for bites by
Rhinoceros Horned Viper
(Bitis nasicornis)

In the event of an actual or probable bite from a Rhinoceros Horned Viper execute the following first aid measures without delay.


  1. Make sure that the responsible snake or snakes have been appropriately and safely contained, and are out of danger of inflicting any additional bites.


  1. Immediately call for transportation.



  1. 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.

  2. 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.

  3. 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.

  4. DO NOT remove the splint or bandages until the victim has reached the hospital and is receiving Antivenom.

  5. Have the SAIMR (South African Institute for Medical Research) polyvalent antivenom ready for the Lifeflight crew to take with the victim to the hospital. Give them the following:

    1. the available antivenom (at least 10 vials)
    2. the accompanying instruction (Protocol) packet
    3. 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
Rhinoceros Horned Viper
(Bitis nasicornis)

The bite of the Rhinoceros Horned Viper with subsequent envenomation is a medical emergency and can be fatal if the patient is not treated appropriately.

  1. First Aid:

    1. 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).

    2. Transport to U.C.S.D. Medical Center Trauma Service.

  2. Medical Management:

    1. 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.

    2. Observe for Signs and Symptoms of Envenomation.

    3. If significant systemic signs or symptoms are present,

      perform the following:

      1. Administer Lactated Ringers Solution at 200 to 250 mls per hour.

      2. Draw samples and collect initial laboratory data.

      3. Dilute the contents of 5 vials of SAIMR Polyvalent Antivenom in Lactated Ringers Solution to a total volume of 300ml. Administer the antivenom I.V. piggyback over 75 minutes at a rate of 240ml/hour (i.e. one vial per 15 minutes). The combined rate of diluted antivenom and Lactated Ringers Solution is now approximately 500ml/hour. The rate of Lactated Ringers Solution may be adjusted accordingly to avoid fluid overload, however a brisk urine output should be a treatment goal.

      4. When one complete vial has been infused (i.e. 15 minutes, 60 cc), remove the splints and crepe bandage slowly over a period 10 minutes. If symptoms progress rapidly, reapply the bandage, wait 10 minutes, and then again release the bandage slowly over 10 minutes while antivenom administration is continuing.

      5. 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.

      6. Monitor Signs, Symptoms, and Laboratory data, and administer additional antivenom in 1 vial increments at a rate of one vial every 15 minutes as necessary to control the progression of symptoms.

      7. The required amount of antivenom will vary with the severity of envenomation. One should anticipate using (including the initial dose):

        5 vials for a minor bite with envenomation

        6-10 vials may be necessary for moderate or severe bites.

for bites by
Rhinoceros Horned Viper
(Bitis nasicornis)

This person has received a bite and probable envenomation from a Rhinoceros Horned Viper (Bitis nasicornis). This is considered a venomous and dangerous snake native to Central Africa. Although there are no documented deaths from the bite of the Rhinoceros Horned Viper, many of the complications from envenomation are potentially life threatening.

Please read and execute the following procedures without delay.

  1. 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.

  2. Make sure 10 vials of SAIMR Polyvalent Antivenom are present with the patient. This antivenom is specific and is only available directly from the San Diego Zoo Reptile Department. Refrigerate the antivenom upon arrival to the hospital.

  3. If the patient has been envenomated, the treatment is a minimum of 5 vials of intravenous antivenom. Envenomation is diagnosed by the presence of characteristic signs and symptoms. Necessary information follows and is organized into the following sections:

    Signs and Symptoms of Envenomation
    Medical Management
    General Considerations
    Special Considerations

Signs and Symptoms of Envenomation:

  1. Local Affects:
    Pain and swelling: onset almost immediately after bite
    Blistering, bleb formation
    Hemorrhagic edema
    Tissue necrosis: onset usually days after bite

  2. Cardiovascular:
    Hypotension: onset immediately
    Cardiac arrest

  3. Hematological:
    Coagulation defects
    Spontaneous bleeding:
    Mucosal bleeding
    Gastrointestinal bleeding
    Internal hemorrhage
    Anemia: secondary to bleeding into bitten limb, spontaneous bleeding, microangiopathic hemolysis etc.

  4. Pulmonary
    Pulmonary edema

  5. Renal/Urinary:
    Renal failure '

  6. General:
    Abdominal pain
    Regional Lymphadenopathy

  7. Fang Marks: The presence of fang marks does not always imply envenomation as the Rhinoceros Horned Viper may bite without injecting venom into the victim. However, the absence of fang marks does not necessarily preclude the possibility of a bite, nor does it give any indication of the severity of the bite. 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. Finally, multiple bites inflicted by a single snake are possible and should be noted if present.

    Those signs and symptoms which give strong evidence for systemic envenomation include hypotension, dyspnea, cardiac arrhythmias, spontaneous bleeding, and local swelling of more that half the affected limb. Antivenom should be administered without delay in such cases.

Medical Management:

  1. Admit patient to the Trauma Service and call consultants listed on the last page. Terence M. Davidson, M.D. is the local consultant for snake bites, and should be notified immediately.

  2. Begin a peripheral intravenous infusion (16 gauge catheter) of Lactated Ringers Solution at a rate of 250 cc/hour.

  3. Draw blood from the contralateral arm, and collect urine for the following laboratory tests. Mark STAT.

    1. Type and Cross Match TWO units of Whole blood.

    2. CBC with differential and quantitative platelet count.

    3. Coagulation Parameters:
      1. Prothrombin Time (PT)
      2. Partial Thromboplastin Time (PTT)
      3. Fibrinogen Levels
      4. Fibrin Degradation Products

    4. Serum Electrolytes, BUN/Creatinine, Calcium, Phosphorus.

    5. Lactate Dehydrogenase (with Isoenzyme analysis). Isoenzyme analysis may indicate multiple targets of the venom components which may dictate further management.

    6. Urinalysis (Macroscopic and Microscopic Analysis).

      Must include analysis for:

      1. Free Protein
      2. Hemoglobin
      3. Myoglobin

    7. Electrocardiogram (Sinus Tachycardia would be expected).

    8. Continuous Urine Output Monitoring (In dwelling Foley Catheter if unconscious). Watch for possible oliguria or anuria.

    9. Additional tests as needed or indicated by the patient's hospital course.
      1. The patient's vital signs should be monitored frequently the first 48 hours after the bite for evidence of hypotension, bradycardia, or circulatory shock.

      2. It may be necessary or practical to repeat some of the above serum and urine tests over the hospital course to monitor the effects of antivenom therapy or to detect late changes in laboratory values.

    10. OBSERVE PATIENT CLOSELY for signs and symptoms of envenomation which usually manifest between 15 minutes and two hours after the bite occurred.

      1. 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).

        1. 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).

      2. If signs and symptoms still fail to manifest, continue CLOSE observation of the patient for an additional 12 to 24 hours.

    11. IF SIGNIFICANT SYSTEMIC SIGNS OR SYMPTOMS become apparent, begin antivenom therapy as follows:

      1. Dilute the contents of 5 vials of SAIMR Polyvalent Antivenom in Lactated Ringers Solution to a total volume of 300ml. Administer the antivenom I.V. piggyback over 75 minutes at a rate of 240ml/hour (i.e. one vial per 15 minutes). The combined rate of diluted antivenom and Lactated Ringers Solution is now approximately 500ml/hour. The rate of Lactated Ringers Solution may be adjusted accordingly to avoid fluid overload, however a brisk urine output should be a treatment goal.

      2. 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. (i.e. 120ml/hour).

      3. After 15 minutes of antivenom administration, the splint and the bandages may be removed. This should be done VERY SLOWLY over a period of 10 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.

    12. Antivenom Therapy is the mainstay of treatment for Rhinoceros Horned Viper envenomation. Many of the signs and symptoms are ameliorated or entirely eliminated by the antivenom alone. Other symptoms will require additional therapeutic modalities in order to be corrected.

      1. Cardiovascular status: Rhinoceros Horned Viper venom has been shown in vitro to be cardiotoxic and may cause arrhythmias as well as decreases in stroke volume and cardiac output. The administration of antivenom alone will dramatically improve hypotension and signs of circulatory shock. Intravenous administration of Lactated Ringers Solution is always warranted but is only efficacious if antivenom has been administered. Severe arrhythmias may require the use of a temporary pacemaker to ensure adequate cardiac output and to prevent cardiac arrest.

      2. Hematological signs and symptoms: Rhinoceros Horned Viper venom has anticoagulant activity and prolongs PT, PTT, and bleeding times. In addition the venom has been shown to impair platelet function and decrease serum fibrinogen levels. The patient should be monitored closely and blood products including whole blood, packed RBC's, platelets, cryoprecipitate, and fresh frozen plasma should be given when indicated.

      3. Pulmonary: The hemorrhagic activity of the venom may result in pulmonary edema, tachypnea, and dyspnea.

      4. Renal: The hemorrhagic activity of Rhinoceros Horned Viper venom may result in hematuria. In addition, hemoglobinuria and myoglobinuria may likewise affect renal function, and if severe (Acute renal failure) the situation may necessitate peritoneal dialysis.

      5. Neurological symptoms are uncommon with Rhinoceros Horned Viper bites. Respiratory distress is nearly always secondary to pulmonary edema rather than muscle paralysis.

    13. It is important to keep venom neutralization current and continuous. The best method to accomplish this is to monitor 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 one vial increments. Dilute the antivenom in Lactated Ringers as before and administer the antivenom I.V. piggyback over approximately 15 minutes.

      Bites with envenomation require at least 5 vials but severe envenomations may require up to 10 vials of antivenom.

    14. It is advisable to perform periodic serum and urine analyses during therapy (as outlined above).

    15. 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.

    General Considerations:

    1. It is important that the patient remain resting and warm. Avoid unnecessary movement.

    2. Symptom variability: There is a marked variability of symptoms in response to a Rhinoceros Horned Viper bite. It is important to note the continual progression of signs and symptoms throughout the course of therapy and to give additional antivenom as necessary.

    3. Circulatory Shock: Hypotension and bradycardia are frequent complications of Rhinoceros Horned Viper bites. Plasma expanders and/or vasopressor agents may be given when appropriate, but will be most effective if adequate antivenom has been appropriately administered.

    4. Fluid Management: The patient should be well hydrated, and a brisk urine output should be maintained. Blood products should not be given until circulating venom has been neutralized with antivenom.

    5. Compartment Syndrome: It should be noted that fascial compartment syndromes in Rhinoceros Horned Viper bites are uncommon. Limbs may swell significantly, but rarely involve specific fascially bound compartments. If however the logistics of the bite raise a high index of suspicion for compartment syndrome, monitoring with a Wick Catheter or appropriate pressure device may be necessary. Fasciotomy is rarely, if ever, recommended.

    6. Tetanus Prophylaxis should be current.

    7. Antibiotics are not recommended prophylactically.

    8. Antivenom is the best treatment for all signs and symptoms of Rhinoceros Horned Viper bites and should be utilized prior to other treatment modalities.

    Special Considerations:

    1. Multiple Bites:

      1. It is possible for a Rhinoceros Horned Viper 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), give the initial dose of 5 vials but be prepared to give a total of 10 vials to adequately treat the bite. Titrate antivenom administration to signs and symptoms as discussed previously.

    2. Testing for Equine Protein Sensitivity:

      1. 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 Rhinoceros Horned Viper envenomation are present.

      2. If there is reason to believe that the patient may be sensitive to equine protein products:

        1. 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.

        2. Administer the diluted antivenom at a rate as tolerated by the patient beginning at a rate of 120ml/hour (as opposed to the normal 240ml/hour rate). If the patient tolerates this, increase the rate up to 240ml/hour.

        3. Monitor Pulse and Blood Pressure carefully. Be prepared to treat for Anaphylaxis.

    3. Clinical Experience with the Rhinoceros Horned Viper:

      1. Much of the information currently known about the Rhino- ceros Horned Viper comes from experimental in vitro and animal in vivo studies. Documented case studies of human envenomation are quite rare and thus complications of a Rhinoceros Horned Viper bite may occur which have previously not been described.

      2. The signs and symptoms of envenomation by the Rhinoceros Horned Viper are likely to be similar to but less severe than that of the Gaboon Viper (Bitis gabonica). Local, cardiovascular, and pulmonary signs and symptoms will likely predominate the clinical picture.


    The following references are recommended for further reading. This material includes case histories, guidelines and recent findings in treatment of Rhinoceros Horned Viper bites. These should be read only after treatment has begun, and the patient is stable.

    1. Marsh, N. and Glatston, A., Some observations on the venom of the Rhinoceros Horned Viper, Bitis nasicornis Shaw. Toxicon 12, 621-628, 1974.

    2. MacKay, Ferguson, J.C., and McNicol, G.P., Effects of the venom of the Rhinoceros Horned Viper (Bitis nasicornis on blood coagulation, platelet aggregation, and fibrinolysis. Journal of Clinical Pathology 23, 789-796, 1970.

    3. Marsh, N.A., Whaler, B.C., The Gaboon Viper (Bitis Gabonica): its biology, venom components and toxinology, Toxicon 22, 669-694, 1984.

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