Jeff:  Welcome back to Emplify, the podcast corollary to EB Medicine’s Emergency Medicine Practice. I’m Jeff Nusbaum, and I’m back with my co-host, Nachi Gupta and we’ll be taking you through the September 2018 issue of Emergency Medicine Practice - Emergency Department Management of North American Snake envenomations.
Nachi: Although this isn’t something we encountered too frequently – it does seem like I’ve been hearing more about snake bites in the recent months.
Jeff: I actually flew someone just the other day because the local ED ran out of CroFab after an envenomation in Western PA.
Nachi: Yeah, this is definitely more than “just a boards topic,” and it’s really important to know about in those rare circumstances. In terms of incidence, there are actually about 10,000 ED visits in the US for snake bites each year, and 1/3 of these involve venomous species.

Jeff:  That’s a good teaser, so let’s start by recognizing this month’s team – the two authors, Dr. Sheikh, a medical toxicologist, and Patrick Leffers, a pharmD, and emergency medicine and clinical toxicology fellow. Both are at the University of Florida Jacksonville, and they reviewed a total of 120 articles from 2006-2017, in addition to reviews from both Cochrane and Dare.

Nachi: And don’t forget our peer reviewers this month, Dr. Daniel Sessions, a medical toxicologist working at the South Texas Poison Center, and our very own editor-in-chief, Dr. Andy Jagoda, who is also Chair of the Department of Emergency Medicine at Mount Sinai in New York City.

Jeff: What a team! But, let’s get back to the snakes. As some background, from 2006-2015 there were almost 66,000 reported snake exposures and 31 deaths from snake envenomation in the US.  Of course, this number likely underestimates the true total.

Nachi: And there are two key subfamilies of venomous snakes to be aware of – the Crotalinae – or pit vipers – which includes rattlesnakes, copperheads, and water moccasins; and the Elapidae – of which you really only need to know about the coral snake.

Jeff:  And while those are the only two NATIVE snake subfamilies to be acutely aware of, don’t forget that exotic snakes, which are shockingly popular pets -- they can also cause significant morbidity and mortality.

Nachi:  Oh, and one other quick note before we get into the epidemiology – most of the recommendations this month come from expert opinion, as high quality RCTs are obviously difficult.  In addition, many of the studies were based in other countries, where the snakes, the anti-venoms and their availability, and the general healthcare systems are different from those that most of us work in.

Jeff:  Unless we have listeners abroad? Do we have listeners in other countries?

Nachi: Oh we definitely do... but we are going to be a bit biased towards US envenomation today. In any case, venomous snake bites occur most frequently in men aged 18 to 49 during warmer months with provoked bites occurring more frequently in the upper extremities and unprovoked bites in the lower extremities.

Jeff:  In one study of poison center data from the last decade, nearly half of all victims of snake bites were victims of unknown type snakes.  However, of those that were known, copperheads were the most common, while rattlesnakes caused the most fatalities – 19 of 31 in this dataset.

Nachi:  In a separate study of snake bites in the early 2000s, 32% of exposures were from venomous snakes and 59% of those resulted in admission. That’s remarkably high.

Jeff:  Snake bite severity depends on several key factors: the amount of venom, the composition of the venom, the body size of the bite victim, the victim's clothing, the size of the bite, comorbid conditions, and the timing and quality of medical care the victim receives.

Nachi:  To be a bit more specific - First, the amount of venom will depend on the species of snake, with variations even occurring within the same species.  Secondly, while there is a correlation between rattlesn