Annals of Burns and Fire Disasters - vol. XVI - n. 1 - 2003
THE TREATMENT OF BURNS CAUSED BY GUNPOWDER EXPLOSION IN FIREWORKS FACTORIES
Chen X.L., Wang Y.J., Wang C.R., Hu D.L., Fang L.S., Li S.S.
Department of Burns, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China
SUMMARY. Patients with burns caused by gunpowder explosion in fireworks factories often have inhalation injury and associated injuries that lead to high mortality. The aim of this study was to analyse the management of these burn patients and to decrease their morbidity and mortality. The 339 patients considered were divided into two groups: patients admitted between 1987 and 1993 (group 1) and patients admitted between 1994 and 1999 (group 2). Data on age, sex, size and depth of burn, inhalation injury and associated injury, management, incidence of sepsis and the multiple organ dysfunction syndrome, mortality rate, and length of hospital stay were collected and compared. No significant difference was found between the patients in the two groups as regards male-to-female ratio, total body surface area and full-thickness burn, inhalation injury, or associated injury. Forty-seven patients in group 1 received inadequate fluid resuscitation and developed severe shock, whereas only 11 patients in group 2 presented severe shock. In the early period post-burn (within 1 week of injury), high-dose vitamin C was administered to 18 patients in group 1 and to 97 patients in group 2. No patients in group 1 received vitamin E, while 45 patients in group 2 received it the early period post-burn. Prophylactic tracheotomy was performed in one patient in group 1 and in 14 patients in group 2. The incidence of the acute respiratory distress syndrome in groups 1 and 2 was respectively 13.1% and 6.4% (p < 0.01). Forty-six patients in group 1 and 83 patients in group 2 underwent early excision and grafting. All associated injuries were well managed and no death was related to associated injuries or their direct complications in either group. The incidence of sepsis and the mortality rate of patients were significantly higher in group 1 than in group 2 (14.2% vs 5.1%, p < 0.01; 19.1% vs 5.8%, p < 0.01). The mean hospitalization period of survivors in group 2 was significantly shorter than that in group 1 (29.1 ± 11.3 days vs 36.3 ± 10.2 days, p = 0.041). In patients who sustain burns due to gunpowder explosions in fireworks factories, the following methods of treatment are crucial: 1. prompt, rapid, and adequate fluid resuscitation; 2. prophylactic tracheotomy with mechanical ventilation in patients presenting upper airways oedema or in whom airways patency is threatened; 3. early excision and grafting of larger deep wounds and coverage using allograft with a 1:10 micro-autograft; 4. vitamin E and high-dose vitamin C; 5. determination and immediate management of life-threatening associated injuries.
China has a very long history of fireworks manufacturing and there are many household fireworks factories in relatively poor areas such as our Anhui province. These are family businesses. Because of the inadequate safety measures, gunpowder explosions following work-related accidents often occur. Burns caused by such explosions in fireworks factories are quite different from thermal burns resulting from the incorrect use of fireworks. The weight of exploding gunpowder is much higher in the first case than in the second. Nearly all patients in the first case sustain burns in an enclosed area, while in the second case the accident occurs in an open area. When gunpowder explodes in an enclosed workshop, two factors cause injury: high temperature/high-speed airflow, and gunpowder’s alkalinity. Many fireworks factory workers suffer severe burns with inhalation injury and associated injuries leading to an elevated mortality rate.
Owing to the complexity of their condition, the management of such patients is always problematic, and there are not many reports in the literature that describe in detail the management of patients burned by gunpowder explosion following work-related accidents in fireworks factories. We reviewed all our patients burned in gunpowder explosions in fireworks factories in the period 1987-1999. The study was undertaken in order to analyse the management, morbidity, and mortality of the patients, with a view to refining our protocols for systemic treatment and wound care.
Materials and methods
During the period January 1987-December 1999, a total number of 7932 patients were admitted in our centre, of whom 351 had sustained burns due to gunpowder explosions in fireworks factories. The clinical notes of 339 patients (208 males and 131 females) presenting such burns were available for review, and only these patients were included in the study. The age range was from 1 to 76 yr (mean, 37 yr). The total body surface area (TBSA) burned ranged from 1 to 98% (mean, 40.9 ± 33.6%), with mean full-thickness burns in 21.7 ± 18.9% TBSA (range, 0-96%). Forty-four patients died as a result of their injuries, a mortality rate of 13%. On the basis of the mechanism of the injury, we developed the following treatment protocols: 1. prompt, rapid, and adequate fluid resuscitation; 2. prophylactic tracheotomy with mechanical ventilation in patients presenting upper airway oedema or in whom airway patency was threatened; 3. early excision and grafting of larger deep wounds and coverage using allograft with a 1:10 micro-autograft; 4. vitamin E and high-dose vitamin C; 5. determination and immediate management of life-threatening associated injuries.
These methods, prior to 1994, were used in only a few patients, while from 1994 onwards the majority of patients received such treatment. On the basis of the year of admission to our hospital, we divided patients suffering from gunpowder explosion burns following work-related accidents in fireworks factory into two groups: group 1, patients admitted between 1987 and 1993; group 2, patients admitted between 1994 and 1999. Data on age, sex, size and depth of burn, inhalation injury and associated injury, management, incidence of sepsis and multiple organ dysfunction syndrome (MODS), mortality rate, and length of hospital stay were collected and compared.
Patient demographics (Table I)
The mean age of Group 1 patients was 35.2 ± 22.7 yr and the male/female ratio was 1.0:0.61. The mean percentage of burned TBSA and full-thickness burns in group 1 patients was respectively 39.5 ± 31.6 and 20.2 ± 17.8. In group 2, the mean age was 38.4 ± 27.9 yr and the male/female ratio was 1.0:0.64. The mean percentage of TBSA and full-thickness burns in group 2 patients was respectively 42.1 ± 38.7 and 22.6 ± 19.9. Inhalation injury was present in 37 patients in group 1 (20.2%) and in 28 patients in group 2 (17.9%); associated injuries were present in 18 patients in group 1 (9.8%) and in 17 patients in group 2 (10.9%). No significant difference was found between patients in the two groups with regard to age, male/female ratio, TBSA and full-thickness burns, inhalation injury, or associated injuries.
Management of patients in the two groups
Intravenous transfusion lines for fluid resuscitation were established for all patients with major burns, including those with inhalation injury or other associated injuries. Forty-seven patients in group 1 received inadequate fluid resuscitation and developed severe shock, whereas only 11 patients in group 2 presented severe shock. In the early period post-burn (i.e. within 1 week of injury), high-dose vitamin C (paediatric dose, 0.5-1 g/kg/d; adult dose, 0.2 g/kg/d) was administered to 18 patients in group 1 and to 97 patients in group 2. No patients in group 1 received vitamin E, while 45 patients in group 2 received vitamin E in the early period post-burn.
Sixty-five patients presented inhalation injury, of whom 47 underwent tracheotomy and required mechanical ventilation. On the basis of the time of the operation, the tracheotomy procedures were classified as prophylactic tracheotomy (performed before development of dyspnoea) and emergency tracheotomy (performed on development of dyspnoea, or later).3 Prophylactic tracheotomy was performed in 15 patients, of whom six died. The other 32 patients underwent emergency tracheotomies, and 29 of these died. The difference in mortality rate between patients subjected to prophylactic tracheotomy and patients subjected to emergency tracheotomy was significant (p < 0.01). Prophylactic tracheotomy was performed in one patient in group 1 and in 14 patients in group 2. The incidence of the acute respiratory distress syndrome (ARDS) in groups 1 and 2 was respectively 13.1% (24/183) and 6.4% (10/156) (p < 0.01).
Large deep wounds needed surgical intervention. In group 1, 46 patients underwent early excision (i.e. within 1 week of injury) and grafting, compared with 83 patients in group 2 subjected to the same procedures. There was a significant difference in the early excision rate between the two groups (p < 0.01). After 1994, excised large deep wounds were covered using an allograft with a 1:10 micro-autograft.
A thorough head-to-toe examination and any necessary check-ups were performed to identify associated injuries when the patients were admitted. Immediately life-threatening associated injuries such as haemopneumothorax were quickly identified and treated on admission, while injuries having little effect on life were dealt with after fluid resuscitation and when stable vital signs were established. All associated injuries were well managed and no deaths were directly related either to them or to their complications in any patient in either group.
Incidence of sepsis and MODS, and mortality rate (Table II)
Sepsis and MODS are the two commonest complications and the leading causes of death in this kind of burn.1 The incidence of sepsis in group 1 was significantly higher than in group 2 (14.2% vs 5.1%, p < 0.01). The incidence of MODS in group 1 was higher than in group 2 (4.9% vs 2.6%), but a statistical analysis showed no significant difference (p = 0.226). The mortality rate in patients in groups 1 and group 2 was respectively 19.1% and 5.8%, with a statistically significant difference (p < 0.01). The mean hospitalization time in survivors in group 2 was significantly shorter than in group 1 (29.1 ± 11.3 days vs 36.3 ± 10.2 days, p = 0.041).
The fireworks-related injuries caused by gunpowder explosion following work-related accidents were always compound injuries. Owing to the high environmental temperature (over 1000 °C) resulting from explosions and to gunpowder’s alkalinity, these thermal injuries were always severe, presenting large, deep wounds - the gunpowder explosions always occurred in enclosed areas, with a resultant high incidence of inhalation injury. In addition to these injuries, the patients also suffered associated injuries arising from the high-speed airflow and subsequent house collapse. There was no significant difference between the two groups of patients as regards age, male/female ratio, size and depth of burn, inhalation injury, and associated injuries. However, the management of burn shock, inhalation injury, and deep burn wounds was quite different, leading to different outcomes. The incidence of sepsis and the mortality rate were significantly lower in group 2 than in group 1, and group 2 patients remained in hospital longer.
More patients received inadequate resuscitation and developed severe shock in group 2 than in group 1. Owing to their extensive burns, inhalation injury, and associated injuries, patients burned in gunpowder explosions in fireworks factories always develop burn shock. Severe burn shock can not only directly cause the patient’s death but also give rise to ischaemia and hypoxic pathological changes in vital organs, leading to an increased incidence of MODS and sepsis in patients who survive the period of shock. In addition to the severity of the burns, inhalation injury and associated injuries should therefore be taken into fully account during resuscitation. Fluid resuscitation formulas are only guidelines - they are not a guarantee of adequate resuscitation.4 In our experience, invasive techniques such as use of the Swan-Ganz catheter are possible in patients presenting burns in more than 70% TBSA, in severe inhalation injury, and in critical associated trauma during the shock period. The haemodynamic data obtained by invasive techniques help to ascertain cardiovascular performance and the endpoints of resuscitation, and also to direct therapy when non-invasive monitoring is found to be inadequate.
The chief ingredients of gunpowder are sulphur, nitrates, potassium chlorate, aluminium, and charcoal.1 Potassium chlorate is a strong oxidant that causes oxygenation of the host. Vitamin C is a water-soluble reductant against oxygenation and is beneficial to patients with burns caused by gunpowder explosion in fireworks factories. Vitamin C also has manifold effects in the early post-burn period: it can reduce post-burn oedema and fluid requirements,5 diminish early post-burn lipid peroxidation,6 and reduce the incidence of bacterial translocation and lung neutrophil sequestration.7 Vitamin E is an antioxidant which can reduce injury due to lipid peroxidation, and it can be beneficial in the early post-burn stage.
Proper initial management of inhalation injury can have a favourable influence on outcome,8 and maintenance of the airways is the first critical step. We prefer tracheotomy to endotracheal intubation because tracheotomy favours the clearance of airway secretion arising from inhalation injury. The mortality rate and the incidence of ARDS were much higher in patients who underwent emergency tracheotomy than in patients subjected to prophylactic tracheotomy. Tracheotomy is required if there is early evidence of upper airway oedema or if airway patency is threatened. If tracheotomy is performed only when dyspnoea is present, or later, hypoxia is always severe and may lead to the development of respiratory failure and subsequent multiple organ dysfunction.8 Patients who required tracheotomy because of airway oedema or pulmonary dysfunction were generally connected to a mechanical ventilator and given positive pressure ventilation. Mechanical ventilation immediately after tracheotomy not only promptly and adequately improved the oxygen supply but also increased the humidity of the airways, which was beneficial for the prevention and management of pulmonary infection.3
The rate of early excision was significantly higher in patients in group 2 than in group 1. Early excision and grafting are crucial for survival in patients with extensive deep burns because the early removal of deep burned tissue not only improves the patient’s haemodynamic and haemorheological state but also reduces the risk of infection and stabilizes the patient’s condition.9 If the haemodynamic parameters obtained by means of the invasive method remain normal and effective pulmonary support for inhalation injury is instituted - usually involving tracheotomy and mechanical ventilation - the initial excision of large deep wounds can be performed within 24-48 h post-burn, with an area of first excision approaching 60%. An excised large deep wound can be covered using an allograft with a 1:10 micro-autograft. Deep wounds in smaller areas or involving functional sites, in particular the hands and face, should be covered as far as possible with autograft sheets in order to improve functional and cosmetic appearance.
Altogether, 35 patients presented associated injuries, all of which were well managed - no patient in either group died from associated injuries or from their complications. The key point in associated injuries, in our opinion, is to make an accurate investigation and diagnosis. The standard trauma protocols are imperative in these patients and any life-threatening problems must be tackled in the primary survey.
Our results suggest that the following methods are crucial in the treatment of patients who have sustained burns due to gunpowder explosion in fireworks factories: 1. prompt, rapid and adequate fluid resuscitation; 2. prophylactic tracheotomy with mechanical ventilation in patients with upper airway oedema or compromised airway patency; 3. early excision and grafting of large deep wounds and coverage using allograft with a 1:10 micro-autograft; 4. vitamin E and high-dose vitamin C; 5. determination and immediate management of life-threatening associated injuries.
RESUME. Les patients atteints de brûlures causées par les explosions de poudre dans les fabriques de feux d’artifice présentent souvent des lésions par inhalation et des lésions associées qui portent à une mortalité élevée. Les Auteurs de cette étude se sont proposés d’analyser la gestion de ce type de patients brûlés et de réduire leur morbidité et leur mortalité. Les 339 patients considérés ont été divisés en deux groupes: patients hospitalisés entre 1987 et 1993 (groupe 1) et patients hospitalisés entre 1994 et 1999 (groupe 2). Les données sur l’âge, le sexe, la dimension et la profondité de la brûlure, les lésions par inhalation et les lésions associées, la gestion, l’incidence de la septicité et du syndrome de dysfonction organique multiple, le taux de mortalité, et la durée de l’hospitalisation ont été recueillies et confrontées. Les Auteurs n’ont pas trouvé aucune différence entre les patients des deux groupes pour ce qui concerne la proportion mâle-femelle, la surface corporelle totale brûlée et les brûlures à toute épaisseur, les lésions par inhalation et les lésions associées. Quarante-sept patients du premier groupe ont reçu une fluidothérapie inadéquate et ont développé une condition de choc sévère, tandis que seulement 11 patients du deuxième groupe ont présenté cette condition. Dans la période précoce après la brûlure (la première semaine), la vitamine C a été administrée à haut dosage à 18 patients du premier groupe et à 97 patients du deuxième. Aucun patient du premier groupe n’a reçu la vitamine E, tandis que 45 patients du deuxième groupe l’ont reçue dans la première période après la brûlure. La trachéotomie prophylactique a été effectuée dans un patient du premier groupe et dans 14 patients du deuxième. L’incidence du syndrome de détresse respiratoire aigu dans les deux groupes 1 et 2 était respectivement 13,1% et 6,4% (p < 0.01). Quarante-six patients du premier groupe et 83 du deuxième ont subi l’excision et la greffe précoces. Toutes les lésions associées ont été bien gérées et aucun décès n’était lié ni aux lésions associées ni à leurs complications directes en aucun des deux groupes. L’incidence de la septicité et le taux de mortalité des patients étaient significativement plus élevés dans le premier groupe par rapport au deuxième (14,2% vs 5,1%, p < 0,01; 19,1% vs 5,8%, p < 0,01). La période moyenne de l’hospitalisation des patients non décédés dans le deuxième groupe était significativement mineure par rapport à celle du premier groupe (29,1 ± 11,3 jours vs 36,3 ± 10,2 jours, p = 0.041). Selon les Auteurs, les méthodes suivantes de traitement sont cruciales dans les patients atteints de brûlures causées par les explosions de poudre dans les fabriques de feux d’artifice: 1. une fluidothérapie prompte, rapide et adéquate; 2. la trachéotomie prophylactique accompagnée par la ventilation mécanique dans les patients atteints d’œdème des voies aériennes supérieures ou dont la perméabilité aérienne est menacée; 3. l’excision et la greffe précoces des lésions profondes plus grandes et couverture moyennant allogreffe avec une microautogreffe 1:10; 4. vitamine E et vitamine C à haut dosage; 5. détermination et gestion immédiate des lésions associées qui mettent la vie en danger.