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Venomous : Past, Present, And Future J Am Board Fam Pract: first published as 10.3122/jabfm.5.4.399 on 1 July 1992. Downloaded from Treatment Options james R. Blackman, M.D., and Susie Dillon, M.D.

Abstract: Background: Venomous continue to cause great morbidity, and treatment options ate confusing the attending physician. In the approximately 45,000 snakebites occur eacl1 , of which some 8000 ate by 20 of venomous . Methods: Information on venomous snakes and snakebite treatment was gathered from the libraries of the Wilderness Medical Society and the Rocky Mountain Center for WUderness in Boise, Idaho (co-supported by the Boise State University and the Practice Residency of Idaho), as well as &om current literature files of physicians practicing wUderness medicine. Results ",,4 ConelflSlmrs: 1bree genera of venomous snakes account for the majority of poisonous in this country. Most hospitalized victims ate bitten either by or copperheads or by unidentified snakes. Most of these bites occur during the summer months and ate found on the extremities. Field treatment focuses on the application of a vacuum extractor and transportation to the neatest medical fadlity. Although band use can be helpful, tourniquets, incision and suction, and ice therapy ate contraindicated. Electric shock therapy is of no use and could cause serious . Hospital management focuses on rapid clinical evaluation and laboratory tests to establish the degree of , looking for clotting abnormalities. If envenomation bas occurred and is reactive, polyvalent antivenin should be administered according to the degree of envenomation. Errors in diagnosis and treatment resuh in increased morbidity and put attending physicians at risk for litigation. Prevention remains the most successful approach to snakebite management. a Am Board Fam Prac:t 1992; 5:399-405.)

There are approximately 2700 species of snakes poisonous snake can be found in every state worldwide, of which about 375 are considered except Alaska, Hawaii, and Maine.3 venomous.l Venomous snakes are responsible for This paper focuses on the treatment of crotalid an estimated 75,000 human deaths annually.2 In envenomation. The Crotalidae are distinguished http://www.jabfm.org/ the United States approximately 45,000 snake­ by facial pits, vertical elliptical , a triangular bites occur each year, of which about 8000 are by , a single row of subcaudal scales, and a 20 species of venomous snakes. Deaths do not apparatus. Further, the is exceed 10 to 12 peryear.l unique in possessing a rattle composed of loosely articulated, interlocking segments of . Al­ though the purpose of the rattle is a warning, it is Background on 28 September 2021 by guest. Protected copyright. TbeSnaie not always sounded before a strike.4 Five genera ofvenomous snakes are indigenous to Pit vipers are named for the paired, short­ the United States. Three genera belong to the range, infrared-heat-sensitive pit organs located family Crotalidae: Crotalus (15 species of rattle­ between the and nostril. Sensitive to tempera­ snakes), Sistrus (pygmy rattlesnakes, massa­ ture changes as little as O.003°C, the organs allow sauguas), and (copperheads, cotton­ for effective night .4 mouth moccasins). The other two (, ) are coral snakes. At least one species of TbeVenom The venom apparatus consists of venom glands, ducts, and fangs. The paired venom glands, ho­ mologous to human parotid glands, are located Submitted, revised, 9 March 1992. behind the eye. They produce and store a quan­ From the Family Practice Residency of Idaho, Boise. Address reprint requests to James R. Blackman, M.D .. Family Practice tity of venom relative to the size of the snake. Residency ofIdaho. 777 North Raymond. Boise, ID 83704. Young snakes have concentrated venom and

Venomous Snakebite 399 therefore are more toxic for their size. The gland diamondback, prame, Pacific, timber, pygmy, J Am Board Fam Pract: first published as 10.3122/jabfm.5.4.399 on 1 July 1992. Downloaded from is connected to the venom duct, which pierces the and eastern diamondback were responsible for fang sheath and ends opposite the upper fang most bites, with diamondbacks causing the most opening. The fang sheath stores part of the fatalities.s venom for transfer to the fang. The curved hol­ The highest number of bites occurs in North low fangs are 5 mm to 20 mm long and have Carolina, followed in descending by Arkan­ an oval-shaped discharge orifice above the tip. sas, , Georgia, West VIrginia, Mississippi, Fangs are attached to a rotating maxilla, which Louisiana, Oklahoma, and . Arizona has enables them to swing from the resting position the highest mortality.} (folded against the roof of the mouth) to the There has been a remarkable change in the position (perpendicular to the upper ). demography of snakebites. Early studies (1929) Fangs have a life span of 6 to 10 weeks and then showed 28.3 percent of bites occurring in those are replaced by reserve fangs. During the change, aged 1 to 10 , 43.1 percent in those aged 10 there is a 4- to 5-day overlap when both can be to 30 years, and 28.6 percent in those aged 30 to functional.4-6 80 years. By 1979, 82.5 percent occurred in the Venom is a yellow fluid, and its primary func­ 10- to 30-year age group.s Early studies showed a tion is to immobilize, kill, and digest prey.6 2:1 male-female ratio, but now that ratio is much Venom contains ions, biogenic amines, greater, 7-9: 1. Snakes, because they are poikilo­ , free amino acids, large and small , thermic, are most active in hot weather. As a polypeptides, and .s 'Within a species, result, more than 95 percent of bites occur be­ can vary with the snake's age, size, health, tween April and October, and 77 percent occur time of year, time of day, length of , during daylight hours, times also of greatest length of time since last strike, geographical area, human activity. and the individual . The Ninety-seven percent of bites occur on the ex­ (LDso) for humans varies considerably among tremities.} Although the majority historically species from a low of 0.23 mglkg in the Mojave were found on the lower extremities, snakebites to a high of 10.92 mglkg for the are now found predominantly on the upper ex­ copperhead. S tremities (85 percent).9 This shift in location Snakes can strike from any position and with might reflect a higher number of illegitimate

considerable force. The S-shaped defensive posi­ bites, i.e., those bites that occur when victims have http://www.jabfm.org/ tion allows a maximum strike length of up to chosen to expose themselves to the risk of bite three-quarters of the snake's length, although ( snakes, handling of snakes).4 Legitimate bites usually less than one-half is used.4 The strike of happen when the victim has no intention of in­ vipers can be directed in any position including dulging in so unnecessary a risk. In 1980, 75 vertically. During the lunge, the mouth is opened, percent of bites were legitimate.s In 1988, 43 fangs are erected, and if contact is made, the percent were legitimate, and 28 percent ofvictims palatine muscles contract to inject the venom. In appeared intoxicated.9 on 28 September 2021 by guest. Protected copyright. human victims, venom is usually deposited in der­ mal or subcutaneous tissues but can be left sub­ Field Treatment fascially. 7 The amount of venom injected in prey Recommended first aid for snakebite has changed is well controlled, but during a defensive bite, the through the years but has been generally directed amount might not be so well controlled. Conse­ toward removing the venom and preventing quently, 20 to 30 percent of Crotalidae bites in spread systemically. Popular past methods have i humans contain no venom.8 ranged from , , application of I various materials, such as split , scrapings r Epidemiology of teeth, or the of a fasting man, Of hospitalized snakebite victims, 0.5 percent of to various plant cures.4 bites were inflicted by coral snakes, 7.3 percent Even now controversies exist. RussellS summed by cottonmouths, 28.6 percent by copperheads, it up when he said, "1 feel the first-aid hubbub has 29.8 percent by unidentified snakes, and 33 per­ been created and nourished under the old idiom, cent by rattlesnakes.} Of rattlesnakes, the western 'You've got to do something.' "

400 JABFP July-August 1992 Vol. 5 No.4 Controversies center primarily around the uses 3. The venom pool can occur anywhere within J Am Board Fam Pract: first published as 10.3122/jabfm.5.4.399 on 1 July 1992. Downloaded from of tourniquets or constriction bands, incision and the area of a circle, the radius of which is suction, cryotherapy, pressure wrappings, and the determined by the length of the fangs, thereby electric stun gun. Experts do agree, however, on making accuracy of location, direction, and the following recommendations:10.ll depth of the incision difficult 4. In inexperienced hands great damage can be 1. Move the victim out of the snake's territory done to underlying , , tendons, 2. Place the victim at rest and 3. Reassure the victim 5. Use of unsterile technique can result in sec­ 4. Cleanse the ondary S. Withhold alcohol and drugs, which could 6. Under field conditions, a 5 to 6 percent re­ clinical infonnation trieval is probably realistic 6. Attempt to identify the snake 7. Immobilize the affected part in a functional The newest device on the market is a suction position pump that delivers approximately 1 atmosphere 8. Transport to the nearest medical facility for of negative pressure. If applied within 3 minutes definitive care as quickly as possible and left on for 30 minutes, it is capable of remov­ ing up to 35 percent of venom.13 Commercial Controversies I" Field MII1IIIgement suction devices are readily available (Sawyer Ex­ Tourniquets have long been promoted to prevent traction Pump"') and should replace the old the proximal spread of venom but now are no method of incision and suction. No incision is longer recommended. Venom uptake occurs necessary with this vacuum device. Human stud­ through the lymphatics, yet tourniquets occlude ies are underway. (Michael Callahan, M.S., per­ venous and arterial flow, leading to lymphedema, sonal communication,]uly 1991.) , , , arteriovenous fis­ Cryotherapy, including ice, ice im­ tula fonnation, and peripheral neuritis.2 Further, mersion, and cold sprays, is no longer recom­ the release of a tourniquet can lead to rapid dis­ mended.8 Animal studies have shown ice to be persal of venom and tissue debris, causing hypo­ effective at retaining venom at the inoculation tension and shock. 12 site, but rapid venom dispersal following re­ 14

Recently a constriction band to occlude only lym­ moval of the ice has produced shock. Expo­ http://www.jabfm.org/ phatic flow has been advocated.8 The band should sure to cold produces vasoconstriction in al­ be 2.5 to 5.0 em wide and placed 2 to 4 inches ready compromised tissues; prolonged exposure proximal to the bite, allowing enough room to slip can result in gangrene, and the victim could one finger beneath. Distal pulses should remain require amputation.8 The American Red Cross palpable, and refill should be brisk. De­ and the Committee on Trauma of the Ameri­ creased venom dispersion has been demonstrated in can College of Surgeons recommend against using this procedure.2 Intermittent release of its use.IS on 28 September 2021 by guest. Protected copyright. the band could propel venom from the bite site and Electric shock treatment for snakebite dates lead to a higher rate of shock. The band can be back to 1899 but was most recendy popular­ loosened as swelling occurs.2 ized after its successful use on the Waoroni In­ In the past, incision and suction (oral or me­ dians of . 16 Seventy-eight percent of the chanical) have been advocated for the removal of tribe, however, were positive for the venom pool from the site of deposit. Propo­ as determined by -linked nents have based this advice on experimental as immunosorbent assay, indicating at least partial well as anecdotal experience.12 Opponents, how­ .19 In controlled animal studies, electric ever, note several problems:8•9 shock therapy has shown no effect.17•18 Venom was not inactivated using electric current from a 1. No controlled experiments have been done commercial stun gun directly applied to a rattle­ on humans snake venom solution in an electrolysis cell.20 2. Survival of experimental has not been Electric shock treatment is not recommended and affected should not replace vacuum suction and rapid

Venomous Snakebite 401 transport to medical facilities for evaluation and should be identified, if possible, and the following J Am Board Fam Pract: first published as 10.3122/jabfm.5.4.399 on 1 July 1992. Downloaded from antivenin. laboratory tests should be ordered: complete count (CBC), platelet count, fibrinogen, Hospital Management PT, PTT, fibrin split products, blood urea nitro­ Appropriate hospital management depends on gen (BUN), creatinine, CPK, and urinalysis. The understanding the pathophysiology of enveno­ circumference of the extremity at the area of mation. Lethal venom proteins (low molecular and 4 inches proximal to the bite should be ) damage endothelial cells and re­ measured and remeasured hourly.9 sult in increased microangiopathic permeability, The severity of envenomation should be de­ edema, hemoconcentration, and lactic acidosis, termined. Severity varies somewhat with the

ultimately causing shock and death. Proteolytic amount and kind of venom (species), field treat­ I~ enzymes damage muscle and subcutaneous tis­ ment, and length of time before medical man­ sues, and allows venom to spread agement. Up to 25 percent of rattlesnake bites through tissues. Phospholipase A2 provokes hista­ contain no venom. Systemic reactions, physical mine release, hemolysis, and necrosis of muscle fmdings, and laboratory abnormalities allow the fibers. Thrombinlike enzymes promote unstable clinician to establish the degree of envenoma­ fibrin clot, afibrinogenemia, , tion, which facilitates planning for antivenin and an increase in fibrin split products.21 Platelets administration (fable 2).24 p 491 The bite is are actively sequestered at the bite site and are graded according to the most severe symptom consumed by intravascular clotting.22,23 or sign, and its status will change over time and As a result of the various interactions between with antivenin administration.9 venom and , a fairly typical clinical picture If no signs or symptoms develop and alliabo­ develops. Blood oozing from the wound and ratory tests are normal after 6 hours, the pa­ numbness around the bite characterize a poison­ tient can be reassured that no envenomation has ous snakebite. Swelling, discoloration, ecchymo­ taken place and can be discharged from medi­ sis, and painful lymph nodes develop. Bullae and cal care. associated with can be severe. As in all puncture , tetanus immune Systemic reactions, such as orthostatic changes, status should be assessed and brought up to date. , , and , can occur and If envenomation has occurred, one then de­

can be associated with a change in laboratory termines the need for antivenin. The amount of http://www.jabfm.org/ markers. Increased creatine phosphokinase (Crotalidae) polyvalent antivenin (Wyeth) ad­ (CPK), proteinuria, and hematuria can be seen. A ministered initially is based on the severity of marked with hypofibrinogenemia, envenomation (fable 3).25 The initial dose of thrombocytopenia, increased fibrin split prod­ antivenin that is decided on from the clinical ucts, and a prolongation of prothrombin time examination should be repeated every 2 hours (P1) and partial thromboplastin time (PTT) is until the patient shows clinical improvement on 28 September 2021 by guest. Protected copyright. seen with moderate and severe envenomations (decreased swelling, fasciculations, paresthesia). (fable 1).9 There is no maximal dose, and therapy is meas­ After arrival in the patient care setting, a rapid ured by clinical response.9 To be most effective, clinical assessment should be made, the snake antivenin should be given during the first

Table 1. SiplIIICI SfmpkJml ollllmlOllllldoa fa 227 PlltiealB.·

Symptoms Percent Signs Percent Abnormal Laboratory Values Percent J 100 I Weakness 80 Fang marks Fibrinogen 3S I' C Nausea, vomiting 70 Swelling 98 Fibrin split products 39 73 Ecchymoses 27 Prothrombin time IS 60 Fasciculations 19 Proteinuria 9 11 Hematuria 8 Bullae 6 Necrosis 4 *Treated at the Los Angeles County-University of Soumem California Medical Center, 1975-1985.9

402 JABFP July-August 1992 Vol. S No.4 1Hble 2. Degree of Crotalid Enftllomatioo. Clinical reactions to antivenin can be both J Am Board Fam Pract: first published as 10.3122/jabfm.5.4.399 on 1 July 1992. Downloaded from Envenomation acute and chronic.2' An immunoglobin E medi­ No envenomation Fang marks ated acute or an anticomplement No local or systemic reaction reaction resembling anaphylaxis can occur, result­ Minimal Fang marks ing in nausea, vomiting, urticaria, abdominal No systemic reactions cramps, hypotension, and bronchospasm, which Local swelling Moderate Fang marks can be treated with diphenhydramine and epi­ Swelling and pain beyond the site nephrine. Theophylline also might be required. of bite A delayed serum sickness can develop within 1 to Systemic reactions: nausea, vomiting, 3 weeks and is associated with fever, malaise, paresthesias, orthostatic changes Laboratory markers change: edema, and headache. Arthralgia, arthritis, and hemoconcentration, mild coagula­ myalgia are frequent, and lymphadenopathy is tion abnormalities one of the most constant features. Symptoms sub­ Severe Fang marks side rapidly with corticosteroid therapyP Swelling and pain in the extremity Systemic reactions: nausea, vomit- Because snake mouths contain anaerobic and ing, paresthesias, orthostatic gram-negative organisms, a broad-spectrum anti­ changes; subcutaneous biotic, such as ceftriaxone, is indicated.28 The ecchymosis Laboratory markers change: wound should be cultured, and SenSItlvIUes hemoconcentration, marked should direct future treatment. coagulopathy with thrombo­ Wounds should be cleaned three times daily cytopenia, hypofibrinogenemia, prolonged PT and PTT, increased with hydrogen peroxide (dilute) after debride­ fi brin split products, increased ment. The limb is immersed for 1 hour three to CPK. proteinuria and four times daily in solution (1:20 solu­ hematuria24 p491 tion of aluminum acetate) with oxygen bub­ PT • prothrombin time, PTT. partial thromboplastin time, bled through an aquarium air stone at 6 Umin CPK. creatine phosphokinase. (hydro-oxytherapy).29 6 hours after a bite. Antivenin administration is Surgical intervention (fasciotomy) should be useful up to 24 hours after a bite and should be entertained only in cases of demonstrated abnor­ tried even later if coagulation defects continue to malities in intracompartmental pressures.s Most cause active hemorrhage.S,2S edema is subcutaneous, and fasciotomy is not http://www.jabfm.org/ Skin testing for serum sensitivity should recommended as primary therapy. Creatine be performed prior to administration of anti­ phosphokinase measurements and compartmen­ venin, but only for those who will definitely need tal pressure monitoring are useful in those cases antivenin. Unnecessary skin testing and antivenin where doubt exists concerning neurovascular administration sensitizes the patient to these pro­ viability of the involved extremity. In animal stud­ teins and puts the patient at risk should antivenin ies researchers have demonstrated successful re­ be needed at a later date. Delaying testing until duction of intramuscular pressure and superior on 28 September 2021 by guest. Protected copyright. the decision is made to use antivenin does not survival and preservation of muscle function with delay antivenin administration.26 Skin-testing antivenin alone when compared with antivenin materials are supplied, along with instructions, plus fasciotomy or fasciotomy alone.7,30 with each vial of antivenin. Testing should not be done with the more potent antivenin. Acute ana­ phylaxis should be anticipated even though the Table 3.1Di1IaI AntIvenIn ([Crotalidae] Polyvalent (Wyet1t)) Dole test is negative. &xonUng to Grade of Se¥erity. Victims who are skin-test-positive can be pre­ Envenomation Amount Administered medicated intravenously with diphenhydramine, No envenomation None and the antivenin can be administered intra­ Minimal oto S vials venously along with epinephrine. Diluted anti­ Moderate 10 to 20 vials venin is administered initially, and the dose is Severe 20 or more gradually increased in strength until a full dose is Place S vials (SO mL) in 200 mL of O.S normal saline; infuse at achieved. 1 mUmin for first 10 minutes.2S

Venomous Snakebite 403

I -"'"" Deaths are unusual (10 to 12 per year), al­ not cause the acute and delayed side effects of J Am Board Fam Pract: first published as 10.3122/jabfm.5.4.399 on 1 July 1992. Downloaded from though death resulted from extended periods of current preparations. The fragments hypotension in many of the nine cases reported with bound venom are more rapidly excreted from Arizona.31 More vigorous treatment with through the renal system, rather than by the intravenous fluids and larger amounts of anti­ much slower reticuloendothelial system for venin might have been helpful. larger molecules. Commercial preparation of this Numerous assessment and treatment errors potentially beneficial antivenin has not yet been have been cited as reasons for increasing morbid­ undertaken. ity and subsequent litigation24 (Table 4). Careful Administration of the antivenin is not innocu­ study of these oversights is indicated for those ous, and early debridement, fasciotomy, and bite physicians caring for patients envenomated by pit excisions leave large wounds with delayed heal­ VIpers. ing. We can only hope for more assistance in the What can we look forward to in the future to future from these new developments. help us manage these complex problems associ­ ated with snake envenomation? Work on a new Prevention antivenin continues. The active component of Because treatment of any type is fraught with crude antivenin is the immunoglobulin (IgG) ~-2 complications, it makes to teach prevention fraction, which accounts for only about 20 per­ to our patients. The following list summarizes cent of the content of crude antivenin. recommendations to prevent snakebites:4,s.32 This active IgG fraction has been extracted using high-yield affinity chromatography.24 Animal 1. Do not place any part of your body where study results confinn the superior efficacy of this you have not first looked product. The next step is to prepare F(ab) frag­ 2. Do not use your hands to lift anything a ments of the purified IgG antibody. The smaller snake could be under fragments are readily distributed to more tissue 3. Gather firewood in the daylight sites to neutralize venom more effectively and do 4. Do not place your camp, boots, or clothes near brush, rubbish, rock piles, cave en- trances, or swampy areas Table 4. Erron In DllIgnosis and '&eatmeot of Crotalid 5. Do not disturb, capture, or attempt to kill Envenomation.

snakes unless you are experienced in han- http://www.jabfm.org/ Not considering snake venom in the case of an dlingthem edematous, ecchymotic extremity in a child who was 6. playing in an area where snakes can be found Do not move suddenly when you hear a Not looking for fimg marks at the site of pain rattlesnake sound; locate the snake and care- Not considering that envenomation grade can change with fully move away. Remember, there could be time and thus that the clinical status of the patient can others nearby worsen over time 7. Take along a friend when traveling in snake Not checking initial coagulation studies and not repeating habitat on 28 September 2021 by guest. Protected copyright. these studies within 12 hours Not considering the diagnosis of envomation because a snake 8. Stay on paths and avoid tall grass and heavy was not seen undergrowth Not administering antivenin early in the envenomation course 9. Wear adequate protective clothing, includ- in the face of progressive signs and symptoms ing tall hoots with pant legs worn on the Not considering administration of broad-spectrum prophylactic outside Not realizing that antivenin can successfully reverse coagu­ 10. Do not handle freshly killed snakes or the lopathy more than 24 hours after envenomation of decapitated snakes, which have Leaving a constriction band or tourniquet on an extremity fur been known to bite reflexively up to one-half I a prolonged period hour after death Not doing a skin test appropriately; that is, not administering the proper dose of horse serum intradermally 11. Carry a flashlight at night Doing a skin test with horse serum when there is no intention 12. Watch for snakes at altitudes of up to 9500 to administer antivenin feet in wann climates, up to 11,000 feet in Performing a &sciotomy without measured substantial 24 California, and up to 14,500 feet in central elevation in intracompartmental pressure Mexico

404 JABFP July-August 1992 Vol. S No.4 16. Guderian RH, Mackenzie CD, WIlliams]R High

13. Do not avoid snake habitats out of , but J Am Board Fam Pract: first published as 10.3122/jabfm.5.4.399 on 1 July 1992. Downloaded from be careful voltage shock treatment for snake bite [letter]. Lan­ 14. Do not keep poisonous snakes as or cet 1986; 2:229. 17. Theakston RD, Reid HA, LarrickJw. Kaplan], Yost consume alcohol when handling them JA Snake venom antibodies in Ecuadorian Indians. ] Trop Med Hyg 1981; 84:199-202. References 18. Snyder CC, Murdock RT, White GL, Kuitu]R. 1. Nelson BK. Snake envenomation. Incidence, clinical Electric shock treatment for snake bite [letter]. Lan­ presentation and management. Med Toxicol Adverse cet 1989; 1:1022. Drug Exp 1989; 4:17-31. 19. Howe NR, Meisenheimer ]L]r. Electric shock does 2. Snyder CC. wounds. Hand Clin 1989; not save snake bitten . Ann Emerg Med 1988; 5:571-90. 17:254-6. 3. Parrish HM. Incidence of treated snakebites in 20. Davis D, Branch K, Egen NB, Russell FE, Gerrish the United States. Public Health Rep 1966; 81: K, Auerbach PS. The effect of an electrical current 269-76. on snake venom toxicity. J Wilderness Med 1992; 4. Klauber 1M. Rattlesnakes, their habits, life , 3:48-53. and influence on mankind. Berkeley: University of 21. Ownby CL, Kainer RA, Tu AT. Pathogenesis of California Press, 1982. hemorrhage induced by rattlesnake venom. Am J 5. Russell FE. Snake venom poisoning. Great Neck, PathoI1974,76:401-14. NY: Scholium International, 1983. 22. Simon TL, Grace TG. Envenomation coagulopathy 6. Davidson TM, Schafer SF, Bracker MD. Rattle­ in wounds from pit vipers. N Engl J Med 1981; snakes: the animal and the venom (Part 1 of 2). Phy­ 305:443-7. sician Sports Med 1989; 17(4):148-59. 23. Riffer E, Curry SC, Gerkin R. Successful treatment 7. Gartin SR, Castilonia RR, Mubarak S], Hargens with antivenin of marked thrombocytopenia without AR, Akeson WH, Russel FE. The effect of anti­ significant coagulopathy following rattlesnake bite. venin on intramuscular pressure elevations in­ Ann Emerg Med 1987; 16:1297-9. duced by rattlesnake venom. Toxicon 1985; 24. Sullivan JB, Wmgert WA bites. Manage­ 23:677-80. ment of wilderness and environmental emergencies. 8. Kunkel DB, Curry SC, Vance MY, Ryan Pl. Reptile St. Louis: CVMosby, 1989:479-511. envenomations. J Toxicol Clin Toxicol 1983-84; 25. Sullivan JB Jr. Past, present, and future immuno­ 21:503-26. therapy of snake venom poisoning. Ann Emerg Med 9. Wingert WA, Chan L. Rattlesnake bites in southern 1987; 16:935-44. California and rationale for recommended treat­ 26. Spaite D, Dart R, SullivanJB. Skin testing in cases of ment. WestJ Med 1988; 148:37-44. possible crotalid envenomation Vetter]. Ann Emerg 10. Russell FE. First-aid for snake venom poisoning. Med 1988, 17:105-6.

Toxicon 1967; 4:285-9. 27. Bielory L. Clinical complications of heterologous http://www.jabfm.org/ 11. Wmgert WA First aid for bites. Wilderness antisera administration. J Wuderness Med 1991; Med Lett 1991; 8(3):9-11. 2(2):127-39. 12. McCollough NC, Gennaro JR Evaluation of ven­ 28. Ledbetter EO, Kutcher AE. The aerobic and anaerobic omous snake bite in the Southern United States flora of rattlesnake fangs and venom: therapeutic im­ from parallel clinical and laboratory investigations: plications. Arch Environ Health 1969; 19:770-8. development of treatment. J Fla Med Assoc 1963; 29. Wmgert WA, Wainschel J. A quick handbook on 49:959-67. snake bites. Med Tunes 1977; 105(4):68-75. on 28 September 2021 by guest. Protected copyright. 13. Bronstein AC, Russell FE, Sullivan JB, Egen NB, 30. Stewart RM, Page Cp, Schwesinger WH, McCarter Rumack BH. Negative pressure suction in field R, Martinez J, Aust ]B. Antivenin and fasciot­ treatment of rattlesnake bite. Vet Hum Toxico11985; omy/debridement in the treatment of the severe 28:297. rattlesnake bite. Am] Surg 1989; 158:543-7. 14. Snyder CC, Knowles RP. Snakebites. Guidelines for 31. Hardy DL. Fatal rattlesnake envenomation in Ari­ practical management. Postgrad Med 1988; zona: 1969-1984. Clin Toxicoll986; 24:1-10. 83(6):52-60,65-8,71-5. 32. Curry se, Horning D, Brady P, Requa R, Kunkel 15. Watt CH Jr. Treatment of poisonous snakebite with DB, Vance MY. The legitimacy of rattlesnake bites emphasis on digit dermotomy. South Med J 1985; in central Arizona. Ann Emerg Med 1989; 18: 78:694-9. 658-34.

Venomous Snakebite 405 L