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Human Vs. Rattlesnake: What to Do If You Are Bitten

Each year in America some 6,000 to 8,000 people report venomous snakebite injuries, most by rattlesnakes. Amazing myths persist about what one should do in such an emergency, everything from sucking out the venom (which doesn't work) to electrocuting the bite victim (which hurts and just might kill you).

Rattlesnake strikingWe at the Wilderness Medicine Institute of NOLS have been teaching people how to handle medical emergencies for over 20 years. While we love a good, improvised traction splint as much as the next person, when it comes to rattlesnake envenomation, we know that there's really very little we can offer a patient besides a speedy evacuation. The truth is that when it comes to rattlesnake envenomation injuries, the only thing that really matters is how quickly the patient gets to the hospital and receives proper antivenom therapy.

Why Most Folk Remedies Are Wrong

It is important to understand that American pit vipers, which include all the rattlesnakes as well as rattle-less cottonmouths and copperheads, possess venom that is primarily hemotoxic in nature, meaning it mostly does damage to the tissue near the bite site. This is different than the (incredibly) more dangerous snakes of Africa, Australia and nearly everywhere else in the world, which often inject neurotoxic venom and require different treatment.* This crucial difference explains why almost every folk remedy for rattlesnake bites is wrong.

It's also important to know that when a rattlesnake bites a person, it may inject no venom, a little bit of venom or a huge amount of venom, based on its personal preference and a variety of other factors. Some 25% of rattlesnake bites are "dry," meaning that the snake injected no venom. Details that influence severity of envenomation include snake size (larger snakes inject more venom), agitation (snakes that have been provoked may inject more venom than those that were merely surprised), and recent hunting activity (snakes may have already used up much of their venom).

Rattlesnake fangsRecognizing Symptoms

If the snake has successfully penetrated the victim's skin, you will see 1 or 2 fang marks. (Rattlesnakes regularly break their fangs and regrow them.) Clean the wound with soap and water.

Of more concern, though, is determining the severity of envenomation. Indications that venom is present include pain out of proportion to the puncture wounds, redness and swelling of the bitten limb appearing within 30-60 minutes, large blisters (likely bloody or dark-colored) forming within hours, and extensive bruising after 3-6 hours. Obviously, the more severe these symptoms are, the more venom has likely been injected.

Other, more distressing symptoms are possible as well. Some patients will have a life-threatening allergic reaction to snake venom and must be treated for anaphylaxis. Changes in blood clotting ability may cause unexpected bleeding from other parts of the body, and more bruising. Difficulty breathing, high heart rate, low blood pressure, nausea, vomiting, diarrhea, headache, numbness and tingling, confusion or apprehension, and muscle twitching are all possible effects of rattlesnake venom.

Providing Treatment

Of the thousands of rattlesnake bite victims each year, only 6 to 10 people die. The deaths often involve cases of elderly patients and delayed hospital care. As a rescuer, your main concern should be transporting the patient to a hospital for prompt treatment with antivenom. It is hard to overstress the point that delaying hospital care, for any reason, is unacceptable.

Rattlesnake bite victimIt shouldn't have to be said, but get away from the snake. Remove any jewelry that may constrict the bitten limb as it swells. Keep your patient as calm as you can, and gently immobilize the bitten limb if possible. For arms, a simple sling-and-swathe will suffice. Only construct a leg splint if you plan to carry, drive or fly your patient to the hospital.

It's ideal if your patient can be transported, meaning they won't have to walk, raise their heart rate and spread the venom faster, but this only makes sense if it won't delay their trip to the hospital. In many wilderness situations, the best thing will be to have the patient walk to a road, where you could meet an ambulance. Time is the important factor.
Things Not To Do

Bad Idea: Tourniquet
Why it is bad: Will not get your patient to the hospital sooner. Also, cutting off the blood supply to healthy tissue means that the venom will do much more damage at the bite site. Hemotoxic venom does not present a dramatic threat to the "core body" so there is no point to attempting to isolate a bitten limb.

Bad Idea: Try to catch or kill the snake
Why it is bad: This is not getting them to the hospital, either. Do you want to get bitten too? Don't be a fool. Let somebody else deal with the snake while you figure out how to get the patient to a hospital quickly. If you must, take a photo.
Bonus knowledge: Identifying a rattlesnake isn't all that important. The ER will evaluate the envenomation based on the patient's symptoms, not your dead snake head in a bag. All suspected rattlesnake envenomations get the same CroFab antivenom these days.
Super-duper bonus knowledge: Dead, severed rattlesnake heads have bitten and injected venom into misinformed people as much as an hour after they were killed!

Bad Idea: Suck out the venom
Why it is bad: Still not getting to the hospital ASAP. Plus, it's impossible. You can't do it. Studies have shown that even though venom-extractor devices will suck body fluids out of a wound, only about 0.04% of any venom injected will come with it. Meanwhile, you could be getting to the hospital. Bottom line: It's a waste of time.
[See Alberts, Shalit & LoGalbo: Suction for Venomous Snakebite: A Study of "Mock Venom" Extraction in a Human Model, Annals of Emergency Med. 2004; 43:181-186.]

Bad idea: Ice the wound
Why it is bad: You stopped at a 7-11 for ice?

Bad idea: Apply electricity to the wound
Why it is bad: Come to my laboratory at WMI of NOLS headquarters for a personal demonstration. I will show you. Also, applying electricity is not the same thing as taking the patient to the hospital.


The decision about how best to evacuate your rattlesnake-bitten patient hinges on 3 main considerations: envenomation severity, access to SAR or other rapid-acting rescue agency, and your self-rescue capability.

•    If you are close to a road and your group has 6 or more strong adults who can swiftly carry out the injured person, you should call 911 and then start carrying.
•    If you are farther away from a road, say, 2 to 4 hours or more, and if you don't have enough people to carry the patient, it makes sense to call 911 (if possible) and then have the patient walk (calmly) toward the road. Multiple-hour carries are unrealistic for adult-sized patients unless you have 12-18 rescuers on hand.
•    In a very remote situation, if you have the ability to request a helicopter rescue, do it! If you are so far from help that walking won't get you anywhere in less than a day or so, well, the best choice might be to have the patient stay put and reserve his or her strength. Hopefully the victim will be lucky enough to sustain a dry bite or a mild envenomation—time will tell. A person who receives a high venom dose while many hours or more from a hospital is in a very bad situation.

Don't be that guy!I don't want to end this article on a downer note, so please appreciate that the vast majority of rattlesnake injuries are 100% preventable. Beyond preventable, they are just plain stupid! The truth is that most bites occur on the hands and arms of people who intentionally pick up rattlesnakes. The victims are drinking alcohol in the majority of cases, too, and they are not in "the wilderness."

A little prudence goes a long way toward preventing snake bites, and experts estimate your worst-case scenario chance of dying from a rattlesnake bite in the wilderness is about 1 in 10 million. Resolve to never pick up a snake, and you'll very probably be just fine.

*Note that the Mojave rattlesnake and the coral snake also live in parts of the US but fall outside the parameters of this article. These snakes inject neurotoxic venom, and bites from either of these snakes should be considered more dangerous than standard pit viper bites. Prompt evacuation is still required, and pressure-immobilization of the bitten limb is recommended. I will write about this in a future post but, if you're impatient to learn then sign up for my Wilderness Medicine Institute of NOLS course.

Below: Newborn rattlesnake. (All photos courtesy of WMI of NOLS, except top photo of rattlesnake by Casey Kanode—correction added 7/23/2012.)

Posted on at 12:31 PM

Tagged: WMI of NOLS, Wilderness Medicine Institute, rattlesnake and snake bites

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Thanks for a great and very informative article. Coincidentally, we had a Southern Pacific rattler on our doorstep yesterday. Fortunately no one was injured as the snake was seen before he got stepped on.

We are planning on taking the WMI WFA course here in SoCal in September. Are rattlesnake and other forms of envenomation covered in that course, or is that reserved for more advanced classes.

Thanks again!

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