Pyrethroid insecticide poisoning
Introduction
Introduction to Pyrethroid Insecticide Poisoning Pyrethroid insecticide poisoning, pyrethroids are chemical structures that mimic natural pyrethrins, using synthetic pyrethroid insecticides. It is stable to light and heat and easily decomposes in an alkaline environment. There are deltamethrin (enemy kill) fenvalerate (speed killing) cypermethrin (Xingmianbao, , ), permethrin, cyfluthrin and so on. This type of insecticide is characterized by its high killing power against insects and little toxicity to humans and animals. It is a broad-spectrum and highly effective insecticide. Carbamates can be absorbed through the digestive tract, respiratory tract and skin. After absorption, they are distributed in liver, kidney, fat and muscle. The content in other tissues is very low. It is metabolized in the liver and partly hydrolyzed, oxidized or with glucuronic acid. Detoxification by combination, a part of the original form or its metabolites are quickly excreted by the kidney, and can be excreted by more than 90% in 24 hours. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people. Mode of infection: non-infectious Complications: respiratory failure
Cause
The cause of pyrethroid insecticide poisoning
Pyrethroid insecticide poisoning, acute poisoning is mainly caused by exposure to a large number of insecticides or self-service or misuse during production, processing and use.
Absorption and metabolism of poisons: Carbamates can be absorbed through the digestive tract, respiratory tract and skin. After absorption, they are distributed in liver, kidney, fat and muscle. The content in other tissues is very low. It is metabolized in the liver and partly hydrolyzed. Oxidation or detoxification by binding to glucuronic acid, part of which is rapidly excreted by the kidney in its original form or its metabolites, and can be excreted by more than 90% in 24 hours.
Pathogenesis: The stereo structure of carbamate insecticides is similar to that of acetylcholine. It can bind to the anion and lipolysis sites of cholinesterase to form a complex and become a carbamoyl cholinesterase egg, which causes it to be lost. Hydrolysis of acetylcholine, causing accumulation of acetylcholine, stimulates cholinergic excitability and produces corresponding clinical manifestations, but this product is easy to hydrolyze, so that cholinesterase activity recovers very quickly.
Prevention
Pyrethroid insecticide poisoning prevention
First, strengthen anti-drug publicity to introduce the prevention and first-aid knowledge about poisoning to the public, such as propagating gas poisoning in the early winter and propagating pesticide poisoning in the rural spraying season.
Second, strengthen the management of poisons Strictly abide by the protection and management system of poisons and strengthen the storage of poisons. The production equipment is sealed to prevent chemical substances from running, running, dripping and leaking. Cars and posts in the mines and toxic substances enhance local ventilation and overall ventilation to discharge poisons. Pay attention to the treatment of waste water, waste gas and waste residue.
Third, prevent chemical food poisoning Before eating special foods, we must pay attention to whether there is toxicity. Do not eat toxic or degenerate animals and plants. Some plants, such as mites, are not toxic if they are not easily identifiable. Some animals and plants such as puffer fish, cassava, and aconite can only be eaten after proper treatment. Galvanized utensils should not be stored in food, especially acidic foods such as refreshing drinks and juices.
4. Containers that prevent the ingestion of poisons or excessive use of drugs or chemicals should be labeled. Highly toxic drugs such as disinfectants and insecticides should be strictly managed. Hospital medication and medicine should be strictly apricot system, so as not to cause accidental or overdose, household medicine should be locked and kept, so as not to cause children to eat. The medicines of mental patients should be properly managed.
Fifth, the prevention of endemic poisoning disease Some places in the drinking water fluoride is too high, can cause endemic skeletal fluorosis, improve water sources can prevent. In some places, the content of strontium in the well salt is too high, which can cause endemic palsy. After the salt was proposed by well salt, the disease was eliminated. Gossypol contains gossypol, which can cause poisoning after eating. Cottonseed oil is treated with alkali to make gossypol form sodium gossypol, which can eliminate toxicity.
Complication
Pyrethroid insecticide poisoning complications Complications, respiratory failure, facial paralysis
1. Delayed multiple neuropathy. Most occur in patients with acute poisoning and moderate poisoning 2 to 3 weeks after the disappearance of symptoms, the realization of sensory, motor-type multiple neuropathy, mainly involving the extremity of the limb, the occurrence of lower limb paralysis, muscle atrophy of the limbs.
2. Intermediate syndrome. Most occur in patients with severe poisoning 24~96 hours and patients with insufficient regenerative medicinal dose. Before treatment of cholinergic crisis disappears, conscious or unrecovered and delayed polyneuropathy, sudden appearance of flexor and proximal limbs Terminal muscle weakness and IIIVII, IV, X muscle weakness in the innervation of the brain, sag, eye abduction, facial paralysis and respiratory muscle paralysis, causing ventilatory dyspnea or failure, can lead to death.
Symptom
Pyrethroid insecticide poisoning symptoms Common symptoms Loss of appetite, difficulty breathing, papules, photophobia, itching, conjunctival congestion, sputum, angle bow, anti-stubbing, coma
1, skin and mucous membrane reaction: after contact, rapid itching, burning sensation, tightness, a small number of patients have sneezing, tearing, eyelid swelling, conjunctival hyperemia, photophobia and red papules or bullous skin damage, more common in the cheeks unit. A rash on the chest and exposed areas that exacerbates when sweating or getting hot water. The rash usually disappears 24 hours after the contact is stopped, and the herpes is required to heal itself for 3 days.
2, acute poisoning classification
(1) Mild: A few hours after spraying the drug, common symptoms include headache, dizziness, nausea, vomiting, loss of appetite, general malaise, and blurred vision. The symptoms of digestive tract are more obvious in oral poisoning patients, and there may be burning in the upper abdomen.
(2) Moderate: In addition to the above symptoms, there are still lethargy, salivation, chest tightness, muscle tremors of the extremities, convulsions, arrhythmia and dry lung sounds.
(3) Severe: quadriplegia, angulation, difficulty breathing, pulmonary edema, cyanosis and coma.
Examine
Examination of pyrethroid insecticide poisoning
Blood Cholinesterase Activity Urine poisoning aids in the determination.
Diagnosis
Diagnosis and identification of pyrethroid insecticide poisoning
diagnosis
Combined with the history of exposure, clinical manifestations and reduction of whole blood cholinesterase activity, the diagnosis is not difficult, the main hydrolysis of carbaryl in the body to 1-nonanol, the increase of urinary naphthol emission is helpful for diagnosis.
Differential diagnosis
Need to be identified with organophosphate insecticide poisoning, heat stroke, Japanese encephalitis and acute gastroenteritis.
