POISINDEX(R) TOXICOLOGIC MANAGEMENTS Topic: GILA MONSTER (HELODERMA SUSPECTUM)0.0 OVERVIEW 0.1 LIFE SUPPORT This overview assumes that basic life support measures have been instituted. 0.2 CLINICAL EFFECTS 0.2.1 SUMMARY OF EXPOSURE A. The bite is usually forceful and tenacious, but in about 30% of the cases no venom is injected. The small puncture wounds caused by the teeth may number from several to 15, and in some cases they may be difficult to find and remove. Pain is always present when venom is injected, and is usually described as burning or intense, reaching its peak in the wound area between 15 and 45 minutes. Some pain may persist for 8 to 24 hours. Edema occurs in most cases, but is slower in developing than in rattlesnake bites, and it is less severe. The area around the puncture wounds may appear bluish and there may be superficial hemorrhage and tissue changes, but ecchymosis is uncommon and necrosis is rare, except in the area of injury. B. Weakness, faintness and dizziness, and sweating are common early manifestations. The area around the wound is generally quite tender, and both lymphangitis and lymphadenitis may be present. Systemic manifestations are uncommon, although nausea, vomiting, tinnitus, increased perspiration, muscle fasciculations, headache, and shock have all been reported. 0.3 LABORATORY A. Complete blood count including platelets, coagulation profile (PT, PTT, fibrinogen), urinalysis, type and hold for cross-matching in severe envenomations, and serum electrolytes. These should be repeated daily during the first three days. 0.4 TREATMENT OVERVIEW 0.4.1 SUMMARY A. The lizard should be disengaged as quickly as possible without breaking teeth off in the wounds. This can often be done by prying open the jaws with pliers, a screwdriver, or crowbar. A match under the lower jaw will sometimes disengage the lizard. B. The patient should be placed at rest, given reassurance, and the injured part lightly immobilized. All constriction bands should be removed, nothing given by mouth, and the patient transported to a medical facility as quickly as possible. Do not incise the fang marks or traumatize the wound area. Probe puncture sites with a 27- or 30-gauge needle to locate any broken teeth; these can be removed under lidocaine. In general, patients rarely require any measures other than bed rest, immobilization of the affected part in a functional position with placement just below heart level, soft diet, mild sedation, analgesics for pain, and the appropriate antitetanus agent. C. The injured part should be soaked for 15 minutes three times a day in aluminum acetate solution (1:20) (c)1974-1993 Micromedex Inc. - All rights reserved - Vol. 78 Exp. 11/30/93 POISINDEX(R) TOXICOLOGIC MANAGEMENTS Topic: GILA MONSTER (HELODERMA SUSPECTUM) (Burow's solution) and after the first day, active exercise carried out as the edema recedes. Infections are uncommon and rarely are antibiotics required. Aspirin is usually sufficient for pain, and diazepam, 5 mg TID, reduces anxiety and the need for stronger analgesics. D. Although hypotension or shock are rare, an IV should be kept open, but the fluids should be kept at a minimum in the absence of shock. It is essential that the patient remain at bed rest or relatively inactive for 2 to 3 days following any Gila monster bite. E. HYPOTENSION: Administer IV fluids and place in Trendelenburg position. If unresponsive to these measures, administer dopamine (2 to 5 mcg/kg/min) (first choice) or norepinephrine (0.1 to 0.2 mcg/kg/min) and titrate as needed to desired response. F. Wounds should be covered with a sterile dressing. In the rare case in which platelets have fallen below 100,000, a return to normal usually occurs within 3 days, even without treatment. Bed rest is advised for at least 3 days. A regular diet is appropriate after the first 24 hours. It is important to keep the injured part out of a completely dependent position for at least one week, but the part should be exercised during this period.1.0 SUBSTANCES INCLUDED/SYNONYMS 1.3 DESCRIPTION A. Helodermatids are large, corpulent, relatively slow-moving, and largely nocturnal lizards. Adult Gila monsters may reach a length of 55 cm or more. They have large flat heads, blunt snouts, and heavy mandibular muscles demarcating the head from the neck. The large rounded tail may measure one-half total body length. The feet bear hand-like claws, and the skin is tough with bead-like scales, black or dark brown reticulum enclosing lighter spots and bars of whitish yellow through shades of pink, or even red. 1.4 GEOGRAPHICAL LOCATION A. Two subspecies, Heloderma suspectum and H. cinctum are found in the US, and extend from southern Utah over much of Arizona, parts of New Mexico and Nevada, a small area of California, and south into Sonora to the Gulf of California. B. H. horridum, the beaded lizard, is found throughout parts of Mexico. 1.6 OTHER A. VENOM APPARATUS: This consists of paired venom glands, venom ducts which lead from the glands to their terminus on the outer surface of the lower gum near the base of certain teeth. The venom is discharged from the ducts into the base of the grooves of the teeth of the lower jaw, where it is drawn up by capillary action into the grooved teeth, and thus into the wound. By this action the venom may be transferred to the larger teeth of the upper jaw. (c)1974-1993 Micromedex Inc. - All rights reserved - Vol. 78 Exp. 11/30/93 POISINDEX(R) TOXICOLOGIC MANAGEMENTS Topic: GILA MONSTER (HELODERMA SUSPECTUM) B. VENOM: An adult helodermatid has about 15 to 20 mg dried weight of venom, and its intravenous LD50 in mice is approximately 0.5 to 1.0 mg/kg, as compared with 2.18 for that of the western diamondback rattlesnake. It is unlikely that a fatal dose of venom could be delivered, except perhaps to an infant or child. The venom contains serotonin, amine oxidase, phospholipase, hyaluronidase, protease, salivary kallikrein, and arginine ethyl ester hydrolase, but appears to lack acetylcholinesterase, nucleotidase, amino acid oxidase, and fibrinogenocoagulase activities. The lethal activity is thought to be associated with the proteolytic activity. It appears that the physiopharmacology is very similar to that of rattlesnake venom poisoning (Russell, 1983).2.0 CLINICAL EFFECTS 2.1 SUMMARY OF EXPOSURE A. The bite is usually forceful and tenacious, but in about 30% of the cases no venom is injected. The small puncture wounds caused by the teeth may number from several to 15, and in some cases they may be difficult to find and remove. Pain is always present when venom is injected, and is usually described as burning or intense, reaching its peak in the wound area between 15 and 45 minutes. Some pain may persist for 8-24 hours. Edema occurs in most cases, but is slower in developing than in rattlesnake bites, and it is less severe. The area aroung the puncture wounds may appear bluish and there may be superficial hemorrhage and tissue changes, but ecchymosis is uncommon and necrosis is rare, except in the area of injury. B. Weakness, faintness and dizziness, and sweating are common early manifestations. The area around the wound is generally quite tender, and both lymphangitis and lymphadenitis may be present. Systemic manifestations are uncommon, although nausea, vomiting, tinnitus, increased perspiration, muscle fasciculations, headache, and shock have all been reported. 2.2 VITAL SIGNS 2.2.4 PULSE A. THREADY: The pulse may be increased and thready in some cases. 2.3 HEENT 2.3.2 EYES A. EXOPHTHALMOS: Bulging eyes has been reported (Stahnke et al, 1970). B. BLINDING LIGHTS: Has been reported (Stahnke et al, 1970). C. PERIORBITAL SWELLING: May occur (Stahnke et al, 1970). 2.4 CARDIOVASCULAR A. HYPOTENSION: Primary shock and hypotension may occur. Severe hypotension was reported in a 23-year-old (Bou-Abboud & Kardassakis, 1988; Preston, 1989). B. T-WAVE: Transient conduction defects and non-specific T-wave changes were described in an otherwise healthy 20 year old male (Roller, 1977). (c)1974-1993 Micromedex Inc. - All rights reserved - Vol. 78 Exp. 11/30/93 POISINDEX(R) TOXICOLOGIC MANAGEMENTS Topic: GILA MONSTER (HELODERMA SUSPECTUM) C. MYOCARDIAL INFARCTION: A 23-year-old, previously healthy male, demonstrated evidence on EKG of an acute anterolateral infarct on admission following a bite by a banded gila monster. Creatinine kinase reported at 4,697 IU with a positive MB band (Bou-Abboud & Kardassakis, 1988). The patient did not have chest discomfort or shortness of breath on admission. The same case was reported by Preston (1989). 2.5 RESPIRATORY A. RATE: Increased respiratory rate may be noted. 2.6 NEUROLOGIC A. WEAKNESS: And dizziness are common and probably related to primary hypotension. Most victims have weakness within 15 to 30 minutes which may persist for several days. B. TINNITUS: May be noted. 2.7 GASTROINTESTINAL A. VOMITING: Nausea and vomiting may be noted. 2.9 GENITOURINARY A. ACUTE RENAL FAILURE: Resulted from a Gila monster bite secondary to severe hypotension (Bou-Abboud & Kardassakis, 1988; Preston, 1989). 2.13 TEMPERATURE REGULATION A. PERSPIRATION: Increased perspiration is common, appearing within 30 minutes and lasting several hours. 2.14 HEMATOLOGIC A. THROMBOCYTOPENIA: There is rarely evidence of coagulation defects. Slight thrombocytopenia is rarely reported in serious bites. Coagulopathy, with elevated PT and PTT and platelet count of 62,000 was reported in one case (Bou-Abboud & Kardassakis, 1988; Preston, 1989). B. LEUKOCYTOSIS: Mild leukocytosis may be noted. 2.15 DERMATOLOGIC A. BITE: The bite has been described as forceful and tenacious; while some may only nip, other may hold on for 10 to 15 minutes. Bites without envenomation can occur. The wounds are simple punctures, varying from 1 to 15 in number. Teeth may be broken off and imbedded under the skin. With envenomation pain is a consistent symptom, present within 30 seconds to 5 minutes. It is usually intense and may spread to involve the entire extremity within 10 minutes. "Radiating" pain up the arm or leg may be described. In minor bites pain peaks in 15 to 45 minutes and then subsides. In major bites pain may last 3 to 5 hours and recede slowly. Shooting pain or dull pain in the extremity may persist up to 8 hours. Local tenderness at the site may last 3 to 4 weeks. Some cyanotic discoloration or ecchymosis may be present, usually without tissue breakdown or necrosis. B. EDEMA: Is an important presenting sign, beginning within 15 minutes and slowly progressing over 4 to 8 hours. 2.16 MUSCULOSKELETAL A. LYMPHADENOPATHY: Axillary lymphadenopathy may be common in severe envenomations, especially when extensive edema is present. (c)1974-1993 Micromedex Inc. - All rights reserved - Vol. 78 Exp. 11/30/93 POISINDEX(R) TOXICOLOGIC MANAGEMENTS Topic: GILA MONSTER (HELODERMA SUSPECTUM)3.0 LABORATORY 3.2 MONITORING PARAMETERS/LEVELS 3.2.1 SERUM/PLASMA/BLOOD A. Complete blood count including platelets, coagulation profile (PT, PTT, fibrinogen), urinalysis, type and hold for cross-matching in severe envenomations, and serum electrolytes. These should be repeated daily during the first three days. B. Renal function tests and creatine kinase levels may also be useful. 3.2.2 URINE A. Urinalysis should be followed daily during the first three days. 4.0 CASE REPORTS A. A 29-year-old female with history of chronic alcohol abuse, recent alcohol abuse, and a seizure disorder presumably resulting from alcoholism was bitten on the abdomen by her pet gila monster. The lizard was dislodged by slashing the neck with a knife. On arrival to the emergency department she complaining of difficulty in breathing and speaking of pain in the area of the bite. She was diaphoretic with an ashen skin color. She developed frequent and profuse vomiting and diarrhea. She was treated with symptomatic and supportive care and was discharged approximately 48 hours after admission (Heitschel, 1986). 5.0 TREATMENT 5.1 LIFE SUPPORT Support respiratory and cardiovascular function. 5.2 SUMMARY A. LIZARD DISENGAGEMENT 1. The lizard should be disengaged as quickly as possible without breaking teeth off in the wounds. This can often be done by prying open the jaws with pliers, a screwdriver, or crowbar. A match under the lower jaw will sometimes disengage the lizard. B. FIRST AID 1. The patient should be placed at rest, given reassurance, and the injured part lightly immobilized. All constriction bands should be removed, nothing given by mouth, and the patient transported to a medical facility as quickly as possible. 2. Do not incise the fang marks or traumatize the wound area. Probe puncture sites with a 27- or 30-gauge needle to locate any broken teeth; these can be removed under lidocaine. 3. In general, patients rarely require any measures other than bed rest, immobilization of the affected part in a functional position with placement just below heart level, soft diet, mild sedation, analgesics for pain, and the appropriate antitetanus agent. C. ALUMINUM ACETATE 1. The injured part should be soaked for 15 minutes three times a day in aluminum acetate solution (1:20) (Burow's solution) and after the first day, active exercise (c)1974-1993 Micromedex Inc. - All rights reserved - Vol. 78 Exp. 11/30/93 POISINDEX(R) TOXICOLOGIC MANAGEMENTS Topic: GILA MONSTER (HELODERMA SUSPECTUM) carried out as the edema recedes. Infections are uncommon and rarely are antibiotics required. Aspirin is usually sufficient for pain, and diazepam, 5 milligrams three times daily, reduces anxiety and the need for stronger analgesics. D. HYDRATION 1. Although hypotension or shock are rare, an intravenous line should be kept open, but the fluids should be kept at a minimum in the absence of shock. It is essential that the patient remain at bed rest or relatively inactive for 2 to 3 days following any Gila monster bite. E. HYPOTENSION 1. If the patient is hypotensive, administer 10 to 20 milliliters/kilogram of isotonic intravenous fluids and place in Trendelenburg position. If the patient is unresponsive to these measures, administer dopamine or norepinephrine. Dose: a. DOPAMINE: Add 200 or 400 milligrams to 250 milliliters of normal saline or D5W to produce 800 or 1600 micrograms per milliliter or add 400 milligrams to 500 milliliters of normal saline or D5W to produce 800 micrograms per milliliter. Begin at 2 to 5 micrograms per kilogram per minute progressing in 5 to 10 micrograms per kilogram per minute increments as needed. If VENTRICULAR ARRHYTHMIAS occur, decrease rate of administration. b. NOREPINEPHRINE (LEVARTERENOL): Add 4 milliliters of 0.1 percent solution (4 milligrams) to 1000 milliliters of D5W to produce 4 micrograms per milliliter. Initial dose is ADULTS: 2 to 3 milliliters (8 to 12 micrograms) per minute or ADULT AND CHILD: 0.1 to 0.2 microgram per kilogram per minute. Titrate to maintain adequate blood pressure. Average adult maintenance doses are 0.5 to 1 milliliter (2 to 4 micrograms) per minute of solution (base). F. WOUND CARE 1. Wounds should be covered with a sterile dressing. In the rare case in which platelets have fallen below 100,000, a return to normal usually occurs within three days, even without treatment. Bed rest is advised for at least 3 days. A regular diet is appropriate after the first 24 hours. It is important to keep the injured part out of a completely dependent position for at least one week, but the part should be exercised during this period. G. ANTIVENIN 1. Two antivenins have been produced experimentally by the Poisonous Animal Research Laboratory of Arizona State University and the Venom Poisoning Center at the Los Angeles County University of S California Medical Center, but there are no commercially available products (Russell & Bogert, 1981).6.0 RANGE OF TOXICITY 6.2 MINIMUM LETHAL EXPOSURE (c)1974-1993 Micromedex Inc. - All rights reserved - Vol. 78 Exp. 11/30/93 POISINDEX(R) TOXICOLOGIC MANAGEMENTS Topic: GILA MONSTER (HELODERMA SUSPECTUM) A. The lethal dose of Heloderma venom for man has been estimated at 5 to 8 milligrams, but this is probably a low figure (Russell & Bogert, 1981). The average yield of venom obtained by milking is 17 milligrams. 6.6 LD50/LC50 A. LD50 (IV) (MOUSE): 0.45 to 1 mg/kg12.0 REFERENCES 12.1 GENERAL REFERENCES 1. Alagon AC, Maldonado ME, Julia JZ et al: Venom from two species of Heloderma Horridum (Mexican beaded lizard): general characterization and purification of N-benzoyl-L-arginine ethyl ester hydrolase. Toxicon 1982; 20:463-475. 2. Bogert CM & del Campo RM: The Gila monster and its allies. Bull Am Mus Nat Hist 1956; 109:1-238. 3. Bou-Abboud CF & Kardassakis DG: Acute myocardial infarction following a gila monster (Heloderma suspectum cinctum) bite. West J Med 1988; 148:577-579. 4. Heitschel S: Near death from a gila monster bite. J Emerg Nurs 1986; 12:259-212. 5. Hendon RA & Tu AT: Biochemical characterization of the lizard toxin gilatoxin. Biochemistry 1981; 20:3517-3522. 6. Mebs D: Biochemistry of kinin-releasing enzymes in the venom of the viper Bitis gabonica and of the lizard Heloderma suspectum. In: Bradykinin and Related Kinins. Plenum Press 1970; 107-116. 7. Preston CA: Hypotension, myocardial infarction, and coagulopathy following Gila monster bite. J Emerg Med 1989; 7:37-40. 8. Roller JA: Gila monster bite: a case report. Clin Toxicol 1977; 10:423-427. 9. Russell FE & Bogert CM: Gila monster: its biology, venom and bite - a review. Toxicon 1981; 19:341-359. 10. Russell FE: Snake Venom Poisoning. Scholium International, 1983. 11. Stahnke HL, Heffron WA & Lewis DL: Bite of the Gila monster. Rocky Mtn Med J 1970; 67:25.13.0 AUTHOR INFORMATION A. Written by: POISINDEX(R) Editorial Staff, Denver, Colorado 80203, 04/84 B. Reviewed by: Barry H Rumack, MD, 04/84 C. Revised by: Findlay E Russell, MD, 06/85 POISINDEX(R) Editorial Staff, 02/89 D. In addition to standard revisions of this management certain portions were updated with recent literature: 04/89 Downloaded from Herp-Net BBS. Copyrighted, may only be used for educational purposes.