Accident Analysis of Many People with Acute Nitrogen Oxide Poisoning (1)

Nitrogen oxide is a general name for a mixture of nitrogen oxides (N2O , NO , NO2 , N2O3 , N2O4 , N2O5, etc. ) . Among them, nitrogen dioxide is relatively stable, not easily soluble in water, and has a relatively high toxicity, and is brownish yellow gas at room temperature. In industrial production, it is produced by the oxidation of ammonia under the action of a catalyst. In addition, nitrogen oxides can be generated when ammonium nitrate is exploding, burning, welding, and argon arc welding. Nitrogen oxides are irritating gases that inhale poisoning and damage the lungs and can cause toxic edema.

Case 1

1. ACCIDENTS

45 minutes county of Hebei Province pulverized ammonium nitrate explosives plants in agglomeration process, ammonium nitrate is blocked block machine eye at 11:29 on May 1972 days. A worker caught the ammonium nitrate on fire when the red hot iron hooked off the hot ammonium nitrate block. At that time, a large number of used shredded paper bags and wood sawdust had been burned in the factory building , and a warehouse stockpiled more than 100 tons of explosives. The smoke-filled brown-yellow smoke column rose skyward, about 100 meters high, and drifted with the slight southwesterly wind down to the side of the wind. The pollution was several kilometers away. At that time, about 2,500 PLA soldiers and local residents participated in the fire fighting and handling of explosives. Fire and handling of explosives at the scene lasted about 2 hours. Caused more than 2,150 firemen and soldiers to experience acute nitrogen oxide poisoning, including 856 hospitalized patients with poisoning and 1,244 outpatient treatment . Four of the hospitalized patients died as a result of the rescue.

2. After the rescue

1 Immediately establish a rescue headquarters. After the accident, the leaders of the Beijing Military Region paid great attention. Immediately after the establishment of the military headquarters and local leaders to participate in the rescue headquarters, the headquarters under the political group, rescue technical guidance group and logistics supply group. The medical personnel who mobilized emergency rescue experience in North and Northeast China were rushed to the scene of the accident to clarify decisive measures, formulate a unified rescue and treatment plan, and organize rescues in a planned manner. More than 700 medical personnel from over 60 units in Beijing, Tianjin, Tangshan, Hebei, and Jilin took part in the rescue work. More than 850 patients were living in the county hospital, the Regional Hospital, Military Hospital, and five nursing homes in the vicinity of two medical units. At different times during the rescue, the rescue headquarters timely revised the plan according to the different requirements of the rescue work, summed up the rescue experience in a timely manner, and promptly organized the exchange of experience so that the rescue work could be carried out smoothly.

2 Identify the source of the poison, determine the cause of poisoning as soon as possible and develop a rescue plan. According to the combustion of the material is mainly ammonium nitrate, ammonium nitrate can emit a brown-yellow nitrogen oxide combustion, which is exactly the same situation at the scene at that time. Of course, the site of the accident is piled with sawdust and paper scraps. The incomplete combustion of these substances can produce carbon monoxide. Therefore, the presence of carbon monoxide at the poisoning site is also entirely possible, but it is secondary in comparison. The main clinical manifestations of poisoned patients are respiratory irritation symptoms, which are the same as those of nitrogen oxide poisoning. The rescue headquarters quickly determined that the poisoning accident was caused by nitrogen oxides, and formulated a rescue plan accordingly.

3 diagnosis of patients with poisoning indexing. At that time, the country did not have nitrogen oxide poisoning standards. According to the clinical manifestations of poisoned patients, the technical guidance group is divided into light, medium and heavy degrees, and severe poisoning occurs in those who develop poisoning pulmonary edema. There are toxic pulmonary edema occurred in 87 856 patients, the diagnosis of severe poisoning. For this group of patients, all efforts were made to rescue pulmonary edema to prevent respiratory failure. For moderate poisoning patients to prevent the occurrence of pulmonary edema, such as giving a sufficient amount of glucocorticoid, an increase of glucose solution increased intravenous dose of vitamin C and so on.

4 to protect the supply of rescue drugs and equipment. More than 2,000 poisoned patients are treated in out-patient and in- patient treatment, requiring a large amount of drugs and equipment. The headquarters has set up a logistic supply group to ensure the rescue of the supply of medical devices. A large number of salvage articles were transported from Beijing and Tianjin Yuanyuan to the rescue site. If you want to rescue critical illness __ people, you should prepare a laryngoscope, tracheal intubation, aspirator, etc., in preparation for a sudden suffocation and caught by surprise. There are 87 patients with pulmonary edema , all need oxygen to relieve the patient's hypoxia. Without so many oxygen cylinders and oxygen bags, the supply team staff temporarily filled the car's inner tubes with oxygen instead of oxygen bags, which solved the problem of oxygen inhalation.

5 latency issues. According to the statistics of 750 patient records, the shortest incubation period for acute nitroxygen poisoning was 1 hour, and the longest was 72 hours. The peak incidence ranged from 1 to 4 hours and the incidence was 73.1 % within 8 hours . There were 2 people who became ill after 72 hours, and 1 of them died of treatment because of delay. Accordingly, the Rescue Command recommends that all those who have participated in firefighting and who have been exposed to poisonous gases should observe more than 72 hours. During the observation period, they should pay attention to rest and avoid exertion.

6 4 people died in this accident . Eight hours after the accident , one patient died of pulmonary edema. The second case died 22 hours after the accident and the third case died 70 hours after the accident . The above 3 cases all died of severe pulmonary edema, spit red foam, and did not do tracheotomy. The fourth case died on the 8th day after the accident . The main cause of death was renal failure. According to the analysis of the technical guidance group, kidney function damage may be caused by hypoxia. Therefore, in the rescue of irritating gas poisoning, we should closely observe whether the normal renal function.

3. Discussion

In this fire accident, 2,000 people were acutely poisoned and 4 people died. The consequences are serious and the lesson is profound. The rescue headquarters conscientiously summed up the experience and lessons as follows.

1 The occupational poisoning prevention knowledge should be vigorously popularized. In the event of a fire, none of the leaders of the unit concerned, the medical personnel, or the firefighters proposed that ammonium nitrate combustion would produce nitrogen oxides, which could lead to knowledge of contact poisoning. Therefore, there is no preventive measure to prevent poisoning in the fire. As a result, so many fire-fighters poisoned.

When many poisoned patients went to local county hospitals and garrison hospitals for treatment, none of them could tell what kind of toxic poisons they were and how to rescue them. Because the medical staff lacks the knowledge of prevention and control of occupational poisoning, they panic when there is a large number of poisoned patients. After receiving the patient, due to the lack of rescue experience such as detoxification, the recognition was not uniform, the rescue measures could not be settled, and the rescue opportunity was delayed, which affected the rescue effect. When medical personnel arrived in Beijing and Tianjin arrived, it was already 8 to 9 hours after the accident. One person had died.

2 Prevent rickets from happening. During the accident rescue process, some patients had rickets-like convulsions, and some patients had hallucinations, visual hallucinations and other psychiatric symptoms. The reasons for these manifestations are as follows. First, in a tense fire-fighting process, tense atmosphere caused by the stimulation of the cerebral cortex of some patients. Second, the Chinese medical personnel in the rescue process panicked and caused mental pressure on some patients. Causes psychiatric symptoms. Therefore, in the rescue process, medical personnel can not only pay attention to medication, medication, and they have to show a self-confidence attitude of success in calming and salvage. They must do ideological work well, give comfort, relief, and supplement with sedative drugs. If one person in a major ward has a rickets-like attack, he or she should be immediately transferred to isolation to prevent "infection."

3 acute nitrogen and nitrogen poisoning should pay attention to the formation of degenerative hemoglobin in patients with poisoning and myocardial injury. During the rescue process, 9 cases of severe hemorrhage with hemorrhagic disease were detected , and 6 cases were significantly increased, so the problem of treating degenerative hemoglobinemia was given to most serious patients. Some patients have abnormal ECG changes, such as ST segment decline, indoor limited conduction block, P- wave double peak, etc. This may be due to lack of oxygen.

4 Prevent lung infections. In this accident, the patient had been hospitalized for one month, and some patients showed fever, increased white blood cells, and lung inflammatory changes on the X -ray. Irritant gas poisoning is mainly a respiratory injury, and the respiratory tract is susceptible to infection after it has been damaged. Therefore, in the rescue process must pay attention to the application of antibiotics to prevent the occurrence of lung infections.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.