October 14th 2021

5:00-6:00PM EST

Envenomation Medicine: Stings and Things

Dr. Sean Bush

September 14th 2021

5:00-6:00PM EST

Toxicology: Wilderness Plant Toxicology - An Approach to Toxic Plant Ingestions

Dr. Mia Derstine

February 4th 2021

5:00-6:00PM EST

Toxicology: Marine Envenomations

Dr. Robert Barry

December 9th 2020

5:00PM - 6:00PM EST

Toxicology: Land Envenomations

Dr. Jeffrey Bernstein

Envenomation Medicine: Stings and Things


Wilderness Plant Toxicology: An Approach to Toxic Plant Ingestions


Toxicology: Marine Envenomations



What would you put in your go-bag if you had to pack light/only the essentials in one of these scenarios?

For a go bag it would really depend on how light you have to pack. Ideally for equipment I would take bandages/gauze/tape, ace wraps for pressure dressings with something to use as a splint and sling, a tourniquet to control massive hemorrhage/arterial wounds, and maybe some forceps or hemostats to help remove foreign bodies on scene. Hot and cold packs are often useful as well, and if I'm in Australia or somewhere that I'm concerned about Chironex then some vinegar. For meds assuming we're forgoing an ACLS bag with epi and things like that I would probably at least bring some Tylenol/ibuprofen and some Benadryl. If room is very limited then splints and tourniquets can often be improvised. Also if your on a boat or something like that that has access to hot water then would probably forgo the hot packs.

When medically managing a jellyfish sting with the tentacle still wrapped, is there a way to know if the venom has been discharged or not since you mentioned sometimes manipulation may actually cause the venom to be released or I guess, further released?

There isn't an easy way to tell if all the nematocysts have been discharged in a tentacle. Safest to assume there is always the potential for further envenomation which is why adjuncts like vinegar can be helpful in certain species and careful removal and avoidance of things like fresh water which will trigger further discharge should be avoided.

Pressure dressings were a common feature in the acute management of many of the bite-mediated marine envenomations. My question is how do they inhibit/slow the movement of the venom, what is the mechanism? Is it simply a matter of minimising venous return?

I think minimizing venous and lymphatic return is exactly the idea. Pressure dressings really just sequester the venom to the wound site and try to slow systemic absorption. By compressing the veins and lymphatic channels and keeping the limb still you inhibit distribution of the venom and subsequently can delay its effects.

You alluded to an increased incidence of Ciguatera where boat wrecks occur, why is this? Is it just a matter of wrecks attracting marine life, which leads to more opportunity for larger predatory fish to eat and concentrate toxins, or maybe some form of leaching from the wrecks into the environment?

Anything that stresses an ecosystem such as boat wreck, a sewage spill, construction, or even natural phenomenon like hurricanes and heavy rains can cause blooms of gambierdiscus toxicus which causes subsequent outbreaks of ciguatera. I know there was large outbreak in Hawaii in 1978 when they built the reef runway at the airport. As to why stress allows this particular dinoflagellate to proliferate, I can't say for certain. I think it would probably have to do with disturbances in the balance of animals that feed on gambierdiscus along with either introduction or liberation of nutrients in the area that allow it to proliferate. These blooms are usually transient, and subside when the ecosystem has re-equilibrated.

I have so many questions. Namely, why have you been stung by so many things?

I wish I knew! A lot of it probably has to do with me not taking my own advice when I was younger, but as they say experience is the best teacher. I will say that I enjoy spending time in the ocean and when you spend as much time there as I do the probability of an encounter goes up. That being said I have never needed to be hospitalized or had any long lasting ill effects so I hope my lecture didn't discourage you from ocean activities.

Toxicology: Land Envenomations


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I was wondering if patients being intoxicated complicates their treatment?

Patients are rarely so intoxicated that you can’t get an exam. Most of them sober up by the time they get to us. Occasionally it might limit the amount of opioid pain medication you can give them. NSAIDS are generally contraindicated because of their affect on platelets. Where it really makes a difference is when someone comes in and claims they’ve been bitten by a coral snake and they are too drunk to adequately describe the snake. Same thing happens with young children (who are basically like little drunks).

What about scenarios where the identity of the snake is unknown? How do you proceed?

There are really only two different types of snakes in the US, the pit vipers/Crotaline, which are the rattlesnakes, Cottonmouth, copperhead and the coral snakes. The clinical picture is very similar for the pit vipers with local tissue distraction, thrombocytopenia, systemic or neurologic symptoms and the antivenom is actually the same for all of them.

For the coral snakes you have to have a good history. Most toxicologist know which snakes are in their geographic area.

Whether it’s a pygmy rattlesnake or a cottonmouth doesn’t really matter. We use the same antivenom for either of those for example. If the snake is completely unknown and maybe an exotic snake, then we examine the patient and treat target organ injury. If the patient has neurologic symptoms then that’s what we treat.

Do you have an anti-venom that acts on more than one snake venom type?

There is a lot of overlap in the binding of antivenom to different species of snakes. Even though some antivenoms are made with specific snakes that may not even be indigenous to where you live, either of the two Crotaline antivenoms would work for almost any US pit viper. For coral snake you have to use coral snake Antivenom. Sometimes we get exotic bites like cobra or mamba. Usually those come from zoos or herpetologist who usually know which snake bit them. In Miami we have an Antivenom team run by Miami Dade fire rescue. Poison centers also keep an index of zoos and aquariums that act as repositories for the antivenoms that correspond to the animals they keep.

If the bite is from an unknown snake is there a risk associated with elevating the limb potentially increasing the extremity.

Yes, good point. If the snake is a neurotoxic snake we would generally keep the extremity at the level of the heart until we have antivenom at the ready.

What's the weirdest case you've had?

I get asked this question a lot and I can never think of one when I need to: We had two guys partying out in the Everglades they got so high that one of them didn’t realize his finger was being chewed on by a coral snake. His friend pulled it off and got bitten himself. They both ended up getting antivenom. We also had a patient unloading crates at the port of Miami from the Middle East. He was bitten by a monocled cobra. I had a patient feeding his pet Python a mouse and holding the mouse in front of his face. The python struck and hit him in the eye and split his upper eyelid in half and punctured the globe. He went to the OR that night. I’ve had several patients bitten on the face from trying to kiss a snake.

How do you project envenomation injuries to change with climate change? Recommendations for providers working in areas not historically concerned with snakes but may see more with incr. warming?

We are generally seeing less snakebites over time because we are paving over their habitat. With over development we are taking away their home and so I think there are a lot less of them. We have seen the effect of global warming in other toxicities, however. Manchineel trees were once located exclusively in the keys, and now have been seen as high as Palm Beach. Irukandji syndrome was once exclusive to Australia and now has been reported off the coast of Florida in the Caribbean and in Hawaii. Red tide and various allergies have flourished in the warmer waters off the West Coast of Florida.

Do people who have been bitten/stung multiple times build up a long-term tolerance to the venom?

Many snake handler‘s have become sensitized to their snakes and develop allergic symptoms when they go near them. This is particularly true for cobra handler‘s. People do develop some antibodies but generally not enough to protect them from a real bite. I know of several cases where someone who thought they were protected from multiple bites have died and others who have almost died.