snake bite by dr. majid nawaz

Every year 5 million people are bitten by a snake in the world.

• Mortality ranges from 30,000 to 40,000

• Non poisonous snake may also bite but the

term snake poisoning refers to the bite of

poisonous snake only

Snakes are cold blooded vertebrates of the class reptilia which also include

1. Crocodile2. Alligators3. Tortoises4. Turtles

There are 3000 species of snakes most of which are non_venomous

Geographic Distribution

Present All over the world except Antarctica and isolated island groups.

Incidence

Every year 5 million people are bitten by a snake in the world. Mortality ranges from 30,000 to 40,000 per year

Most snakes have evolved specialized glands (salivary Glands) which produce venom.

• These are the venoms which assist in prey acquisition, digestion and defense against predators.• Venoms are complex mixtures of enzymes, non enzyme proteins and other non protein substances.

• In Pakistan snake bite is common in both agricultural area as well as mountains of Baluchistan.

• Snake envomation is an acute public health problem in Sindh especially in Tharr.

1. Cobra

Naja Naja

2. Krait

a. Russel,s viper

b. saw scaled viper

c. sea snakes

In Pakistan the peak incidence of snake bite occur in the month of June to August

This is because of 1. Floods and rain 2. Sleeping in open space 3.Hatching of kobra and Krait in summer

• Toxic saliva secreted by modified parotid glands of a venomous snake

• Amber colored when fresh • Constituents Toxins Enzymes Miscellaneous : neurotoxins cardio toxins hemolysin etc

• Neurotoxin cobra, krait• Hemotoxin viperidae• Myotoxin sea snake • Krait and russell’s viper is much more toxic than that of

cobra

Local • Pain• Swelling• May be followed by necrosis

Systemic• Ptosis• Glossopharyngeal paralysis• Rapid pulse• Death due to respiratory paralysis

• Mild Local Pain

• Mild swelling

• Muscle Weakness

Local

• swelling at the site of bite

• Sever pain at the site

• Discoloration of skin around the site of bite

Systemic

• Hemorrhage

• Hematoma

• Epitaxis

• Malena

• Sharp initial prick & thereafter painless

• Stiffness Of muscles of neck , back & proximal part Of the limbs

• Although snakes have are consider as one of the worlds most dangerous and disgusting creatures on the planet, they actually have some benefits:

1. They save farmers a minimum of seventy-five dollars annually by ridding their fields of destructive rodents

2.Snakes eat harmful rodents (mice, rats, etc.) and insects that may carry harmful diseases

3.Snakes also possess an oil that can be harvested that is used to remedy pain in joints, such as rheumatoid arthritis

4. The fats and the oils extracted from the snakes have a high content of Eicosapentaenoic acid (EPA), which has anti inflammatory properties.

1. Naag Naagan couple picture theory.

2. Snake as a Indian god.

3. Army crawl theory.

4. News paper 1988 and recently Afghanistan man to snake conversion.

5. Once snake bite again every year bite

6. Onion theory umar coat 25km choor

• Aims of management

1. Retarding the absorption of venom.

2. Neutralization of venom that has been absorbed.

3. Relief of symptoms and prevention of complication.

History

• Time of bite

• Description of snake

• Sign and symptoms since bite

Examination

• Examination of bite site

• Neurological defects

• Repeated check up of natural orifices for bleeding.

Diagnosis of bite

• Finding of fang marks

• Sign and symptoms arising ,giving indication of snake bite.

• In sea snake bite hyperkalemia is detected by ECG

• Clotting and bleeding time are also helpful.

The venom is detected from a dry swab of the bite site using monoclonal antibody techniques

. The 20-minute whole blood-clotting test is a useful bedside tool in

remote areas; a 2-3 ml sample of venous blood from the victim is left undisturbed at ambient temperature for at least 20 minutes.

The vessel containing the blood is then tipped once & may be compared with a normal control.

If it has not clotted, there is haemostatic disturbance from systemic envenoming.

All patients should have a full blood count, urea/electrolytes, liver function tests, creatine kinase, ECG.

Treatment1. Relieve the anxiety

2. Tourniquet

3. Cut and suck technique

4. Cold pack method

5. Electric shock method

6.Use of specific anti venom

Supportive and symptomatic measures

1. Bed rest

2. Adrenaline injection

3. Artificial respiration

4. Antibiotics etc

• 1. The most useful bed-side test to suggest snake bite envenemoation is:

• A. Prothrombin time.

• B.20 minute whole blood clotting test.

• C. ECG.

• D. Electrolytes.

Management of snake bite includes all except• A.Immobilize the bitten part.• B. Apply a firm bandage

• C. Incision & sucking of the bitten site.

• D. Massage over the bitten site to relieve pain and prevent edematous swelling

• E.Reassure the patient.

• Q. 10 year-old boy sustains a rattlesnake bite on his left ankle. Pain and swelling of the bitten area become rapidly intense. While the boy is transported to the closest medical facility, which of the following is the most appropriate initial step in management ?

A. Apply ice over the bitten areaB. Apply a tourniquet proximal to the bitten areaC. Apply iodine to the bitten areaD. Immobilize the bitten part in horizontal positionE. Perform incision and suction on the bite

Which type of vessels are involved in venom absorption from bitten site?

1.Arteries

2.Veins

3.Capillaries

4.Lymphatics