Excerpt from The Prepper's Medical Handbook. Page reference numbers point to more in-depth treatment and self-reliant care available within the book.
With regard to the visual identification of the most common poisonous snakes in North America, pit vipers take their name from the deep pit, a heat-receptor organ, between each eye and nostril. Most of them have triangular heads and catlike vertical elliptical pupils.
While not pit vipers, coral snakes (Micrurus fulvis, family Elapidae) also have vertical elliptical pupils. Some nonpoisonous snakes do as well. Color variations in coral snakes make the old saying “red on yellow can kill a fellow, red on black, venom lack” a very treacherous method of identification. This is particularly true in Central and South America. Coral snake bites should be treated as described below under Neurotoxic Snakebites.
The essential steps in treating snakebites are calm the victim, cause no additional harm, decide about evacuation urgency, and arrange for appropriate long-term wound care. The field first aid care of snakebites differs for nonpoisonous snakes, pit vipers (including rattlesnakes, cottonmouth/water moccasins, and copperheads—all in the family Crotalidae), and neurotoxic snakes (coral snakes, cobras, green mambas, kraits, and all poisonous Australian snakes, all the family Elapidae). That being said, the actual first aid care is easy to accomplish and will generally depend on where geographically the snake bite occurs. Treat North American pit viper snakebites without compression, and treat snakebites received elsewhere as neurotoxic bites requiring compression and immobilization, as indicated below.
Regardless of the type of snakebite, the first step is to calm the patient and treat for shock. How do you calm a person who has just been bitten by a snake? Not surprisingly, just telling him to remain calm won’t work. In a remote area when something terrible has happened, it’s only your actions and demeanor that will provide comfort. Depending on the individual, you may need to treat for shock immediately, as described on page 13.
All snakebites are puncture wounds, and nonpoisonous bites and “dry” North American pit viper bites should be treated as indicated in the puncture wound section on page 133. Studies indicate that 20% of eastern diamondback rattlesnake bites and 30% of cottonmouth/water moccasin bites are dry, which means no venom has been injected into the victim.
Signs and Symptoms of Pit Viper Bite
What are the signs and symptoms of envenomation from pit vipers? The first indication noted by many is a peculiar tingling in the mouth, often associated with a rubbery or metallic taste. This symptom may develop in minutes and long before any swelling occurs at the bite site. Envenomation also may produce instant burning pain. Weakness, sweating, nausea, and fainting may occur with either poisonous or nonpoisonous snakebites, due simply to the trauma of being bitten. In case of envenomation, within 1 hour there will generally be swelling, pain, tingling, and/or numbness at the bite site. As several hours pass, bruising (ecchymosis) and discoloration of the skin begin and become progressively worse. Blisters may form, which are sometimes filled with blood. Chills and fever may begin, followed by muscle tremor, decrease in blood pressure, headache, blurred vision, and bulging eyes. The surface blood vessels may fill with blood clots (thromboses), and this can, in turn, lead to significant tissue damage after several days.
Treatment of Pit Viper Bite
For rattlesnakes, copperheads, and water moccasins, treat for shock and calm the patient as indicated above. Remove any constricting objects such as rings. Immobilize the injured part at heart level. And evacuate if you can.
It has been said that the best snakebite kit is a set of car keys. The reason is that envenomation can make a person very ill (on average seven people die yearly in North America from these bites), and it can cause serious tissue damage that is best treated with antivenin. There is a golden hour and a half before North American pit viper venom causes significant generalized effects that might make the victim nonambulatory. You might want to start walking the victim toward the nearest road to shorten the length of a litter evacuation, which will become necessary if his condition deteriorates. This walk out should be performed in a calm but urgent manner. Attempting to carry any but a very light individual will excessively prolong it.
Do not apply compression or a tourniquet to the swelling associated with this type of bite because the venom causes considerable tissue damage from squeezing blood vessels, and further compression makes this effect worse.
Do not apply ice, as this results in increased local tissue destruction. Avoid the use of a constricting band between the bite site and the heart, as this has never been shown to be effective and there is a real danger of it being applied too tightly, resulting in a tourniquet effect that increases tissue destruction.
If no grid exists, treat as indicated above: immobilization with the injured part at heart level. As most bites are dry bites or partial venom loads, this may be all that one needs to do. If local swelling starts, slightly elevate the limb to decrease pressure within it. Trunk and facial bites, while rare, are even more of a challenge. Treat for shock, prevent hypothermia, and provide Tylenol for pain, avoiding aspirin and anti-inflammatory medications. While the use of steroids is not required in an on-grid hospital setting, without access to care the use of steroids (Decadron, 4 mg every 12 hours for 3 days) probably reduces inflammation.
Neurotoxic Snakebites
Coral snakes, all Australian snakes, and most African, Indian, and South American snakes are all capable of injecting neurotoxins into their victim’s system with their bites. In 1979 Australia adopted pressure and immobilization as the first aid treatment for the very dangerous snakes found on that continent and dropped their yearly death rate from snakebites to virtually zero. In Australia the wound is not washed prior to wrapping, as special “snake venom detection kits” are available at hospitals that can identify the snake from venom in the wound. The wound is not manipulated in any way; instead, pressure and immobilization is applied immediately as indicated in figure 8-2.
The pressure dressing works to slow the venom from migrating into the main body, allowing time for the antivenin to be acquired. Without antivenin, treat the patient for shock (page 13) and try to maintain breathing with respiration-assisted breathing (see page 19);
there is not anything else you can do. If you are moving off the grid into Australia, India, or South America, poisonous animal encounters add a whole level of risk. (Also read below concerning neurotoxic venom).
Treatment of Coral Snake Bites
North American coral snakes envenomate by a slow chewing process, so that a rapid withdrawal from the attack may result in no envenomation. For treatment: (1) treat for shock as necessary, (2) wash the bitten area promptly to possibly remove some venom, (3) make no incisions, (4) apply pressure/immobilization, and (5) evacuate to a hospital if possible. Since, like the cobra, the coral snake is an Elapid family of snake, signs and symptoms of envenomation take time to develop, and deterioration then proceeds so rapidly that the antivenin may be of no avail. Without the possibility of evacuation, after initial care of the wound as above, allow the victim to rest with adequate protection from the environment. Just leave the compression dressing on, making sure that it is not acting as a tourniquet. If severe pulmonary symptoms develop, see paragraph below. Provide breathing assistance as long as possible.
Cobra, Russell’s viper, green mamba, and krait bites outside of Australia result in thousands of deaths yearly. While many areas of the world have a local source of antivenin for the species of snakes that are of concern in that locale, often the antivenin may be inaccessible. The use of a class of compounds called anticholinesterases can be lifesaving when dealing with neurotoxic envenomations if no antivenin is available. For physician use only, a suggested protocol is the administration of 0.6 mg of atropine IV (0.05 mg/kg for children) to control intestinal cramping, followed by 10 mg of Tensilon (0.25 mg/ kg for children). If there is improvement, further control of symptoms can be obtained by titration of a dose of neostigmine, 0.025 mg/kg/hr by IV injection or continuous infusion. Note: These medications are not included in the recommended Rx Injectable Medication Module.