Is it possible to survive after drinking paraquat? How to treat it?

Author: Qiu Zewu, Chief Physician of the Fifth Medical Center of the General Hospital of the Chinese People's Liberation Army

Reviewer: Wang Lixiang, Chief Physician, Third Medical Center, PLA General Hospital

The 10th Chairman of the Science Popularization Branch of the Chinese Medical Association

I believe you must have heard of the name paraquat in news reports. In fact, it is not difficult to see from the name that paraquat is a pesticide, or more precisely, an organic heterocyclic contact herbicide. The leaves of weeds will quickly change color after contact with it, and it is a fast-killing herbicide.

Figure 1 Original copyright image, no permission to reprint

Paraquat is a terrifying poison, and the mortality rate of paraquat poisoning in humans is very high.

There are many ways for paraquat to be poisoned, including through the respiratory tract, skin, digestive tract, and there are also rare cases of poisoning by injection. From a clinical point of view, the most common route of poisoning is through the digestive tract, and poisoning through the respiratory tract is also rare.

When paraquat comes into contact with the skin, it can cause local skin damage and skin inflammation, such as contact dermatitis. At high concentrations, paraquat can also cause blisters, fever, and pain on the skin.

After paraquat is taken orally and absorbed by the human body through the digestive tract, it can cause nausea, vomiting, abdominal pain, oral mucosal ulceration, esophageal burning pain, stomach pain, etc. The patient drools constantly, has difficulty swallowing, and cannot eat. Most of these symptoms occur one week after taking the poison.

After paraquat is absorbed into the blood through the digestive tract, the blood concentration reaches a peak within 1-4 hours, and paraquat will enter various tissues and organs, such as the lungs, liver, kidneys, muscle tissue, etc., with the lungs being the main target organ. When the blood concentration of paraquat is high, it can cause liver and kidney damage, leading to liver and kidney failure, especially renal failure. After paraquat erodes the lungs, it can cause coughing, sputum, chest tightness, chest pain, shortness of breath, and finally respiratory failure. The larger the poisoning dose of paraquat, the higher the concentration, and the later the treatment, the more severe the systemic symptoms it causes will be.

Figure 2 Original copyright image, no permission to reprint

Treatment of paraquat poisoning is difficult now because there is no better and more effective treatment. Although some people think that there is no regret after taking paraquat, this is not entirely true. Paraquat poisoning does not necessarily lead to death, but not all cases can be successfully treated. At present, the overall treatment success rate, including mild, moderate and severe poisoning, is about 60%.

Generally speaking, if the oral dose of paraquat is less than 100 ml, most patients have a chance of survival if they are treated in time; if the oral dose of paraquat is more than 200 ml, the chance of survival is very small, and there is no hope of survival if the treatment is not timely. Of course, some patients are particularly sensitive to paraquat, and even a smaller dose, such as 5 ml, can lead to death if not treated in time.

Go to the hospital immediately after oral paraquat poisoning. For poisons that have not yet been absorbed into the blood, the first measure is to remove them through gastric lavage. For poisons that have already been absorbed into the blood, blood purification methods are currently commonly used, such as blood perfusion, which is one of the more common methods for treating paraquat poisoning. Second, anti-free radical treatment, use some anti-free radical drugs for treatment. Third, use hormones to reduce inflammatory reactions and increase stress resistance. Fourth, symptomatic support, anti-infection treatment, etc.

After the patient is admitted to the hospital, they should be fully informed and told that they need to be patient and perseverant and cooperate with the doctor to recover. Most patients with serious conditions need to be hospitalized for 3-4 weeks.

When skin and mucous membranes come into contact with paraquat, the higher the concentration of paraquat, the greater the damage to the skin and mucous membranes. The simplest and most direct way to deal with it is to immediately wash the contacted area repeatedly with plenty of clean water, and soapy water is more effective.

Eye contact with paraquat may cause symptoms such as photophobia, tearing, pain, blurred vision, and fear of opening the eyes. The first response measure is also to immediately rinse the eyes with plenty of water. Since the cornea is extremely sensitive, if it is not cleaned in time, it may damage the cornea, cause scars, and induce conjunctivitis.

While taking emergency measures, you should seek medical attention promptly. If the area has not been flushed before, flush it first after being sent to the hospital. Second, you can use some anti-inflammatory drugs locally to help the local mucosal tissue recover.