% vol = 14 number = 2 prevlink = 60 nextlink = 69 titolo = "A BRIEF CLINICAL REVIEW OF THE TREATMENT OF 36 CASES OF BURN PATIENTS INJURED BY GAS EXPLOSION" volromano = "XIV" data_pubblicazione = "june 2001" header titolo %>
SUMMARY. In order to highlight the characteristics of the diagnostics and treatment of patients injured by gas explosion, with a view to providing references for the future improvement of treatment, an analysis was made of the gender, age, burn wound area and location, admission time to hospital after injury, blood gas analysis, blood routine, renal function, serum cardiac and hepatic enzymes, the identification of burn wound bacteria and sensitive antibiotics, mortality, and the duration of hospitalization time in 36 patients injured by gas explosion. Certain indices observed in deceased patients were compared with those observed in surviving patients. Gas explosion injury accounted for 0.8% of all burn patients (often male youths) in the period considered. The four main findings were: 1. The burn wound area was usually less than 50% TBSA. Shallow wounds (superficial and deep-partial second-degree burns) were often seen, with little involvement of internal organs. 2. In the three fatal cases, the burn wound and third-degree burn areas and the incidence of inhalation and internal organ injury were more marked than in surviving patients. 3. The six suspected cases of inhalation injury were subjected to tracheostomy, leading to improvement in ventilatory function and prevention of suffocation. 4. Hospitalization time was positively related to operation times. In conclusion, gas explosion injury occurred in special circumstances with high on-the-scene mortality. On-the-spot rescue treatment is of great importance. Tracheostomy is recommended in cases of suspected inhalation injury, and early operation on candidate patients is advocated.
Gas explosions occurring in coal-mine shafts are mainly caused by the explosion of a variety of explosive gases, principally composed of methane (CH4). The victims often suffer not only from burn injury on the surface of the skin but also from poisoning by various toxic gases, explosive (especially pulmonary) injury, hot contact injury, and inhalation injury.1
Gas explosion injury usually affects many people at once, owing to its occurrence in a specific site in the mine shaft. Field rescue is thus very complicated and difficult, but should be implemented immediately in order to increase the survival rate.
In order to improve the clinical management of victims injured in gas explosions, 36 patients suffering from of gas explosion injury admitted to our department in the past 10 years were analysed with reference clinical signs and treatment.
This study included 36 patients (35 male and 1 female) of average age 31.6 ± 10.3 yr (range, 9 to 56 yr). All the victims were injured in a coal-mine shaft. The injuries covered the whole body, but the head, face, and upper extremities were the commonest sites.
The average burn area in the 36 cases was 41.83 ± 27.14% (superficial partial-thickness, 19.33 ± 17.71%; deep partial-thickness, 15.5 ± 21.32%; third-degree, 6.22 ± 15.95%.
Three out of the patients ultimately died, giving a mortality rate of 8.3%.
The average burn area of the deceased patients was 92.67 ± 7.51% (all more than 85%) (superficial partial-thickness, 24.32 ± 20.87%; deep partial-thickness, 64.33 ± 44.73%; third-degree, 26.67 ± 46.19%).
The causes of death were severe shock due to insufficient fluid resuscitation, severe systemic infection, multiple organ failure (failure of pulmonary, renal, cardiac, digestive, and cerebral function), and possible explosion injury. Medium or severe inhalation injury was found in all three patients who underwent tracheal intubation or tracheostomy.
Mechanical ventilation was implemented in two of these three patients, who died respectively on days 4, 6, and 8 post-burn.
Six out of the patients cases suffered from inhalation injury (including those who died), who all of whom underwent tracheal intubation and/or tracheostomy. Two cases were complicated by reactive post-burn psychiatric symptoms finally managed by chlorpromazine.
The pre-hospitalization and transfer time for all 36 patients ranged from 1 h to 226 h (average, 57.43 ± 55.09 h). The hospitalization time of all the 36 patients ranged from 4 to 162 days (average, 37.64 ± 33.76 days).
Fourteen patients were treated by non-operative procedures, with a hospitalization time of 4-42 days (average, 18.07 ± 10.4 days). The other patients were treated surgically from one to three times (hospitalization time, 8 to 162 days; average time, 50.09 ± 37.62 days). This was much longer than the hospitalization time of patients not treated surgically (p <0.01). Apart from the fact that no patient in the non-surgically treated group of patients suffered from third-degree burn, there were no differences between the patients with and without operation in terms of TBSA and burn depth.
In the surgically treated group, there was a positive correlation between hospitalization time and operation time (Pearson test, r = 0.645, p <0.01).
Most of the patients underwent conventional burn management such as fluid resuscitation, administration of antibiotics, and simple wound bandaging before being admitted to our hospital. However, some patients came directly to our hospital without any pre-hospital treatment. On admission, fluid resuscitation, antibiotic application, and intramuscular injection of tetanus antitoxin were immediately initiated, and the burn wound was exposed or semi-exposed with the surface application of iodophore, silver sulphadiazine, etc. Endotracheal intubation or even tracheostomy was performed in patients suffering from severe inhalation injury, hypoventilation, or malventilation. Attention was also paid to post-burn nutritional support.
Different depths of burn wounds were treated with different operative or non-operative measures. In particular, tangential excision or escharectomy was used in deep burn wounds. However, conservation of the burn wound crust was adopted in superficial partial-thickness burn or less, with natural healing or subeschar healing of most wounds.
All the data were expressed in ¯ ± s. SPSS 10 was employed to treat all the experimental parameters. Single factor analysis of variance (ANOVA) and correlation analysis were carried out with p <0.05 as significantly different and p <0.01 as much more evidently different.
Changes in certain blood analysis indices (Table I)<% CreateTable "Table I","Post-burn changes of some blood gas analysis indices (x ± s)",";Time;PBD 1;PBD 3;PBD 5;PBD 7;PBD 10;PBD 14@;pH;7.38 ± 0.09;7.39 ± 0.06;7.42 ± 0.03;7.42 ± 0.04;7.44 ± 0.03;7.46 ± 0.06@;PaO2;87.8 ± 23.;81.4 ± 14.23;94.4 ± 18.44;75.7 ± 18.83*;93.2 ± 17.87;121.1 ± 34.02@;PaCO2;28.4 ± 6.61*;33.9 ± 6.75;35.0 ± 7.38;5.1 ± 8.61;32.8 ± 6.59;35.0 ± 2.21@;HCO3;17.7 ± 3.35*;20.3 ± 3.78;22.6 ± 4.46;22.7 ± 4.53;21.4 ± 2.88;24.0 ± 2.88","* p < 0.05; referral normal values: pH, 7.35-7.45; PaO2, 95-100 mmHg; PaCO2, 35-45 mmHg; HCO3, 22-27 mmol/l.
Table I demonstrates in that in this group of patients, in the early post-burn stage, there was only slight compensated metabolic acidosis.
Post-burn changes in certain routine blood indices (Table II)<% CreateTable "Table II","Post-burn changes of some routine blood indices (x ± s)",";Time;PBD 1;PBD 3;PBD 5;PBD 7;PBD 10;PBD 14@;WBC;14.1 ± 6.59*;7.70 ± 3.46;9.74 ± 4.88;12.03 ± 4.07;14.18 ± 6.34;12.33 ± 4.23*@;RBC;5.04 ± 1.20;4.17 ± 0.79;4.58 ± 1.23;3.95 ± 0.55;3.72 ± 0.78;3.90 ± 0.60@;Hb;144.47 ± 29.84;126.08 ± 24.39;134.37 ± 31.38;124.0 ± 18.6;108.0 ± 17.29;115.68 ± 20.42@;Hct;0.46 ± 0.11;0.39 ± 0.07;0.40 ± 0.07;0.37 ± 0.05;0.33 ± 0.06;0.35 ± 0.07@;Plt;138.5 ± 125.4;94.1 ± 51.3;117.5 ± 129.6;131.1± 61.2;202.8 ± 133. 9;316.1 ± 127.7*","* p < 0.05; referral normal values: WBC, 4-10 x 109/l; RBC, 2.5-5.5 x 1012/l; Hb, 110-170 g/l; Hct, 0.35-0.55;
It was observed that the white blood cell count did not obviously decrease, as previously reported,1 but increased on day 1 post-burn and 1 week later. The red blood cell, haemoglobin, haematocrit, and thrombocyte count remained in the normal range post-burn.
Post-burn changes in renal function indices (Table III)<% CreateTable "Table III","Post-burn changes of renal function indices (x ± s)",";Time;PBD 1;PBD 3;PBD 5;PBD 7;PBD 10;PBD 14@;Urea;6.40 ± 2.1;8.17 ± 4.75;7.88 ± 5.62;9.41 ± 10.78;5.00 ± 1.77;5.86 ± 3.25@;Su;11.55 ± 6.15;9.45 ± 7.32;6.88 ± 2.53;7.81 ± 4.34;6.15 ± 0.97;5.03 ± 1.34@;Cr;141.0 ± 73.59;155.01 ± 120.46;133.5 ± 145.7;146.95 ± 200.07;76.69 ± 17.40;62.71 ± 11.44@;Na;138.93 ± 49;139.18 ± 6.46;141.89 ± 12.53;138.9 ± 9.24;138.94 ± 6.59;139.26 ± 3.30@;Cl;105.47 ± 5.71;104.46 ± 7.76;107.48 ± 9.98;104.03 ± 7.67;104.93 ± 9.18;101.84 ± 3.03","Referral normal values: urea, 3.0-7.2 mmol/l; Su: 3.0-6.4 mmol/l; Cr, 53-115 mol/l; Na, 135-140 mmol/l; Cl,96-111 mmol/l",7, 550, true %>
Except for the finding that the blood urea nitrogen level in the deceased patients 5 days post-burn was much higher than that in the surviving patients, other indices remained within the normal range.
Post-burn changes in the indices of serum myocardial and hepatic enzymes (Table IV)<% CreateTable "Table IV","Post-burn changes of serum hepatic and myocardial and hepatic enzymes (x ± s)",";Time;PBD 3;PBD 5;PBD 7;PBD 10;PBD 14@;ALT;32.0 ± 34.74;29.79 ± 13.89;32.89 ± 17.73;79.92 ± 75.46;120.33 ± 86.52*@;TB;20.64 ± 2.44;25.53 ± 31.40;16.48 ± 4.87;20.05 ± 10.50;13.49 ± 4.68@;y GT;12.0 ± 7.21;103.86 ± 208.25;87.62 ± 79.38;86.29 ± 77.32;96.74 ± 67.70@;a HBDH;182.40 ± 118.23;323.0 ± 188.09;325.67 ± 228.96;438.5 ± 99.70;319.5 ± 127.99@;ALP;55.0 ± 7.0;47.50 ± 16.20;93.0 ± 57.85;91.43 ± 30.13;145.89 ± 68.90@;AST;60.75 ± 54.52;93.43 ± 82.19;0.0 ± 24.08;64.38 ± 32.24;82.33 ± 66.60@;CKMB;37.00.00;43.75 ± 55.65;44.38 ± 48.77;60.40 ± 6.51;19.20 ± 0.28","* p < 0.05; referral normal values: ALT, 5-45 IU/l; · HBDH, 76-195; CKMB, < 25; ALP, 42-128; TB, 6-21 Ìmol/l; AST, 5-45; Á GT, 4-50.",6, 550, true %>
The results revealed no remarkable changes in enzymes post-burn, which suggests that there was no evident internal organ injury in this group of patients injured by gas explosion.
Comparison of burn wound areas in survivors and non-survivors (Table V)<% CreateTable "Table V","Comparison of burn area of different degrees between survivors and deaths (x ± s)",";Degree;TBSA;Superficial second degree;Deep second degree;Third degree@;Survivors (%);38.62 ± 24.26;21.86 ± 14.47;17.48 ± 19.11;16.43 ± 13.91@;Deaths (%);92.67 ± 7.51*;24.32 ± 20.87;64.33 ± 44.73*;26.67 ± 46.19","TBSA = total burn surface area; * comparison between survivors and deaths; p <0.05.",5, 550, true %>
The data indicate that there were larger burn areas and deeper burn wounds in non-survivors.
Samples of burn wound, blood, and venous catheters were examined for bacteria culture and antibiotic sensitivity tests in all 36 patients. Six blood cultures exhibited negative findings. The burn wound bacteria included 23 kinds of bacteria and fungi: Pseudomonas aeruginosa (19), Staphylococcus aureus (17), Serratia (14), aerogenic Enterobacteria (8), Staphylococcus epidermidis (7), methicillin-resistant Staphylococcus aureus), Proteus rettgeri, Hay bacillus, yeast-like colony, Enterobacteriaceae agglomerans, Micrococcus, Streptococcus faecalis, Neisseria catarrhalis, diphtheroid bacillus, etc. The effective antibiotics tested included ciprofloxacin, cefoperazone, ceftazidime, imipenem with cilastatin, cefuroxime Na, aztreonam, ticarcillin with clavulanate, kitasamycin, cefoperazone with sulbactam, etc.
Burns caused by gas explosions are not infrequently encountered in clinical work. Oh et al.1 reported 48 cases of burns due to explosion treated in their medical centre (Hallym Medical Centre) over a 5-yr period, which accounted for 1.6% all their in-patients. In our study, 36 cases of gas-explosion-induced burns in the last 10 yr constituted 0.8% of the 4284 cases treated in our institute.
The management of gas-explosion-induced burns is usually more complicated than the treatment of common burns.2 In addition to the victims thermal injury, induced by the high temperature (up to 1850 °C, and even 2650 °C in a closed environment) engendered by a gas explosion, there may also be poisoning caused by inhalation of toxic components contained in the gas. Common causes of gas poisoning are CO2, NO2, and CO (carbon monoxide). Also, the blast wave engendered during a gas explosion may lead to explosive injury to the head, chest, abdomen, and the extremities. The victims possible subsequent collapse after a gas explosion may cause traumatic injury. On-the-spot mortality is thus very high in the event of a gas explosion, as reported by Benmeir et al.3 following the destruction of two trains in the Urals 2000 km east of Moscow, when an explosion due to a leaking natural gas pipeline involved some 3000 persons. Most of these (2200) died immediately, while the other 800 were badly burned.
In our report, only one patient out of 36 was female, and the average age was 31 yr. This is due to the fact that nearly all the injured were young male coal-miners and that most of the gas explosions occurred in coal-mines. Most of the 36 patients were admitted to our department two days post-injury. The most severely injured victims and those with lethal complications died on the spot or before entering our hospital. This explains why the conditions of these patients was not on the whole very serious. In our opinion what we should do in the future is strengthen the relationship between the general hospital and the on-the-spot rescuing team, in order to shorten the time before victims are treated effectively, normally, and comprehensively.
The commonest sites of burn injury in this group of patients were in the upper extremities and head, the neck, and the face. The average TBSA was 42%, mostly partial-thickness burns (nearly 35%). The average full-thickness skin loss was only 6%. This indicated that the burn injuries caused by gas explosion were mostly superficial burns, even in patients who eventually died. This may be related to the very short time duration of a gas explosion.
Six of the patients in this group exhibited symptoms of inhalation injury. Tracheal intubation or tracheostomy were implemented in these cases in order to prevent death due to suffocation. There were no obvious signs of severe ARDS or exfoliation of the tracheal mucosa, which can be caused by inhalation of rapid waves of dry hot gas from the gas explosion. This suggested that tracheal intubation or tracheostomy should be advocated in patients with possible inhalation injury or hypoventilation who have been injured in a gas explosion. In such cases, pulmonary complications can be prevented and airway management is easy to conduct. It is also useful to apply a respirator to these patients. Also, simple tracheostomy can maintain the airways clear in most victims of gas explosion, which greatly benefited the patients during the course of their treatment.
A comparison of the hospitalization times of patients undergoing surgical or non-surgical methods of treatment showed that patients receiving non-surgical treatment were usually suffering from smaller burn areas and shallower burn wounds, without third-degree burns. These patients burn wounds therefore healed more quickly. Patients treated surgically tended to be injured in bigger areas and to present deeper burn wounds.
Hospitalization time correlated positively to the timing of surgical operations. These results indicate that patients with more extensive burn areas and deeper burn wounds stay longer in hospital and undergo more operations. We therefore suggest that in order to shorten the hospitalization time of patients who ultimately need surgical therapy, the assessment of burn wound depth and area should be done early, so that surgery, if necessary, can be performed as soon as possible. This may also be beneficial as regards the patients financial expenses, the prevention of the formation of burn wound scarring, and post-burn dysfunction.
Blood gas analysis indicated that in most cases over-ventilation existed in the early post-burn stage. Ischaemic and hypoxic injury due to burn shock lead to hypoxaemia and metabolic acidosis in these patients, in whom pH was in the near normal range. In order to improve the tissue ischaemic state, sedation, analgesia, and oxygen inhalation should be administered to such patients. Routine blood tests indicated that white blood cells decreased remarkably after gas explosion injury. For instance, white blood cells decreased to 2900 and thrombocytes to 42 within 3 days post-burn in two of the three patients who died. This suggested that possible bone marrow inhibition was well correlated with the severity and mortality of the injury caused by gas explosion. It still has to be established whether the bone marrow inhibition and the decrease of WBC and thrombocytes were caused by severe systemic infection due to post-burn immunosuppression.
Renal functional indices and serum cardiac and hepatic enzymes in this group of patients exhibited no differences with regard to normal values. This indicated that internal organ injury in this group of patients was not severe, which encouraged us to treat these patients actively, possibly with effectively better results.
With regard to burn wound bacterial culture, many kinds of bacteria were found in these patients. This indicates that there was serious wound contamination in patients injured by gas explosion. The cultured bacteria matched the common strains isolated in our burn ward in recent years.4 All the strains of bacteria were dominant ones. Emphasis should therefore be laid on the importance of correct management of the burn ward and on the prevention of cross-infection. Until the results of burn wound bacterial culture were known, we empirically employed antibiotics sensitive to S. aureus, P. aeruginosa, and Serratia, such as ciprofloxacin, cefoperazone, and imipenem, etc. Optimal antibiotics must be administered when the bacteria culture has been established.
In brief, considering that gas explosions generally occur in specific places, safety in production methods must be emphasized if injuries are to be prevented. Better standards of immediate post-burn rescue work should be made available as close to the scene as possible, in order to improve the recovery rate. Patients on the spot who have survived usually exhibit shallow skin burns with limited internal organ injuries. However, as there is a possibility of inhalation injury in these patients, tracheal intubation and tracheostomy should be performed where indicated. Reactive mental symptoms and other complications should also be managed. With deeper burn wounds, surgical operations should be performed in good time in order to shorten hospitalization time and improve outcome.
RESUME. Pour souligner les caractéristiques du diagnostic et du traitement des patients lésés dans les explosions de gaz, dans le but doffrir des lignes directrices pour lamélioration future du traitement, les Auteurs ont analysé le sexe, lâge, la surface totale brûlée et la zone atteinte, les temps de lhospitalisation après laccident, les gaz hématiques, les examens de routine du sang, la fonction rénale, les enzymes cardiaques et hépatiques séreux, lidentification des bactéries présentes dans les zones brûlées et des antibiotiques sensibles, la mortalité et la durée de lhospitalisation dans 36 patients lésés par explosion de gaz. Certains indices observés dans les patients décédés ont été comparés avec les indices observés dans les patients non décédés. Les lésions provoquées par des explosions de gaz représentaient 0,8% de tous les brûlés (souvent des jeunes du sexe masculin) pendant la période considérée. Le Auteurs sont arrivés à quatre résultats principaux: 1. La surface brulée était normalement moins de 80% de la surface corporelle totale. Les lésions étaient souvent peu profondes (brûlures superficielles et brûlures de deuxième degré dépaisseur variable profonde et partielle), sans lésions particulières des organes internes. 2. Dans les trois cas des patients décédés, les lésions et les zones de brûlure de troisième degré, comme aussi la fréquence des lésions par inhalation et des lésions internes, étaient plus marquées par rapport aux patients non décédés. 3. Les six patients qui présentaient les caractéristiques ont été soumis à la trachéotomie. Ce traitement améliorait la fonction ventilatoire et prévenait la soffocation. 4. La période de lhospitalisation était associée en manière positive aux temps opératoires. En conclusion, les Auteurs observent que les lésions par explosion de gaz se sont vérifiées dans des circonstances particulières et ont provoqué un taux élevé de mortalité immédiate. Les soins sur place sont très importants. Les Auteurs recommandent la trachéostomie dans les cas possibles de lésion par inhalation, et lopération chirurgicale précoce est préconisée.
<%riquadro "This paper was received on 23 February 2001.