**7.1 Prehospital care**

As we mentioned before, efforts should not be made to catch the snake, since this might result in wasted time and further bites. The basis in prehospital care is to limit the spread of venom throughout the body. Compressive bandages might be of help. These can be done with elastic bandages, if available, or torn clothing after removing clothes and jewelry. The extremity should be kept below the level of the heart. The bandage should be tight enough to help delay systemic absorption of the venom. Please be aware that incisions and suction are not indicated and could actually promote the development of further infections (D. L. Morgan et al., 2007). Remember that all bite wound are already considered contaminated wounds and that these invasive measures might actually worsen the problem unless performed in the first 30 minutes after the attack has taken place and in a sterile environment (Robert L Norris & Adler, 2011). Tourniquets that completely occlude vascular irrigation have created more problems than those solved, therefore, they are not recommended for their prehospitalary care.

#### **7.2 Emergency room care**

130 Complementary Pediatrics

In Coral Snake bites, the inoculation of venom is neurotoxic. Clinical manifestations from a coral snake envenomation are mild pain (against intense pain from a pit viper snakebite), swelling, erythema and paresthesis in the area of the wound. The wound is represented by puncture marks, abrasions or scratches (D. L. Morgan, Borys, Stanford, Kjar, & Tobleman, 2007). Most snake bites do not leave important local signs other than one or two punctures and sometimes small teeth marks. Systemic effects appearing after several hours include nausea, vomiting, dizziness, malaise, slurred speech, muscle weakness, respiratory

The laboratory tests are of little importance to diagnose a snakebite, with the exception of the ELISA test, which is available to identify the species involved, based on venom antigens. These studies are expensive and are not fully available and are of no value except for epidemiological studies. In a hospital setting , laboratory studies are important to

Changes in the blood include anemia, leukocytosis and thrombocytopenia, the blood smear may show evidence of hemolysis. Also, prolonged clotting times and decreased fibrinogen may be present. Among the metabolic changes we can find hypokalemia and respiratory

Urinalysis may reveal hematuria, proteinuria and hemoglobinuria. Electrocardiographic changes are usually nonspecific and may include rhythm disturbances, mainly bradycardia, AV block with ST segment elevation or depression. Cholesterol lowering has been documented and can be explained by transcapillary lipoprotein loss. There have been reports of changes in the electroencephalogram in up to 96% of patients with snake bites, but none showed clinical changes or encephalopathy. In 62% of the patients, the electroencephalogram showed grade I changes, 31% showed grade II changes. (Avila-

Science has made enormous advances regarding the pharmacologic treatment of children and adults who have been victims of snake bites. Successful treatment will always depend on the rapidness with which management begins, even at the scene of the attack, and, of

As we mentioned before, efforts should not be made to catch the snake, since this might result in wasted time and further bites. The basis in prehospital care is to limit the spread of venom throughout the body. Compressive bandages might be of help. These can be done with elastic bandages, if available, or torn clothing after removing clothes and jewelry. The extremity should be kept below the level of the heart. The bandage should be tight enough to help delay systemic absorption of the venom. Please be aware that incisions and suction

course, once the patient arrives for appropriate management to a hospital.

monitor poisoning victims, as well as when determining stages of treatment.

depression, or seizures (Hodge III & Tecklenburg, 2006).

**5.2 Coral snakes** 

**6. Laboratory** 

Aguero: ML199).

**7.1 Prehospital care** 

acidosis if neuroparalysis occurs.

**7. Management and treatment** 

As soon as the patient reaches the hospital it is important to asses the CAB (circulation, airway and breathing) before starting any kind of treatment, this includes appropriate management of any active bleeding and of the airway to avoid respiratory failure or aspiration. Monitoring of vital signs can be useful to forecast complications and most of the times this can be done in the emergency room without sending the patient to the ICU. After these measures have been taken care of, hydration is next, since one of the effects of snake venoms is to mobilize intravascular fluid to the interstitial space, leaving the patient dehydrated. For this, normal saline or Ringer´s lactate is used. Laboratory tests that are useful in these settings are CBC, PT/PTT, serum electrolytes, CPK, urinalysis, BUN and creatinine and a cross-match for blood.

The wound should be inspected, if fang marks are found, the distance between them needs to be measured in order to get an idea of the size of the snake. The distance between fang punctures smaller than 8 mm suggests a small snake, between 8 and 12 mm a medium snake and a distance greater than 12 mm suggests a large snake. In the case of the patient being bitten by a rattlesnake, the fang punctures could be hidden by hemorrhagic blebs and edema. If no puncture wounds can be found, we need to consider the fact that scratches and abrasions could be envenomed wounds until we demonstrate otherwise. When a snake attacks and bites 10 % to 20% of the time it does not inject any venom (dry bite) and if we are dealing with a non-venomous snake we could observe a row of tiny teeth without fang punctures. As a precaution, the circumference of the limb should be measured every thirty minutes for 6 hours and every 4 hours until 24 hours have passed with the aim of preventing the development of complications related to important edema. If no systemic symptoms are evident, the wound should be cleansed, dressed and slightly elevated.

In the setting of not only the subject being bitten, but also suffering from envenomation, the use of antivenins is required. In the case of pit viper attacks, there are two antivenins, the Polyvalent Crotalic Antivenin (PCAV), which is the oldest, derived from horse's serum and highly antigenic, which is the reason for it to be discontinued from the United States market. In 2000, the FDA approved the Crotalic Polyvalent Fab Immune (FabAV) to manage patients with mild to moderate envenomations by American crotalus and since the Polyvalent Crotalic Antivenin is no longer marketed, the Fab Immune represents the only treatment option available in the United States, regardless of the severity of the envenomation. This alternative is derived from sheep's serum, a property that makes it less antigenic that its predecessor. FabAV appears to be effective in the management of severe crotaline snake envenomation (Lavonas, Schaeffer, Kokko, Mlynarchek, & Bogdan, 2009). It is available as a powder that needs to be reconstituted with normal saline. Regarding the use of PCAV, the

Snake Bites in Pediatric Patients, a Current View 133

ml of saline. The infusion is started slowly to see if there is a reaction to medication, if not, the rest of the load is administered in one hour. The initial dose is fixed, regardless of the degree of poisoning. Subsequent doses are administered depending on the progression of

Modified scale that correlates of clinical signs, edema and dose of antivenom in children (Christopher-Rodning) Loading dose Subsequent doses

0 0 0

Table 2. Modified scale correlation of clinical signs, edema and dose of antivenom in

First hour 100 ml dilute solution (glucose-normal saline 2:1)

Following three hours in 250 ml mixed solution

2-3 4 Rate 4 bottles Assess clinical status

5 10 6-8 bottles Assess clinical status

5 20 6-8 bottles 4-5 bottles every 4

25 25 10 bottles 4-5 bottles every 4

Maintenance (value)

hours

hours

Direct (intravenous) 1ml/min Normal saline

the clinical evolution.

Grade Signs and

0 Evidence of bite

1 Mild poisoning,

3 Severe poisoning,

petechiae,

4 Severe poisoning, bleeding bite marks, bruising and petechiae extensive data of disseminated intravascular coagulation, acute renal failure, respiratory distress, multiple organ failure.

children.

2 Moderate

symptoms

without poisoning (probably dry bite)

pain and edema less than 10 cm from the lesion.

poisoning: pain, edema greater than 15 cm from the lesion site, changes in skin, lymph regional.

swelling around the affected limb, vomiting, dizziness, fever, most notable changes in skin (ecchymosis, bullae,

numbness, oliguria)

dosing should be greater in children than in adults; for FabAV, since it can be eliminated before the venom emerges from tissues, therefore, a fixed dosing schedule is used. When using PCAV, a crash cart (including instruments to ensure airway patency, IV adrenaline, antihistaminics, steroids, etc) should be readily available because of the antivenin's elevated immunogenicity and risk of anaphylactic reactions. Skin testing should be performed and is done by injecting 0.02 ml of 1:10 diluted antivenin. Skin testing is not necessary for use of FabAV. Even though the use of antivenin is the only treatment for envenomations, its use is not free from adverse reactions, some of which could be life-threatening such as anaphylaxis. Some authors recommend the use of 0.25 ml of 1:1000 subcutaneous adrenaline to reduce the risk of acute adverse reactions to the serum (Premawardhena, C. E. de Silva, Fonseka, Gunatilake, & H. J. de Silva, 1999). If no adverse reactions appear, the full dosage should be administered (one vial with 10 ml saline solution) diluted in normal saline 1:4 as a slow infusion (1 or 2 ml per hour). Even after negative skin tests, one should be aware of the signs or symptoms of anaphylaxis within the first 10-20 minutes. If data suggestive of an anaphylactic reaction are not observed, the remaining volume should be passed on within two hours. The initial dose should be repeated until the swelling has stopped. There are reports in children of up to 75 bottles being used. In case of anaphylactic reaction, the infusion must be stopped and diphenhydramine administered (1 or 2 mg / kg IV). The infusion can be restarted at a slower rate, but a close watch should be kept and if symptoms of anaphylactic reaction reoccur treatment with antivenom should be discontinued.

Fig. 2. Diagram that shows actions that should be taken care of when helping a snakebite victim.

In patients who receive FabAV, the starting dose consists of four to six bottles in a period of one hour. Each vial is reconstituted with 10 ml of sterile water mixed in a total dose in 250

dosing should be greater in children than in adults; for FabAV, since it can be eliminated before the venom emerges from tissues, therefore, a fixed dosing schedule is used. When using PCAV, a crash cart (including instruments to ensure airway patency, IV adrenaline, antihistaminics, steroids, etc) should be readily available because of the antivenin's elevated immunogenicity and risk of anaphylactic reactions. Skin testing should be performed and is done by injecting 0.02 ml of 1:10 diluted antivenin. Skin testing is not necessary for use of FabAV. Even though the use of antivenin is the only treatment for envenomations, its use is not free from adverse reactions, some of which could be life-threatening such as anaphylaxis. Some authors recommend the use of 0.25 ml of 1:1000 subcutaneous adrenaline to reduce the risk of acute adverse reactions to the serum (Premawardhena, C. E. de Silva, Fonseka, Gunatilake, & H. J. de Silva, 1999). If no adverse reactions appear, the full dosage should be administered (one vial with 10 ml saline solution) diluted in normal saline 1:4 as a slow infusion (1 or 2 ml per hour). Even after negative skin tests, one should be aware of the signs or symptoms of anaphylaxis within the first 10-20 minutes. If data suggestive of an anaphylactic reaction are not observed, the remaining volume should be passed on within two hours. The initial dose should be repeated until the swelling has stopped. There are reports in children of up to 75 bottles being used. In case of anaphylactic reaction, the infusion must be stopped and diphenhydramine administered (1 or 2 mg / kg IV). The infusion can be restarted at a slower rate, but a close watch should be kept and if symptoms

of anaphylactic reaction reoccur treatment with antivenom should be discontinued.

Fig. 2. Diagram that shows actions that should be taken care of when helping a snakebite

In patients who receive FabAV, the starting dose consists of four to six bottles in a period of one hour. Each vial is reconstituted with 10 ml of sterile water mixed in a total dose in 250

victim.

ml of saline. The infusion is started slowly to see if there is a reaction to medication, if not, the rest of the load is administered in one hour. The initial dose is fixed, regardless of the degree of poisoning. Subsequent doses are administered depending on the progression of the clinical evolution.


Table 2. Modified scale correlation of clinical signs, edema and dose of antivenom in children.

Snake Bites in Pediatric Patients, a Current View 135

• No incisions in places where the bite is located, as excesive bleeding and the risk of

• Do not use tourniquets since they hinder blood flow and therefore cause more tissue

• Do not use any chemicals or extracts of plants or animals of any kind, so far none have

• Do not suction with the mouth, this favors infections on the bite site and can be dangerous if you have a cavity or open lesion in your mouth. In addition there is no

Snakebites are not an infectious disease, they do not have an epidemic potential and snakes themselves are not vectors that carry important diseases throughout the world. Nonetheless, the mortality caused by these attacks is greater than the mortality attributed to other diseases such as dengue hemorrhagic fever, cholera and Chaga's disease. At least 100 000 people die as a result of snake bites each year, and around three times as many amputations and other permanent disabilities are caused by snakebites annually and agricultural workers and children are the most affected (World Health Organization, n.d.). It is important to be familiar with first aid procedures as well as proper treatment in a hospital environment in order to decrease deaths and prevent complications and sequels derived

Science has made tremendous progress with regard to drug treatment for children and adults who have been bitten by snakes. Successful treatment will always depend on the speed with which you begin handling the victim from the outpatient level, as well as the availability of the drugs for proper treatment once the patient enters the hospital. Keep in mind that treatment recommendations published in 1999 could represent insufficient dosages and it is necessary an accurate clinical assessment to provide an effective therapy.

Alirol, E., Sharma, S. K., Bawaskar, H. S., Kuch, U., & François Chappuis. (2010). Snake Bite

Avila-Agüero M. L.; Nuevos conceptos en el manejo de pacientes pediátricos mordidos por serpientes venenosas. *Acta Pediàtrica costarricense* V13 N13 San José 1999 Chippaux, J. P. (1998). Snake-bites: appraisal of the global situation. *Bulletin of the World* 

Consejo de Salubridad General. Cuadro Básico de Medicamentos, 2nd ed. México, D.F. :

Glaudas, X. G. X., & Winne, C. T. W. C. T. (2007). Do warning displays predict striking

behavior in a viperid snake, the cottonmouth (Agkistrodon piscivorus)? *Canadian* 

in South Asia: A Review. *PLoS Neglected Tropical Diseases*, *4*(1), 1-9.

guarantee of how much venom you can withdraw with this method.

• Do not apply ice, it worsens local lesions caused by poison.

• Do not administer electric shocks of any kind.

been proven scientifically effective as treatment.

infection are favored.

• Do not give alcoholic beverages.

from this very important health issue.

doi:10.1371/journal.pntd.0000603

*Health Organization*, *76*(5), 515-524.

*journal of zoology*, *85*(4), 574–578.

1999. p. 23-29

damage.

**10. Conclusion** 

**11. References** 

When facing bites by Coral Snakes, the FDA extended the expiration date on the only product available in the United States to treat these envenomations. Wyeth's *Micrurus fulvius* Antivenin is no longer in production and there has been a need to obtain antivenoms produced in other countries (eg, Brazil, Costa Rica) for non-North American coral snakes. Mexico shares snake distribution with the United States. This country produces antivenom that is likely effective for coral snake bites in the United States. In the absence of such antivenom care must be entirely supportive. (R. L Norris, n.d.). Wound care should include irrigation, cleansing and dressings. Is convenient to consider tetanus prophylaxis and analgesia in case of need.
