Envenimation

A envenimation is the absorption of a poisonous substance in the organization by inoculation. One distinguishes two types of inoculations:

By inoculating apparatus - a dart, a poisonous hook, a bite are modes of inoculation per inoculating apparatus:

the dart is used by the hyménoptères, scorpionidés, certain poisonous fish, the monotrèmes (Ornithorynque, échidés), the jellyfish S and some corals, sponge S, Anémone S…
the hooks are used by the Serpent S, the Araignée S, some Myriapode S…
the bite is used inter alia by octopuses of the kind Octopus.

By contact:

Certains trees is poisonous because the contact with their Sève causes irritations.
the Amphibien S are poisonous, a contact with the venom delivered by their parietal glands can cause a envenimation. however, in practice, even the Dendrobate S which are the most poisonous Amphibians for the man cause only benign envenimations by contact which can be avoided by washing the hands after a handling. They will then be considered poisonous for the man only in the event of ingestion of the batrachotoxine, which can cause mortals effects.

Principal symptoms met at the time of a envenimation:

The Venin is a true cocktail of active molecules, it would be illusory to believe that a poisonous species has a single effect which is clean for him. The result of a envenimation is the result of the action of this molecular cocktail to the sometimes contradictory effects (a molecule will have anticoagulant properties whereas another has coagulating properties). For as much, it is not rare to note a dominating effect which will be sometimes the only one to put the vital diagnosis concerned. It is often the case of the Neurotoxine S which, in addition to their action faster than other toxins, can be in quasi exclusiveness present in venom (such as for example at the Mamba). The best treatment against a envenimation bringing into play the vital prognosis is, of not to doubt, the immunothérapie (in the past called serotherapy). However, a symptomatic treatment adapted to the Pathologie also makes it possible to increase the chances of survival.

Neurotoxic symptom

This symptom is due to the absorption of Protéine S of molecular weight weak acting directly on the transfer of the nerve impulse to the level of the synapses. It can be compared with an intoxication with the Curare. However, it is not treated in the same way because, if the effects are the same ones, each toxin will have a particular operating process. It has as a result a flask paralysis of the Muscle S volunteers, the muscles which one can control (the biceps or the diaphragm is voluntary muscles because one can control the movements of his arm just as its breathing, the Cœur and the Sphincter S are not because one cannot control them). The neurotoxic symptom appears rather quickly, sometimes in the minutes which follow the envenimation. It appears by a lassitude, difficulties of being expressed, then to swallow, eyelids heavy, sometimes nauseas and is quickly followed breathing difficulties. The victim remains conscious until the respiratory stop which will quickly be followed of a fainding by Asphyxie, then by death. No vital function other that breathing does not seem to be touched by toxins responsible for this kind of symptom. This is why, any victim presenting this kind of symptom will be subjected to the artificial respiration thanks to a respirator which will have to be disconnected under no pretext. Victims of dendrosapis polylepis (black Mamba) presenting an allergy to the serum were saved after more than one month in the coma under artificial respiration, and this, without serious after-effects.

According to the work carried out by the IRD:

Symptom hemotoxic

This symptom is due to the absorption of proteins of high molecular weight and Enzyme S known as “haemolytic”, mainly of thrombins. It is characterized by a dysfunction of the factors of coagulation. it is observed in a way more or less marked in all the envenimations, with the result that an analysis of the sedimentation of a blood sample in a dry tube is a relatively reliable indicator of the severity of a envenimation, but especially of its evolution. In the case of the envenimations by Vipéridé S, for which this symptom is more problematic, antagonistic effects are often observed. Generally, there is suractivation of thrombosis, which results in:

the creation of Thrombus (clots) which can cause a Embolism.
the consumption of all the factors of coagulation involving a Hemophilia.

The hemophilia which results from the consumption of the factors of coagulation is one of the antagonistic effects being able to failing this put a expert not informed of this phenomenon. Nicole Viloteau was thus saved of a bite of Crotale thanks to strong amounts of Héparine, an anticoagulant. It presented already symptoms of hemophilia but the anticoagulants are rigorously proscribed in the event of hemophilia. Its doctor however persevered in this way, which made it possible to avoid the formation of clot and the associated risk of embolism.

Symptom myotoxic

This symptom is due to the absorption of proteins of high molecular weight and enzymes known as “proteolytic” supporting the degradation of proteins of fabrics and called proteases. These toxins will have local effects being able to go from the simple irritation to the Nécrose of the member, necroses it being able to in the case of reach the bone bite by some hydrophidés.

The fabrics in contact with these toxins will be degraded quickly, with the result that the envenimations involving this symptom can easily gangréner by Surinfection. This intoxication often involves after-effects and, if it does not put concerned the immediate vital prognosis, it should not be neglected for as much because it can involve a very delicate clinical picture then to treat.

Others

In addition to these effects, one can also note the following symptoms:

Reaction allergic, certain venoms contain Histamine or histamino-liberators. That results in edema S on the level of the seat of the bite, to see anaphylactic shocks.
Symptom cardiotoxic, destabilizing the Cardiac rhythm.
Symptom nephrotoxic, leading to a renal blocking , it can be due to the attempt of the body to get rid of toxins thanks to the filters which are the kidneys. The latter, too requested and weakened by a poor general state can then be destroyed definitively, or at least not to more ensure their role of filter the moment when the body needs some precisely.

First aid

The recommendations concerning first aid in the event of bite of snake change, partly because the various snakes have various types of venom.

Some have little local effect, others of the systemic effects representing a vital danger. In this last case, to contain venom in the area of the bite (for example, by immobilization by a pressure, the use of a Not of compression, etc) is strongly desirable. Other venoms create localized fabric damage around the bitten sector, and the immobilization can increase the severity of the damage in this sector, although it also reduces affected entire surface. These various points remain prone to polemic. Since the snakes change from one country to another, the methods of first aid also change; the methods of treatment adapted to the bites of rattlesnakes with the the United States could be mortals if steady to a bite of tiger snake, in Australia.

This article does not replace the legitimate professional medical councils. The readers are strongly invited to asresser with the organizations known of first aid in their own area, and to take guard with the remedies of the vintage or anecdotic.

What it is necessary to do

To immobilize the victim, to put it at ease, to reassure it. The sitting position or lengthened seem the best.
To protect the patient (and others, there-included/understood yourself) against from other bites. While the identification of the species is desirable, not to risk other bites or not to delay the suitable medical care while trying to capture or kill the snake. If the snake did not already run away itself, it would be desirable to move the patient, without it moving by its own means, out of the sector where the snake is.
To calm the patient and to ask of the assistance, for example using the cell phone or satellite in order to obtain transport, as soon as possible, from the patient towards the hospital nearest, hospital where the antivenom one for the snakes common to the sector will be often available.
To take care to keep the member bitten in a functional position and below the level of the heart of the victim in order to reduce the flow of blood turning over in the middle and to other bodies of the body.
To remove all clothing or objects which can tighten the bitten member if it inflates (bracelet, watch, shoe, etc)
Garder always the patient as much as possible motionless, with half lengthened, the head and the top of the body (in particular the heart) above the remainder of the body (the back and the head fixed to the top, with clothing, a backpack, cushions).
To clean the wound with water or the soap. Not to use alcohol, nor of Disinfecting coloured.
the Australian first-aid workers recommend to bandage the member reached (often an arm or a leg) with an elastic band on the basis of the end at the base of the member. This binding should never block blood circulation, but only lymphatic circulation which is very often the only network reached by the bite (the bite of a Veine or a Artère is very rare). In this case, it is imperative not to withdraw binding as long as the victim is not dealt with by medical team. According to Doctor Xavier Maniguet, in addition to one total immobilization of the patient, to avoid the diffusion of blood (to even decrease the toxic effect of venom), the body of the victim can be semi-immersed in water fraiche of a river while waiting for the helps.

What one does not need Faire

not to incise the bitten site. Many organizations, including American medical association and the American Red Cross, recommend to wash the bite with water and soap. However, not to try to clean the sector with chemicals, some is the type.
not to give to the patient something to eat or drink. It is particularly important with alcohol, a known vasodilatator which accelerates the absorption of venom. It was proven that alcohol fixes venom on the nervous system, making the Neurotoxine S much more effective. Not to manage stimulants or Antalgic S with the victim, unless that is not prescribed by a doctor. One will be able to possibly propose water with the patient, if this last does not present central nervous system disorders which could make it swallow through and complicate a respiratory distress.
As proteins of toxins of venoms are in general destroyed by heat, some recommend, immediately after bite (in the seconds which follow), the application of a heat sudden and intense on the bite, obtained for example by an electric shock created, on the place of the bite, by the application of two cables connected to the poles of a battery of car, by a cigarette, a red iron, etc These practices are not of any medical interest, and, apart from the possible comfort that they will be able to bring to the persuaded victim stressed that these practices as useless as heroic represent its only safety, will not have for consequences that local complications due to the infections which will result from it.
the administration of poisonous anti serum apart from a sufficient structure of care lends to polemic. Indeed, 50% of the bites of poisonous snakes are “white”, i.e. without inoculation of venom. In spite of progress as well in term of spectrum of species concerned with the same serum as in terms of purification of the serum which will reduce the risks of reaction, the best route of administration of a serum is the slow Intraveineuse (or Perfusion), almost impassable operation in situation of survival. in all the cases, it is essential to consult a doctor accustomed to this kind of treatment (center anti poison, specialized local doctor) before planning to carry some with oneself.
aspi-venom and other pumps with venom are of a notorious technical inefficiency. However, their side effects are less devastators than those described above, dependant on the heat or to the débridage of the wound. This apparatus can be used to reassure and calm the victim.
the stones has snakes, preparations parapharmaceutic in all kinds and others grigris are to be forgotten, their use sometimes being able to involve complications.

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