IMMEDIATE FIRST AID
for bites by
In the event of an actual or probable bite from a Tiger Snake, 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.
- 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 TIGER SNAKE ANTIVENOM (Commonwealth Serum Laboratories) ready for the Lifeflight crew to take with the victim to the hospital. Give them the following:
- the available antivenom (at least 5 vials)
- the accompanying instruction (Protocol) packet
- the victim's medical packet
DO NOT cut or incise the bite site
DO NOT apply ice to the bite site
Summary for Human Bite
The bite of the Tiger Snake with envenomation can occasionally be fatal (as early as 30 minutes due to allergic reaction). Please read the attached Medical Management Protocol and respond appropriately.
- First Aid:
- Bandage and Immobilize the bitten limb with crepe
bandages and splint as described in the Immediate First Aid section. Rest this extremity below the level of the patient's heart (if practical).
- Transport to U.C.S.D. Medical Center 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 significant systemic 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.
- Dilute the contents of 1 vial (3000 units) of Commonwealth Serum Laboratories Tiger Snake Antivenom in Lactated Ringers Solution to a total volume of 60 cc. Adminster the antivenom I.V. piggyback over 30 minutes at a rate of 2 cc per minute (i.e., 1 vial per 30 minutes or 100 units per minute).
- Remove the splints and crepe bandage slowly over a period of 10 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 Benadryl, Epinephrine, and/or Corticosteroids. A patient with known sensitivity to horse serum may be pretreated with 1 gm of Solumedrol, administered I.V. push.
- Monitor Signs, Symptoms, and Laboratory data, and administer additional antivenom in 1 vial (3000 units) increments at a rate of 100 units per minute as necessary to control the progession of symptoms.
- The required amount of antivenom will vary with the severity of envenomation. One should anticipate using (including the initial dose):
0-1 vial total for a minor bite with envenomation.
2-5 vials or more may be necessary for moderate or severe bites, however this is quite rare.
for bites by
This person has received a bite and probable envenomation from a Tiger Snake (Notechis species). This is a very venomous and dangerous snake native to Australia, which has caused a significant number of human fatalities. Envenomation may cause neurotoxic, hemolytic, coagulopathic, and myolytic reactions; paralysis or death can ensue in as short as 30 minutes, but more commonly occurs whithin 6-24 hours.
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 5 vials of Tiger Snake Antivenom are present with the patient. This antivenom is specific and is only available directly from the San Diego Zoo Reptile Department. Refrigerate on arrival to the hospital.
- If the patient has been envenomated, the treatment is 0-5 vials of intravenous antivenom. 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:
- Neurological and Neuromuscular: These symptoms are often the first to manifest some within the first 15 to 30 minutes following the bite. However, the time course of development can be highly variable (up to several hours later). Not all signs and symptoms will necessarily develop, even with severe envenomation.
- Headache, vomiting
- Eyelid drooping (Ptosis)
- Blurred vision or difficulty seeing
- Difficulty with Speaking or Swallowing
- Sudden loss of consciousness
- Flaccid paralysis
- Stumbling gait (Ataxia)
- Respiratory arrest or Dyspnea
- Hematological and Vascular:
- Spitting or vomiting blood (Hematemesis)
- Coagulation defects
- Circulatory collapse
- Renal and Urinary:
- Acute Renal Failure
- General: These symptoms may manifest very early, and are important to recognize for prompt diagnosis of envenomation.
- Abdominal Pain
- Regional lymph node tenderness
- Profuse sweating
- Swelling, Edema
- 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). Tiger Snakes typically strike low and quickly recoil; fangs are short (3.5 to 5.5 mm maximum) and stout. 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 the Trauma Service and call consultants listed on the last page. Dr. Terence M. Davidson, M.D. is the local consultant for snake bites, and should be notified immediately.
- Begin a peripheral intravenous infusion (16 gauge catheter) of Lactated Ringers Solution at a rate of 250 cc/hour.
- Draw blood from the contralateral arm, and collect urine for the following laboratory tests. Mark STAT.
- Type and Cross Match TWO units of Whole blood. Obtain fresh, frozen plasma.
- CBC with differential and platelets.
- Coagulation Parameters:
- Prothrombin Time (PT)
- Partial Thromboplastin Time (PTT)
- 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 (Sinus Tachycardia would be expected).
- Continuous Urine Output Monitoring (Indwelling Foley
Catheter if unconscious). Watch for possible oliguria or anuria.
- Additional Tests as needed or indicated by patient's hospital course, ie. CPK and coagulation parameters at four hour intervals.
- It may be necessary or practical to repeat some 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 laboratory values.
- OBSERVE PATIENT CLOSELY for signs and symptoms of envenomation which usually manifest between 15 minutes and two hours after the bite occurred.
- If NONE of the signs or symptoms have been noted after TWO 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 envenomated 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 12 to 24 hours.
- IF SIGNIFICANT SYSTEMIC SIGNS OR SYMPTOMS become apparent, begin antivenom therapy as follows:
- Dilute the contents of 1 vial (3000 units) of Commonwealth Serum Laboratories Tiger Snake Antivenom in Lactated Ringers Solution to a total of 60 mls. Administer the diluted antivenom intravenously over a period of 30 minutes at a rate of 2 ml per minute, (ie. 1 vial per 30 minutes or 100 units per 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 Corticosteroids, Epinephrine, Benadryl, Atarax and/or Antihistamines. As soon as the patient is stabilized, continue the antivenom infusion at a slower rate.
- After 15 minutes of antivenom administration, the
splint and the bandages may be removed. This should be done VERY SLOWLY over a period of FIVE minutes to prevent a bolus release of venom. If the patient's condition worsens, reapply the crepe bandage, wait 10 minutes and release the bandage again slowly over 10 minutes while antivenom administration is continuing.
- Antivenom Therapy is the mainstay of treatment for Tiger snake envenomation. Many of the symptoms are ameliorated or entirely eliminated by the antivenom alone. Other symptoms will require additional modalities of therapy to correct.
- Neurological Symptoms (especially respiratory obstruction or failure) are usually the most immediate cause of dangerous problems. Many may be improved by the antivenom. If breathing becomes impaired, provide respiratory assistance. Secretions may become copious necessitating suctioning.
- Hematological symptoms may present as Disseminated
Intravascular Coagulopathy, and are treated as are other DICs.
- Renal symptoms may complicate the situation, and if
severe (Acute Renal Failure) may necessitate Peritoneal Dialysis.
- 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. Give all additional antivenom in 1 vial (3000 unit) doses. Dilute one vial in Lactated Ringers Solution to a total volume of 60 mls and deliver I.V piggyback over 30 minutes at a rate of 2 mls per minute (i.e., 1 vial per 30 minutes or 100 units per minute). One should anticipate using (including the Initial dose):
0-1 vials total for a minor bite with envenomation.
2-5 or more vials may be necessary for moderate or severe bites.
- 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 all symptoms abate.
- 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 vital functions are not impaired. Carefully note the progress of any paralysis which may be present.
- Respiratory obstruction and failure are the greatest immediate concern. Should the patient develop difficulties in breathing or airway impairment, respiratory support will be required. If the tongue, jaw or pharynx become paralyzed, insert an oral airway. 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. Blood replacement SHOULD NOT be started (as it would be ineffective) until the circulating venom anticoagulants have been fully neutralized.
- 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. Diazepam (Valium) may be given, but not in large quantities.
- 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:
- It is possible for a Tiger Snake to deliver more than one bite in a single attack. 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.
TWO vials (6000 units) diluted in Lactated Ringers Solution to a total volume of 120 mls, and delivered over 30 minutes at a rate of 4 mls per minute (ie. 2 vials per 30 minutes or 200 units per minute).
- Severe Envenomation:
- If the patient shows severe signs of envenomation, particularly if early after the bite, increase the INITIAL dose of antivenom 2X or 3X. Administer over a period of 30 minutes. If the patient is in extreme fluid load, antivenom may be delivered at more concentrated volumes until the patient is in appropriate fluid balance.
- 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 Tiger snake envenomation are present.
- If there is reason to believe that the patient may be sensitive to equine protein products:
- Premedicate the patient with 1 gm Solumedrol, administered I.V. push. Assuming the patient's condition is stable, wait 15-30 minutes before administering the antivenom.
- Administer the antivenom at a rate as tolerated by the patient, and beginning at a rate of 1.0 ml/minute. If the patient tolerates this administration rate, increase the rate to 2.0 ml/minute.
- Monitor Pulse and Blood Pressure carefully. Be
prepared to treat for Anaphylaxis.
- Clinical Experience with Notechis species:
- The Common Tiger Snake as well as the properties of its venom are well studied and documented in the snakebite literature. Several detailed clinical accounts of envenomation and treatment have been published.
- Clearly one of the most important, common and dangerous causes of snakebite accidents in Australia, it has been responsible for many human deaths. Prior to the development of specific antivenom, Tiger Snake bite fatalities probably approached 60-70% with severe envenomation.
- The clinical presentation of envenomation can be highly variable, both in terms of the actual signs and symptoms which develop and in terms of the time course. Much of this depends upon the amount of venom injected, the specific toxicity of the particular species of Tiger Snake, and the individual sensitivity of the patient to the venom components. Envenomation may present with predominately systemic and neurotoxic manifestations including respiratory paralysis and loss of consciousness. Acute renal failure, rhabdomyolysis and extensive coagulopathy have also been reported.
- Prompt recognition of clinical envenomation, and adequate amounts of antivenom delivered early in the treatment course will facilitate a good recovery.
The following references are recommended for further indepth reading. This material includes case histories, guidelines and recent findings in Australian elapid literature. These should be read only after treatment has begun, and the patient is in stable status.
- COMMONWEALTH SERUM LABORATORIES: Treatment of Snake Bite in Australia and Papua New Guinea using Antivenom (Package Insert with Antivenom). CSL, June 1982.
- HARVEY, P.M, et al.: Envenomation by a King Island Tiger Snake (Notechis ater humphreysi). Med. J. Aust., 2:192, 1982.
- GAYNOR, B.: An Unusual Snake Bite Story. Med. J. Aust., 2:191, 1977.
- SUTHERLAND, S.K., COULTER, A.R.: Three Instructive Cases of Tiger Snake (Notechis scutatus) Envenomation -- How Radioimmunoassay Proved the Diagnosis. Med. J. Aust., 2:177, 1977.
- HOOD, V.L., JOHNSON, J.R.: Acute Renal Failure with Myoglobinuria after Tiger Snake Bite. Med. J. Aust., 2:638, 1975.