Hydrogen Sulfide Poisoning
Introduction
Introduction to hydrogen sulfide poisoning Hydrogen sulfide (hydrogensulfide) is a colorless gas with irritating and asphyxiating properties. The low concentration exposure only has local irritation of the respiratory tract and the eye. At high concentration, the systemic effect is obvious, which is characterized by central nervous system symptoms and asphyxia, hydrogen sulfide. It has a "smelly egg-like" odor, but very high concentrations quickly cause olfactory fatigue without feeling its taste. Mining, smelting, sugar beet making, carbon disulfide, organophosphorus pesticides, as well as leather, sulphur dyes, pigments, animal glue and other industries have hydrogen sulfide production; organic waste sites such as marshes, gullies, septic tanks, sewage sedimentation A large amount of hydrogen sulfide can escape during operation in the pool, etc. It is not uncommon for workers to be poisoned. basic knowledge The proportion of illness: rare incidence, the incidence rate is about 0.002% - 0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: headache, ataxia, disturbance of consciousness, coma, coma, pulmonary edema, pneumonia, acute respiratory distress syndrome, angina pectoris
Cause
Causes of hydrogen sulfide poisoning
Environmental factors (90%):
Extraction of copper, nickel, cobalt, etc. from mining and ore, low-temperature coking of coal, mining and refining of sulfur-containing oil, rubber, tanning, sulphur dyes, paper, pigments, pickles, beet sugar, etc. Hydrogen sulphide production; excavation and remediation of marshes, ditches, wells, sewers and the removal of rubbish, dirt, manure, etc., as well as analytical chemical laboratory workers have access to hydrogen sulphide; natural gas, mineral water, volcanic jets and Water accumulated under the mine is also often accompanied by hydrogen sulfide. Since hydrogen sulfide is soluble in water and oil, it can sometimes cause accidental poisoning accidents with water or oil flowing away from the source.
Pathogenesis
Hydrogen sulfide enters the body through the respiratory tract, dissolves quickly in contact with the water in the respiratory tract, and combines with sodium ions to form sodium sulfide, which has a strong stimulating effect on the eye and respiratory mucosa. Hydrogen sulfide absorption mainly affects cytochrome oxidation in the respiratory chain. Enzymes and disulfide bonds (-SS-) act to affect the cell oxidation process, causing tissue hypoxia. When inhaled at very high concentrations, it strongly stimulates the carotid sinus, causing respiratory arrest reflexively; it can also directly paralyze the respiratory center and immediately Causes suffocation, resulting in "electric shock" death.
Prevention
Hydrogen sulfide poisoning prevention
Hydrogen sulfide is a colorless, smelly egg smelling gas that is highly toxic and is an atmospheric pollutant. Some industrial waste gases contain hydrogen sulphide. When manufacturing and using sulphurized fuel, there may be overflow of hydrogen sulphide. When the sulfide encounters an acid, hydrogen sulfide is produced. In addition, it should be noted that hydrogen sulfide gas may be produced in corrupt fish, meat, eggs, gutters and septic tanks. In the event of acute hydrogen sulfide poisoning, patients should be promptly transferred to fresh air, artificial respiration should be given to the apnea, and sent to the hospital as soon as possible. When entering the pool, the inside of the pool and other places where the air is not circulating to rescue the poisoned person, the rescuer must wear an oxygen-containing breathing mask, a seat belt or a rope, and have a special person to prevent the rescuer from poisoning himself and delay the rescue of the poisoned person.
Measures to be taken in normal work and life:
1. Respiratory protection: Wear a transitional gas mask (half mask) when the concentration in the air exceeds the standard. It is recommended to wear an oxygen breathing apparatus or an air breathing apparatus during emergency rescue or evacuation.
2. Eye protection: Wear chemical safety glasses.
3. Body protection: Wear anti-static overalls.
4. Hand protection: Wear chemical resistant gloves.
5. Others: Smoking, eating and drinking are strictly prohibited on the job site. After work, take a shower and change clothes. Change the work clothes in time. Operators should learn to save themselves from each other. Entry into tanks, restricted spaces or other high concentration areas requires supervision.
Complication
Hydrogen sulfide poisoning complications Complications headache, ataxia, disturbance of consciousness, coma, pulmonary edema, pneumonia, acute respiratory distress syndrome, angina pectoris
1. Central nervous system damage is the most common:
(1) After exposure to higher concentrations of hydrogen sulfide, headache, dizziness, fatigue, ataxia, mild disturbance of consciousness may occur, and eye and upper respiratory tract irritation often occurs first.
(2) After exposure to high concentrations of hydrogen sulfide, the symptoms of encephalopathy are obvious, headache, dizziness, irritability, gait, irritability, confusion, convulsions, epilepsy-like convulsions can be a systemic tonic, etc.; Coma; dyspnea or cardiac arrest after respiratory arrest, fundus examination can be seen in some cases of optic nerve head edema, some cases can be accompanied by pulmonary edema, symptoms of encephalopathy often appear earlier than respiratory symptoms, may be due to mucosal irritation The role takes a certain amount of time.
(3) Death can occur after exposure to extremely high concentrations of hydrogen sulfide, that is, respiratory arrest within a few seconds or minutes after contact, heartbeat can occur after a few minutes; coma can be coma immediately or within minutes, and breathing can be stopped And die.
2. Respiratory system damage: chemical bronchitis, pneumonia, pulmonary edema, acute respiratory distress syndrome, etc., a few cases of poisoning can be the main clinical manifestations of pulmonary edema, and the nervous system symptoms are mild, may be associated with conjunctivitis , keratitis.
3. Myocardial damage: In the course of poisoning, some cases may have palpitations, shortness of breath, chest tightness or angina-like symptoms.
Symptom
Symptoms of hydrogen sulfide poisoning Common symptoms Weak throat, dry itching, nausea, throat, dryness, burning, dizziness, coma, runny nose, chest tightness, itchy conjunctival congestion
Acute hydrogen sulfide poisoning is generally rapid, with clinical manifestations of brain and/or respiratory damage, and may be associated with organ dysfunction such as the heart. Clinical manifestations may vary significantly depending on factors such as the concentration of hydrogen sulfide exposed.
Mild poisoning
Mild poisoning is mainly caused by irritation, which is characterized by tearing, eye irritation, salivation, burning sensation in the throat, or symptoms such as headache, dizziness, fatigue, and nausea. Check for conjunctival hyperemia in the visible eye, dry snoring in the lungs, and recovery in the short term after disengagement.
2. Moderate poisoning
After exposure to high concentrations of hydrogen sulfide, the brain disease is markedly manifested, headache, dizziness, irritability, gait convulsions, irritability, confusion, paralysis, epilepsy-like convulsions can be a systemic tonic-clonic seizure, etc.; sudden coma can occur; The heartbeat stops after a dyspnea or respiratory arrest. Fundus examination revealed optic nerve head edema in individual cases. Some cases can be accompanied by pulmonary edema. Symptoms of encephalopathy often appear earlier than respiratory symptoms. X-ray films show enhanced lung texture or flaky shadows.
3. Severe poisoning
Electroshock-like death can occur after exposure to very high concentrations of hydrogen sulfide, that is, respiratory arrests within a few seconds or minutes after contact, and cardiac arrest can occur after a few minutes; or coma in immediate or few minutes, and respiratory arrest and death. Death can occur without warning. When the smell of hydrogen sulfide is detected, the sense of smell can be lost immediately. In a few cases, the disgusting sweetness can be smelled immediately before the coma. There is usually no aura symptom before death, and the breathing may first occur deep and fast, followed by breathing and gathering.
Examine
Hydrogen sulfide poisoning inspection
There are currently no specific laboratory tests.
(1) Increased content of hydrogen sulfide or sulfide in the blood can be used as an absorption index, but it is inconsistent with the severity of poisoning, and its half-life is short, so it is necessary to collect blood within a short time after stopping contact.
(2) The content of urinary thiosulfate can be increased, but it can be interfered by factors such as the measurement time and the sulfur content in the diet.
(3) Sulfemoglobin (SHb) in blood cannot be used as a diagnostic index, because hydrogen sulfide does not combine with normal hemoglobin to form thiohemoglobin, which has nothing to do with the mechanism of poisoning; many studies have shown that there is no blood in humans and animals killed by hydrogen sulfide. Significant thiohemoglobin concentration.
(4) The sulfur content in the blood and tissues of the corpse can be interfered by factors such as rot of the corpse, which affects its reference value.
Diagnosis
Diagnosis and identification of hydrogen sulfide poisoning
1. Have a clear history of hydrogen sulfide exposure
The patient's clothing and exhalation have a smell of stinky eggs as an indicator of exposure. Hydrogen sulfide can be produced or measured at the scene of the accident. The patient smells the smell of the stinky egg before the onset of the disease.
2. Clinical features
Clinical manifestations of brain and/or respiratory damage.
3. Laboratory inspection
(1) Increased content of hydrogen sulfide or sulfide in the blood can be used as an absorption index, but it is inconsistent with the severity of poisoning, and its half-life is short, so it is necessary to collect blood within a short time after stopping contact.
(2) The content of urinary thiosulfate can be increased, but it can be interfered by factors such as the measurement time and the sulfur content in the diet.
(3) Hemoglobin in blood can not be used as a diagnostic index, because hydrogen sulfide does not combine with normal hemoglobin to form thiohemoglobin, which has nothing to do with the mechanism of poisoning; many studies have shown that there is no significant thiohemoglobin concentration in the blood of humans and animals killed by hydrogen sulfide. .
