Antivenom for python bites?

[saratoga]

Interesting article that highlights the fact that Venom Detection Kits (VDKs) should only be used to determine what type of antivenom should be used to treat a snake bite , and the antivenom should only be used where symptoms of envenomation are clearly evident.

Python venom traces could waste antivenom - UQ News Online - The University of Queensland

 

[Firepac]

If the doctors follow the correct protocols this should never happen, but it is not unknown for AV to be given to asymptomatic patients. Complicating things a bit are various symptoms of physical and mental shock that can be induced by a snake bite especially where the person doesn't know what bit him can be very similar to genuine symptoms of envenomation.

 

[OzGecko]

Funny you should bring this up. I work in a diagnostic laboratory and have long wondered whether pythons would give a false positive. My reasoning for this was we all know how much even the smallest python bite bleeds. I wondered if there may have been something in the saliva causing that. I actually wanted to do some work on it, but a colleague in haemostasis who has done a lot of work on snake bite victims told me he didn't believe the kits would cross react. I'd like to show him this link.

 

[Brodie]

Ozgecko, BGF did the work a few years ago. He famously concluded colubrids are venomous, he performed the same tests on pythons, nadda.

I don't trust SVDKs. When I was bitten by a tiger, the SVDK came up as a black snake. The Drs at the hospital did not believe me, I was lucky to know a few pro herpers who backed up my ID so that I was given the correct AV. I can still remember hearing BGF screaming so loud while he was on the phone to the Dr. that I could hear it from a few metres away.

Can't keep anything requiring tiger snake AV in NT. You have me to thank for that folks, lol.

 

[OzGecko]

Thanks Brodie. This wasn't something that just popped up, I've been wondering this for quite a while now.

Don't get me wrong, the kits have flaws. Unfortunately a lot of doctors use them first rather than managing the patients. Here in SA, you're not likely to see a python let alone get bitten by one. I had a bag that was mauled by a black tiger, gave it to haemostasis to tell me what had done it, their response "I hope it was a death adder"

 

[Firepac]

Snake Venom Detection Kits are the most reliable method of determing which of the 6 main types of antivenom is most effective for a particular bite. Note that it does NOT identify which snake a person was bitten by only which immunotype the snake belongs to. Having said that as far as I know a Tiger Snake bite should indicate Tiger Snake AV.

 

[Brodie]

Hoplocephalus have also shown up as black snake when tiger AV should be used. I guess that's a bit different notechis showing up as pseudechis though.

 

[Paintbrushturkey]

Hoplocephalus have also shown up as black snake when tiger AV should be used. I guess that's a bit different notechis showing up as pseudechis though.

It's Aspidites melanocephalus (Black headed python) that shows up as tigersnake ;-). The reason for this is that A. melanocephalus secretes both C-type lectins (cytotoxins) as well as 3-Finger toxins (neurotoxins) which are detected by the SVDK as Tigersnake venom, however the actual quantities are microscopic, are only detectable using methods such as LC MS-MS (Liquid chromatography followd by mass spectrometry), and as such show no physiological effects. SVDKs generally are specific for the antivenom used, and to my knowledge there is no case of a SVDK falsely indicating Brownsnake AV for a Tigersnakebite, especially as the two venom profiles are distinctly different, see here: CSL Antivenom Handbook - Snake Venom Detection Kit. administration of antivenom is also highly unlikely if there are no systemic effects ;-)

 

[snakehandler]

As Bryan himself has said, this is not evidence of venom, simply the relics of venom:
"Bryan Grieg Fry:As is very apparent, we have been very careful to avoid any sensationalism regarding pythons having 'venom'. We have made it crystal clear we are talking about relics here that are not only very cool from an evolutionary perspective, but also quite important in regards to the potential for false positives in the venom detection kit and possibly as sources of novel molecules for use in drug design and development."

I have had a number of reports during my visits to remote area where false positives have occurred! This is directly from the hospitals that we visit!


Sent from my iPad using Tapatalk HD

 

[Tsubakai]

One of my pet annoyances is mistreatment of snake bites by people who don't understand. Its a fairly simple concept however some doctors panic through lack of understanding and misinterpret the role of SVDK and the results obtained.

In response to a couple of the posters, the SVDK does not identify the snake that bit you - it identifies the best antivenom to use to reverse a patient's envenomation syndrome so it is not impossible to get a result that is different to the family of the snake that caused the envenomation. Its a subtle difference but an important but is also dependent on properly administering the SVDK in the first place.

 

[Firepac]

One of my pet annoyances is mistreatment of snake bites by people who don't understand. Its a fairly simple concept however some doctors panic through lack of understanding and misinterpret the role of SVDK and the results obtained.

In response to a couple of the posters, the SVDK does not identify the snake that bit you - it identifies the best antivenom to use to reverse a patient's envenomation syndrome so it is not impossible to get a result that is different to the family of the snake that caused the envenomation. Its a subtle difference but an important but is also dependent on properly administering the SVDK in the first place.

Totally agree. One of the problems as I see it is that in 2009 there were close to 28,000 primary care practitioners in australia and given that there are only around 300 snake bites per year that require treatment with antivenom, it is easy to see that there are not many doctors who have treated a snake bite victim let alone treated them correctly. This is one reason why, when I get a callout for a relocation, I always carry a laminated card with the current medical treatment in medical terms with me, so in the event i get envenomated the card can be given to the doctors.