Free Surviving the Extremes: A Doctor's Journey to the Limits of Human Endurance by Kenneth Kamler Page A

would be impossible. But less than half of all bites from poisonous snakes actually inject venom. Fang marks are sometimes hard to see, particularly because they are often obscured by swelling. Tingling, facial numbness, palpitations, and difficulty breathing can be early indicators of envenomation, but given the near hysteria aroused by snakebites, those signs can be present in anyone.
    If I were treating a snakebite, my first job would be to calm the patient down—not just for the psychological benefit but to slow the spread of the venom. At Zancudo Cocha I had an extractor, a plunger type device that if applied to the bite wound within the first few minutes might draw out some of the venom. It might also be a waste of time. No one knows for sure how effective it is. I would not try sucking the venom out by mouth, though not because I would be afraid of swallowing poison. As potent as they are, these poisons are easily broken up by stomach enzymes. Snake venom only works when it enters the bloodstream directly. Anyway, venom is so thick that sucking it out by mouth would not work. Even worse would be making a cut over the bite and trying to squeeze the venom out. That would expose more blood vessels to the venom and probably drive itin deeper under pressure. I could slow the poison by applying a wide bandage over the whole limb. With just enough pressure, I might be able to block the veins from carrying contaminated blood to the heart while still allowing inflow from the deeper arteries, which would carry fresh blood into the limb to keep it alive.
    I didn’t bring any antivenin on this expedition but not because I forgot. The most effective antivenins are specific for each species of snake, and there are over one hundred varieties of poisonous snake in the Upper Amazon Basin. General antivenins are not as effective. Many bottles are required, the injections themselves are dangerous to give outside a hospital, and worst of all, they have to be kept refrigerated. Antivenins are antibodies, natural body chemicals that patrol the bloodstream and deactivate antigens—foreign chemicals, such as snake venom, that find their way inside the body and cause havoc. Each antibody is specific to one kind of antigen and only manufactured in quantity once the body has been exposed to it. When enough is manufactured, it can counteract the antigen and stop the problem. This is how we “get over” a cold. But snake venom, like many deadly diseases, doesn’t allow enough time for the antibody response. The solution is to have the antibodies ready to go—premade by injecting sublethal doses of venom into animals and then collecting the antibodies they develop. This is how vaccines work. But antivenins have a lot of impurities and can create their own deadly side effects. After consulting with experts at the Bronx Zoo, I decided they would be too impractical for this expedition. People on expeditions understand they assume risks when they enter an extreme environment. Practical decisions I make may have fatal consequences. The responsibility would be mine.
    There would be nothing more I could do if a snake sunk its fangs into a member of my team. Evacuation was impossible. We were surrounded by thousands of miles of trees and plants . . . but maybe one of them held a cure for snakebites. I asked Antonio what he would have to offer if one of us were bitten. He said he once treated somebody who had been bitten by a bushmaster—probably the deadliest snake in the Amazon. He made a poultice from the inside of a treebark, added a few plants, then boiled it until it had turned into a syrup. He gave the victim one dose every day. The plan was to give a total of five doses, but on the third day the patient died.
    “Yeah,” I mused. “I don’t know why that happens. Sometimes you follow the treatment protocol exactly, and the patient still doesn’t get better.”
    The laws of nature are sometimes simply overwhelming, and doctors are