CHEMICAL BURNS - OUR EXPERIENCE OVER ELEVEN YEARS

Sinha S., Sinha J.K., Tripathi F.M., Bhattacharya V.

Burns Unit, Division of Plastic Surgery, Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005 India

SUMMARY. An eleven-year review is made of chemical burns consisting of 59 cases presenting at the University Hospital, Varanasi. Chemical burns are an uncommon entity which require special considerations in management. In the period studied, they constituted 4.7% of all burn admissions. Most cases were intentionally inflicted with acids, following property disputes. The patients were usually in their second, third or fourth decades. Depth of burn at the initial assessment was often found to be fallacious. Ocular involvement was common (30.5%). Slough separation was delayed compared to thermal bums. Hydrotherapy was the mainstay of first-aid and casualty department care. Early debridement and skin grafting yielded good results especially in chemical burns of the ear and hand.

Chemical bums are relatively infrequent and consequently the experience of doctors in any centre is limited. Social development and industrialization influence the type of corrosive involved. Industrial accidents, which constitute a major proportion of cases in the west, are but a small case group in India. We present our experience with chemical burns over the past eleven years at the Burns Unit, Division of Plastic Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi.

Materials and methods

Over the period January 1979 to December 1989 a total of 1248 patients with burns were admitted to the Burns Unit at Varanasi, of whom 59 had chemical burns (4.7%). Fifty of these patients were in the second to fourth decades of life (84.8%) while only one patient was less than ten years of age (Table 1). 67.8% of patients were males. Acid burns by far exceeded all other types of burns and sulphuric acid was the commonest agent (Table 2). Most of the cases were intentionally inflicted (71.2%) while only 18.6% were accidental. In 10.2% of cases the aetiology was unknown. In most cases the burns surface constituted less than 15% of total body surface area (Table 3), with the head being the commonest region affected (74.6%) (Table 4). The neck and trunk were other areas to be commonly affected. Estimation of depth of burn was often incorrect initially and frequent reassessment was required subsequently. Most of the burns were third degree (60%) while about 25% of the burns were second degree, the remaining being first degree. 18 patients (30.5%) had associated ocular burns while fractures were present in 4 patients. 5 patients (8.5%) had systemic toxicity owing to absorption of the chemical.
On presentation, the patients were received in the casualty department. Most patients presented late (after 24 hours). In those presenting early, hydrotherapy by copious water irrigation of the burned area was performed. This was given for an average of about 30 minutes. Analgesics and intravenous fluids (3 mI crystalloid solution per kg for each % of BSA burned) were given as required. Two patients needed blood transfusion due to associated fractures. Consciousness, vital signs, urine output and electrolytes were monitored.
The patients were subsequently transferred to the Burns Unit where topical chemotherapy with 1% silver sulphadiazine cream was performed. The wound was dressed on alternate days with bi-weekly baths in a Hubbard tank. Debridement was performed as required either after sedation at bedside or under general anaesthesia in the operating theatre, and split thickness skin grafting was performed. Physiotherapy was commenced in the hospital and patients were discharged following recovery.

Separation of slough required a longer time than in thermal burns and generally occurred between 3 and 5 weeks post-burn. Wounds were sterile in the first two weeks (80% of patients). Most cases showed bacterial growth after 30 days (86%). The common organisms involved were Staphylococcus aureus, Pseudomonas aeruginosa, Proteus and E. Coli in order of frequency. The hospital stay of these patients was prolonged - generally between 3 and 8 weeks, with one patient staying 66 days before discharge. Only two patients died and in both cases the cause was overwhelming septicaemia following burn wound sepsis.
The commonest operation performed was split thickness skin grafting (29%) which either followed spontaneous eschar separation or was done following debridement (Table 5). Early debridement and split thickness grafting was performed in most cases of burns of the car and this helped minimize the problem of intractable chondritis. Early debridement and split thickness skin grafting yielded good results in selected cases.

The outstanding feature of chemical burns is the prolonged period for which the burning effect continues. Most patients in our region present late (after 24 hours). In patients presenting early, dilution and removal of the chemical by hydrotherapy is now well established, both as a first-aid measure and in the casualty department (1, 2, 3). In alkali burns there is a place for hydrotherapy even in those patients who present late, as there may be a prolonged burning effect at the subeschar level (4). It is important to minimize the time interval between contact with the chemical and hydrotherapy (5) and time spent in searching for neutralizing agents leads to more extensive burns (3).
In the period studied, 4.7% of burn admissions were chemical burns. This is in contrast to other reports between 1.4% and 4.8% (6, 7, 8) Most of the cases were intentional and occurred outside industry, compared to a high incidence of industrial chemical burns in the west (3). In this region the bums can be attributed to two major groups. The first is due to property feuds where corrosives are poured on the face of a sleeping adversary involved in disputes regarding property. Often a definite attempt is made to damage the eyes, a fact which accounts for the high percentage of ocular burns in this series (30.5%). Serious ocular burns have also been reported by others (1, 9). Such burns usually occur in males. The other major group is composed of young girls on whom acid is thrown out of sexual frustration. These two factors also account for the burns occurring in the active age group.
Sulphuric acid was the commonest agent involved, with a low incidence of alkali burns in contrast to the high incidence of alkali and hydrofluoric acid burns in the west (3). Lysol burns proved to be a special occupational hazard to hospital staff and doctors, in hospitals where lysol is used to sterilize instruments. It is thus important to educate all hospital staff in the handling of lysol.
Assessment of the depth of burn at the onset was often inaccurate. Areas of apparent partial -thickness burns often turned out to be full-thickness burns.
Slough separation is delayed in chemical burns probably owing to the sterilizing action of the chemical as well as the tough leathery impenetrable eschar that usually results. It usually occurs between 3 and 5 weeks (8). Wound cultures are sterile in the first two weeks but are positive in most cases by the end of the fourth week (8).
In many cases no operation is required and the wound heals spontaneously. The commonest operation performed is split thickness skin grafting. This may be performed following debridement or after spontaneous separation of the eschar (8). Early debridement and skin grafting yield good results especially in chemical burns of the car, where a delay may result in intractable chondritis or crippling deformities.
Chemical burns require intensive therapy and specialized care. The literature on the subject is unfortunately scanty. Better communication among those involved in the treatment of such cases is required in order to improve the outcome.

RESUMÉ. Les Auteurs analysent 59 cas de brûlures chimiques qu'ils ont traitées pendant une période de 11 ans à l'Hôpital Universitaire de Varanasi. Les brûlures chimiques représentent une maladie pas commune qui a besoin d'une gestion toute particulière. Ces patients constituaient 4,7% de tous les brûlés hospitalisés pendant la période. Dans la plupart des cas il s'agissait de brûlures intentionnelles infligées avec des acides, à la suite de contestations pour des questions de propriété. L'âge des patients variait normalement entre 10 et 40 ans. L'évaluation initielle de la profondité de la brûlure au moment de l'hospitalisation se révélait souvent fallacieuse. Les yeux étaient fréquemment affectés (30,5% des cas). La séparation de l'escarre avait lieu en retard par rapport aux brûlures thermales. L'hydrothérapie était à la base du secourisme et des soins pratiqués dans le Service des Urgences. Le débridement précoce et la greffe cutanée ont donné de bons résultats, particulièrement dans les brûlures chimiques de l'oreille et de la main.

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