a. Types of Venom. Snake venoms contain a very complicated mixture of
different substances that are toxic to many cells and tissues of the body. Most venoms
are either primarily neurotoxic (poisonous to the nervous system), such as the venom of
the coral snake; hemotoxic (poisonous to the circulatory system), such as the venom of
the rattlesnake, or a combination of the two.
b. Snake Venom Functions. The snake subdues its prey primarily by toxic
peptides. The snake digests its prey using approximately 26 different toxic enzymes,
although no single venom contains all of these. These enzymes develop the majority of
the signs and symptoms of snakebites.
c. Hemotoxic Venom Signs and Symptoms. There is no venom injected in
some 20 percent of snakebites involving poisonous snakes. When it is injected, there is
usually a rapid, voluminous swelling at the site of the bite and it is so severe that it may
spontaneously burst the skin. The victim usually has a rapid onset of excruciating and
burning pain and exhibits stimulation followed by depression rapidly. The anticoagulant
component of venom causes blood to appear in the urine or stool, bleeding from the
lips, gums, nails and oozing at the site of the bite. The puncture may become
discolored (erythema, ecchymosis), followed by necrosis and the snakebite victim may
go into shock.
d. Neurotoxic Venom Signs and Symptoms (Affects the Central Nervous
System). In this case, there is little or no pain at the site of the bite, and very little or no
swelling (i.e., from the coral snakebite). The victim suffers vertigo, blurred vision or
blindness, and paresthesia (numbness) in the area of the bite, and around the mouth
and throat. He has difficulty in hearing, increased salivation, slurred speech, and
respiratory arrest. Of course, respiratory distress may be exhibited in all poisonous
snakebites but the primary danger is with neurotoxic venom. Additionally, the victim
may suffer GI disorders (violent abdominal pain) and convulsions.
OBJECTIVES OF SNAKEBITE FIRST AID
First aid is administered to reduce the circulation of blood through the bitten area,
to delay absorption of the venom, to prevent aggravation of the local wound, and to