In our study these deaths were found to account for 1.91% of all medicolegal deaths in our region. Previous studies reported medicolegal death rates of 1.98% and 1.90%.^4,5

Our study has demonstrated higher rates of electrocution deaths in males (90.7%) compared with females (9.3%). This is keeping with several other studies that have shown the percentage of male electrocution to range from 81% to 95%.^3,6,7 The reason for such a marked male predominance is likely to be due to the fact that males are more likely to use a variety of electrical equipments in both work and the domestic environment.

Similar to previous studies we found that the upper extremity (52.3%) was the most common site involved^1,2,5,8 because most of the cases occurred at the time of repairing faulty electrical equipment.

In our study, in 97 cases electric burn marks were only present at the point of entry of the current, while in 13 cases electric burn marks were present at both entry and exit points. This can be explained by the fact that the point of exit of the current corresponds with the point where the body was earthed, which is a relatively wide area in most cases. There were no electric burn marks in eight victims, who died from an electric shock in water. Since water lowers both the skin resistance and the density of the electrical current, no wounds would be expected in these cases. These results are similar to the finding of other studies.^5,9

The general household electricity supply in India is 240 V so domestic electricity is classified as low voltage (<1000 V). Most of the electrical deaths in this study (83%) were due to low voltage. Household injuries as well as occupational injuries resulting from the use of small power tools are due to low voltage, while contact with overhead lines or occupational or incidental exposure to outside power lines causes high-voltage lesions. These data are comparable with other studies where low-voltage electrocution ranged from 48.25% to 88%.^1,3,6,10

Specific marks or burns may not occur if the area of electrical contact is broad or there is cooling from water, such as in a bath. ‘Electrical petechiae’ represent a non-specific but typical finding in electrocution irrespective of the mechanism leading to death. Unlike electrical burns, petechiae also indicate the vital origin of the events. The relevance of this typical morphological sign in the examination of possible electrocution fatalities is therefore emphasized. Karger et al. ⁷ reported that 26 cases (74%) in their series had petechial haemorrhages. However, in our study we found petechiae documented in 57 cases (48.3%) of the 118 cases.

Deaths due to electrocution (50 cases, 42%) occurred most frequently in the summer months in our study. These results are similar to the findings of Tirasci et al. ¹¹ while a much higher summer incidence (74%) was reported by Rautji et al. ⁵ This may be due to increased sweating in the summer which decreases skin resistance and increases the flow of current through the body.^3,9

In the majority of our cases death was instantaneous (82%) as a result of ventricular fibrillation, which is the most common cause of death due to low-voltage current (220–240 V), which acts on the conduction system of the heart leading to ventricular fibrillation. This is consistent with the study of Rautji et al. ⁵

There were no cases of suicidal or homicidal electrocution in our study.

Conclusion

While deaths due to electrical injuries are low compared with deaths due to other injuries, there is still scope for reduction in numbers due to the preventable nature of many of these injuries. For example, recent advances in electrical safety equipment in the home (e.g. electrical safety switches) and rigorous standards for electrical appliances have afforded a degree of protection to individuals from electrocution injury.

Our findings that deaths are most likely to occur at home highlights the frequent preventable causes of electrocution, such as carelessness, misuse or improper maintenance of equipment. Such injuries can be prevented with proper educational programmes designed to suit the community.

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