IMMEDIATE FIRST AID
for bites by
Puff Adder
(Bitis arietans)
In the event of an actual or probable bite from a Puff Adder, execute the
following first aid measures without delay.
Snake:
- Make sure that the responsible snake or snakes have been appropriately
and safely contained, and are out of danger of inflicting any additional
bites.
Transportation:
- Immediately call for transportation.
Telephone:
Victim:
- 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 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
by
Puff Adder
(Bitis arietans)
The bite of the Puff Adder with subsequent envenomation is a medical
emergency and can be fatal if the patient is not treated appropriately. 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 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
initial dose):
5 vials for a minor bite with envenomation
10 vials may be necessary for moderate or severe bites.
The use of less than five vials of antivenom in the treatment of a bite
with systemic envenomation increases the risk for complications and may even
result in death.
MEDICAL MANAGEMENT
for bites by
Puff Adder
(Bitis arietans)
This person has received a bite and probable envenomation from a Puff Adder
(Bitis arietans). This is a very venomous and dangerous snake native to much
of Africa and portions of Saudi Arabia. Studies have shown that more than 50%
of severe envenomations left untreated result in death. Envenomation may cause
severe hypotension/shock as well as hemolytic, coagulopathic, hemorrhagic, and
local reactions. Death may ensue rapidly but more commonly occurs in 12-24
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 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.
- If the patient has been envenomated, the treatment is at least 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
- Consultants
- References
Signs and Symptoms of Envenomation:
- Local Affects:
- Pain and swelling: onset almost immediately after bite
- Blistering, bleb formation
- Ecchymosis
- Tissue necrosis: onset usually days after bite
- Cardiovascular:
- Hypotension: onset immediately
- Bradycardia
- Tachycardia
- Hematological:
- Coagulation defects
- Thrombocytopenia: onset within four hours after bite
- Spontaneous bleeding:
- Mucosal bleeding: within 4 hours after bite
- Epistaxsis
- Ecchymosis
- Gastrointestinal bleeding
- Internal hemorrhage
- Hematuria
- Anemia: secondary to bleeding into bitten limb,
spontaneous bleeding, microangiopathic hemolysis etc.
- Renal/Urinary:
- Hematuria
- Hemoglobinuria
- Myoglobinuria
- Renal failure
- General:
- Nausea/Emesis
- Fever
- Regional Lymphadenopathy
- Fang Marks: The presence of fang marks does not always
imply envenomation as the Puff Adder is known to 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 symtoms which give strong evidence for systemic
envenomation include spontaneous bleeding, thrombocytopenia, hypotension,
bradycardia, and local swelling of more than half the affected limb. Antivenom
should be administered without delay in such cases.
Medical Management:
- 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. Obtain fresh, frozen
plasma.
- CBC with differential and quantitive platelet count.
- Coagulation Parameters:
a. Prothrombin Time (PT)
b. Partial Thromboplastin Time (PTT)
c. Fibrinogen Levels
d. 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
- Hemoglobin
- Myoglobin
- 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
course.
- The patient's vital signs should be monitored frequently the first 48
hours after the bite for evidence of hypotension, bradycardia, or circulatory
shock.
- Coagulation parameters should be repeated at four hour intervals until
coagulation factors begin to recover.
- CBC with platelet counts should be repeated periodically. Plateletes
and hematocrit levels may continue to decline up to 48 hours after the bite
especially in the undertreated patient.
- 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
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 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.
(i.e. 120ml/hour).
- 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.
- Antivenom Therapy is the mainstay of treatment for Puff Adder snake
envenomation. Many of the symptoms are ameliorated or entirely eliminated by
the antivenom alone. Other symptoms will require additional therapeutic
modalities in order to be corrected.
- Cardiovascular status: The administration of antivenom alone will help
correct hypotension, bradycardia, and signs of circulatory shock provided the
patient is not hypovolemic. Intravenous administration of Lactated Ringers
Solution is warranted in all cases. Cardiovascular stability and a brisk
diuresis are desired.
- Hematological signs and symptoms: Puff Adder venom has both
procoagulant and anticoagulant activity, and thus bite victims may show a
variety of responses. In addition the venom is toxic to vascular endothelial
tissue and has hemorrhagic activity as well. Bite victims frequently develop
thrombocytopenia, decreased fibrinogen levels, and spontaneous bleeding.
Disseminated intravascular coagulopathy and anemia may likewise occur. Case
reports reveal no consistent change in the PT or PTT; these parameters may be
normal or prolonged. Death from severe envenomation is usually the result of
internal hemorrhage and circulatory shock. 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.
- Renal: Puff Adder venom binds to renal tissue resulting in hematuria.
Hemoglobinuria and myoglobinuria may likewise affect renal function, and if
severe, acute renal failure may necessitate peritoneal dialysis.
- Neurological symptoms are uncommon with Puff Adder bites.
- 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.
General Considerations:
- It is important that the patient remain resting and warm. Avoid
unnecessary movement.
- Symptom variability: There is a marked variability of symptoms
in response to a Puff Adder 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 Puff Adder 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 Puff Adder 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
Puff Adder bites and should be utilized prior to other treatment
modalities.
Special Considerations:
- Multiple Bites:
- It is possible for a Puff Adder 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
Puff Adder 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 Puff Adder:
- The Puff Adder (Bitis arietans) probably accounts for
more deaths than any other snake in Africa. An adult Puff Adder may have
enough venom to kill 4-5 men and studies show severe envenomations have a 52%
mortality rate. The utilization of antivenom dramatically reduces the
mortality rate but deaths have occurred when inadequate amounts of antivenom
(i.e. four vials or less) have been administered.
- Prompt recognition of clinical envenomation, and adequate amounts of
antivenom delivered early in the treatment course will facilitate a good
recovery. The use of at least 5 vials of antivenom reduces the incidence of
serious complications.
References:
The following references are recommended for further reading. This
material includes case histories, guidelines and recent findings in treatment
of Puff Adder bites. These should be read only after treatment has begun, and
the patient is stable.
- Warrell, D.A., Ormerod, L.D., Davidson, N. NcD., Bites by
Puff-Adder (Bites arietans) in Nigeria, and value of antivenom, British
Medical Journal, 1975, 4:697.
- Mebs, D., Pohlman, S., Von Tenspolde, W., Snake venom hemorrhagins:
neutralization by commerical antivenoms, Toxicon, 1988, 26:453.
- Brink, S., Steytler, J.G., Effects of Puff-Adder venom on coagulation,
fibrinolysis and Platelet aggregation in the baboon, South African Medical
Journal, 1974, 48:1205.
- Homma, H., Tu, A.T., Morphology of local tissue damage in experimental
snake envenomation, British Journal of Experimental Pathology, 1971, 52:538.
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