A Study on Epidemiology, Clinical Profile and outcome of Snake Bite Envenomation

INTRODUCTION : Snakes are fascinating part of nature. Their colour, movement and secret habits make them more mysterious. India is home to some of the most poisonous snakes in the world, most of which are found in rural areas. Snake bites cause substantial mortality and morbidity in India. A large proportion of snake bites occur when people are working barefoot in the fields, or while walking at night or early morning through fields or along roads. Superstitions, wrong practices, misconceptions handicap doctors who care primary attention. Of 3000 species of snakes known to world, in India, we have around 216 species, out of which 52 are known to be poisonous. Our venomous species belong to two major families: Elapidae, Viperidae. Snake bite envenomation is a common problem in this part of state. The clinical profile and outcome depends on various factors. Large number of cases are admitted every day in Coimbatore Medical College Hospital. Our study is to analyse the epidemiology of snake bite envenomation cases in this part of state, to study the clinical profile and various complications of snake bite envenomation, to study the influence of the time interval between the starting of treatment with reference to prognosis, to study the amount of ASV that may be useful in treatment and preventing morbidity and mortality. AIM OF THE STUDY : 1. To study the epidemiology of snake bite envenomation cases in this part of state. 2. To study the clinical profile and various complications of snake bite envenomation. 3. To study the influence of the time interval between the starting of treatment with reference to prognosis. 4. To study the amount of ASV that may be useful in treatment and preventing morbidity and mortality. 5. To study the prognostic factors in snake bite envenomation. MATERIALS AND METHODS : Study type : Descriptive study. Population : Patients with definite history of snake bite envenomation Setting : Intensive medical care unit Coimbatore Medical College, Coimbatore. Duration: September 2009 to May 2010. Inclusion criteria : Patient admitted in intensive care unit with definite history of snake bite or with signs of envenomation and not having any of the exclusion criteria. Exclusion criteria: Patients admitted with unknown bite, or with history of bite by non poisonous snakes or with no signs of envenomation. Methodology : 200 patients with definite history of snake bites or with definite features of envenomation as evidenced by cellulitis, bleeding manifestation, neurotoxicity or prolonged clotting time enroll for study. History included regarding application of tourniquet, type of snake, time interval between bite and treatment in previously treated hospital and regarding native treatment. History elicitation also regarding various symptomatology. Detailed clinical examination of the patient will be done. CONCLUSION : In our study: 1 . Males were commonly affected. Seasonal variation was present in snake bite .Incidence and mortality were more during March - April. Most of the cases of the snake bite are from rural area. 2. The clinical profile of our study is more hematological toxicity, 62% seek medical advice within 6 hours of bite. Lower extremity is the common area of bite. 3. Of the identified snakes, Viper was the commonest and because of high incidence of haematological toxicity alone viperidae may be common species here. Viper bite was the commonest cause of renal failure in snake bite. 4. Hypotension, conjunctival haemorrhage,anuria during presentation were associated with increased mortality. 5. Mortality was less in patients who came within 6 hours and least in patient who had received 10 vials of ASV within 6 hours. 6. Neuroparalysis, hypotension,subconjunctival haemorrhage necessitates administration of more than 20 vials. 7. Mortality in our study was 5%. 8. Commonest cause of death are septicemia, renal failure, and coagulation abnormalities.