toxinologist
Active Member
Hi all,
First of all, if you don't know where the nearest supply of antivenom is, let alone what the appropriate antivenoms are for the types of snakes you are keeping - you should not have venomous snakes in the first place!
Second, there is no shortage of antivenom in Australia. CSL produces more than enough to meet the needs of Australian snakebite patients, as well as producing an excess for use here in Papua New Guinea. The reality is that many hospitals do not themselves maintain large stocks - simply because snakebite in Australia is a rare event, and other hospitals can and do make available additional stock if it is needed in a emergency.
Third, the practice of administering large amounts of antivenom to patients in Australia is not based on clinical evidence, but rather on the perceptions and misconceptions that many Australian physicians have about the actual role of antivenom. Commonly patients treated for brown snake envenoming may receive anywhere from 1-40 vials of antivenom - typically with the clinical objective of reversing coagulopathy and restoring haemostasis. The reality is that while the antivenom binds the venom toxins it does not restore haemostasis by itself, and having reviewed the available literature my view is many doctors keep administering large volumes of antivenom quite unnecessarily in the mistaken belief that it will bring about a miraculous restoration of normal haemostatic values. It does not do this. After venom is bound by antivenom and neutralised it may take the body upwards of 6-10 hours to replace depleted coagulation factors via normal pathways - giving more antivenom will not speed up this process - and frankly in the absence of high quality clinical evidence to demonstrate otherwise, giving repeated vials of antivenom is both unnecessary and inefficacious in terms of result being sought.
Fourth, the concept that antivenom should be withheld from any person with systemic envenoming is completely and utterly wrong. It's an idea that belongs to the 1960's. Australia's antivenoms are very safe by global standards. The adverse reaction rate for monovalent antivenoms is around 8-9%, and in Australia, these reactions can be very well managed by the vast majority of hospitals. Likewise this idea that antivenom can only be given four times is just simple fiction! Just ask some of the herpers on this list who have snakebite histories longer than their snakes themselves ...
Fifth, antivenom does not stay in the body for life. Just like other substances in the blood stream it is both metabolised and/or excreted via the kidneys. We are currently running a prospective study here in PNG to determine what the venom and antivenom concentrations in the circulation are over the time from bite to patient discharge, so I will be able to report the definitive timepoints later in the year when the study concludes.
Sixth, Sadji what would you know about Mark O'Shea and how genuine he might or might not be? I suspect the green-eyed monster lurks ... Mark has been a personal friend and colleague of mine for more than a decade and I can tell you quite emphatically that he is 1000% genuine herper through and through. Unless you know him personally I suggest you keep your opinions to yourself. He is neither false, nor a showoff. And in television ego is a definite advantage. As for the show where he deferred riding on horseback - 99.9% of the other people in this world who are allergic to equine proteins would probably do the same - for very good reason - anaphylaxis can be rapidly fatal.
Last, repeated antivenom does not confer immunity to snake venom. Repeated exposure to snake venom itself however may well confer transient immunity while the person continues to expose themselves to the immunogen. For those interested in the topic, there is a great paper by Dr Saul Werner from CSL - published in the 1960's and based on experiments undertaken to immunise the late Charlie Tanner with tiger snake venom.
Tasol nau, lukim yu man n meri
David
First of all, if you don't know where the nearest supply of antivenom is, let alone what the appropriate antivenoms are for the types of snakes you are keeping - you should not have venomous snakes in the first place!
Second, there is no shortage of antivenom in Australia. CSL produces more than enough to meet the needs of Australian snakebite patients, as well as producing an excess for use here in Papua New Guinea. The reality is that many hospitals do not themselves maintain large stocks - simply because snakebite in Australia is a rare event, and other hospitals can and do make available additional stock if it is needed in a emergency.
Third, the practice of administering large amounts of antivenom to patients in Australia is not based on clinical evidence, but rather on the perceptions and misconceptions that many Australian physicians have about the actual role of antivenom. Commonly patients treated for brown snake envenoming may receive anywhere from 1-40 vials of antivenom - typically with the clinical objective of reversing coagulopathy and restoring haemostasis. The reality is that while the antivenom binds the venom toxins it does not restore haemostasis by itself, and having reviewed the available literature my view is many doctors keep administering large volumes of antivenom quite unnecessarily in the mistaken belief that it will bring about a miraculous restoration of normal haemostatic values. It does not do this. After venom is bound by antivenom and neutralised it may take the body upwards of 6-10 hours to replace depleted coagulation factors via normal pathways - giving more antivenom will not speed up this process - and frankly in the absence of high quality clinical evidence to demonstrate otherwise, giving repeated vials of antivenom is both unnecessary and inefficacious in terms of result being sought.
Fourth, the concept that antivenom should be withheld from any person with systemic envenoming is completely and utterly wrong. It's an idea that belongs to the 1960's. Australia's antivenoms are very safe by global standards. The adverse reaction rate for monovalent antivenoms is around 8-9%, and in Australia, these reactions can be very well managed by the vast majority of hospitals. Likewise this idea that antivenom can only be given four times is just simple fiction! Just ask some of the herpers on this list who have snakebite histories longer than their snakes themselves ...
Fifth, antivenom does not stay in the body for life. Just like other substances in the blood stream it is both metabolised and/or excreted via the kidneys. We are currently running a prospective study here in PNG to determine what the venom and antivenom concentrations in the circulation are over the time from bite to patient discharge, so I will be able to report the definitive timepoints later in the year when the study concludes.
Sixth, Sadji what would you know about Mark O'Shea and how genuine he might or might not be? I suspect the green-eyed monster lurks ... Mark has been a personal friend and colleague of mine for more than a decade and I can tell you quite emphatically that he is 1000% genuine herper through and through. Unless you know him personally I suggest you keep your opinions to yourself. He is neither false, nor a showoff. And in television ego is a definite advantage. As for the show where he deferred riding on horseback - 99.9% of the other people in this world who are allergic to equine proteins would probably do the same - for very good reason - anaphylaxis can be rapidly fatal.
Last, repeated antivenom does not confer immunity to snake venom. Repeated exposure to snake venom itself however may well confer transient immunity while the person continues to expose themselves to the immunogen. For those interested in the topic, there is a great paper by Dr Saul Werner from CSL - published in the 1960's and based on experiments undertaken to immunise the late Charlie Tanner with tiger snake venom.
Tasol nau, lukim yu man n meri
David
