Snakebite Medicine With Dr Abo: Times Have Changed

Michael T. Hilton, MD, MPH; Benjamin N. Abo, DO, EMT-P


March 26, 2019

Editor's Note:
Oh my, the handling of venomous snakes! Here is an exclusive interview with Benjamin N. Abo, DO, EMT-P, an attending emergency medicine physician and assistant professor of emergency medicine at the University of Florida College of Medicine. Abo is a medical director of the Venom One and Venom Two response units and serves on multiple fire and technical rescue task forces in Florida. He is also a cofounder of the Florida Wilderness Medical Association and an instructor for the Wilderness EMS Medical Director Course.

Abo was the 2014 recipient of the EMS Provider of the Year from the National Collegiate EMS Foundation after saving the life of a unconscious man who fell onto the PATH train tracks as a train was approaching the station in Greenwich Village in New York City.[1]

Michael T. Hilton, MD, MPH, interviewed Abo to learn more about venom teams, and how EMTs and paramedics should treat patients with snakebites.

Aren't You Afraid of Snakes?

Hilton: You're an emergency medicine and emergency medical services (EMS) physician who is very involved with wilderness EMS. I follow you on social media and recently saw some intriguing and frightening 3D pictures of you handling snakes (Figures 1 and 2). Were they venomous?

Figure 1. Benjamin N. Abo, DO, EMT-P, Venom Team medical director.

Abo: The snake in this picture is not venomous.

Hilton: I have a slight fear of snakes and try to avoid them, but it seems you are not scared of snakes.

Abo: To the contrary: I had a huge fear of snakes until recently. It took me a few years of working with snakes and the venom teams before I overcame my fear. I think I can say I had finally gotten over this fear in March 2018, when I became licensed to handle venomous snakes.

Hilton: How did you become involved with snakes?

Abo: Initially, I got involved in snakebite and envenomation care through my passion for wilderness and austere EMS and while providing medical care in developing areas of the world. Venom care is a big part of this. In residency, I had the opportunity to work and learn from the Venom One Team. I learned a lot about snakebite management that was directly applicable to my interest in wilderness and austere medical care.

I learned about how much incorrect knowledge is out there about snakebites, including incomplete and misinformed textbook chapters, and myths about snakebite management. I have seen improper venom care be given to snakebite victims. Healthcare providers still talk about electrical therapy and local suction for snakebites. It's literally shocking.

Early on, I became very passionate about appropriate venom care. In the United States, so many snakebite victims suffer from permanent pain and disability because of the lack of knowledge of snakebite management. Internationally, many snakebite victims die because of this lack of knowledge, but also because of lack of access to appropriate care and to antivenom.

Venom Teams and a Physician's Role

Hilton: What is your role with the venom team?

Abo: I am the principal investigator for the Venom One Team (aka Miami-Dade Fire Rescue Venom Response Program), which is located in Miami-Dade County in Florida and was started 20 years ago by Miami-Dade Fire Rescue. I provide medical direction to the team, working alongside Florida Poison Control. I am also the medical director for the Venom Two Team (which was started in 2018, and is housed in Lake County, Florida) and for the Nature Coast Anti-venom Index. The Nature Coast Anti-venom Index assists hospitals and clinics in locating and transferring antivenom and has information on all civilian-accessible banks of antivenom for a wide variety of venoms.

Figure 2. Ben asks, "Would you care to hold the snake?"

Hilton: What does a venom team do?

Abo: A venom team provides a multipronged approach to snakebites and envenomation. The teams are trained to know what antivenoms go with which species of snake, similar to the function of poison control centers for poisonings and toxin exposure. Venom teams also are a repository of antivenoms and the antivenom delivery service. Because many antivenoms are expensive and rarely used, it is costly to stock them. Venom teams regionalize stocking, storage, access, and costs to maintain this resource.

The second prong of the venom team is snake handling. Team members are trained to capture, handle, and relocate venomous species. This mostly involves snakes but team members are trained to handle any venomous species of animal.

The third prong that further distinguishes venom teams from any other resource out there is its role as an education delivery service, whether this is giving lectures or providing real-time "bedside" education. You may think any medical toxicologist already knows all there is to know about envenomations. But even for a board-certified toxicologist, venom care is less than 10% of their curriculum. A lot of physicians, even toxicologists, may never treat snakebites. The Venom Teams can provide real-time education to physicians, nurses, and pharmacists in the emergency department or intensive care unit to ensure proper care and help iron out wrinkles that occur because of lack of knowledge of the clinical management of envenomations, or even worse, to correct incorrect knowledge.

Even though venom teams are based only in Florida, the states with the highest rates of snakebites, but not necessarily venomous snakebites, are Arizona, Kentucky, and West Virginia, all with greater than 4 bites per 100,000 inhabitants. Florida is in the middle category, with 2-4 bites per 100,000 inhabitants. [2]

Hilton: Do the venom teams charge for these services?

Abo: The venom teams only charge membership fees, which go toward the costs of transporting antivenoms. Venom Teams also receive grant funding and charge medical insurance. There are no direct charges to patients and no charge for consults with healthcare providers.

Hilton: How many venom teams exist in Florida and other states in the United States?

Abo: There are three venom teams in Florida, including the Nature Coast Anti-venom Index. They all have the logistics to facilitate care and transport antivenom anywhere. Two exotic-species bites occurred in Michigan this year, and we got the appropriate antivenom to them. But there are no other venom teams in the United States.

In the Michigan case, local medical toxicologists first tried generic antivenom from the Toledo Zoo. The patient's condition continued to worsen because this was not the correct treatment. The toxicologists reached out to the Miami-Dade Venom Response Team (Venom One), the appropriate antivenom was sent, and the patient survived. [3]

Hilton: Do the venom teams respond outside of Florida?

Abo: It all depends. For example, in the Michigan case, we consulted by telephone with the Michigan Poison Control Center. We shipped antivenom with same-day delivery via airlines through existing contracts.

Abo: In another case, we handed off antivenom to American Airlines, which then transferred it to the local Louisiana state police on arrival. Other times, we deliver antivenom by our response trucks, helicopter, or fixed-wing aircraft.

Hilton: Who is eligible to become a member of the venom teams? What training is required?

Abo: Each unit is different. It depends on the post agency (the agency that hosts the team). For Miami-Dade Venom One, started by now Chief Al Cruz, the members were all firefighter paramedics. All were officers and carried venomous reptile licenses for the State of Florida, which certifies that they have spent more than 1000 apprentice-hours handling venomous creatures and that they understand fish and wildlife laws.

Figure 3. Green tree python, nonvenomous.

Venom Two is similar, with members receiving specialized training for handling creatures from the Florida Fish and Wildlife Conservation Commission, and they undergo training on how to deliver education. All receive continuing education on updates to venom care, venomous species, and herpetology. They also receive training on the proper care of domestic species, such as pit vipers, crotalids, and coral snakes—especially eastern coral snakes—and other exotic species.

Hilton: Are the teams trained to handle both wild and pet snakes? And do they capture snakes?

Abo: Teams can handle both wild and pet snakes (Figure 3). All are treated as wild and venomous (or "hot," as we call it), to ensure good habits in snake handling and safety. The teams capture the snakes if needed, especially if the snake is encroaching or is a nuisance on public property and there is a safety concern. Team members also confiscate snakes from individuals who capture them from the wild and are keeping them as unlicensed pets.

Every state has different laws, rules, and regulations regarding the capture or captivity of venomous species. It may go to a snake refuge; they may relocate it, or they may deliver it to the Florida Fish and Wildlife Conservation Commission.

More on Antivenoms

Hilton: What antivenoms do the teams stock? Do the teams carry only antivenom for snakes?

Abo: The venom teams stock antivenom for native and nonnative snake species. Venom One has a bank of over 1500 vials of more than 50 types of antivenoms. These are primarily for human use and cover bites and stings for everything, including spiders, snakes, jellyfish, man-of-war, and even scorpions.

Hilton: Besides the venom teams, who else stocks antivenom?

Abo: We make it easier to get the antivenom you need. Other than from the venom teams (including the Nature Coast Anti-venom Index), people generally don't know where to get antivenom for domestic species.

Antivenom is expensive, so there are not many sources that stock it. Hospital pharmacies rarely stock it because it's expensive and rarely used. If the pharmacies do have antivenom, they don't stock enough doses for the patient. Poison control centers don't stock it.

A single dose of antivenom can range from $3000 per dose to over $14,000. [5,6]

Abo: For exotic species, certain licensed snake keepers may have it. Zoos may stock it, but not necessarily, and the zoo may not share it. First, the zoo has to have the species-specific antivenom you need, and you may not be able to get hold of someone at the zoo during an emergency. Second, the zoo may not be willing to give the antivenom up because it is primarily held for their staff in case one of them is bitten. Third, there are the logistics of transporting the antivenom to the hospital.

Again, the venom teams make it easier to get you the antivenom you need. We had a consult for a patient in Pittsburgh who was bitten by a cobra. The attending physician, who was also a toxicologist, called the Pittsburgh Zoo. That particular zoo didn't have a cobra, and therefore no antivenom. Ultimately, they had to fly antivenom from the Philadelphia Zoo.

Venom teams are up to date on the current availability of antivenoms. Poison control centers, toxicologists, and physicians may not be up to speed on what's on the market. People are under the impression that manufacturers don't make eastern coral snake antivenom anymore, which is not true. Another company now makes it and the new product will be released soon, but I don't foresee release until the current stockpiles of old product gets used up.

Hilton: How many calls do the venom teams get every year? What is the breakdown of snakes versus other animals?

Abo: The venom teams get mostly snake calls, but we see other species, such as Africanized honeybees (Hymenoptera) too. We even had a death in Florida from these bees in the last year.

We see many snakebites and a large number of exotic snake envenomations in Florida, partly because of climate and the presence of hobbyists. In addition, we have the Everglades. It's not all exotic species. We see a variety of domestic venomous species in Florida, in contrast to Texas, California, and Arizona, where most are rattlesnakes.

Roughly 99% of what the venom teams treat is snakebites as opposed to other venomous species. Individuals with bites from jellyfish and black widows usually don't need antivenom, although two individuals did require antivenom in Florida this year. Stonefish and other envenomations are rarer.

Data published online by the Venom One team show that in 2008, they responded to 105 calls for envenomations; the majority were for native species snake envenomations. [7]

The venom teams deliver antivenom for maybe 180 snakebites each year. We are also a major connection for South America and Central America trade and customs enforcement programs.

Hilton: What are some of the most challenging issues you have faced when treating snakebite victims?

Abo: The most challenging and frustrating aspect of this work is dealing with practitioners who lack knowledge and experience in treating patients with snakebites. Also, the status quo.

Back in the day, the treatment for snakebites was harmful, but now we have safer products. For copperheads, many people still say, "Don't treat the bites." True, copperhead envenomations won't kill, but we are trying to prevent not just loss of life but also chronic pain. People undertreat copperhead envenomations frequently.

With eastern coral snakes, we have to treat the bites because some of the effects are permanent. The old myth was that you didn't treat them, and then people were left suffering with disability. We had a child with envenomation by an eastern coral snake. Because of a disagreement with providers who recommended watching and waiting and not treating with antivenom, the child ended up with permanent effects. He couldn't play in recess because of diplopia and dysconjugate gaze. Antivenom is safe when used properly (but it only works if used within first few hours), and the benefits outweigh risks.

Another challenge is that victims, bystanders, and even providers may assume a bite wound is a "dry bite," which leads to delay in recognition of an envenomation and therefore delay in care, with an increased risk for death and disability. Finally, many providers think that there are only two types of venom: hematologic and neurologic. But there is a lot of overlap.

Hilton: What have been some of your greatest successes when treating snakebite victims?

Abo: Recently, we had a hypotensive patient in the intensive care unit (ICU), in shock, on three vasopressors, tachycardic to the 160s, with gross hematuria. He was very sick, and we treated him aggressively with antivenom, which is what you need to do with these patients. He returned to work full-time 1.5 weeks later, with no permanent effects. It's impressive, because his job requires a lot of physical labor.

We also have had some recent cobra bite victims. Their care went really well, and they had great outcomes. They have been in the news recently.[3]

Medical Advice for Physicians and Paramedics

Hilton: How should EMS medical directors direct EMTs and paramedics to handle snakebites?

Abo: Here are my recommendations:

  • Make sure EMS protocols are up to date and not based on myth.

  • Immobilize the injured body part in a nonconstricting way in a position as elevated as possible. For example, if it's a leg injury, raise the foot like you would raise your arm to ask a question in class.

  • Provide adequate analgesia—these are very painful injuries!

  • Providers should mark the leading edge of the wound as soon as possible and then every 10-15 minutes. This refers to the leading edge not of redness or of swelling, but of pain and tenderness.

  • Providers should absolutely stay away from nonsteroidal anti-inflammatory drugs (NSAIDs), tourniquets, and constricting bands. There should be no cutting, sucking, or excising; no use of venom extractor kits or electrical therapy; and no ice. All of these, except NSAIDs, have been proven to cause more damage that is irreversible.

  • No fasciotomies! This is a medical toxin emergency, not a surgical emergency. Between Dr Spencer Green, another snakebite expert, and me, we have treated over 1000 snakebite wounds. We have never needed a fasciotomy when snakebite wounds are treated appropriately.

  • Do not bring the snake, dead or alive, to the hospital! We do not need the snake for identification. Providers can take a picture of the snake, or they can provide a description. It's important that providers remember that even a decapitated head can still envenomate a person.

A brochure published by Miami-Dade Fire Rescue can be helpful when identifying venomous snakes and offers first aid and prevention tips. [8] JAMA Surgery also recently published a clinical review on identifying patients with severe snake envenomation. [9]

Hilton: What advice do you have for an emergency physician in a community ED who sees a patient with a snakebite?

Abo: The emergency physician should contact the local or regional poison control center or a vetted snakebite expert for guidance. The initial first aid care is the same as I mentioned for EMS providers. It is important for physicians to realize that the leading edge of pain and tenderness is the snakebite vital sign. It tells us how quickly things are progressing.

The rate of progression helps determine whether to treat with an antivenom and how much to give. We treat to signs of the injury, not on the basis of a patient's weight or a specific preprescribed dose. In some cases, a child might get more antivenom than an adult would. It all depends on control of the bite and progression of symptoms, especially pain and tenderness. We only have control when we have halted the progression of the local effects, and there are no lab abnormalities (or when labs are trending to normal) and no more systemic effects (eg, syncope, dysrhythmias, and hypercoagulation).

As for initial lab tests, physicians should order a complete blood count, fibrinogen level, and coagulation studies for domestic species or pit vipers. If it's an exotic species, add renal function tests.

If you can't identify the snake species, there is no change to general treatment. Treat bites on the basis of progression of symptoms, not how much venom was injected.

Education and Tips for the Public

Hilton: What advice do you have for communities on bite-wound first aid and prevention?

Abo: Poison control centers and the venom teams offer free education. Follow the first aid care mentioned earlier. It's important to remember that snakes won't hunt you, and they aren't out to hurt you. Humans are bitten when snakes are being defensive. To avoid snakebites, learn about snake habitats and avoid or be careful in these environments. High grasses and crevices are places where snakes are likely to hide. Wear boots when walking in these areas and when picking up debris before or after a storm. Also, look and pry into crevices or storage containers before sticking your hand inside.

Figure 4. Angolan python hiding in a crevice using camouflage.

Remember that snakes can be hard to see and can camouflage well as part of their defense (Figures 4 and 5). In Texas, California, and Arizona, the snakes are primarily rattlesnakes. Pay attention to the rattle. It's a defensive warning device. Stay away!

Figure 5. Python barely visible, hiding in the mud.

In the United States, the population at risk for snakebites is between the ages of 10 and 50 years. There is a peak incidence of snakebites (at > 5 per 100,000 population) for those between the ages of 10 and 14 years. There are twice as many snakebites in men than women. Most bites occur from late spring to fall. [2]

Planning for Environmental Disasters

Hilton: Over the past few years, large areas of the southern United States were devastated by hurricanes. What considerations should healthcare providers and community members have with regard to snakebites during such a disaster?

Abo: Prevention and preparedness are the key for both the public and for such rescuers as the disaster medical assistance teams and urban search and rescue teams (USARs). During the most recent hurricane, Florida Task Force 1 (of which I am a member) was the only USAR team that had antivenom. The only other disaster teams that have antivenom are the state teams in Texas, because they require it for treatment of their team dogs. Other teams need to know how to request resources and where to turn if they are treating snakebite victims.

Prevention really is the most important issue for the rescuers and for the public. Avoiding the bite in the first place is better than trying to treat it afterward. If you see a snake or if it has bitten someone, don't hunt or kill the snake, because that puts you at risk of getting bitten.

Snakebite envenomation rates increase before and after storms. After storms, snakes get flooded out of their homes. They follow food sources, such as rodents, that may flee flooded areas, heading to drier land. Snakes are usually hiding in places under debris. During the recovery from the storm, as people clear the debris, it puts them at risk for snakebites if they aren't careful. Before storms, snakebites occur because we humans are in their areas. As we prepare for storms, we walk and reach into places we usually don't, places that snakes have made their homes. Snakes are being defensive as we are encroaching, and that's when they bite.

Hilton: Any final advice, comments, or interesting anecdotes you would like to share?

Abo: What we have been talking about is envenomation care in the United States. We are lucky, because most people don't die of snakebites in our country, but many are left with permanent pain and disability.

For the public, avoid snakebites if possible. If you have a bite wound, don't assume it's a dry bite. Immobilize without constriction, elevate, and call for help. Don't try to capture the snake. Don't handle the snake, dead or alive. Don't bring the snake to the hospital or into the ambulance.

Remember, even a dead snake can still envenom you. We had a beloved fire marshal who died when he was handling a dead snake. There was also a case covered in the New York Times recently of a man in Texas who picked up the head of a snake that had been cut off a day earlier, and he ended up in the ICU and nearly died because of the effects of envenomation.[10]

The number of snakebites in the Americas ranges from 0.28 per 100,000 inhabitants in Canada to 55 snakebites per 100,000 inhabitants in Panama. In the United States, there are 1.5 snakebites per 100,000 population, which is about 5000 snakebites per year. Except for the United States and Canada, all other countries have greater than 3 snakebites per 100,000 inhabitants. Deaths from snakebites range from 0 per 100,000 inhabitants in Canada to 0.63 per 100,000 inhabitants in French Guiana. There is 0.002 death per 100,000 inhabitants in the United States or about 5 deaths per year. [2]

For healthcare providers, the pain and disability that are the sequelae of snake envenomations could potentially be avoided with earlier, more aggressive antivenom treatment. Call your poison control center. They can get in touch with a venom team.

Again, in the United States, people don't usually die of snakebite envenomation, but in other countries people do die. There are more deaths in other countries because of lack of access to care after bite wounds and because of lack of access to antivenom once care is initiated. Because of this, I've helped found the Asclepius Snake Bite Foundation with other snakebite experts to reverse the cycle of poor snakebite outcomes and create a snakebite chain of survival.

For more information about the Venom Teams or snakebite management, contact the Miami-Dade Fire Rescue Public Information Officer (305-814-8051) or Lake County Fire Rescue (352-343-9458). You may also visit the Miami-Dade Venom Response Program website. [11]

Miami-Dade Fire Rescue offers additional information on snakebite treatment and prevention. [12] Lastly, the Centers for Disease Control provides information about venomous snakes. [13]

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