SNAKEBITE

a wound resulting from penetration of the flesh by the fangs of a snake, especially a snake secreting venom through or near the fangs. A bite by a snake known to be nonvenomous is treated as a puncture wound. A bite by a venomous snake may be serious, depending on the size of the victim, the location of the bite, the amount of venom injected, the speed of absorption of the venom into the victim's circulation, and the amount of time between the bite and the application of specific antivenin therapy. Snake venom contains a number of enzymes or proteinaceous substances, present in varying amounts according to the species of snake, which attack the blood, the nervous system, or other tissues. Some venoms produce direct toxic effects, but not all of them are lethal to human beings. Some are systemically lethal (e.g., the venom of the rattlesnake), whereas some are destructive primarily to tissue in the vicinity of the bite but may cause the development of gangrene. First aid in cases of snakebite on the extremities (by far the most commonly bitten areas) consists of the immediate immobilization of the limb in a horizontal position and the application of a broad, firm bandage on the bitten area and around the entire limb if possible; a splint is recommended. Cutting and suction of the wound and the application of arterial tourniquets are inadvisable. Exertion and excitement should be avoided to prevent an increase of the pulse rate and consequent increased circulation; for the same reason, stimulants should be avoided. The application to the wound of such substances as ice or potassium permanganate is likely to be harmful rather than helpful. Most types of snake-venom poisoning can be treated with the use of antivenins. Prepared by the immunization of animals (especially horses) against the venoms, the effectiveness of the antivenin depends upon its specificity, its antibody content, and the degree of purification or concentration of the product. Although the use of a specific antivenin is preferable in the treatment of a particular snakebite, some antivenins may protect against the venom of various related snakes. For example, the antivenin for the tiger snake (Notechis scutatus) is also effective against the venoms of several other snakes. See also venom.