Venomous snake bites: emergency medical treatment

According to WHO, snake venom poisoning is registered annually in 500,000 people, among them 6-8% of cases are fatal. The most poisonous for humans are considered to be representatives of four families:

• asps (cobra);
• vipers (vipers, efa, gyurza and rattlesnakes);
• pit vipers (shield vipers);
• sea snakes (bonito).

There are two main groups of poisonous snakes: those with a "short tooth" (asps and some pit vipers) and those with a "long tooth" (vipers, pit vipers). The former contain a neurotoxin that blocks pain and causes respiratory and circulatory arrest. The latter secrete a hematotoxin that causes local necrosis, severe pain, and DIC syndrome. Some pit viper species (cascawela, massasauga) contain both toxins.

The most severe poisoning occurs when a snake bites the head and neck or when the poison gets directly into the blood. When bitten by asps and sea snakes, there is often no pain, but within 20-30 minutes the condition deteriorates sharply, weakness develops, a feeling of numbness in the face and body, and collapse due to the release of histamine. Subsequently, paralysis and peripheral paresis may develop, including the diaphragm, which can lead to asphyxia and circulatory arrest.

Viper and pit viper bites are characterized by the occurrence of acute pain at the site of the bite, a pronounced local reaction, serous-hemorrhagic edema of the limb spreading to the body. DIC syndrome and shock develop.

First aid for snake bites

A venous tourniquet or pressure bandage is applied for 30 minutes only in case of bites of asps and sea snakes. In case of bites of vipers and pit vipers, a tourniquet cannot be applied, as this leads to a sharp deterioration in blood circulation in the limb. The victim must be placed in the shade with raised legs, the poison squeezed out and removed, the wound treated with ethanol, brilliant green, but not potassium permanganate, as oxidizers increase the damaging effect of the poison, it is also necessary to ensure immobilization of the limbs, administer antihistamines. Pain relief is carried out with non-narcotic analgesics (rarely narcotics).

In case of snake bites, it is forbidden to cauterize the wound, apply cold, cut or inject the bite site with any preparations, as this leads to additional infection of the wound, increasing the resorptive effect of the poison. It is not recommended to suck out the poison by mouth due to the risk of poison damage through microtraumas of the oral cavity of the rescuer.

In case of bites of elapids, in particular cobras, a monovalent equine antitoxic purified concentrated liquid serum against cobra venom is used, and in case of bites of vipers and pit vipers, it is necessary to use a polyvalent equine purified concentrated liquid serum against the venom of blunt-nosed vipers, vipers, cobras, or, if there is reliable information about the type of snake, monovalent serums. Initially, the serum is administered in a 1:100 dilution intradermally in an amount of 0.1 ml, then, if there is no allergic reaction, 0.1 ml in undiluted form subcutaneously and after 30 minutes the entire dose of 10-50 ml is administered intramuscularly in the subscapular region (serum administration according to the Bezredka method). For vital indications, anti-snake serum is administered intravenously from 10-20 ml (500-1000 U) to 70-80 ml after preliminary intravenous, intramuscular administration of 1% diphenhydramine (diphenhydramine) solution 1 mg/kg and prednisolone at a dose of 5 mg per 1 kg of body weight.

Serum administration is provided for signs of systemic action of the poison, development of DIC syndrome and severe increasing "ascending" edema. In case of mild poisoning without obvious somatic reactions, it is undesirable to administer serum due to the high risk of developing severe allergic reactions, including anaphylactic shock. In case of respiratory and circulatory disorders as a result of a snake bite, artificial ventilation and cardiopulmonary resuscitation, treatment of hypovolemic shock and DIC syndrome are indicated.

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