IMMEDIATE FIRST AID
for bites by
Rhinoceros Horned Viper
In the event of an actual or probable bite from a Rhinoceros Horned Viper
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
- 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
- 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 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:
- the available antivenom (at least 10 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
Rhinoceros Horned Viper
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.
- 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
- Draw samples and collect initial laboratory data.
- 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.
- 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.
- 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 increments at a rate of one vial every 15
minutes as necessary to control the progression of symptoms.
- The required amount of antivenom will vary with
the severity of envenomation. One should anticipate using (including the
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
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.
- 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 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
- 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:
- Local Affects:
- Pain and swelling: onset almost immediately after bite
- Blistering, bleb formation
- Hemorrhagic edema
- Tissue necrosis: onset usually days after bite
- Hypotension: onset immediately
- Cardiac arrest
- Coagulation defects
- Spontaneous bleeding:
- Mucosal bleeding
- Gastrointestinal bleeding
- Internal hemorrhage
- Anemia: secondary to bleeding into bitten limb,
spontaneous bleeding, microangiopathic
- Pulmonary edema
- Renal failure
- Abdominal pain
- Regional Lymphadenopathy
- 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
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.
- 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.
- 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.
- CBC with differential and quantitative platelet count.
- 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
- Urinalysis (Macroscopic and Microscopic Analysis).
Must include analysis for:
- Free Protein
- Electrocardiogram (Sinus Tachycardia would be expected).
- Continuous Urine Output Monitoring (In dwelling Foley
Catheter if unconscious). Watch for possible oliguria or anuria.
- Additional tests as needed or indicated by the patient's hospital
- The patient's vital signs should be monitored frequently the first 48
hours after the bite for evidence of hypotension, bradycardia, or circulatory
- 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.
- OBSERVE PATIENT CLOSELY for signs and symptoms of envenomation which
usually manifest between 15 minutes and two hours after the bite
- 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
- 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
- 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 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.
- 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 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
- 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.
- 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.
- 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.
- Pulmonary: The hemorrhagic activity of the venom may
result in pulmonary edema, tachypnea, and dyspnea.
- 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.
- Neurological symptoms are uncommon with Rhinoceros Horned Viper bites.
Respiratory distress is nearly always secondary to pulmonary edema rather than
- 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.
- 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 remain resting and warm. Avoid
- 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.
- 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.
- 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.
- 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.
- Tetanus Prophylaxis should be current.
- Antibiotics are not recommended prophylactically.
- Antivenom is the best treatment for all signs and symptoms of
Rhinoceros Horned Viper bites and should be utilized prior to other treatment
- Multiple Bites:
- 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.
- 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
Rhinoceros Horned Viper 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 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.
- Monitor Pulse and Blood Pressure carefully. Be prepared to
treat for Anaphylaxis.
- Clinical Experience with the Rhinoceros Horned Viper:
- 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.
- 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.
- Marsh, N. and Glatston, A., Some observations on the venom of the
Rhinoceros Horned Viper, Bitis nasicornis Shaw. Toxicon 12,
- 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,
- 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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