Southeastern United States, are comparatively thin snakes with small bands of red, black, and yellow (or almost white). Some nonpoisonous snakes have the same coloring, but in the coral snake the red band always touches the yellow band. Its short, grooved fangs must chew into its victim before the poison can be introduced. The bite pattern is shown in figure 4-68. In a snakebite situation, every reasonable effort should be made to kill or at least to positively identify the culprit, since treatment of a nonpoisonous bite is far simpler and less dangerous to the victim than treatment of a poisonous bite.
Snake venom is a complex mixture of enzymes, peptides, and other substances. A single injection can cause many different toxic effects in many areas of the body. Some of these effects are felt immediately while the action of other venom components may be delayed for hours or even days. A poisonous bite should be considered a true medical emergency until symptoms prove otherwise.
The venom is stored in sacs in the snakes head.
It is introduced into a victim through hollow or grooved fangs. An important point to remember, however, is that a bitten patient has not necessarily received a dose of venom. The snake can control whether or not it will release the poison and how much it will inject. As a result, while symptoms in a poisonous snakebite incident may be severe, they may also be mild or not develop at all. It is essential that you be able to quickly diagnose a snakebite as being envenomated or not.
Usually enough symptoms present themselves within an hour of a poisonous snakebite to erase any doubt. The victims condition provides the best information as to the seriousness of the situation. The bite of the pit viper is extremely painful and is characterized by immediate swelling and edema about the fang marks, usually within 5 to 10 minutes, spreading and possibly involving the whole extremity within an hour. If only minimal swelling occurs within 30 minutes, the bite will almost certainly have been from a nonpoisonous snake or from a poisonous snake that did not inject venom. When the venom is absorbed, there is general discoloration of the skin due to the destruction of blood cells. This reaction is followed by blisters and numbness in the affected area. Other signs that may occur are weakness, rapid pulse, nausea, shortness of breath, vomiting, shock, headache, fever, chills, drop in blood pressure, and blurred vision. Severe poisoning can cause pulmonary edema and internal bleeding. The eastern diamondback rattler bite is further characterized by numbness and tingling of the mouth and possibly also of the face and scalp. A metallic taste on the tongue may be noted.
The aim of first aid for envenomated snakebites is to reduce the circulation of blood through the bite area, delay absorption of venom, prevent aggravation of the local wound, maintain vital signs, and transport the victim as soon as possible to a medical treatment facility. Other aid will be mainly supportive:
1. Apply a constricting band (i.e., rubber tubing, belt, necktie, stocking) above and below the bite. Each band should be approximately 2 inches from the wound, but NEVER place the bands on each side of a joint. If only one constricting band is available, place it above the wound. It should be tight enough to stop the flow of blood in the veins, but not tight enough to shut off the arterial blood supply. The victims pulse should be palpable below the band. Advance the constricting band to keep ahead of the swelling.
2. If the victim cannot reach a medical treatment facility within 30 minutes of the time of the bite, and there are definite signs of poisoning, use a sterile knife blade to make an incision about 1/2 inch long and 1/4 inch deep over each fang mark on the long axis of the extremity. This technique is done only on the extremities, not on the head or trunk. Apply suction cups to help remove some of the injected venom. Suction by mouth is recommended only as a last resort, because the human mouth contains so many different bacteria that the bite could become infected. Incision and suction later than 30 minutes from the time of the bite is not recommended.
3. Check the pulse and respiration frequently. Give artificial ventilation if necessary.
4. Calm and reassure the victim, who will often be excited or hysterical. Keep the victim