eMedicine Specialties > Emergency Medicine > Environmental
Snake Envenomation, Coral: Treatment & Medication
Updated: Dec 17, 2008
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Treatment
Prehospital Care
Of utmost importance is prompt movement of the victim to a medical facility capable of rendering advanced care, including possible antivenom administration and airway support.
- Briefly attempt to identify the snake (especially, note the color pattern). If possible, take a digital photo of the snake from a safe distance. Efforts to catch or kill the animal can result in wasted time and further bites.
- Rapidly apply a compressive bandage (eg, elastic bandage, crepe bandage, torn clothing) to the bitten extremity, starting distally and progressing to encompass the entire limb. Wrap it as tightly as one would wrap a severe sprained ankle. Then, splint the extremity and, if possible, keep it at approximately heart level. This technique may significantly delay systemic absorption of elapid venoms, including coral snake venom. Research suggests that, in a simulated snakebite scenario, even after focused, intensive hands-on training, people tend to underestimate the application tension required for the technique to be effective. See Media file 3.
The Australian pressure immobilization technique. This technique has been shown to be helpful in delaying systemic absorption of elapid venoms, but its use in cobra bites remains controversial. A broad pressure bandage is immediately wrapped, beginning distally (Media file 3), around as much of the extremity as possible (see Media files 4 and 5). No effort should be spent removing clothing prior to bandage application. The bandage is wrapped snugly, as for a severely sprained ligament. A splint (or sling when applied to the upper extremity) is then placed (see Media files 6 and 7), and the victim is carried from the scene. The victim should expend no effort in getting to definitive care. Pressure immobilization should remain in place until the victim has reached medical care. The doctor will decide when to remove the bandages. If venom has been injected, it will move into the bloodstream quickly once the bandages are removed. The doctor should leave the bandages and splint in position until appropriate antivenom is available. Used with permission from Commonwealth Serum Laboratories.
- No incisions are indicated.
- Suction is of no benefit and may be harmful.
- Avoid applying ice or initiating any other cooling measures.
Emergency Department Care
- Aggressively manage any signs of impending respiratory failure with endotracheal intubation to prevent aspiration.
- Immediately institute cardiac and pulse oximetry monitoring.
- Monitor vital signs closely.
- Start at least one large-bore intravenous line of normal saline or Ringer's lactate at a maintenance rate. If evidence of hypotension or hypoperfusion is present, select an appropriate, faster rate.
- Although numerous recommended grading scales are available for judging the severity of pit viper bites, these scales rely heavily on local findings, which are often minimal in coral snake bites.
- Do not use such scales for coral snake bites.
- Because of the lack of early signs and symptoms, the severity of coral snake bites may be underestimated at presentation. Maintain a high index of concern.
- Historically, if the snake was positively identified as an eastern or Texas coral snake and the victim was asymptomatic, or if signs and symptoms of envenomation were already present, the recommendation was to obtain and immediately administer appropriate antivenom. In the United States, however, as of October 2008, all available stocks of Wyeth's North American Coral Snake Antivenin will have expired, and this country will find itself without a commercially available antivenom.
- Some research centers may have access to other Micrurus antivenoms that may be useful on a research or compassionate care basis in cases of severe bites.
- Absent an available antivenom, victims can be managed with sound supportive care (as outlined above) with an expectation of excellent outcome as long as airway management and respiratory support are adequate, though ventilator dependence could persist for many days following serious bites.
- Bites by Sonoran coral snakes tend to be very mild (there has never been a documented fatality) and are treated with supportive measures alone.
Consultations
- Consult a toxicologist or expert in snakebite management.
Medication
Definitive therapy for coral snake envenomation is antivenom administration. Antivenom (usually derived from horses or sheep) is generally specific for closely related species of snakes, and no advantage exists to giving antivenom developed for unrelated snakes. Administering antivenom made from the venoms of unrelated snakes may add complications of acute allergic reaction (eg, anaphylactoid reactions, delayed serum sickness) to an already serious situation. If specific antivenom is unavailable, compression and immobilization should be maintained and the airway and respiratory status supported as necessary. An appropriately applied compression/immobilization device should be removed only after supportive measures are in place and antivenom is obtained (if available).In the United States, the product used to treat Micrurus bites for the last several decades, Wyeth's Micrurus fulvius Antivenin, is no longer in production. Other antivenoms are produced in other countries (eg, Brazil, Costa Rica) for non-North American coral snakes. Mexico produces an antivenom that is likely effective for coral snake bites in the United States. It may prove that one of these exotic antivenoms will be required to be imported into the United States for use in serious bites here. In the absence of such an antivenom, care must be entirely supportive.
Care for persons bitten by Sonoran coral snakes is entirely supportive because no specific antivenom is available for this species.
Any appropriate, available antivenom should be administered according to the manufacturer's instructions.
As with any form of bite, tetanus status should be updated as necessary.
Antibiotic prophylaxis is not indicated. Because of the relative paucity of enzymatic necrotic components in their venoms, coral snake bites tend to cause little local tissue damage, and secondary infections are rare.
Antivenom
Imparts passive immunity to the patient against the venom components of the snake(s) for which it is manufactured. Heterologous antibodies administered bind with venom antigens and block their deleterious effects.
Micrurus fulvius Antivenin
Historically the DOC for significant bites by M fulvius (eastern coral snake) and M tener (Texas coral snake); however, it is no longer being produced. Unless another known effective antivenom is available, care for victims bitten by coral snakes in the United States will have to rely entirely on supportive care (as per the text above), though the outcome should still be good.
Adult
As per the manufacturer's package insert for the appropriate, available product
Pediatric
Pediatric doses of snake antivenoms are the same as for adults
None reported
Documented hypersensitivity; may still be indicated for significant envenomation despite allergy if the reaction is easily reversed with appropriate medications (eg, epinephrine, antihistamines, steroids)
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Anaphylactic/anaphylactoid reactions and delayed serum sickness are a concern; appropriate therapeutic agents for anaphylaxis treatment should be ready for immediate use; while use in pregnancy has not been well studied, it is generally felt that the benefits of antivenom administration outweigh the risks
Antihistamines
H1 and H2 blockers may blunt or prevent acute allergic reaction when given before the administration of antivenom. If an anaphylactoid reaction occurs despite pretreatment, further antihistamine dosing may be required. They are also useful in managing pruritus in cases of delayed serum sickness, which may appear days to weeks following antivenom treatment.
Diphenhydramine (Benadryl)
Administered parenterally and often is the H1 blocker of choice in treating or preventing anaphylactic/anaphylactoid reactions. Also effective in oral form for treating itching associated with serum sickness.
Adult
Pretreatment for antivenom: 1 mg/kg/dose IV; not to exceed 100 mg/dose; if acute allergic reaction subsequently occurs, additional doses may be required; not to exceed 300 mg/d
Serum sickness: 1 mg/kg PO q6h prn itching; not to exceed 400 mg/d
Pediatric
Pretreatment for antivenom: Administer as in adults
Serum sickness: 1 mg/kg PO q6h prn itching; not to exceed 300 mg/d
Potentiates effect of CNS depressants; because of alcohol content, do not give syrup dosage form to patient taking medications that can cause disulfiramlike reactions
Documented hypersensitivity; MAOIs
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
May exacerbate angle-closure glaucoma, hyperthyroidism, peptic ulcer, and urinary tract obstruction
Cimetidine (Tagamet)
Administered parenterally and often is the H2 blocker of choice in treating or preventing anaphylactoid reactions. Use this medication in addition to H1 antihistamines.
Adult
300 mg IV q6h prn
Pediatric
5-10 mg/kg IV q6h prn; not to exceed 300 mg/dose
Can increase blood levels of theophylline, warfarin, tricyclic antidepressants, triamterene, phenytoin, quinidine, propranolol, metronidazole, procainamide, and lidocaine
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Elderly persons may experience confusional states; may cause impotence and gynecomastia in young males; may increase levels of many drugs; adjust dose or discontinue treatment if changes in renal function occur
Cardiovascular agents
These agents are useful in treating acute allergic reactions that may occur with antivenom administration and in supporting the blood pressure and tissue perfusion of hypotensive patients with shock unresponsive to IV fluids and antivenom.
Epinephrine (EpiPen, Adrenaline)
DOC for treating anaphylactoid reactions. Has alpha-agonist effects that increase peripheral vascular resistance and reverse peripheral vasodilatation, systemic hypotension, and vascular permeability. Conversely, beta-agonist activity of epinephrine produces bronchodilatation, chronotropic cardiac activity, and positive inotropic effects.
Adult
0.01 mL/kg of 1:1000 (1 mg/mL) IM/SC; not to exceed 0.5 mL
Pediatric
0.01 mL/kg of 1:1000 (1 mg/mL) IM/SC; not to exceed 0.3 mL; may be repeated q10-20min prn
For severe hypotension: 0.05 mcg/kg/min IV initially (ie, 1 mg in 500 mL isotonic saline, starting at 0.025 mL/kg/min); titrate to effect
Concurrent use with alpha- or beta-blockers is not recommended; nonselective beta-blockade allows alpha-receptor effects to predominate; increasing vascular resistance leads to increased BP and reflex bradycardia; closely monitor vital signs if the patient is taking a beta-blocker; pressor action is increased when coadministered with alpha-agonists; increases toxicity of halogenated inhalational anesthetics
Documented hypersensitivity; cardiac dysrhythmias or angle-closure glaucoma; do not use during labor (may delay second stage of labor)
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Caution in elderly persons, prostatic hypertrophy, hypertension, cardiovascular disease, diabetes mellitus, hyperthyroidism, and cerebrovascular insufficiency; rapid IV infusions may cause death from cerebrovascular hemorrhage or cardiac dysrhythmias
Dopamine (Intropin)
May be required to support BP with hypotension caused by anaphylactoid reaction that is unresponsive to fluids and epinephrine or by direct coral snake venom effects that are unresponsive to fluids and antivenom.
Adult
5-20 mcg/kg/min IV; titrate to effect
Pediatric
Administer as in adults
Phenytoin, alpha-adrenergic and beta-adrenergic blockers, general anesthesia, and MAOIs increase and prolong the effects
Documented hypersensitivity; pheochromocytoma; ventricular fibrillation
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Closely monitor urine flow, cardiac output, pulmonary wedge pressure, and BP during infusion; prior to infusion, correct hypovolemia as indicated; monitoring central venous pressure or left ventricular filling pressure may be helpful in detecting and treating hypovolemia
Norepinephrine (Levophed)
May be used as alternative to dopamine to support BP in the face of hypotension caused by anaphylactoid reaction unresponsive to fluids and epinephrine.
Adult
0.5-1 mcg/min IV; titrate to effect
Pediatric
0.1 mcg/kg/min IV; titrate to effect
Atropine may enhance pressor response by blocking reflex bradycardia
Documented hypersensitivity; peripheral or mesenteric vascular thrombosis because ischemia may be increased and area of infarct extended
Pregnancy
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
If possible, correct intravascular volume depletion before therapy; extravasation may cause severe tissue necrosis and, thus, should be administered into a large vein; caution in occlusive vascular disease
Corticosteroids
Essential for management of acute and delayed allergic phenomena following antivenom administration. Steroids have no primary role in the management of snake envenomation.
Methylprednisolone (Solu-Medrol, Adlone)
Ameliorates the delayed effects of anaphylactoid reactions and may prevent biphasic anaphylaxis. In severe cases of serum sickness, parenteral steroids may reduce the inflammatory effects of this immune-complex mediated disease.
Adult
125 mg IV q6-8h
Pediatric
1-2 mg/kg IV q6-8h
Coadministration with digoxin may increase digitalis toxicity secondary to hypokalemia; estrogens may increase levels; phenobarbital, phenytoin, and rifampin may decrease levels (adjust dose); monitor patients for hypokalemia when taking medication concurrently with diuretics
Documented hypersensitivity; viral, fungal, or tubercular skin infections
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Hyperglycemia, edema, osteonecrosis, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, growth suppression, myopathy, and infections are possible complications of glucocorticoid use
Prednisone (Deltasone)
This or other PO forms of corticosteroids (eg, prednisolone) are useful in managing mild-to-moderate serum sickness on an outpatient basis.
Adult
1 mg/kg PO qd until symptoms resolve; taper over 1-2 wk
Pediatric
Administer as in adults
Coadministration with estrogens may decrease clearance; concurrent use with digoxin may cause digitalis toxicity secondary to hypokalemia; phenobarbital, phenytoin, and rifampin may increase metabolism of glucocorticoids (consider increasing maintenance dose); monitor for hypokalemia with coadministration of diuretics
Documented hypersensitivity; viral, connective tissue, fungal, or tubercular skin infections; peptic ulcer disease; hepatic dysfunction
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Abrupt discontinuation of glucocorticoids after long-term therapy may cause adrenal crisis; hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression, and infections may occur with glucocorticoid use
Immune globulins
Immune globulins bind toxoids, stimulate an immune response, and offer transient protection while the host immune system develops antibodies.
Tetanus immune globulin (Hyper-Tet)
Used for passive immunization if wound might be contaminated with tetanus spores when the patient has no history of completing a primary tetanus immunization series.
Adult
Prophylaxis: 250-500 U IM in different anatomical site than tetanus toxoid administration
Clinical tetanus: 3000-10,000 U IM
Pediatric
Prophylaxis: 250 U IM in different anatomical site than tetanus toxoid administration
Clinical tetanus: Administer as in adults
None reported
Since antibodies in globulin preparation may interfere with immune response to vaccination, do not administer within 3 mo of live-virus immune globulin administration; may be necessary to revaccinate persons who received immune globulin shortly after live-virus vaccination
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Persons with isolated immunoglobulin A (IgA) deficiency have potential for developing antibodies to IgA and could have anaphylactic reactions to subsequent administration of blood products that contain IgA; do not perform skin testing since intradermal injection of concentrated gamma globulin may cause localized area of inflammation and can be misinterpreted, causing the medication to be withheld from a patient not allergic to this material; true allergic responses to human gamma globulin given in prescribed IM manner are extremely rare; do not admix with other medications since usually incompatible
Tetanus toxoid
Used to induce active immunity against tetanus.
Tetanus toxoid
The immunizing agent of choice for most adults and children >7 y is tetanus and diphtheria toxoids. Necessary to administer booster doses to maintain tetanus immunity throughout life. Pregnant patients should receive only tetanus toxoid, not a diphtheria antigen-containing product. In children and adults, may administer into deltoid or midlateral thigh muscles. In infants, preferred site of administration is the mid-thigh laterally.
Adult
Suggested dosing:
Primary immunization: 0.5 mL IM, give 2 injections 4-8 wk apart and a third dose 6-12 mo after second injection
Booster dose: 0.5 mL q10y
Pediatric
Administer as in adults
Patients receiving immunosuppressants, including corticosteroids or radiation therapy, may remain susceptible despite immunization due to poor immune response; cimetidine may enhance or augment delayed-hypersensitivity responses to skin-test antigens; avoid concurrent use of medication with systemic chloramphenicol since it may impair amnestic response to tetanus toxoid; concurrent use of tetanus immune globulin may delay development of active immunity by several days (interaction is nevertheless clinically insignificant and does not preclude its concurrent use)
Documented hypersensitivity; a history of any type of neurological symptoms or signs following administration of this product; FDA recommends that elective tetanus immunization be deferred during any outbreak of poliomyelitis because tetanus toxoid injections are an important cause of provocative poliomyelitis
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Do not use to treat actual tetanus infections, or for immediate prophylaxis of unimmunized individuals (use instead tetanus antitoxin, preferably human tetanus immune globulin), diminished antibody response to active immunization may be seen in patients receiving immunosuppressive therapy; better to defer primary diphtheria immunization until immunosuppressive therapy discontinued; routine immunization of symptomatic and asymptomatic HIV-infected persons is recommended
More on Snake Envenomation, Coral |
| Overview: Snake Envenomation, Coral |
| Differential Diagnoses & Workup: Snake Envenomation, Coral |
 Treatment & Medication: Snake Envenomation, Coral |
| Follow-up: Snake Envenomation, Coral |
| Multimedia: Snake Envenomation, Coral |
| References |
| « Previous Page | Next Page » |
References
Watson WA, Litovitz TL, Rodgers GC Jr, et al. 2004 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. Am J Emerg Med. Sep 2005;23(5):589-666. [Medline].
Davidson TM, Eisner J. United States coral snakes. Wilderness Environ Med. 1996;1:38-45.
German BT, Hack JB, Brewer K, et al. Pressure-immobilization bandages delay toxicity in a porcine model of eastern coral snake (Micrurus fulvius fulvius) envenomation. Ann Emerg Med. Jun 2005;45(6):603-8. [Medline].
Gray S. Pressure immobilization of snakebite. Wilderness Environ Med. Spring 2003;14(1):70-1. [Medline].
Kitchens CS, Van Mierop LH. Envenomation by the Eastern coral snake (Micrurus fulvius fulvius). A study of 39 victims. JAMA. Sep 25 1987;258(12):1615-8. [Medline].
Norris RL, Bush SP. North American venomous reptile bites. In: Auerbach PS, ed. Wilderness Medicine. 4th ed. St. Louis: Mosby; 2001:896-926.
Norris RL, Dart RC. Apparent coral snake envenomation in a patient without visible fang marks. Am J Emerg Med. Jul 1989;7(4):402-5. [Medline].
Norris RL, Ngo J, Nolan K, et al. Physicians and lay people are unable to apply pressure immobilization properly in a simulated snakebite scenario. Wilderness Environ Med. 2005;16(1):16-21. [Medline].
Parrish HM, Khan MS. Bites by coral snakes: report of 11 representative cases. Am J Med Sci. May 1967;253(5):561-8. [Medline].
Simpson ID, Tanwar PD, Andrade C, et al. The Ebbinghaus retention curve: training does not increase the ability to apply pressure immobilisation in simulated snake bite--implications for snake bite first aid in the developing world. Trans R Soc Trop Med Hyg. May 2008;102(5):451-9. [Medline].
Further Reading
Keywords
snake envenomation, snakebite, snake bite, coral snake, Elapidae, Micrurus fulvius, eastern coral snake, Micrurus tener, Texas coral snake, coral snake envenomations, coral snake bite, Micruroides euryxanthus, Sonoran coral snake, Arizona coral snake
