Wednesday, October 21, 2009


Out for a day hike on some boulder fields. Great weather, a little Indian-summerish, not a care in the world and then WHAM! Something stings you in the back of your calf.

Rattlesnakes usually don't kill people and this one didn't either, but it did force an admission to the ICU and a consultation with the Vascular Surgeon just in case. The venom from a 'wet strike' here is mostly proteolytic and hemolytic (severe local swelling and coagulation abnormalities), but can also be centrally acting on the heart. Compartment syndrome can result from these bites and if not diagnosed can, well, it can rot your leg, or hand, or arm off.

Used to be we gave anti-venin made from horse serum for severe envenomations, and, while it worked to stop the progression of the snake-bite (crotalid bite if you are on the pedantic side of academics), it also gave the patient a terrible case of serum sickness and hospital stays for severe envenomations were quite long because of this. Enter big-pharma.

Big-Pharma, we all know, roasts babies on spits for fun and is in league with big-Tobacco in the shamefully capitalistic pursuit of profit-making. If Satan existed they would be in league with him too, but for now just picture Dick Cheney with his shotgun. Somehow, in spite of all this however, they managed to produce crofab, which has revolutionized the treatment of crotalid envenomation.

I think, though, now that we know it works, that further profit from this drug should be confiscated and given to, uh, mmm, a non-profit organization. Power to the people in power! Huzzah!


  1. Please stop worrying about compartment syndrome - it is so rare as to be almost a negligible concern. Pheonix data has a rate of <1% comparment syndrome incidence from rattlesnake bites. The venom is injected into and causes primarily subQ edema not muscle compartment edema

    Now finger or toe bites can be concerning enough to warrant a little myotomy of the affected digit but almost never a true fasciotomy.

    Also a new crofab is in development that is an Fab2 fragment that might obviate the need for repeat dosing of crofab that we have to do now. Might have a higher rate of allergies though.

  2. dear guaic,
    thanks for your post. out of the three wet envenomations i've seen, two had fasciotimies for compartment syndrome. these were extremely late presentations. I also testified in one case where the doctor did not worry about compartment syndrome from a copperhead bite to the foot and the patient received an AKA a month later. it will also be a bit of a job getting the "worry" about compartment syndrome out of all of our textbooks. because something is rare means nothing when you walk in the room.

  3. On two separate occasions, we had two pets get bit by rattlesnakes. Our spaniel's head swelled up like a balloon. I'm not sure what the treatment was. My brother's horse also got a bite on the nose. I do recall dad giving him injections of something, and we used a feed bag with ice packs on his nose. It took a while for the swelling to go down, and his nose never looked quite the same afterwards. But he was still a functional horse. Until he got hit by a truck.

  4. The best I've seen and the nuclear scientists who brought a live copperhead in a box that had just bitten their son, opening it the room to show everyone. The thing almost got out. That would have been great-nurse getting snake bite in the ED.

  5. peggyU,
    i'm working on an immunization against truck strikes... only be a bit, writing my NIH grant proposal now.

    in my case it was not a copperhead in a box, but a bat in a bag... a fucking live bat in a plastic bag brought in by alleged bat-bite victim. holy fucking shit people are stupid.

  6. I've seen quite a few fasciotomies for snakebites that were not indicated. The swelling is very impressive and can be quite tense - however the key question is there muscle necrosis/muscle edema since that is what will inhibit blood flow(with some exceptions like fingers).

    I am curious how delayed the 2 presentaitons were that got fasciotomies - do you recall if a CK was markedly elevated or ir a pressure was measured.

    Even more striking to me is the need for an AKA a month after a copperhead bite. I don't know what you're able to share in terms of details but I don't think I've heard of such a case from a copperhead in the literature. I wonder if anything else was going on in that case. I assume no antivenom? Was the AKA done due to necrosis of muscle - was there infection, etc.

    I agree just because something is quite rare does not mean we shouldn't watch out for it. However we do have to recognize that signs of compartment syndrome in traumatic injuries might not apply to snakebites - unfortuantely another good model really isn't out there. Personally I wait for some objective evidence of ischemia(since when it does develop it is typically a gradual progression) though I do always admit these patients

  7. dear guaic,

    to the best of my ability and in compliance with hipaa...

    the two fasciotomies on my patients were done in the OR hours or days after admission by the vascular surgeon. as to the criteria they used to justify the fasciotomies i can not speak so you may well be right.

    i can however tell you about the aka. for the sake of this story let's make this person a 40yo 70kg male of white european descent (and therefore, perhaps, deserving of an aka... wow, obama has really got to me).

    he was admitted to a podunk hospital and was kept for three days. during that time he lost pulses in his leg. many panicked calls were made by his nurse to the admitting physician. this physician, in my opinion, in the opinion of the vascular surgeon, in the opinion of the orthopedic surgeon, committed malpractice because the only thing he did was turn up the narcs. then a jury threw the case out. abso-fucking-lutely amazing. patient sent home on crutches, went to other provider, got hyperbarics, failed, went to BKA and then AKA due to proximal necrosis. happened within the past 50 years in a state or territory of the US or in mexico or guatemala.

  8. Cro-Fab is around $1,500/vial. Good reason to have insurance of some sort.

    There is a rattlesnake vaccine for dogs, from Red Rock. Useful for hunting and ranch dogs.

    I am sure evil BigPharma is keeping it from being used on humans.

  9. I LIKE Eastern Diamondbacks,
    keeps those annoying Jehohah's Witnesses on their toes.


  10. Yet another reason I'm glad I have knee-high boots.

  11. Rejoice, we do not live in Australia!
    Irukandji jellyfish, funnel-web spiders and other little critters.
    The only way I am willing to see Australia is on a video and I do travel a lot, but this is a huge turn-off for me. I know, I am a wimp when it comes to those things. Ask my husband: he is the designated insect/bug killer and he saves my life on a regular basis :-)

  12. Amy - Those funnel web spiders would totally freak me out, and I don't generally mind spiders or snakes.

    I read that those damned things eat mice, are aggressive rather than evasive, and can bite through shoe leather. I wonder what preys on them?

  13. Sad to say, most people who are bitten by snakes are trying to mess with them or kill them. Is it too much to ask people to just leave the wildlife alone? And those twits who brought the copperhead to the ER were risking getting themselves envenomated while capturing it, although I'm frankly shocked that they didn't just bludgeon it to death with a shovel (like most ophiophobes) and bring in the corpse (and if they do that, do NOT handle the corpse; they can bite you as a reflex for quite a while after apparent death).

  14. Meh. Knee-high boots aren't that helpful; a good sized rattler, or cottonmouth, or copperhead, can easily penetrate leather that is thin/flexible enough for boots. Some folks wear "snake chaps," heavy plasticky/ canvas doohickeys. I've tried plastic shields that cover your calves and boot-tops, but their both clumsy solutions. Personally, I just follow the old rule of "step on the rock/fallen tree, not over it." Stepping over an object exposes the back of your leg to a critter that is freaked out by the sudden appearance of your leg. I suspect 911 stepped over a boulder, as a guess. The rule is to step on the object, then take your next step as far away from the object as you safely can.

    I also don't mess with the boots/chaps/calf guards anymore, because the good-sized rattlers we have around here can break your freakin' leg with a strike; imagine Mike Tyson, in his prime, with a free shot at your tibia. My rule is (knocks on wooden head) avoid, avoid, avoid!

  15. CJrun,
    i didn't get struck... it was my patient. he was not happy.

  16. I about stepped on a rattlesnake once. Out for a walk mid-morning and stumbled across it in the dirt driveway that led to my mom's house. It blended in very well!

    Fortunately for me, it must have been feeling sluggish when it crawled out there to soak up the sun. It made a noise which caught my attention as I approached it. As to a critter being freaked out by my appearance, I assure you the feeling was mutual!

  17. 911, I too wondered, "What'd that 911 get himself into now? He's got time on his hands, thinks he'll go out hiking... shoulda just stayed at the old job!" So glad it wasn't your personal story :o)

    I have a friend who got tossed off a horse r/t rattler. He landed on a rock, big time open femur.

  18. Any of you docs care to do a post on the whole Swine Flu thing? Thoughts about the vaccine the government's pushing that nobody can get. At least Louisiana can't get it because George Bush doesn't like black people...wait a minute...

    Are you docs vaccinated, are you going to be? The chances of horrible side-effects is no greater than with any flu shot is it? Got a friend who'se an ER nurse, and she's like "I'm not taking a first run vaccine." And I was like but every flu vaccine is a first run vaccine. It's new every year.

    Why does it not surprise me that Obama's government can't deliver the 140 million doses that were promised and so far we only have 11 million available. I mean, he's the president. Why hasn't he solved the problem already?


  19. As a non-medico, I have a thought on vaccine production. I'll bet you could produce a lot of vaccine, operating 24 hours a day, 7 days a week, but you'd have to charge big bucks for that, to cover all of the overtime. Then, you'd be called out for gouging people during a "crisis." Screw that and the trouble. Just crank it out at a moderate rate and stay under the radar. Productivity may be punished!

  20. Yeah, but apparently we've got enough to share with people in other countries. WTF?