IMMEDIATE FIRST AID
for bites by
Indian or Common Cobra
(Naja naja naja)
In the event of an actual or probable bite from an Indian or Common Cobra, 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. (See the attached copy from "First Aid for Snakebite", by Dr. S.K. Sutherland.)
- 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 Haffkine Bio-Pharmaceutical Corp. Polyvalent Antivenom ready for the emergency 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 (if available)
DO NOT cut or incise the bite site
DO NOT apply ice to the bite site
Summary for Human Bite
Indian or Common Cobra
(Naja naja naja)
The bite of the Common Cobra with envenomation can be rapidly fatal (possibly as early as 60 minutes). 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 a medical center emergency or 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 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.
- Reconstitute the contents of 2 vials (20 mls) of Haffkine Bio-Pharmaceutical Corp. Polyvalent Antivenom with Lactated Ringers Solution (10 mls/vial). Administer the antivenom I.V. piggyback over 20 minutes at a rate of 1 vial (10 mls) per 10 minutes.
- 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 Corticosteroids, Epinephrine, Benadryl, Atarax and/or Antihistamines as appropriate.
- Monitor Signs, Symptoms, and Laboratory data, and administer additional antivenom in 1 vial (10 mls) increments at a rate of 1 vial per 10 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):
3-5 vials total for a minor bite with envenomation.
10-15 vials or more may be necessary for moderate or severe bites.
for bites by
Indian or Common Cobra
(Naja naja naja)
This person has received a bite and probable envenomation from an Indian or Common Cobra (Naja naja naja). This is a very venomous and dangerous snake. In this particular species, envenomation usually presents predominately with local necrosis and systemic manifestations. Drowsiness, Neurological and Neuromuscular symptoms may develop early; paralysis, ventilatory failure or death could ensue rapidly.
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 10 packages of Haffkine Institute Polyvalent Antivenom are present with the patient. This antivenom contains the appropriate fractions necessary to neutralize the components of Indian Cobra venom.
- If the patient has been envenomated, the treatment is 3 to 10 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 signs and symptoms will usually manifest earliest. Not all of these will necessarily develop, even with severe envenomation.
|Eyelid drooping (Ptosis)
|Respiratory paralysis or Dyspnea
|Head drooping (Cervical muscle paresis or paralysis)
|Sudden loss of consciousness
|Stumbling gait (Ataxia) |
- General: These symptoms typically manifest within one to four hours following the bite if envenomation occurred.
- Nausea and Vomiting
- Flushing of the face
- Warm skin
- Pain around bite site
- Abdominal Pain
- Cardiotoxicity: Increased Blood Pressure and increased Cardiac Output followed by Myocardial Depression and Asystole. Mortality approaches 100% if cardiotoxic complications occur.
- Local Symptoms: In some Cobra bites, local tissue destruction and necrosis can dominate the clinical presentation. Gangrene requiring amputation can occur. Local tissue damage appears to be less frequent and less severe in most cases of Indian Cobra (Naja naja naja) envenomation, but may include:
- Localized discoloration of skin
- Vesiculation (usually small and localized)
- Necrosis (can be extensive, but is characteristically localized to the bite site)
- Local edema (usually minimal)
- 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). In general, the fang marks from an Indian Cobra tend to be small, but deep. The snake in delivering the bite may hold on and chew savagely, and may inject up to 60% of its venom. 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 an emergency or trauma service and call the consultant identified by the Poison Control Center.
- Begin a peripheral intravenous infusion (16 gauge catheter) of Lactated Ringers Solution at a rate of 250 cc/hour.
- Draw blood from the unbitten extremity, and collect urine for the following laboratory tests. Mark STAT.
- Type and Cross Match TWO units of Whole blood.
- CBC with differential.
- Coagulation Parameters:
- Prothrombin Time (PT)
- Partial Thromboplastin Time (PTT)
- Platelet Count
- 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 (Place the patient on continuous monitoring).
- Additional Tests as needed or indicated by patient's hospital course.
- It may be necessary or practical to repeat some or all 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 parametric values.
- OBSERVE PATIENT CLOSELY for signs and symptoms of envenomation which usually manifest between 15 minutes and two hours following the bite.
- If NO 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 envenomed 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 24 hours.
- IF ANY SIGN OR SYMPTOM becomes apparent or has been noted during the course of evaluation, begin Antivenom Therapy as follows:
- Each vial of Haffkine Institute Polyvalent Antivenom is packaged as a lyophilized dry preparation in a glass vial with an accompanying vial of sterile water (to reconstitute the antivenom). It is preferable to reconstitute the antivenom in Lactated Ringers Solution. The contents of TWO vials of antivenom are to be used as the Initial dose. CAREFULLY score both vials, and break open. Withdraw 20 ml of room temperature Lactated Ringers Solution into a sterile syringe, and then transfer 10 ml to each antivenom vial.
- Carefully mix and reconstitute the antivenom in each vial by covering the open ends with several thicknesses of sterile gauze sponges and then shaking each vial vigorously for one minute. Allow the vials to stand still for one minute to clear. Withdraw the CLEAR solution into a clean sterile syringe (leaving froth and undissolved particles behind), and prepare to transfer to intravenous piggyback set-up.
- Administer the reconstituted Antivenom intravenously over a period of 20 minutes at a rate of 1 vial per 10 minutes (i.e., 1.0 mls 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 epinephrine, steroids and antihistamines. As soon as the patient is stabilized, continue the antivenom infusion at a slower rate.
- After the first two vials of antivenom has been administered, the splint and the bandages may be removed. This should be done VERY SLOWLY over a FIVE minute period to prevent a bolus release of venom. If the patient's condition worsens:
- Reapply the crepe bandage.
- Prepare a third vial of antivenom (1 vial in 10 mls of Lactated Ringers Solution) immediately as directed above.
- Infuse this dose at 1.0 ml per minute for 10 minutes.
- Release the bandage again slowly over 5 minutes.
- In any case, an additional vial of antivenom should be prepared and allowed to dissolve fully. Anticipate giving this next dose approximately Two hours after the first two vials has been delivered. If the patient's symptoms should persist or worsen, administer this dose 60 or 90 minutes following the first dose or doses.
- Antivenom Therapy is the mainstay of treatment for cobra envenomation. Many of the symptoms are ameliorated or entirely eliminated by the antivenom alone. Other symptoms will require additional modalities of therapy to correct. Local symptoms may take several days to weeks to completely resolve; their progression, however, may be treated with antivenom therapy.
- Neurological Symptoms (especially respiratory obstruction or failure) are usually the most immediate cause of dangerous problems. Often, these are improved by the antivenom. If breathing becomes impaired, provide respiratory assistance. Secretions may become copious, necessitating suctioning.
- Hematological symptoms may present as a Disseminated Intravascular Coagulopathy, and are treated as are other DICs. This, however, is uncommon with cobra envenomation.
- Renal symptoms are rare in cobra envenomation, but may complicate the situation, and if severe (i.e., Acute Renal Failure) may necessitate Peritoneal Dialysis.
- If severe muscle paralysis develops and persists, administer 0.6 mg of Atropine IV. Follow by giving 0.5 mg of Neostigmine IV every 30 minutes for a maximum of FIVE doses.
- 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. The antivenom should ideally be diluted 1 to 10 in Lactated Ringers Solution, and always given by intravenous infusion at a rate of One vial per 10 minutes (1.0 mls per min). Give all additional antivenom in one vial doses. One should anticipate using Three to Five vials for a minor bite. Ten to Fifteen 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 symptoms are stabilized.
- It is important that the patient be placed at rest, kept warm, and avoids 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 neurological functions are not impaired. Carefully note the progress of any paralysis which maybe present.
- Respiratory obstruction and failure are the greatest immediate concerns. Should the patient develop difficulties in breathing or airway management, respiratory support will be required. If the tongue, jaw or pharynx become paralyzed, insert an oral airway; intubation may be required. 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.
- 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.
- 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.
- Local Necrosis:
- The degree of local necrosis appears to be less with Indian Cobra (Naja naja naja) envenomation than with other Naja naja subspecies. Prompt delivery of antivenom following the bite may lessen the extent of local tissue damage, although some evidence suggests that certain antivenoms have less efficacy in ameliorating or protecting against the local action of certain cobra venoms. This latter statement should not be held as a contraindication to the use of antivenom in those cases of cobra bite in which local symptoms predominate.
- Multiple Bites:
- It is possible for a cobra to deliver more than one bite in a single attack, and thus may inject a larger volume of venom. 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: (i.e., four vials in 40 mls of Lactated Ringers solution delivered over 40 minutes at a rate of one vial per ten minutes). Always watch closely for signs of allergic response; if they occur, treat appropriately and slow infusion rate. Give all subsequent doses in One vial increments at 1 vial per 10 minutes as necessitated by the presence of continued signs and symptoms.
- Severe Envenomation:
- If the patient shows severe signs of envenomation, particularly if early after the bite, treat as a multiple bite administering four vials of antivenom over the first 40 minutes. Give all subsequent doses in ONE vial increments at a rate of one vial per 10 minutes as necessitated by the presence of continued signs and symptoms.
- 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 cobra envenomation are present.
- If there is reason to believe that the patient may be sensitive to equine protein products (e.g., previous snake bite treated with antivenom in which a sensitivity reaction was noted, multiple previous snakebites):
- Administer 1 gram of Solumedrol I.V. push.
- Wait 15 minutes before administering the antivenom.
- Administer the antivenom at a rate of one vial ten minutes, but be prepared to infuse more slowly if allergic symptoms manifest.
- Be prepared to treat for anaphylaxis with epinephrine and other vasoactive medicines.
The following references are recommended for further indepth reading. This material includes case histories, guidelines, and recent findings in elapid literature. These should be read only after treatment has begun, and the patient is in stable status.
- Haffkine Bio-Pharmaceutical Corporation: Lyophilised Polyvalent Anti-Snake-Venom Serum: Directions of Use (Package Insert with Antivenom). CSL, December 1978
- TIGER, M.E., BRECHER, E., BEVAN, D.: Cobra Bite in Philadelphia. PA Med. 82:53, 1975.
- STUEVEN, H., APRAHAMIAN, C., THOMSON, B., HOROWITZ, L., DARIN, J.: Cobra Envenomation: An Uncommon Emergency. Ann Emerg Med. 12:79, 1983.
- REID. H.A.: Cobra Bites. Brit Med J. 2:540, 1964.