IMMEDIATE FIRST AID
for bites by
In the event of an actual or probable bite from a Krait, execute the following first aid measures without delay.
- Make sure that the responsible snake or snakes have been appropriately and safely contained, and are out of danger of inflicting any additional bites.
- Immediately call for transportation.
- Keep the victim calm and reassured. Allow him or her to lie flat and avoid as much movement as possible. If possible, allow the bitten limb to rest at a level lower than the victim's heart.
- Immediately wrap a large crepe bandage snugly around the bitten limb starting at the site of the bite and working proximally up the limb (the full length if possible). The bandage should be as tight as one might bind a sprained ankle. (See the attached copy from "First Aid for Snakebite" by Dr. S.K. Sutherland.)
- Secure the splint to the bandaged limb to keep the limb as rigid and unmoving as possible. Avoid bending or moving the limb excessively while applying the splint.
- DO NOT remove the splint or bandages until the victim has reached the hospital and is receiving Antivenom.
- Have the Commonwealth Serum Laboratories Tiger Snake Antivenom ready for the emergency crew to take with the victim to the hospital. Give them the following:
- the available antivenom (at least 10 vials)
- the accompanying instruction (Protocol) packet
- the victim's medical packet (if available)
DO NOT cut or incise the bite site
DO NOT apply ice to the bite site
Summary for Human Bite
The bite of the Krait species with envenomation is capable of delivering one of the most lethal venoms compared to other Asian snakes. Species are found from southeast Asia and Thailand to China and south Indonesia. Prior to the development of adequate antivenom, reported mortality rates of Indian Kraits were as high as 77%. One may expect, depending on the species, the onset of neurotoxic symptoms from minutes to hours after envenomation.
- First Aid:
- Bandage and Immobilize the bitten limb with crepe bandages and splint. Rest the extremity below the level of the patient's heart (if practical).
- Transport to a medical center emergency or trauma service.
- Medical Management
- Call your local Poison Control Center or the San Diego Regional Poison Control Center (800 876-4766). They should locate a consultant to help you treat this patient.
- Observe for Signs and Symptoms of Envenomation.
- If signs or symptoms are present, perform the following:
- Administer Lactated Ringers Solution at 200 to 250 mls per hour.
- Draw samples and collect initial laboratory data.
- If signs or symptoms are present, dilute one vial (3000 units, 7.6 cc) of Tiger Snake Antivenom in 60 mls of Lactated Ringers Solution, this makes a 1:10 dilution. Administer INTRAVENOUSLY 100 units/minute (2.0 ml/minute).
- Remove the splints and crepe bandage slowly over a period of 5 minutes. If symptoms progress rapidly, reapply the bandage, and administer an additional vial of antivenom. Again attempt to remove the bandage.
- Allergic or untoward reactions to the antivenom should be treated with Corticosteroids, Epinephrine, and/or Antihistamines as appropriate.
- Monitor Signs, Symptoms, and Laboratory data, and administer 1-3 additional vials of antivenom as needed to neutralize the signs and symptoms.
- Literature has shown Tiger Snake Antivenom to be very effective against Krait envenomation. However, due to the scarcity of reported case histories, ranges of antivenom vials needed for minimum to severe bites is not well documented. Therefore we recommend administering 1-3 (or more) additional vials of antivenom at the above rate to neutralize signs and symptoms.
for bites by
This person has received a bite and probable envenomation from a Krait (Bungarus species). These are very lethal snakes with a high mortality rate if not treated with antivenom. They are generally nocturnal snakes whose symptomatology is similar to the cobra's neurotoxic effects, but without local symptoms (ie. necrosis, bleeding). Symptoms of envenomation include drowsiness, neurologic/neuromuscular manifestations, and abdominal pain which may develop; proximal limb paralysis, ventilatory failure and/or coma can ensue rapidly.
Please read and execute the following procedures without delay.
- A crepe bandage and splint have been applied as immediate first aid adjuncts to retard the absorption of the venom. DO NOT remove until the patient has arrived at the hospital and is receiving the antivenom.
- Make sure that at least 10 packages of Commonwealth Serum Laboratory Tiger Snake Antivenom are present with the patient. This antivenom contains the appropriate fractions necessary to neutralize the components of Indian Krait venom.
- Envenomation is diagnosed by the presence of characteristic signs and symptoms. Necessary information follows and is organized in sections:
- Signs and Symptoms of Envenomation
- Medical Management
- General Considerations
- Special Considerations
Signs and Symptoms of Envenomation:
- Neurologic/Neuromuscular: These signs and symptoms will usually manifest earliest. Not all of these will necessarily develop, even with severe envenomation.
- Glossopharyngeal palsy (dysphagia)
- Strabismus, blurring vision
- Pupils dilated
- Proximal limb paralysis
- Intercostal & diaphragmatic paralysis (respiratory failure)
- Increased oral secretion
- Facial paralysis (Malayan kraits)
- Decreased tendon reflexes (Malayan kraits)
- General: These symptoms typically manifest within one to three hours, though for Kraits it can be up to 12 hours following the bite.
Abdominal pain is usually moderate to severe and confined to the epigastrium, but can be generalized.
Diffuse muscle tenderness rarely occurs.
- Hematology: One may expect a polymorph leucocytosis ranging up to 22x103 WBC with 90% polys.
- Cardiotoxicity: A small amount of cardiotoxin is present in Indian Krait snake venom, but usually demonstrates no heart manifestations. A transient (5-15 minutes) decrease in arterial pressure without further changes has been reported.
- Local Symptoms: In Krait bites, rarely if ever does local tissue destruction and necrosis appear. One can find minimal edema and pain at the bite site.
- Fang Marks: Fang marks may be present as one or more well defined punctures, as a series of small lacerations or scratches, or there may not be any noticeable or obvious markings where the bite occurred. The absence of fang marks does not preclude the possibility of a bite (especially if a juvenile snake is involved). In general, the fang marks from a Krait are made from a quick, snapping motion. Multiple bites inflicted by a single snake or by more than one snake are also possible, and should be noted if present (See Special Considerations below). The presence of fang marks does not always imply that the injection or deposition of venom into the bite wound (envenomation) actually occurred.
- Admit patient to an emergency or trauma service and notify the consultant identified by the Poison Control Center.
- Begin a peripheral intravenous infusion (16 gauge catheter) of Lactated Ringers Solution at a rate of 250 cc/hour.
- Draw blood from the unbitten extremity, and collect urine for the following laboratory tests. Mark STAT.
- Type and Cross Match TWO units of Whole blood.
- CBC with differential.
- Coagulation Parameters:
- Prothrombin Time (PT)
- Partial Thromboplastin Time (PTT)
- Platelet Count
- Fibrinogen levels
- Fibrin Degradation Products
- Serum Electrolytes, BUN/Creatinine, Calcium, Phosphorus.
- Lactate Dehydrogenase (with Isoenzyme analysis). Isoenzyme analysis may indicate multiple targets of the venom components which may dictate further management.
- Urinalysis (Macroscopic and Microscopic Analysis). Must include analysis for:
- Free Protein
- Electrocardiogram (Place the patient on continuous monitoring).
- Additional Tests as needed or indicated by patient's hospital course.
- It may be necessary or practical to repeat some or all of the above serum and urine tests periodically over the hospital course to monitor the effects of antivenom therapy or to detect late changes in parametric values.
- Obtain an arterial blood gas, especially if the patient is beginning to experience respiratory difficulty.
- OBSERVE PATIENT CLOSELY for signs and symptoms of envenomation which usually manifest between 15 minutes and two hours following the bite.
- If NO signs or symptoms have been noted after TWELVE hours, there is the possibility that the patient received a dry bite (no venom injected).
- VERY SLOWLY begin to remove the bandages and splint watching carefully for any changes in the patient's status. If any changes occur, assume the patient has been envenomed and prepare to give antivenom immediately (as directed below).
- If signs and symptoms still fail to manifest, continue CLOSE observation of the patient for an additional 24 hours.
- IF ANY SIGN OR SYMPTOM becomes apparent or has been noted during the course of evaluation, begin Antivenom Therapy as follows:
- Dilute the contents of ONE vial of Tiger Snake Antivenom (3000 units, 7.6 cc) in 60 ml of Lactated Ringers (Hartmann's solution) a 1:10 dilution.
- Administer the diluted antivenom intravenously over a period of 30 minutes at a rate of about 100 units/minute (2.0 ml/ minute).
- Should any signs of ALLERGY/ANAPHYLAXIS (e.g., coughing, dyspnea, urticaria, itching, increased oral secretions, etc.) develop, immediately discontinue the administration of antivenom, and treat symptoms with epinephrine, steroids and antihistamines. As soon as the patient is stabilized, continue the antivenom infusion at a slower rate.
- After the first vial of antivenom has been administered, the splint and the bandages may be removed. This should be done VERY SLOWLY over a FIVE minute period to prevent a bolus release of venom. If the patient's condition worsens:
- Reapply the crepe bandage.
- Prepare a second vial of antivenom (1 vial in 60 mls of Lactated Ringers Solution) as directed above.
- Infuse this dose at 2.0 ml per minute over 30 minutes.
- Release the bandage again, slowly, over a 5 minute period.
- Literature has shown Tiger Snake Antivenom to be very effective against Krait envenomation. However, due to the scarcity of reported case histories, ranges of antivenom vials needed for minimum to severe bites is not well documented. Therefore, we recommend administering 1-3 (or more) additional vials of antivenom at the above rate to neutralize signs and symptoms.
- Antivenom Therapy is the mainstay of treatment for krait envenomation. Many of the symptoms are ameliorated or entirely eliminated by the antivenom alone. Other symptoms will require additional modalities of therapy to correct. Local symptoms if any, may take several days to weeks to completely resolve; their progression, however, may be treated with antivenom therapy.
- Neurological Symptoms (especially respiratory obstruction or failure) are usually the most immediate cause of dangerous problems. Often, these are improved by the antivenom. If breathing becomes impaired, provide respiratory assistance. Secretions may become copious necessitating suctioning.
- If severe muscle paralysis develops and persists, administer 0.6 mg of Atropine IV. Follow by giving 0.5 mg of Neostigmine IV every 30 minutes for a maximum of FIVE doses.
- It is important to keep venom neutralization current and continuous. The best method to accomplish this is to keep a close watch on the patient's status. If the present condition does not improve, or should it worsen for any reason, additional antivenom should be administered. The antivenom should ideally be diluted 1 to 10 in Lactated Ringers Solution, and always given by intravenous infusion at a rate of One vial per 30 minutes (2.8 mls per min). Give all additional antivenom in one vial doses.
- It is advisable to perform periodic serum and urine analyses during therapy (as outlined above).
- It is always best to keep the patient in an Intensive Care setting until free of major symptoms for 24 hours. The patient should be observed in the hospital for at least 24 hours after symptoms are stabilized.
- It is important that the patient be placed at rest, kept warm, and avoid unnecessary movement.
- The onset of dangerous Neurotoxic symptoms can be rapid and subtle. In addition, they are more rapidly reversed in their early stages than when fully developed. It may be necessary to wake the patient and perform a brief neurologic check every hour or so to assure that breathing and other neurological functions are not impaired. Carefully note the progress of any paralysis which maybe present.
- Respiratory obstruction and failure are the greatest immediate concerns. Should the patient develop difficulties in breathing or airway management, respiratory support will be required. If the tongue, jaw or pharynx become paralyzed, insert an oral airway; intubation may be required. Make sure adequate suction equipment is available and operative.
- Fluid management is very important in snake bite cases. The patient should be well hydrated and a brisk urine output maintained.
- If any signs of Oropharyngeal paralysis or impaired swallowing exist, give NOTHING BY MOUTH, and keep patient on his side with head down. Watch for airway compromise and aspiration.
- Morphine is CONTRAINDICATED because of its tendency to suppress respiration. Alcohol should also be avoided.
- In cases in which Circulatory Shock remains uncorrected by antivenom therapy, plasma volume expanders and/or vasopressor agents may be given with appropriate considerations.
- Tetanus prophylaxis should be current.
- Antibiotics are NOT recommended prophylactically.
- Multiple Bites:
1. It is possible for a Krait to deliver more than one bite in a single attack, and thus may inject a larger volume of venom. If there is evidence that such an attack occurred (i.e., history or multiple bite sites), twice (2X) the initial dose of antivenom should be given: (i.e., two vials in 120 mls of Lactated Ringers solution delivered over 60 minutes at a rate of one vial per thirty minutes). Always watch closely for signs of allergic response; if they occur, treat appropriately and slow infusion rate. Give all subsequent doses in One vial increments at 1 vial per 30 minutes as necessitated by the presence of continued signs and symptoms.
- Severe Envenomation:
1. If the patient shows severe signs of envenomation particularly if early after the bite, treat as a multiple bite, administering two vials of antivenom over the first 60 minutes. Give all subsequent doses in ONE vial increments at a rate of one vial per 10 minutes as necessitated by the presence of continued signs and symptoms.
- Testing for Equine Protein Sensitivity:
- It is NOT ADVISABLE to utilize subcutaneous or intradermal testing for sensitivity to equine products in that such testing may be unreliable, and may unnecessarily delay antivenom therapy which must be used if any signs of envenomation are present.
- If there is reason to believe that the patient may be sensitive to equine protein products (e.g., previous snake bite treated with antivenom in which a sensitivity reaction was noted, multiple previous snakebites):
- Administer 1 gram of Solumedrol I.V. push.
- Wait 15 minutes before administering the antivenom.
- Administer the antivenom at a rate of one vial per thirty minutes, but be prepared to infuse more slowly if allergic symptoms manifest.
- Be prepared to treat for anaphylaxis with epinephrine and other vasoactive medicines.
The following references are recommended for further indepth reading. This material includes case histories, guidelines, and recent findings in elapid literature. These should be read only after treatment has begun, and the patient is in stable status.
- Ahuja, M.L. and Singh, G: Snake Bite in India. Ind. Jou. Med. Res. 42:4, 661-678, Oct. 1954.
- Bernheimer, A.W., Weinslein, S.A. and Linder, R.: Isoelectric analysis of some Australian elapid snake venoms with special reference to Phospholipase B and Hemolysis. Toxicon, 24:8, 841-849, 1986.
- Brown, J.H.: Toxicology and pharmacology of venoms from poisonous snakes. Charles C. Thomas, Springfield, IL, 1973.
- Buckley, E.E., and Porges, N: Venoms, 198. The American Association for the Development of Science, Washington, D.C.
- Commonwealth Serum Laboratories: Treatment of snakebite in Australia and Papua New Guinea using antivenom. (Package insert) CSL, September, 1985.
- Habermehl, G.G.: Venomous animals and their toxins, 2nd Edition, 1977. Springer-Verlag, New York, 1981.
- Minton, S.A.: Venom Diseases. Charles C. Thomas, Springfield, IL, 130-131, 1974.
- Minton, S.A.: Snake venoms and envenomation. Marcel Dekker, Inc., New York. 1971.
- Russell, F.E. and Saunder, P.R.: Animal Toxins. Pergamon Press, Ltd. London, England, 265-285, 1967.
- Russell, F.E.: Snake Venom Poisoning, 2nd Edition. Scholium International. Great Neck, New York. 1983.
- Tu, A.T.: Chemistry and molecular biology, 1st. edition. John Wiley and Sons, New York. 178-201, 1977.
- Viravan, C., Veeravat, U., et. al.: ELISA confirmation of acute and past envenomations by the Moncellate Thai cobra (Naja Kaouthia). Am. J. Trop. Med. Hyg. 35(1), 173-180, 1986.
- Warrel, D.A., Looaressuwan, S., et.al.: Severe neurotoxic envenoming by the Malayan Krait, Bungarus candidus (linneaus): Response to antivenom and anticholinesterase. Brit. Med. Jour., 286, 678-680, 2/26/83.
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