How is a Rattlesnake Bite Treated?

Rattlesnake (xiangweishe) (crotalusadamanteus) vertebrates, reptiles, Viperidae (rattlesnake family). A kind of venomous snake, the venom is blood circulation poison. The general body length is about 1.5 ~ 2 meters. The body is yellow-green with diamond-shaped dark brown spots on the back. The tail end has a series of keratin rings, which are the remnants after repeated molting. When encountering an enemy or a sharp movement, quickly swing the tail ring at the tail, which can swing 40 to 60 times per second, and can make a loud sound for a long time Because the enemy did not dare to approach or was scared away, it is called a rattlesnake.

Belong to:

Rattlesnake has 2 genera:

According to the British New Scientist Magazine, the Animal World's Excellent Planned Parenthood Award should be awarded to the Eastern Diamondback Rattlesnake. Females of this rattlesnake can store semen in the body for at least 5 years before giving birth to offspring. ^[3]

A 67-year-old woman was bitten by her right middle finger with a rattlesnake. The injured man had moderate dyspnea, obvious swelling around the wound, obvious swelling of the mouth, and a progressive increase in oral secretions. The patient's bitten hand is fixed and held at the same level as the heart. Horse serum sensitivity test was negative.Diphenhydramine 50 mg, methyl dehydrocortisol sodium succinate 250 mg were given intravenously, and air adrenaline was injected to eliminate progressive airway and facial swelling.Tetramuscular injection Toxins are administered intravenously to a broad-spectrum cephalosporin antibiotic. Intubation was performed due to the progressive collapse of the airway, and 100% oxygen was inhaled, and the blood oxygen saturation was maintained at 100%; gross hematuria was seen with catheterization. Laboratory examination showed abnormal coagulation: thromboplastin time 38.3, fibrinogen 137, prothrombin time 16.3, total platelets 5,000; urine red blood cells were full of vision. With anti-venom serum, 5 ampoules were added to 100 ml of normal saline at one time, and the drug was administered through a second intravenous access. The infusion rate should be slow in the first 15 minutes, and gradually increase after the patient adapts. 15 ampoules of anti-venom serum were infused in approximately 1 hour. After the patient's airway swelling was controlled, the trachea was removed and the anti-venom serum counteracted the blood venom, and the blood coagulation returned to normal. The patient developed serum disease 7 days after the diagnosis of snake bite. Initially, a rash appears, and symptoms develop similar to tetanus-like muscle spasms and closed teeth. Corticosteroids and antihistamines are administered in a decreasing manner. Three months after the patient was poisoned, there were still some residual snake venom effects. Serum disease is a type III hypersensitivity reaction caused by the injection of heterologous or exogenous proteins or serum. Serum disease is an inevitable consequence of the application of anti-venom serum, and it is also a consideration for weighing the advantages and disadvantages of applying anti-venom serum to patients. Typical clinical manifestations include fever, joint pain, lymphadenopathy, and rash. There may also be muscle pain, joint pain, chest pain, and difficulty breathing. Laboratory tests do not help much to confirm the diagnosis. The purpose of treatment is to reduce the immune response against snake venom. Medications used to treat serum diseases are corticosteroids, antihistamines, and anti-inflammatory drugs.

The poisonous components of snake venom are divided into 4 categories: enzymes, glycoproteins, low molecular weight peptides and metal ions. These enzymes can cause coagulopathy, cell lysis, bleeding, hemolysis, and the destruction of nucleic acids, mitochondria and other cells; they can trigger the release of vascular bradykinin, histamine and serotonin from damaged cells, causing allergic reactions. The actual total venom in a snakebite is always an unknown. In predicting the severity of snake bites, the type, age, size of the snake, the age, weight of the victim, the number and location of the wounds, the usual physical conditions and the severity of the symptoms must be considered. Juvenile rattlesnake bites are thought to cause fibrinogen clotting more easily than adult snake bites. However, adult snakes have the ability to secrete large amounts of venom. The literature requires that snake bite patients be monitored for more than 10 hours. If no symptoms appear after 8 to 10 hours, there may be slight or no snake venom effect. The presence of snake bite wounds and the symptoms of snake venom are necessary to confirm the diagnosis of snake venom poisoning. The dose of antisnake serum depends on the severity of the snake venom. The most common signs and symptoms of rattlesnake bites are burning pain and swelling at the wound. Wyeth, an American snake venom anti-venom maker, has classified snake venom into five levels, ranging from 0 to 5. Grades 0 and 1 represent minimal snake venom, grades 2 are moderately toxic, and grades 3 and 4 are severely toxic. Other factors must also be considered when applying anti-venom serum, such as the immune response to horse serum. The lyophilized antiviral serum must be completely dissolved before administration, and it is not required to perform an allergy test before application; it is recommended that H1, H2 antagonists and corticosteroids be given in advance 15 minutes before the application of antivenom serum; subcutaneous injection 1: 1 000 epinephrine 0.25 ml can reduce the acute adverse reactions caused by the application of anti-venom serum. Manufacturers of anti-venom serum still advocate skin tests. Positive results after injection of anti-venom serum can choose to use corticosteroids, epinephrine, hydroxyzine hydrochloride and other necessary drugs.

Whether broad-spectrum antibiotics are given to snake bites and whether the wound ends are elevated is still controversial. Most literature considers the use of broad-spectrum antibiotics to be harmless, supporting the fixation and keeping of wounds at the heart level, although raising the wounds may not be harmful. ^[6]

Glenn et al. (1978) reported on rat LDs from rattlesnake toxin in different regions. There are big differences. The rattlesnake in southern Arizona and California has strong virulence and is injected intraperitoneally with mouse LD. 0.13 to 0.54 mg / kg, said toxin A. The rattlesnake in Central Arizona has weak virulence, and mice were injected intraperitoneally with LD :. For 2.3 to 3.smg / kg, said toxin B. From the clinical manifestations of rattlesnake bites, it has been reported that local symptoms are mild and neurological symptoms are obvious. It has been reported that neurological symptoms are rare and local poisoning is obvious. It is suggested that the research and treatment of rattlesnake venom should consider the composition of snake venom. This article analyzes the biological characteristics of toxins A and B obtained from different regions. As a result, the toxins of six rattlesnakes in central Arizona belonged to toxin B. Mouse peritoneal LDs. For 2. ~ 6 ·. ms / kg. Toxins from five southern Arizona rattlesnake belong to toxin A, DLS. It is 0.22 to 0.46 mg / lin. The difference between toxins A and B has nothing to do with the sex and age of snakes. Toxin B has a lethal time of 24 to 48 hours; toxin A is within 24 hours, and most of them are within 12 hours. The protease activity of toxin A is 40 times lower than that of toxin B, and the cool enzyme activity is comparable. The hemolytic activity was measured subcutaneously in rabbits. Toxin A50 fights g without hemolysis, and toxin B25 fights g causes bleeding spots with a diameter of 10 mm. Gel electrophoresis and electrophoresis scans of the stick compounds of toxins A and B were performed. As a result, toxin A contained 9 Pa neurotoxicity on average, while toxin B contained only trace amounts or no neurotoxicity. The author used taxonomic methods to compare 13 B snakes and 18 A snakes without any difference. The toxic properties of the same snake species can vary from region to region, so geographical distribution should also be considered when observing snake venom. ^[7]

Hot eye system

Both rattlesnake and viper snakes have "hot eyes" that grow between the eyes and nostrils, called the cheek fossa. The cheek fossa is usually 5 mm deep and only one centimeter long. The cheek fossa is a trumpet shape with the trumpet mouth facing diagonally forward, with a thin film divided into two parts inside and outside. The inner part has a thin tube that communicates with the outside world, so the temperature inside is the same as the temperature of the surrounding environment where the snake is located. The outer part is a heat collector. If there is a hot object in the direction of the bell mouth, infrared rays will pass through here to the outer side of the film. Obviously, this is higher than the temperature on the inner side of the film, and the nerve endings covered by the film sense the temperature difference, and generate a biological current, which is transmitted to the snake's brain. The snake knew where there was a hot object in front, and the brain issued a corresponding "command" to capture the object.

A rattlesnake tail has a keratinous chain ring at the tip of the tail, which forms a cavity. The keratin cuts the cavity into two annular cavities, as if they are two air oscillators. When the rattlesnake keeps shaking its tail, an airflow is formed in the cavities, and the air bubbles oscillate back and forth as it enters and exits, and the cavities make a "gala gala" sound. ^[1]