AN EPIDEMIOLOGIC STUDY OF BURNS

Benito Ruiz J., Navarro Monzonis A., Baena Montilla P.

Department of Plastic Surgery and Burn Centre Hospital La Fe, Valencia, Spain

SUMMARY. We report a retrospective epidemiological study based on 710 charts of patients admitted to our Burn Centre between 1985 and 1988. During this period we assisted 9794 people at our Casualty Centre. The average age of the patients was 24 yrs and 66% were males. Burns were much more frequent in children < 10 yrs, especially due to scalding by hot water. Nearly 47% were children under 15 years old. The two leading causes were scalding and flames. Other significant causes were gunpowder and electricity. Contact burns, fire and chemicals were less frequent. Massive burns were due to flames and gunpowder. The deepest lesions were produced by electricity and contact burns. Regarding the place where the accident happened, burns occurring in the home were due to scalding and fire. Accidents outdoors were produced by improper use of gunpowder and by electricity (high voltage). Work-related accidents occurred mainly to chemists and electricians. Males outnumbered women regarding street and work-related accidents (p <0.000001). The face and neck were most commonly afTected when the cause was flames and chemicals, the trunk and upper limbs in the case of scalds and flames, the lower limbs with flames and hot contact, and the hand and wrists with electrical and gunpowder injuries. Gunpowder and scalds were involved in genitalia burns.

Burns are one of the most frequent injuries treated in a Casualties Service, and they carry an important medical, social and economical cost. Medical management of these injuries has improved considerably in recent years and the survival of even very severel~ burned patients is being achieved.
Nonetheless the best way to cope with the problem is to prevent it. A proper burn prevention programme must be based on previous studies about causes, population groups affected and where the injury takes place, etc. These data are provided by epidemiologic studies from the Burn Centres.
The aim of this work was to identify the epidemiologic features of the burn injury in our community in order to accomplish a new programme of prevention.

We have reviewed 710 charts of patients who were admitted to our hospital from December 1984 to December 1988. During this period we assisted 9794 patients at our Casualties Service. 9084 out of them were managed as out-patients, which makes an admission rate of 7.25%.
Data were stored and subsequently analysed on a database programme.

Age

The average age was 23.84 +/- 24.06 years. Fig. 1 shows the number of patients by age groups. We should point out that 333 patients (46.9%) were children under 15 years old.

Sex

469 out of the 7 10 patients were male (66%). This predominance occurs for all ages (Fig. 2), except for elderly patients ( >70 yrs), in which case women were slightly more numerous than men. This is probably due to the greater female population at this age.

Burn size

The average burn size was about 14% (14.04 +/17 ' 76%). Fig. 3 depicts the distribution of the patients regarding burned body surface. 113 out of the whole total (15.9%) sustained extensive burns ( >30% TBS), and 61.8% had minor burns ( <10% TBS).
The mean burn extent was larger in general terms in the male population (Fig. 4), except for children under 10 yrs and women between 61 and 70 yrs, but the difference was not statistically significant.
There were minor differences regarding burn size and cause of injury. Nevertheless, women sustained the largest burns by gunpowder, fires and chemicals (Fig. 5).

Fig. 1 Distribution of patients by age Fig. 2 Distribution by sex Fig. 3 Distribution of patients by bum size Fig. 4 Distribution of burn size by sex and age Fig. 5 Average bum size by sex and cause Fig. 6 Age/Accident Relationship

Type of accident

We have distinguished three main groups depending on the place where the injury happened: home, street and work-place. These three groups comprise 91.9% of the burned population. The rest (8. 1%) includes traffic accidents, sport-related injuries, self-induced and criminal burns (aggressions), and others (e.g. sunburn).
The most frequent site of the burn injury was the home (43 5/7 10, followed by the street (119) and the work-place (99). The distribution of the burned population by agd and type of accident is displayed in Fig. 6. Accidents in the home were especially frequent at extreme ages. 82.67% (253/306) of patients under 10 yrs, and 89.28% (75/84) of patients above 60 yrs sustained bums at home. Injuries as a result of playing in the street were frequent in patients between 11 and 20 years old (46%, 58/126). Patients from 21 to 60 yrs were more often injured at work, accounting for 40.25% of the accidents at this age (64/159).
Regarding sex, injuries produced in the home affected women more frequently than men (85.9% vs 48.6%), whereas street- (7% vs 21.7%) and work-related accidents (1% vs 20%) were predominant in men (p < 0.00000 1) (Fig. 7).

Causes

The different causes of the burn injury have been broken down as follows: scalds, flames, gunpowder, electrical, hot contact, fire, chemicals and others. Burns by fire refer to those produced mainly by live coals or braziers, but also sometimes by lighters, candles, the burners of cookers and heaters, depending on the personal view of the physician on call.
Scalds (263/710) and flames (263/710) were the most frequent causes involved in the burn injury (Fig. 8).
The average age varied in relation to the cause (Fig. 9). Fire affected people in general (mean 51.5 yrs), whereas gunpowder, electricity, hot contact and chemicals affected young adults. Children are commonly burned by hot liquids (scalding).
Males were in general more affected regardless of the cause of injury. The difference between the sexes was greater when the burn was provoked by gunpowder, electricity and chemicals (Fig. 10).
We have observed that the average age in females was higher for all causes except work-related burns (electrical, hot contact and chemicals) (Fig. 11).

Fig. 7 Sex/Accident Relationship Fig. 8 Frequency of causes Fig. 9 Average age by causes Fig. 10 Distribution by sex and causes Fig. 11 Average age by sex and cause Fig. 12 Bum depth

Table 1 shows the main causes of the bum injury in relation to age. Children were most commonly affected by scalding (64%), and flames were the most frequent cause for the rest of patients, being the exclusive cause of the burn injury in patients above 80 years. Gunpowder (fireworks) was an important cause in teenagers. Electrical and chemical burns corresponded to working ages (10.6% and 4.76%). Fire and hot contact afTected aging patients (61-80 yrs).
Regarding the place where the accident happened, we found that scalds, flames, hot contact and bonfire were mainly domestic (94%, 52%, 69%, and 85% respectively); gunpowder burns were street accidents (83,9%) and electrical and chemical injuries happened at work sites (52.6% and 53% respectively) (Table 2).

Bum Depth

Fig. 12 shows the number of patients in relation to burn depth at admission evaluation. 140 patients had sustained pure full-thickness burns, and 188 had both partial- and full-thickness burns. Only 15.47% had sustained minor injuries (simple erythema and/or partial -thickness burns).
Scalding was the commonest cause of first- and second-degree injuries. Flames were responsible for both second- and third-degree burns. Hot contact and electricity caused mainly full-thickness burns, whereas gunpowder and chemicals usually provoked deep-dermal plus full-thickness bums (Table 3).

Location of bums

Table 4 shows the parts of the body involved by the bum injury on admission, related to the cause. Face and neck burns were more affected by flames (56.7%) and chemicals (42%); the trunk (chest, abdomen and back) was involved by scalding (46.7%) and flames (44%), as also the upper limbs (49.8% and 49% respectively); the wrists and hands were injured by electricity (61.4%) and flames (41.6%). Burns on the lower limbs were caused by flames (52%) and hot contact (48%) (exhaust pipes and heaters). Scalding (baths) and gunpowder blasts (from firecrackers and small rockets kept in the pockets and lighted inadvertently) were the main causes involved in buttocks and genitalia burns. Injuries to the lips and tongue were exclusively caused in children by low-voltage electricity. Massive ( >90%T1IS) burns were due to gas and gunpowder (fireworks industry) explosions.

Length of stay

69.85% of the patients were discharged from our hospital within two weeks of admission. Nearly 21% were kept as in-patients for more than five weeks (Table 5). The average burn extent in this group was 23.67%, with 75.85% full-thickness or partial-plus full-thickness burns.

The exact incidence of the burn injury in our area cannot be estimated from our data from 1984 to 1988, as the national Health Authority did not establish clearly the population to be covered. In January 1989 a clear "sectorization" was defined, which will let us estimate our prevalence rate. Nevertheless, the number of patients assisted at our Casualties Service is very similar every year and remains stable (about 2000 patients/yr). Most of them have minor injuries which do not require hospitalization and can be followed on an out-patient basis. Only 7% required hospital management; 16% presented a burn size larger than 30% (as Clark and Fromm, 1987).

The burns in this, as in other studies (Silverstein, 1987; Clark and Fromm, 1987), mainly affected young people. The average age of our patients was about 24 yrs. This is due to the high predominance of children in our burned population (46.9%), which is in line with other reports (Elberg et al., 1987).
The male population ran twice as much risk of sustaining burns as the female population. This is because men more frequently handle dangerous substances and devices, both by playing and by working with them. Not only were there more burned men but they had the largest burn sizes as well. We found that women older than 60 yrs had larger burns than males at the same age, which coincides with observations made by Clark and Fromm (1987).

Accidents occurred mainly at home (61%), affecting women and people at extreme ages. This value is somewhat lower than that reported by Lyngdorf (Lyngdorf, 1987). Otherwise, adult males were more commonly injured at work. This distinct distribution is statistically significant at p --0.000001.
Scalding and fires were also in our experience the most frequent cause of burns. These two account for 70.3% of the whole number. Children were most commonly involved by scalding, usually due to kettles and pots in the kitchen or to tapwater scalds. Elderly patients above 70 yrs were in particular burned by flame accidents, typically by domestic fires. Electrical and chemical burns affected the working population, and the use of fireworks as a means of entertainment by teenagers and youngsters at local festivities and celebrations caused many burns. The worst accidents were those occurring at fireworks factories due to sudden blasts.
We do not know why women were more frequently involved in accidents by gunpowder, electricity or chemical products. Maybe it is due to the fact that they are more inexperienced with such materials than their male counterparts.
A special chapter in burns regards road accidents, which may provoke burns when a car catches fire after a crash. The victims are usually young people about 20 yrs old. Related to motor traffic, the most frequent burns are those provoked by the exhaust pipes of motorbikes (hot contact), when the patient puts his/her leg against the pipe. We also had six patients involved in explosions of butane gas, which is used quite frequently as fuel by taxi-cabs.
Taking into account the location of the injury, scalding affects the upper limbs and trunk; flames affected every part of the body because of ignition of clothes; exposed areas, such as the limbs, hands and face/neck, were frequently involved in electrical and gunpowder accidents, both in children and in.adults. Electrical flashes affected a typical pattern of face and dorsum of the hands. Hot contact caused burns in the lower limbs, mainly due to exhaust pipes and heating devices used by the aged (braziers). Chemical injuries were in our series more frequent in sites other than the hand (lower limbs, face and neck), as would be expected.
These conclusions have led us to consider several groups to whom the prevention programme should be addressed in our area:

• the elderly, with especial regard to the use of safer heating appliances and to the observance of basic rules to avoid domestic fires;
• parents with small children, to avoid in particular scalds from baths (by checking the water temperature before bathing) and in the kitchen (by watching children during food preparation and food consumption);
• teenagers and youngsters in relation to the use of fireworks as an entertainment, In this regard, our local authorities have recently introduced laws regulating the size and amount of fireworks commercially available;
• the industrial and working population, especially electricians and chemists;
• motorists, in order to try to minimize unnecessary fire-risks like the use of butane as fuel for cars (taxis).

RÉSUMÉ. Les Auteurs présentent les résultats d'une étude retrospective basée sur 9794 patients brûlés soignés pendant les quatre ans 1985/1988. L'âge moyen était 24 ans et le sexe masculin constituait 66% des cas. Les brûlures étaient très fréquentes chez les enfants ( >10 ans), particulièrement à cause de l'ébouillantement. Presque 47% des cas étaient enfants âgés de moins de 15 ans. Les deux causes principales des brûlures étaient l'ébouillantement et les flammes. Les autres causes significatives étaient la poudre et l'électricité. Les brûlures causées par les solides chauds, le feu et les produits chimiques étaient moins fréquentes. Les brûlures massives ont été causées par les flammes ou par la poudre, et les lésions plus profondes par l'électricité et les solides chauds. Pour ce qui concerne le lieu des accidents, les brûlures domestiques ont été causées par l'ébouillantement et par le feu, et les accidents en plein air par l'emploi impropre de la poudre et par l'électricité (haute tension). Les accidents du travail affectent les chimistes et les électriciens. Pour ce qui concerne les accidents de la route et' du travail, la population masculine est plus nombreuse (p <0.000001). Le visage et le cou ont été atteints plus fréquemment dans le cas des brûlures causées par les flammes ou les produits chimiques, le tronc et les membres supérieurs par l'ébouillantement et les flammes, et les mains et les poignets par les lésions électriques et la poudre. Les brûlures aux organes génitaux ont été causées par la poudre et l'ébouillantement.

BIBLIOGRAPHY

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2. Elberg J.J., Schroder H.A., Glent-Masden L., Hall K.V.: Bums: epidemiology and the effect of a prevention programme. Bums, 13: 391-394. 1987.
3. Lyngdorf P.: Epidemiology of severe burn injuries. Bums, 12: 491-495, 1986.
4. Silverstein P., Lack B.O.: Epidemiology and prevention. In: Boswick J.A. (Ed.), "The Art and science of burn care", 11-19, Aspen, 1987.