Distribution—Known throughout most of the state except the extreme eastern part, it may be expected in many more counties from which records of its occurrence have not yet been received. It is definitely known in these counties: Andrews, Aransas, Archer, Armstrong, Atascosa, Bandera, Bastrop, Baylor, Bee, Bell, Bexar, Blanco, Borden, Bosque, Brazoria, Brazos, Brewster, Briscoe, Brooks, Brown, Burnet, Caldwell, Calhoun, Cameron, Clay, Coke, Comal, Comanche, Concho, Coryell, Cottle, Crockett, Crosby, Culberson, Dallam, Dallas, Dawson, Deaf Smith, DeWitt, Dickens, Dimmit, Donley, Duval, Eastland, Ector, Edwards, El Paso, Erath, Fisher, Foard, Frio, Galveston, Garza, Gillespie, Goliad, Gonzales, Guadalupe, Hardeman, Harris, Hartley, Hays, Hidalgo, Howard, Hudspeth, Hutchinson, Irion, Jack, Jackson, Jeff Davis, Jim Hogg, Jim Wells, Karnes, Kendall, Kenedy, Kent, Kerr, Kimble, King, Kinney, Kleberg, Knox, Lampasas, La Salle, Lavaca, Limestone, Live Oak, Llano, Lubbock, Lynn, Martin, Mason, Matagorda, Maverick, McCulloch, McLennan, McMullen, Medina, Midland, Milam, Mills, Mitchell, Moore, Motley, Nolan, Nueces, Oldham, Palo Pinto, Pecos, Porter, Presidio, Randall, Real, Reeves, Refugio, San Patricio, Scurry, Shackelford, Somervell, Starr, Sterling, Stevens, Tarrant, Taylor, Terrell, Throckmorton, Tom Green, Travis, Uvalde, Val Verde, Victoria, Ward, Webb, Wells, Wilbarger, Willacy, Williamson, Wilson, Winkler, Wise, Wichita, Young, Zapata, and Zavala.
This is the most dangerous and, at the same time, the most common poisonous snake in the state. Therefore, it is one which all Texas outdoorsmen should be able to recognize on sight. A summary of snake bite cases in the United States over a 10-year period shows that more people died from bites of this species than from bites of any other North American snake. There are several reasons why this snake is responsible for so many bites and such a high number of deaths. Chief among these is its large size. It ranks as one of the two largest poisonous snakes in the country, being second only to the eight-foot eastern diamondback rattlesnake of the southeastern states. In direct proportion to its size, it has long fangs and poison glands which hold a great amount of venom. These factors insure a long strike and deep fang penetration. In addition, it has an unusually furious disposition and, if threatened with danger or sufficiently annoyed, will vigorously defend itself instead of seeking immediate escape.
Although strictly a land snake, the diamondback may sometimes be found crossing streams or ponds and, occasionally, individuals will venture out into lakes and bays.
Description—This snake is much like the larger canebrake rattler but lacks the dark stripe from the eye to the back of the mouth, and generally is without the reddish-brown stripe down the middle of its back. Dark brown chevron shaped crossbands contrast with the general body color of yellowish tan. In some specimens black stippling occurs between the markings. Both black and light color phases of this snake are found in some parts of its range. It is unknown whether the dark specimens occur in Texas. The tail is marked with three or four dark bands on the lighter specimens but is altogether black on the darker ones.
Size—Throughout its range this snake has an average length of from three and a half to four feet, but a specimen six feet long is on record.
Young—The number in a brood varies from three to 12. Length of the newborn is eight or nine inches.
Distribution—The timber rattlesnake prefers rocky hills and mountains that are not too heavily wooded, but it sometimes inhabits bogs and swamps at lower elevations. In either situation, it seldom survives for long in areas heavily populated by man. In common with most other rattlesnakes, it seeks escape when approached by man and fights only when surprised or cornered. Known in northeastern Texas, it is reported from Cooke, Denton, Eastland, Grayson, Lamar, Red River, Taylor, and Wise Counties.
Like the prairie rattler, it often seeks the same denning areas year after year and congregates in numbers to hibernate for the winter.
Description—This is a large and heavily built snake with a brown or tan back marked by a series of wide, dark, chevron shaped crossbands. It may be distinguished from the similar timber rattlesnake by its larger size, its more vivid markings, and the presence of a dark stripe from the eye to the angle of its mouth. Generally, a narrow, reddish-brown stripe extends down the middle of the back. Its tail, as in some other rattlesnakes, is entirely black.
Size—In Texas this snake reaches a length of about six feet, while in nearby Louisiana exceptionally large specimens, some nearly seven feet long, have been found. Length averages four and a half feet.
Young—About eight or ten are born in a brood.
Distribution—This species prefers wooded areas in wet bottomlands. It has been found in the following counties: Austin, Bexar, Bosque, Bowie, Brazoria, Brazos, Cass, Cooke, Coryell, Dallas, Denton, Eastland, Ellis, Falls, Fayette, Freestone, Gonzales, Grayson, Hardin, Harris, Henderson, Jasper, Jefferson, Liberty, Madison, McLennan, Navarro, Robertson, San Jacinto, San Patricio, Taylor, Victoria, Waller, Williamson, and Wise.
Description—This snake is very similar to the mottled rock rattlesnake, with which it might be confused, but from which it differs by having a more mottled appearance between the crossbands and a dark stripe from the eye to the angle of the mouth. It has a pattern of about 18 or 20 widely spaced dark crossbands with irregular edges in contrast to its gray body color. Belly color varies from cream to pink.
In the Chisos Mountains, where there is much reddish igneous rock, the normal color of this snake is pinkish; the variety has been given the name of “pink rattler” by people of that region. Specimens from the limestone ledges along the Pecos Canyon at Howard Creek and Sheffield are very light in color, resembling the limestone rock on which they are found.
Size—This is one of our smallest rattlesnakes, having an average length of two feet. The rattle is rather large in proportion to the small size of the snake.
Young—About four are born in a brood and they measure about seven and a half inches at birth.
Distribution—This form is restricted to the mountainous areas of the western and southwestern parts of the state; it has been found in the following counties: Brewster, Culberson, Edwards, Jeff Davis, Maverick, Pecos, Presidio, Real, Terrell, and Val Verde.
Because of its small size and distribution restricted to rocky places at high elevations, the banded rock rattlesnake cannot be considered a serious menace to man. Apparently there is no record of anyone ever having been bitten by this snake. It has a quiet disposition and, if alarmed, will immediately retreat within the masses of jumbled rock which are its home.
Description—This species and the banded rock rattlesnake look much alike. Both are small and slender, and marked with a series of widely-spaced dark crossbands along the length of the body and tail. The banded rock rattlesnake, however, has about 20 or 22 dark brown or black crossbands, which contrast strongly with its greenish-gray body color. It further differs from the banded rock rattlesnake in lacking a dark stripe from the eye to the angle of its mouth.
Size—Adults average two feet in length.
Young—A record of one brood is the only known published information concerning the young of this snake. Carl F. Kauffeld of the Staten Island Zoo mentioned a litter of four and wrote:
All were irritable from the first, promptly broke through the membranous sacs in which they were enclosed and struck violently at any passing object. All were marked and colored much like the adults except that the delicate pink along the venter of the latter was not in evidence; and the tails, which in the adults are salmon or terra cotta red (including the basal segment of the rattle) were brilliantly sulphur yellow for at least their distal half....
The newborn snakes measured about eight inches in length.
Distribution—This subspecies is found in much the same type of country as the banded rock rattlesnake, being partial to rock slides high in the mountains. The two counties in the state in which it is known, El Paso and Culberson, are both in extreme western Texas. In disposition it is said to be quite timid; however, at times, it becomes irritable without much provocation.
Description—There are about 32 dark rhomboid markings along the back. These light edged blotches are centered with one or two irregular light areas, while the outer edges form bars which extend down each side to the belly. Body color varies from gray to olive green, while the blotches are dark brown or black. The tail is uniformly black, as its name implies.
Size—The blacktailed rattlesnake is one of our largest poisonous snakes. Texas specimens average three and a half feet but may grow somewhat longer. One, nearly 50 inches long, was collected at Persimmon Gap in Brewster County.
Young—About five young comprise the average brood.
Distribution—Records are available from the following counties: Bandera, Bexar, Brewster, Burnet, Comal, Culberson, Edwards, El Paso, Hudspeth, Jeff Davis, Kendall, Kerr, Kimble, Medina, Pecos, Presidio, Real, San Saba, Terrell, Travis, Upton, and Val Verde.
Hilly areas with steep canyons are the preferred habitat of this snake. In the Big Bend region of Texas, where apparently it is the most common rattlesnake, specimens have been taken from as high as 7,400 feet elevation. It shows an inclination to coil in bushes or on tree limbs near the ground, although by far the majority of specimens encountered are found on rocky ledges. Its disposition has been reported by some to be very irritable, while others claim it is quiet and docile.
Description—This moderately slender snake is very similar in color and markings to the western diamondback rattlesnake. Its body is olive green with a pattern of darker diamond shaped markings down the middle of the back. These blotches are well defined by a border of light scales. It differs from the western diamondback in having narrower black tail rings and wider white spaces between these rings. A narrow light line extends from the eye to above the angle of the mouth.
Size—Average length is three feet, or shorter than the diamondback rattlesnake. Because of its more slender form, it does not appear as large as a western diamondback of equal length.
Young—The average litter contains eight, the young being similar to the adults in color and marking.
Distribution—The Mojave rattlesnake is known in Brewster, Hudspeth and Presidio Counties.
Unlike most other rattlers, this species is reported to be most active during daylight hours. It is rather quiet by nature and does well in captivity.
Description—Color of the back is greenish or grayish. A series of dark, rounded blotches extends down the middle of the back. These markings, with narrow white borders, become wider and shorter near the tail to form bands. In front of the eye is a narrow light line which extends backward and downward to the mouth.
Size—Rather slender in form, this snake reaches a maximum size of five and a half feet. Average length is three feet.
Young—Broods average 12 but vary from four to 21.
Distribution—Texas records of this snake are widely scattered. Counties in which it is know include: Andrews, Armstrong, Baylor, Brewster, Briscoe, Callahan, Carson, Castro, Childress, Crane, Crosby, Dallam, Dawson, Deaf Smith, Dickens, Ector, El Paso, Garza, Gray, Hansford, Hartley, Haskell, Hemphill, Hockley, Hutchinson, Kent, Lamb, Lipscomb, Lubbock, Lynn, Midland, Moore, Ochiltree, Oldham, Pecos, Potter, Presidio, Randall, Reeves, Roberts, Sherman, Taylor, Tom Green, Ward, Wheeler, Wilbarger, Winkler, and Yoakum.
When aroused, this snake becomes a vicious adversary but, like most snakes, is satisfied to go its way if given half a chance.
The single representative of this family (Elapidae) in Texas is small, slender, and brightly colored with rings of red, yellow and black. The head is small and rounded and eye pupils are circular. Its venom-conducting fangs, in the front of the upper jaw, are small and permanently erect; consequently, some chewing is required before the snake can inject its poison with certainty. As if to make up for its poor biting equipment, the coral snake possesses a venom of high toxicity, a venom much more potent than that of the pit vipers which are so well adapted for injecting their poison quickly and deeply. Because this poison produces scarcely any severe local symptoms, the danger from a bite may be overlooked and treatment delayed. Although pain is present, the usual dramatic symptoms of snake poisoning, such as extensive discoloration and great swelling at the site of bite, are scarcely noticeable. This absence of conclusive symptoms may lead the victim to believe he has been bitten by a harmless snake. In all coral snake bites, prompt action is necessary.
Left, coral snake; right, Mexican milk snake
Description—Generally less than two and a half feet long, this is our most colorful venomous snake and, at the same time, the least dangerous in appearance. Its small, narrow head, slender body and brightly colored pattern can be dangerously misleading. Children, especially, are inclined to pick it up because they are attracted by its colors and convinced that such beauty must be harmless. The pattern consists of red, yellow and black rings which encircle the body in the following order: a broad black ring, a much narrower yellow ring, a broad red ring, a narrow yellow ring, a broad black ring, and so on. Note that the red and yellow rings on the body touch one another. The snout is black and a broad yellow ring crosses the back of the head.
Identification of this snake would be simple were it not for the fact that several harmless snakes resemble it in form and coloration. These mimics are marked with yellow, red and black rings—but the arrangement is consistently different from that of the coral snake. The red and yellow rings of the coral snake touch one another, while in the harmless forms these colors are separated by black rings. A simple rhyme adopted by Boy Scouts to help them associate “danger” with the color combination found on the coral snake is, “Red and yellow kill a fellow.” Remember this easy rhyme and, when you find yourself involved with a colorful little snake with adjacent red and yellow rings, be cautious.
The harmless kind most closely resembling the coral snake probably is the Mexican milk snake, technically known as Lampropeltis doliata annulata and found south of Kerrville. The head of this snake normally is black. Body and tail are marked with a series of from 19 to 25 narrow yellow rings bordered by slightly wider black rings. The red rings on the body are just as wide as the combined yellow and two adjacent black rings. Another of these mimics is the western milk snake (Lampropeltis doliata gentilis), a small species usually less than two feet long, which is native to central and western Texas. It has a pattern of from 25 to 40 yellow rings which are bordered by black. The red rings are separated from the yellow by black rings. All rings on this form are very narrow. In the southeastern part of the state is found still another of these mimics—the Louisiana milk snake (Lampropeltis doliata amaura). Rarely reaching a length of two feet, this form has a pattern of narrow yellow rings which are bordered on each side by narrow black rings. The much wider red rings are separated from the yellow by the black rings. In the scarlet snake (Cemophora coccinea) of eastern and coastal Texas, the pattern is a series of wide red blotches bordered by much narrower black bands. The yellow bands, about half the width of the red ones, are separated from them by the black bands. The belly is unmarked white or yellow. Adults are about a foot and a half long but a 25-inch specimen is on record.
Size—The coral snake is generally less than two and a half feet long with a body diameter of about three-eights of an inch. The largest known specimen is nearly 42 inches long and was collected on the mid-Texas coast.
Young—This is the only poisonous Texas snake which lays eggs. From two to nine eggs constitute the egg complement of this form.
Distribution—This snake is known in the following counties: Angelina, Aransas, Atascosa, Austin, Bandera, Bastrop, Bee, Bell, Bexar, Bosque, Brazoria, Brazos, Brooks, Burleson, Burnet, Caldwell, Calhoun, Cameron, Chambers, Colorado, Comal, Dallas, DeWitt, Duval, Ellis, Fort Bend, Galveston, Goliad, Gonzales, Guadalupe, Hardin, Harris, Harrison, Hays, Henderson, Hidalgo, Houston, Jackson, Jasper, Jefferson, Jim Hogg, Karnes, Kendall, Kenedy, Kerr, Kleberg, Lavaca, Lee, Leon, Liberty, Live Oak, Llano, Mason, Matagorda, McLennan, Milam, Montgomery, Morris, Nacogdoches, Newton, Nueces, Orange, Palo Pinto, Panola, Polk, Real, Refugio, Robertson, San Jacinto, San Patricio, Sutton, Tarrant, Terrell, Tom Green, Travis, Victoria, Walker, Waller, Wharton, Willacy, Williamson, and Wilson.
Unlike most other poisonous snakes, this species is a burrower, coming to the surface after a warm rain to feed upon small lizards and snakes. Contrary to even expert opinion, it is not primarily nocturnal, but becomes active during daylight and evening hours. It is often found in or under decaying logs or other trash, especially in damp regions; in the San Antonio area, specimens frequently are found under flagstones near homes.
In spite of its inoffensive nature, the coral snake is no different from other snakes in that it will bite if stepped upon or restrained. It does not deliberately coil and strike with accuracy like the pit vipers. Instead, it swings the forward part of the body from side to side until it can secure a hold to bite and then begins a chewing motion to imbed its short fangs.
The notion that its mouth is too small to bite effectively has in some instances resulted in careless disregard for its deadliness. It is true that the head appears very short and the mouth not capable of opening widely. Actually, the skull is rather elongated and the mouth can be opened to a greater degree than might be expected. Even when it bites a relatively flat surface, such as the back of the hand, the snake’s closing mouth will pinch the skin, allowing the fangs to penetrate.
Generally speaking, snake venoms are divided into two broad categories, neurotoxic and hemorrhagic, depending on their destructive actions. Neurotoxic poison is characteristic of cobras and coral snakes and produces considerable pain but little or no swelling and discoloration at the bite. Death from this type of poison is the result of respiratory failure and is preceded by such symptoms as headache, muscular weakness, lethargy and facial paralysis with accompanying difficulty in speech.
Hemorrhagic venom, on the other hand, affects primarily the blood cells and vessels. Local reaction is evident soon after injection of the venom and consists of pain, discoloration, and swelling at the site of the bite. All of these symptoms gradually become more extensive. Weakness, nausea, vomiting and—occasionally—diarrhea may follow in a few hours. In many cases of snake bite, shock is present.
Although every snake’s venom contains both the neurotoxic and hemorrhagic elements, the proportion of these components varies with each kind of poisonous snake. For example, the venom of the coral snake is primarily neurotoxic in action, but produces a small hemorrhagic effect as well. On the other hand, water moccasin venom, although basically hemorrhagic in action, has a greater amount of the neurotoxic element than do the poisons of the copperheads or rattlesnakes. Furthermore, neurotoxic effects are more evident following the bites of the Mojave and massasauga rattlers than they are in poisonings by other Texas rattlesnakes.
FIRST AID KIT
Equipment necessary for first aid treatment of snake bite includes a sharp cutting instrument such as a razor blade or sharp knife for making incisions, a constricting band to retard the flow of lymph, iodine or alcohol for sterilizing the knife and bitten area, and a suction device for removing the venom-contaminated lymph. This last item is especially important if you are alone and cannot reach the wound to apply suction by mouth.
Snake bite kits containing the essential items can be purchased at most drug or sporting goods stores at a cost of from two to five dollars, depending upon the make. Anyone who spends much time outdoors should carry a snake bite kit at all times, and he should know how to use it. A smaller kit can be more easily carried and is less likely to be left at home or in the car.
To make certain that a poisonous snake has caused the bite, first examine the wound for teeth marks. In a perfect bite by a poisonous snake (excluding the coral snake), the pattern will reveal two distinctly larger holes where the fangs have entered the flesh. There also may be two rows of smaller teeth marks between these punctures.
Furthermore, if the snake engages the lower jaw, two additional rows of small teeth impressions will be seen below the first group.
Frequently the bite pattern is not a clear one. For example, if the snake pulls to one side as it disengages the fangs after a strike, the result is a series of scratch marks instead of punctures. There is also the possibility that the snake will engage only a single fang; or, perhaps, during fang replacement, two fangs are temporarily in position on one or both sides of the upper jaw. Any of these conditions, as well as others, can contribute to an obscure bite pattern.
The bite of a coral snake often is difficult to diagnose by examination of the wound. Because this snake impels its fangs in a sort of chewing motion, the pattern created by its bite may be two groups of closely spaced punctures where the fangs have entered the flesh a number of different times.
A clearly defined harmless snake bite pattern consists of a series of uniformly small punctures (four rows made by teeth in the upper jaw, two rows by teeth in the lower), but always without the large fang holes. More typically, a non-poisonous bite produces several rows of scratches.
Pit-viper poisoning is diagnosed primarily by the presence of local signs and symptoms. The most important of these are:
1. Pain accompanies most poisonous snake bites. Generally intense and burning in character, it becomes more severe with the passing of time. This symptom alone is not conclusive because pain can be imagined following a non-poisonous bite. Occasionally in a severe bite, the pain is replaced by numbness and tingling.
2. Swelling at the bite area is present in every case of poisoning. It will appear within five to 30 minutes. In a severe case, the swelling may continue to spread for 24 hours. There will be no swelling from a bite by a non-poisonous snake or by a poisonous snake that injected no venom.
Snakebite swelling3. Discoloration, reddish or bruise-like in appearance, begins around the fang punctures within a half hour and becomes gradually more extensive.
Intense local pain is symptomatic of coral snake poisoning but, unlike a case of pit-viper poisoning, swelling and discoloration are not pronounced. Diagnosis of coral snake envenomation is difficult and must be based primarily on systemic symptoms: headaches, weakness, lethargy and facial paralysis.
Even after the bite has been diagnosed as venomous, it is not immediately possible to predict the course it will follow. The severity of each case of snake poisoning is determined by the speed with which symptoms progress. Although the bite of a large snake is generally more serious than one caused by a small snake, the seriousness of a bite cannot be gauged by snake size alone. Some variable factors that affect the severity of each case include:
It is important that every snake bite victim receive first aid treatment as soon as possible. The patient must not exert himself by running, because increased circulation brought on by such physical activity will speed up absorption of the poison. For the same reason, the use of whiskey or other stimulants should be avoided.
The victim’s state of mind is important; he must promptly be convinced that his chances for recovery are good—and, indeed, they are. He should not be terrified by the thought that every snake bite means certain death. Actually, a survey of case histories shows that with prompt and proper treatment, only about one or two per cent of all snake bites in this country are fatal.
There is a considerable difference of opinion about the correct first aid treatment for poisonous snake bite. The Division of Medical Sciences of the National Research Council, a section of the National Academy of Sciences, recently made a study to determine the most effective method of such treatment. It recommended immobilization of the bitten limb, application of a constricting band, and prompt incision and suction.
Based on these recommendations, the following first aid treatment for poisonous snake bite is suggested:
1. IMMOBILIZE THE AFFECTED ARM OR LEG whenever possible. Where this is not practicable, keep movement of the bitten limb to a minimum. Muscular activity helps increase the spread of venom. Whenever feasible, transport the victim by litter to further medical aid.
2. APPLY A CONSTRICTING BAND from two to four inches above the bite, between the wound and the heart. This will help to limit the spread of venom until it can be removed by incision and suction or neutralized by antivenin. A piece of rubber tubing or a strap tourniquet, included with every snake bite kit, is best for this purpose. When these are not available, items of clothing may be used. A shoe lace, neckerchief or a strip of clothing torn from shirt or trousers will do. The poison, unless injected directly into a major blood vessel or deeply into a muscle, is absorbed slowly by the lymphatics below the skin. Therefore, do not restrict the deeper blood circulation by applying the constricting band too tightly. It should be loose enough for a finger to be slipped under it with little difficulty. Remember that during first aid treatment the constricting band must be loosened every 15 minutes for about two minutes. This precaution may prevent gangrene. If the bite is on the hand or forearm, take off rings, bracelets or other jewelry because subsequent swelling may make their removal difficult.
Applying constricting band3. MAKE INCISIONS after sterilizing the cutting instrument and the bite area with iodine or alcohol. If no antiseptic is available, the blade of the cutting instrument can be sterilized by holding it over a flame (a match will do). Make one cut over each fang mark parallel with the long axis of the bitten limb, not across it. Incisions should be one-quarter inch long and one-eighth to one-quarter inch deep, but definitely no longer than the diameter of the suction apparatus being used. This would allow air to enter the suction bulb from the outside and the device would then be unable to work. Incisions are of the utmost importance to first aid treatment; without them little or no poison can be withdrawn from the wound by suction. However, making even a small incision involves some risk and this operation should be done with considerable care. Improper or carelessly applied first aid may actually do more harm than good. Although a physician may later decide to make additional incisions to relieve the pressure of swelling, only the cuts over the fang marks are recommended for first aid.
Making incision4. APPLY SUCTION to the cuts. This can best be done with one of the suction devices manufactured for that purpose but, if none is available, suction can be applied by mouth. There is little danger in oral suction unless the lips or inside of the mouth have cuts or abrasions. Contrary to popular opinion, a tooth cavity will not permit passage of venom into the blood. Moreover, snake venom is destroyed by the stomach’s digestive juices, so if some is accidentally swallowed, there is little need to worry if you have a healthy system. Only during the first 30 minutes following the bite can much venom be removed by incision and suction.
Applying suctionSnakebite kit5. GET TO MEDICAL AID as soon as possible—but keep in mind that unnecessary physical exertion is harmful.
Antivenom may be administered soon after first aid has been started, but this is best left to a doctor. The North American Antisnakebite Serum made by Wyeth, Inc., of Philadelphia 3, Pennsylvania, is effective against pit viper bites but is of less value in the treatment of coral snake poisoning. Because coral snakes cause so few bites in the United States, no serum to neutralize their venom is prepared in this country. In South America, where these snakes are common and may reach a length of five feet, a serum to neutralize the poison is being produced by the Instituto Butantan at Sao Paulo, Brazil. It and other foreign snake bite serums often are available at larger zoos where exotic poisonous species are exhibited.
In most areas of Texas, snake bite is an uncommon medical emergency, and one with which few doctors have had experience. For this reason, the following recommendations by the National Research Council’s Division of Medical Sciences are included for the benefit of the physician.
The routine admission history and physical examination should provide and record, if possible, the identity and length of the snake, the time of the bite, and the details of all first aid measures employed, including the time lapse for each and the mode of transportation to the hospital. The record should state whether a tourniquet, incision and suction, or the ligature-cryotherapy technique has or has not been used. Inquiry should be made concerning previous bites, allergic manifestations in general, and whether or not the patient had previously received horse serum. The admission examination should provide information from which the severity of the envenomation can be estimated as a guide to the need for the administration of antivenin and other therapy. Sensitivity tests should be instituted promptly during admission if not previously begun.
When the patient enters the hospital, blood should be drawn immediately for typing, matching and coagulation studies.
Although envenomation by one of the snakes of North America may present severe signs and symptoms, death is rare except in children or following envenomation by a large snake. However, permanent damage of an involved extremity is frequent following a bite by certain of the North American venomous snakes; plastic or orthopedic surgical repair to restore function, or amputation, are not unusual consequences. Early and continuing close observation is needed to determine if certain therapeutic measures prevent or promote undesirable results.
No rigid set of rules regarding therapy can be justified; the responsible physician must use his best judgment in his choice of tests to be performed as a guide to procedures to be used.
Clinical studies could include items such as repeated hematologic tests, hepatic and renal function studies, serial electrocardiograms, electroencephalograms, and other studies to therapy, depending on the composition of the venom involved and within the limits of personnel, time and equipment available.
1. Immobilization. During transportation, admission procedures, and most of the early hospitalization period, immobilization of the affected part and absolute rest should be continued. A sedative or analgesic may be administered to relieve restlessness and anxiety; ice bags may be applied to alleviate severe pain. The extremity should be immobilized in the position of function, and active and passive exercises to prevent contracture started after the third day if consistent with the patient’s condition.
2. Blood Transfusion. Postmortem examinations have at times revealed extensive retroperitonial and intraperitonial hemorrhage, and hemorrhage into the viscera, including the liver and kidney. Progressive decrease in the total volume of circulating red blood cells has been attributed to the development of a massive hemolytic anemia or internal hemorrhage. Blood transfusions may be necessary and at times have been followed by marked improvement. Studies of the several factors involved in blood clotting may be useful as guides to treatment. The first and subsequent specimens of urine should be especially examined for the presence of red blood cells, hemoglobin, and protein.
3. Electrolyte Balance. Abnormality of fluid and electrolyte balance should be detected and corrected on a continuing basis.
4. Antivenin. Polyvalent or specific antivenins prepared from venoms of snakes in the same geographic area should be administered in therapeutic quantity as recommended by the manufacturer only with full realization that the hazard of immediate allergic reaction or delayed serum sickness are factors to be evaluated in the decision to carry out this type of treatment. During hospitalization, antivenin should be given intravenously, provided that sensitivity tests indicate that the patient is not allergic to the antiserum to be used. Desensitization, if necessary, should precede the administration of antivenin by any route. The use of antivenin in such cases should be carefully evaluated. Injection in normal muscles in other extremities would be the second choice, since local injections into the deposit site do not diffuse efficiently into the entire damaged area and would increase the hazard of pressure ischemia leading to increased tissue necrosis. Epinephrine should be available for immediate use when foreign protein is being administered.
5. Corticosteroids. The use of corticosteroids should be restricted to the prevention or treatment of late manifestations of allergy following administration of antivenins.
6. Antibiotics. A broad-spectrum antibiotic should be administered promptly in appropriate dosage if the reaction to envenomation is severe. Since the nature of the injury markedly predisposes to infection, and pathogenic bacteria are found in the wound, this use of antibiotics seems justified. Laboratory sensitivity tests, if available, should control the continuing choice of antibiotics to be used. A massive wound infection with severe systemic reaction could be mistaken for severe envenomation. Repeated blood and wound cultures would be of help in making the distinction.
7. Tetanus Prophylaxis. Tetanus toxoid should be administered upon admission if it has not been given as a first aid measure.
8. Respiratory Paralysis. If respiratory paralysis develops following envenomation by one of the Elapidae (this family includes the coral snake), the use of tracheostomy and intermittent positive pressure artificial respiration is indicated.
9. Renal Shutdown has been an occasional occurrence following massive envenomation. An awareness of this possible complication can do much toward the prevention and treatment of secondary effects arising after its occurrence. Routine daily tests such as B.U.N., CO₂ combining power, and serum potassium levels are indicated in severe cases.
1. Tourniquet (Constricting band). A tourniquet applied following a bite by a venomous North American snake should be removed if envenomation seems mild or after a potent antivenin is given in therapeutic quantity. The prolonged use of a tourniquet or of a constricting band would increase local tissue damage due to the action of venom and might delay the vascular transport of antivenin into envenomated areas.
2. Incision and Suction. Substantial amounts of venom can be removed during the first half-hour from subcutaneous deposits by incision and suction. On the other hand, if the casualty is admitted to the hospital one hour or more following envenomation, an attempt to remove venom by incision and suction at the site of the bite would be of little value. However, if marked subcutaneous pitting edema develops, interstitial pressure can be relieved by several longitudinal incisions extending into the subcutaneous tissues. Suction and fasciotomy may be required at times.
Parrish (1961), using a modification of Wood, Hoback and Green’s (1955) clinical classification of pit viper venenations, has proposed the following guide for determining the severity of a poisonous snake bite. This classification is based upon present signs and symptoms and the clinical course of the patient during the first 12 hours of hospitalization. It will be useful as a guide in treatment.
Grade O (No venenation). Fang or tooth marks present, minimal pain, less than one inch of surrounding edema and erythema, and no systemic involvement.
Grade I (Minimal venenation). Fang or tooth marks present, moderate pain, from one to five inches surrounding edema and erythema in the first 12 hours after bite, and no systemic involvement.
Grade II (Moderate venenation). Fang or tooth marks present, severe pain, six to 12 inches of surrounding edema and erythema in the first 12 hours after bite, with systemic involvement—nausea, vomiting, giddiness, shock or neurotoxic symptoms present.
Grade III (Severe venenation). Fang or tooth marks present, severe pain, more than 12 inches of surrounding edema and erythema in the first 12 hours after bite, with systemic involvement (as in Grade II).
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