Treatment and outcomes
Among 128 patients who received surgical treatment for burn wounds, 124 cases were given early-stage eschar excision or late-stage granulating wound debridement and skin grafting, and 4 cases were given transposition skin flaps. A total of 485 patients were discharged after healing or stabilization. Three patients transferred to another hospital. One patient was discharged against advice (the patient gave up treatment on the 13th day after injury). Among the three deaths, two died of hydrofluoric acid poisoning and one of severe concomitant crush injury.
The association of clinical features of patient groups is analyzed in Table
3. Two patient groups were significantly different in causes of chemical burn, first aid treatment, and pre-job training (p < 0.001). Group 1 had less inappropriate operation rate than group 2. The majority of patients in group 1 did immediately treat the wounds on site and had received pre-job training before. Unexpectedly, compared to patients in group 2, patients in group 1 had higher burning area (p < 0.001), and suffered from more severe inhalation and chemical poison (p = 0.007 and 0.032, respectively). The above findings suggested that knowing the concept that the wound should be immediately treated on site did not reduce the damage caused by chemical burn. There is no difference in prognoses status between two patient groups (p = 0.078).
Table 3
Clinical features of all patients classified by patient groups
Cause of chemical burns | | | | < 0.001* |
Facility problem | 88(17.89%) | 74(28.14%) | 14(6.11%) | |
Inappropriate operation/handling | 351(71.34%) | 161(61.22%) | 190(82.97%) | |
Other | 53(10.77%) | 28(10.64%) | 25(10.92%) | |
First aid treatment | | | | < 0.001* |
Without any treatment | 241(48.98%) | 13(4.94%) | 228(99.56%) | |
Flush with running water | 231(46.95%) | 230(87.45%) | 1(0.44%) | |
Using counteractive agent | 17(3.46%) | 17(6.47%) | 0(0%) | |
Other | 3(0.61%) | 3(1.14%) | 0(0%) | |
Total body surface area burned (%) | 4(1.5,8) | 5(3,10) | 2(1,7) | < 0.001* |
Inhalation | | | | 0.007* |
No | 450(91.65%) | 230(87.78%) | 220(96.07%) | |
Slight | 22(4.48%) | 18(6.87%) | 4(1.75%) | |
Moderate | 14(2.85%) | 10(3.82%) | 4(1.75%) | |
Severe | 5(1.02%) | 4(1.53%) | 1(0.43%) | |
Chemical poisoning | | | | 0.032* |
No | 482(97.97%) | 254(96.58%) | 228(99.56%) | |
Slight | 4(0.81%) | 4(1.52%) | 0(0%) | |
Moderate | 4(0.81%) | 4(1.52%) | 0(0%) | |
Severe | 2(0.41%) | 1(0.38%) | 1(0.44%) | |
Pre-job training
†
| | | | < 0.001* |
Yes | 137(31.64%) | 115(49.78%) | 22(10.89%) | |
No | 296(68.36%) | 116(50.22%) | 180(89.11%) | |
Prognoses | | | | 0.078 |
Cured | 401(81.51%) | 207(78.71%) | 194(84.72%) | |
Improvement | 84(17.07%) | 54(20.53%) | 30(13.10%) | |
Hospital transfer | 3(0.61%) | 1(0.38%) | 2(0.87%) | |
Discharged against advice | 1(0.20%) | 0(0%) | 1(0.44%) | |
Death | 3(0.61%) | 1(0.38%) | 2(0.87%) | |
In our survey, inappropriate operation or handling of chemicals, lack of employee awareness about appropriate action and a lack of effective personal protective equipment were key factors contributing to chemical burns. We found that the workplaces of private enterprises and sole proprietors had a greater share of occupational injuries than larger industrial companies. This may be due to the more recent and rapid development of private business in Zhejiang where middle- to small-sized private chemical companies are abundant throughout the province. It may also be the result of the lower education levels of employees in private enterprises and the higher turnover rate, which means that most employees were without orientation training, operational proficiency and awareness of safety issues, coupled with a lack of effective onsite first-aid. The companies also appeared to be suffering from failure of management since 62.2% of the burned patients were working in workplaces deprived of any protective equipment. Even when such equipment was provided, only 42.0% of patients put on the protective gear as instructed, indicating lack of safety education and training in procedures. These results suggest that the effective route to chemical burn prevention is through enforcing safety education, improving awareness and supervision of all personnel, and providing personal protection for all employees.
It is noteworthy that a certain number of chemical burns occurred in non-chemical industries. Protection was generally inadequate in these companies due to a lack of awareness at the managerial level down to the common first-line workers of the hazards related to the chemicals being used. Prior to the present study, no systematic investigation was made of the occurrence of burn accidents and events. The potential hazards of low-grade hydrofluoric acid (about 5% concentration or 2.5 mol/L), the main component of the rust remover Qu-xiu-ling (triadimefon), which is readily available in the market, are often ignored because the agent causes little skin discomfort at first contact but results in chemical burns 2-3 hours later if left untreated [
9]. The product label of Qu-xiu-ling failed to include the ingredients on the outer packaging. Although there were notices requiring users to wear rubber gloves, the warning was insufficient and unnoticeable. Therefore, we recommend that in addition to the enforcement of safety education, there should be prominent warning signs on the outer packages of potentially dangerous chemical products in order to prevent similar events from occurring. This could perhaps be influenced by the purchasing departments of industries that use the products.
Among all substances contributing to chemical burns, hydrofluoric acid caused the largest share of casualties, likely due to the high concentration of the fluorochemical industry in Zhejiang. Besides the presence of large fluorochemical plants that are engaged in inorganic or organic fluorine production, the province has seen a rapid growth of small- and middle-sized fluorochemical companies in recent years. These plants, large or small, either produce hydrofluoric acid or use hydrofluoric acid as a raw material. There is a potential for chemical burns during the production, loading, and transportation of hydrofluoric acid. Furthermore, since low-grade hydrofluoric acid is used as a cleaning agent in metal casting, glass processing, and electronics industries, it results in a higher incidence of burns. Burns caused by hydrofluoric acid are fairly uncommon but when they do occur they can be severe and sometimes fatal [
10]. Hydrofluoric acid has been responsible for mass casualties. It is also notable that a medium or small area of hydrofluoric acid burn can generate severe chemical poisoning [
10]. Following a hydrofluoric acid burn, fluoride rapidly enters blood circulation through the skin and concentration peaks within an hour [
11]. With swift development, fluoride poisoning can lead to death in a short period of time due to life-threatening electrolyte disturbances, even as a result of small, highly concentrated acid burns [
4]. Throughout the study period, the two deaths from chemical poisoning were caused by hydrofluoric acid burns and these patients died within eight hours following the accident. Hatzifotis et al. presented a management strategy for hydrofluoric acid burns that included the application of calcium gluconate with dimethyl sulphoxide (DMSO) in surgical jelly for the potentially fatal injury caused by cutaneous exposure to hydrofluoric acid [
10]. This method could easily be incorporated into industry procedures for emergency care. As in most occupational burn cases, treatment should commence immediately after at least 30 minutes of lavage with water. Clinical management of hydrofluoric acid burns calls for immediate washing of the burned area with water and external application of calcium as described above [
10]. For hypocalcemia patients, calcium gluconate should be injected intravenously, depending on the individual patient's blood calcium levels. Arterial delivery of calcium gluconate is also possible, which allows the drug to combine with fluoride ions in the wounds, a method generally applied to hydrofluoric acid burns on the extremities (e.g., fingers and toes) [
9,
12] or to burns on the head and face [
13]. Because of the special and dangerous nature of hydrofluoric acid burns, Kirkpatrick and Burd (1995) developed an algorithmic approach to treatment of these burns and it remains a reference for clinicians [
14]. In our study, surviving patients with deep burns from hydrofluoric acid were left with scars after healing, but with no other sequelae. However, when treatment of hydrofluoric acid burns to the fingers was delayed more than 48 hours, the distal end of the fingers would show signs of necrosis, turn black, and would become shortened.
After contact with the human body, chemicals not only produce immediate harm through inflammatory response, but they also cause progressive damage leading to epidermal and dermal lesions [
15] and major burns affecting a significant body surface area may lead to compromise of the circulation and air exchange, fluid and electrolyte imbalance and systemic shock and sepsis [
16]. Some chemicals such as hydrofluoric acid can be absorbed and produce systemic chemical poisoning. The delivery of effective onsite management in a timely fashion is a direct determinant of the degree and prognosis of damage. Our survey showed that no skin graft surgery was needed for all patients whose wounds had been immediately irrigated with massive amounts of water for 30 minutes or more, and all those requiring skin graft or transposition skin flaps had received inadequate onsite wound management. In spite of varying substances and different causes of damage, massive water irrigation is the most convenient and effective means of onsite first-aid, for it not only prevents further harm by washing out the chemical, but it serves as a cooling agent by taking away the heat. Provided there is no life-threatening concomitant injury, water irrigation should be initiated as early as possible and continue for a minimum of 30 minutes [
17]. We also found that about half of the patients were not aware of the correct onsite management of chemical burns. Some patients, and even the attending medical staff, had a clear misunderstanding that water plus concentrated sulfuric acid produces heat, hence aggravating the damage. There is an urgent need to promote knowledge about correct chemical burn first-aid so that the correct action can be taken early onsite instead of waiting for treatment by medical professionals.
Among work-related burns, those of the upper extremities occur most often in our study and others and it is the cause that directs the course of action [
4]. For example, thermal or heat burns must be assessed for depth and for systemic effects. The deepest partial-thickness burns and more severe burns with pulmonary effects or shock require evaluation by burn specialists outside the workplace. Chemical burns, as we've noted, require irrigation and identification of the causative chemical; however, the causative chemical may indicate that specific topical applications are needed before water lavage such as for phenols and metal fragments [
4].
Onsite protection in industry for exposure to skin irritants first requires physical protective countermeasures such as the wearing of protective gear for operating equipment or handling chemicals; it may also require availability of appropriate pharmacologic topical treatment to prevent the development of burns or to provide an immediate antidote if harmful exposure occurs, either of which may help avoid complications and later surgical treatment of burns [
15]. In a statewide, cross-sectional study of all workplace burns during one year, most of the injuries were to the upper extremities and head and were caused by either exposure to caustic chemicals or hot objects or substances; investigators concluded that availability and use of protective gear for the upper extremities and head could prevent a significant number of this type of injury and that education and prevention programs directed to high-risk workers was the best management approach [
8]. Burn injuries outside of the workplace have been declining, largely as a result of safer homes (e.g., smoke detectors, home construction measures), burn education in schools and focused efforts to reduce home fires [
8]. Prevention of occupational burns clearly requires a similar focus.
Our study is limited by the use of a new Chinese questionnaire designed by the authors and not previously tested or validated. This study also focused exclusively on patients with chemical burns and did not survey all industries or all workers for work-related injuries. Future study must be more comprehensive, including all industries and all workers in a given population.