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The product is
prepared from hyperimmunised equines against the venoms of
the four most commonly encountered poisonous snakes.
- Cobra (Naja-Naja)
- Common Krait
(Bungarus Caeruleus)
- Russell's
Viper (Vipera Russelli)
- Saw Scaled
Viper (Echis Carinatus)
Plasma obtained
from the hyperimmunized equines is enzyme refined, purified
and concentrated. Each ml. of the reconstituted Anti Snake
Venom Serum neutralizes not less than the following quantities
of standard venoms when tested in white mice.
| - |
|
Cobra
|
0.6
mg |
Common-Krait
|
0.45
mg |
Russell's
Viper
|
0.6
mg |
| Saw
scaled Viper |
0.45
mg |
Snake venom envenomation is serious and could be life threatening.
In case of Cobra and Krait poisoning, constitutional symptoms
are more prominent than local pain and swelling. General intoxication
is soon followed by a sense of creeping paralysis begining
in the legs and ascending to the head by way of trunk. Paralysis
of the muscles of the eyelids, staggering gait, incoordination
of speech, paralysis of the limbs, drooping of the head and
complete paralysis of all volunatry muscles develop. Nausea
and vomiting frequently occur. Breathing gets more and more
difficult and finally stops. In the case of Krait poisoning,
in addtion there are convulsions and violent abdominal pains
due to internal harmorrages.
In cases of Russell's and Saw-scaled Viper poisoning, the
local symptons are prominent and severe. There is great and
persistent pain and intensive swelling at the site of the
bite. The venom of the viper contains several enzymes which
may possibly act synergistically to produce shock, consumption
coagulopathy, spontaneous haemorrhages in the organs and tissues,
acute necrosis and death. There is constant and incessant
oozing of blood from the punctures. Sloughing occurs permitting
other infections. The constitutional symptoms are characterised
by haemorrhages, both external and internal. Haemorrhages
in the abdomen are responsible for pain, tenderness and vomiting.
Death is due to heart failure, there is no paralysis. The
venoms of Cobra and Krait act very rapidly if a large amount
of venom is absorbed into the circulation. Hence it must be
understood that unless the absorption of the venom into the
circulation is retarded by ligation, the anti-snake-venom-serum
does not get a fair chance to neutralise the venom and save
the victim.
Treatment of Snake Bite
First-Aid
-
Keep the patient calm
let the patient lie down to ensure that the bitten part
is at rest with minimal activity in a well ventilated
quiet place.
-
Clean the bitten part
by washing with care without disfiguring or defacing
bite mark. Apply a broad and firm antiseptic dressing/bandage.
Specific Serum Treatment
1. Immediate neutralisation of the circulating venom is of
utmost importance.
2. For fast effect, the Anti Snkae Venom Serum should be injected
intravenously as soon as possible after the bite. As a first
dose, at least 20 ml. of the reconstituted serum should be
injected intravenously very gradually (for every 1 ml per
minute).
3. The second dose should be repeated two hours after the
first dose or even earlier. If the symptoms persist. If the
symptoms, which vary with different snake venoms, indicate
persistence of venom action, further doses should be repeated
aftr every six hours until the symptoms disappear completely.
4. At present, there is no simple method to measure the amount
of circulating venom in the body, therefore the antivenin
dose cannot be accurately recommended. It has been found that
the clotting time returns to normal about two hours after
the neutralisation of venom therefore repeated testing of
clotting time after the antivenom therapy is necessary. Close
monitoring of the patient's condition with urine output, BP,pulse,
respiration and urea and electrolyte estimations must be done.
Local pain and necrosis at the site of bite may need attention,
but is usually not very serious except in special circumstances
such as a bite on the digit which can become gangrenous.
5. In case of Viper bite, some of Anti Snake Venom Serum should
also be injected around the site of the snake bite additionally
to prevent gangrene which is one of the more distructive effects
of localised Viper Venom on tissue.
6. First Aid treatment should never be relaxed even when the
serum is administered. Intravenous injection of a reconstituted
Anti Snake Venom Serum in equine serum sensitive subjects
can produce very severe serum reactions and even acute anaphylaxis.
Further care should be taken to prevent these reactions.
7. Intravenous injection is the most effective but if expert
medical aid is not available the serum may be administered
by a subcutaneous or through intramuscular route. It is more
efficacious to dilute the serum 5-10 times with normal or
glucose saline and be administered as slowly as possible.
Associated Treatments
1. In case of Russell's and Saw-scaled viper envenomation,
sedatives such as small doses of barbiturate and/or analgesics
(e.g. aspirin) may be given to relieve nervousness and pain.
2. In case of syncope / shock, strychnine,pituitrin or other
general stimulants like coramine may be used. The use of corticosteroids
would help minimise serum reaction and other minor allergic
reactions.
3. Treatment of antibiotics may also be given to combat local
sepsis in severely envenomated cases, infusion of a large
amount of physiological saline or transfusion of blood or
plasma may not only bring substantial releif but may be life
saving in borderline cases.
4. Cases of respiratory paralysis should be treated by tracheostomy
and artificial respiration.
5. Anti Tetanus injection may be given.
Directions for Use
Reconstitution of Lyophilised Serum
- Draw 10 ml. of sterile water for injection in a sterile
syringe.
- Transfer the sterile water from the syringe to the serum
vial and shake well till the contents dissolve.
- Let the vial stand for one minute for the serum to clear.
The reconstituted serum will become crystal-
clear and ready for injection. Froth and undissolved particles,
if any, should be left in the vial.
- For the second and subsequent injections, you will have
more time to dissolve the lyophilised serum. For these
add 10 ml. sterile water for injection to the serum
vial and rotate it between the palms of your hands until
the serum is fully dissolved, and let the vial stand
for serum to clear.
Storage
Liquid serum
is very unstable at room temperature. It requires storage
at 0° to 4°. Even then it deteriorates, and 2 years
from the date of manufacture, the serum becomes unfit for
use. In India, proper cold-storage facilities are not freely
available and, therefore, liquid serum may only be stored
at the risk of very rapid deterioration. Lyophilised serum
obviates this difficulty. It is many times more stable than
liquid serum. It should retain its potency for 5 years even
if stored in any cool dark place. Thus Anti Snake Venom
Serum can be made available for use far away from cold-storage
facilities. It can be safely kept at rural dispensaries
and even carried in a haversack if an occasion demands it.
However, it is preferable to store it in a refrigerator
if one is available.
Prevention of Serum Reaction
Before injection of Anti-Snake Venom Serum, it is necessary
to enquire from the patient:
- Whether he has had injections of serum (eg. anti-tetanus
or anti-diphtheria serum) before.
- Whether there is personal or familial history of allergy,
i.e. asthma, eczema or drug allergy.
The sensitivity of the patient to Anti-Snake Venom Serum
is tested by injecting subcutaneously 0.1 ml of this serum
diluted 1:10. The patient should be observed for 30 minutes
for local and general reactions. If the test dose shows
either local reaction such as flare or general anaphylactic
reaction such as pallor, sweating, nausea, vomiting, urticaria,
and fall of blood pressure, these should be countered immediately
by intramuscular injection of 1 ml of 1:1000 adrenaline
and with corticosteroids which should be always kept handy.
In allergic or sensitive patients, it is better to inject
the Anti-Snake Venom Serum under cover of anti-histaminics
such as antistine (100 mg.) and hydrocortisone (100 mg.)
intramuscularly 15 to 30 minutes before the administration
of Anti-Snake Venom Serum. The administration of adrenaline
and hydrocortisone may be repeated if necessary.
When symptoms of snakebite are severe it may not be advisable
to wait for 30 minutes to observe reactions to test-dose
of serum. In such cases it may be better to inject 1 ml.
of 1:1000 adrenaline intramuscularly at the same time as
the serum in order to lessen the risk of anaphylaxis. Half
the dose of adrenaline may be repeated 15 minutes later
if necessary.
Packing
One dose vial of lyophilised Anti-Snake Veno Serum with
10 ml. ampoule of Sterile water for injection.
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