Snake bites

     A nonvenomous (nonpoisonous) snake bite is a bite or puncture wound made by a snake that is incapable of secreting a toxin. This should be distinguished from a dry bite. A dry bite is a bite by a venomous snake that does not inject any toxin. Even bites that are from a nonvenomous snake or are dry need to be evaluated as they can lead to significant tissue damage or infections.A venomous (poisonous) snake bite is a bite or a puncture wound made by a snake that is capable of injecting, secreting, or spitting a toxin into the penetrated skin wound, mucus membranes or the eyes where the toxin can be absorbed.this is is a medical emergency as they can be deadly if not treated quickly.

Diagnostic investigations

1. History -Time and place of definite or possible exposure to a snake.
2. Description of a snake, if seen (colour, size).
3. Number of times bitten (multiple bites are usually more severe
4. Prothrombin time and INR
5. CBC and peripheral blood smear
6. Serum electrolytes
7. Serum BUN and creatinine
8. ABGs
9. Fibrinogen and its products
10. Chest radiograph- to determine pulmonary oedema
11. Urinalysis to monitor for health of kidney and presence of myoglobin

Management 

    There are many aspects to effective treatment of snakebite. They start with a correct approach to managing envenoming cases. There are urgent measures that may be needed. For significant envenoming, anti-venom is generally the treatment of choice.

1. Check the patient's airway for patency, normal breathing and adequate circulation
2. Intubate if the airway begin to become swollen and narrowed
3. Immobilize patient's body part 
4. Monitor vital signs
5. Insert large-bore IV cannula
6. Oxygen therapy
7. Grade the severity of effect of snakebite venom (mild, moderate and severe)
8. Antivenin (CroFab)
• Administered within 4-6 hours after the snakebite
• Can cause either anaphylaxis or serum sickness
• Binds the toxins in the venom to neutralize and reduce its damaging effects
9. Antibiotics (Cephalosporin show benefit in most severe cases)
10. Immunization (Diptheria tetanus toxoids since snakebite can carry different types of bacteria)
11. Fasciotomy is carried out if there is increased compartmental pressure, in order to prevent compartment syndrome.

References

• Gold, Barry S., and R. A. Barish. "Venomous snakebites. Current concepts in diagnosis, treatment, and management." Emergency medicine clinics of North America 10.2 (1992): 249-267.
• Jerry R. Balentine, F. (2015). Snakebite: Learn First Aid Procedures and Treatment. [online] eMedicineHealth. Available at: http://www.emedicinehealth.com/snakebite/article_em.htm [Accessed 27 Apr. 2015].
• Jacob L. Heller, a. (2015). Snake bites: MedlinePlus Medical Encyclopedia. [online] Nlm.nih.gov. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000031.htm [Accessed 28 Apr. 2015].